A warm Summer is possible for much of Eastern Canada this year (more information below).

Summer is once again fast approaching the Northern hemisphere and I’ve been getting fired with questions relating to what is to be expected. For those of you who recall my prediction for Spring-Summer 2010 stated at the end of March and previously in between on several occasions dating back to since I created the weather thread for 2009, I predicted a possible overall warm Spring-Summer period this year. As it turns out, all of the Spring months, so far, have well exceeded the norm in terms of temperatures, including a record-breaking March and April. With respect to May, apart from the unseasonably cool second week, the month was absolutely stellar, including a blast of July-like weather seen during this last week. May 2010 turned out to be the third warmest May in recorded history next to May 1998 and 1999 with some of the hottest temperatures not heard of for nearly 50 years for the month (i.e., yesterday, the 26th, attaining almost 35 C while next door into Cornwall and Ottawa registering values closer to 36 C). Similarly, I successfully predicted the patterns exhibited by this past Winter beforehand in terms of being mild and snow-deprived, although I never anticipated that it would be as warm as it was. If you’re interested, for additional information and corresponding tabulated statistics, please refer to the link below for a closer examination of the late Fall-Winter months described through the 3rd, 4th and the last part of the 5th post (note that some figures were later corrected).

http://www.montreal-fireworks.com/forum/index.php?action=vthread&forum =5&topic=873&page=2

Summer 2010 outlook

Temperature

The El Nino present since July of 2009 was at the forefront of my assessments and predictions. To briefly reiterate my last analysis from March with respect to this Summer, though El Nino has been dwindling since February, I suspect that its influence, along with near-neutral conditions, will continue to linger on into the Summer months before the equatorial Pacific completely reaches a neutral state (no El Nino or La Nina signals) by September. As such, I believe that this Summer will continue on the same track left behind by the Spring months, and therefore being an above normal one in terms of temperatures. The models from the National Weather Service (affiliated with NOAA), The Weather Network and Environment Canada are practically in agreement with these predictions. Bare in mind, however, that this does not necessarily imply that every single day of the Summer will in fact be very warm/hot and humid, but rather that the general trend will be above normal with more episodes of very warm to hot weather breaching into Eastern Canada – quite the contrast from the last two years.

Precipitation

Precipitation patterns are a little tricky to forecast, especially with the variability expressed by the previous months – that is, April being above normal in precipitation, while May displaying opposing results. However, with a warmer and possibly moister Summer, it is with a fair likelihood that convection currents would be more pronounced, particularly in Eastern Canada – this would allow for increased available energy for convective rains and thunderstorms, and so we could see heightened thunderstorm activity this Summer, a few of which could reach severe limits, much like those that erupted yesterday evening, the 26th of May (notice that we were off to an early start to storms this year, with the first occurring on the evening of April 6th). With this in mind, it is certainly possible to see near normal to perhaps slightly above normal precipitation patterns in some areas of both Ontario and Quebec due to the stochastic nature of thunderstorms. If the jet stream continues to keep systems South of the border, then this would conversely result in below normal precipitation amounts. Further South, I believe that hurricane activity will return to normal as compared to the below normal activity of last year (due to El Nino). Severe weather has been frequent in the U.S so far this year, even for tornado season standards.

EDIT: Interesting to note is that the daytime high of 34.7 C attained yesterday (the 26th of May) in Montreal is the hottest temperature ever measured for the city in recorded history for the month of May.
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With respect to the fireworks displays of 2010, weather reports will be posted roughly two days in advance of each display with subsequent updates to follow up, if necessary. I will keep the forecasts condensed and simplified where applicable, though a little more detail may be required if or when the atmosphere is demonstrating instability on fireworks days. You are also more than welcome to post updates, but be sure to pay particular attention to wind speed/direction, temperature, humidity (dewpoint/moisture) and the threat of precipitation, if any. I know that wind and unsettled conditions were the backdrop for a fair number of last year’s competitors, but I do hope for ideally beautiful Summer nights for all of the 2010 entrants.

Trav.

Following an overall cool and wet start to June for much of Canada, the weather patterns are starting to adjust to more Summer-like standards for this coming week, baring a closer resemblance to what was seen for the last two weeks of May with the exception of more unstable conditions. With the jet stream being zonal/latitudinal for the first week of June, temperatures were fairly uniform (being mostly below seasonal) across Canada while a train of systems developed and were able to quickly travel across the country, resulting in persistent rains and one incident of severe weather just West of here on the 5th (an EF1 tornado spawned near the Ontario-Quebec border that afternoon).

As a nice ridge is building in for this weekend in both Ontario and Quebec, temperatures will, consequently, be rising back to seasonal to slightly above seasonal standards with a boost in humidity levels. However, because of the area of low pressure advancing from the Southwest (which is generating the ridge), this will invite the chance for some instability tomorrow (Saturday) afternoon into the evening-overnight hours along the Northern flanks of the warm front. With the air a little more rich in moisture, the chance exists for isolated pockets of convective showers and thunderstorms (heavy to severe thunderstorms mostly concentrated in Southern Ontario) during the late afternoon-evening period Saturday and running into most of Sunday. As far as highs go, mid 20's Celsius are certainly possible for the weekend while feeling like the high 20's to very low 30's with the humidity factored in. Saturday evening hovering around 17-18 C.

Winds should predominantly be light in nature during the afternoon-evening period Saturday and should not be exceeding 12 km/h at this time. Wind direction, however, may pose a problem for those stationed on the Western banks of the St-Lawrence River (Notre-Dame steet, the Western parts of the bridge and possibly the Old Port) due to the possible Easterly to Northeasterly wind tendency later in the day.

That's the way the weather should generally behave. I will continue to monitor the system's trajectory (especially in terms of wind speed/direction and precipitation tendency) and provide an update later this evening to finalize everything.

Trav.

Many thanks, Trav, to report your analyses again this year. Your posts are really useful, providing us with first hand information for the specific conditions of the event. Though they may be a bit too detailed and technical for some people, I like to read all details because weather forecast, despite the simplicity of icons often used by the media, are made of complex models and statistic methods and can't always produce a clear-cut forecast. The www.montreal-fireworks.com community is really priviledged to have its in-house meteorologist!

Fred

After monitoring the various weather model outputs as they came in today, most of what I stated in my previous post still holds truthful.

Because the system is maintained mostly to our South, humidity levels will not be as oppressive as in Southern and Southwestern Ontario for tomorrow (Saturday). Nevertheless, much like today (Friday), humidity values in Southern Quebec will continue on in the moderate-high range for tomorrow due to a steady Southerly flow. As such, with the warm front just to our South, this will generate mostly overcasted conditions for a good portion of the day into the evening with sporadic embedded showers - there is not sufficient instability and energy for strong thunderstorms to develop, but enough for some scattered showers.

As for the winds, there is variability between the East-Southeast (ESE) and East-Northeast (ENE) - this may, at times, be problematic for those on Notre-Dame, though more so for the sections of the street situated farther away from the bridge going North. Winds are also quite light in nature and may sometimes not be enough to blow the smoke quickly away (considering the humidity levels) when the display becomes more active.

Putting it together, Saturday evening's weather for Italy's performance should be mostly cloudy with the slight chance for some embedded showers (30-40%). Temperatures again hovering around 17-18 C (closer to 24-25 C during the day, depending on how much sun is present) and moderate-high humidity will make it feel a little muggy. Winds light at typically 7-8 km/h and variable between ESE and ENE, though the tendency seems more to the SE (Southeast) and ESE.
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Hi Fred,

because weather forecast, despite the simplicity of icons often used by the media, are made of complex models and statistic methods and can't always produce a clear-cut forecast.

That's exactly it. Though the computer models are essential for creating short and long term forecasts, they do not provide a concise picture of the true atmosphere. Because the models, as complex as they are, cannot interpret the realistically chaotic nature of the atmosphere, they are instead bound to several key assumptions - the models, then, idealize atmospheric conditions with time, making them subject to errors when things change suddenly in reality. Consequently, the farther you advance into the future, small errors in the short term can lead to larger ones over the longer term, which is sometimes the main reason behind long term forecasts, such as a week or more ahead, being much less reliable than, say, a few hours from now - at best, long term forecasts should serve as a general idea of what could be expected by whatever period in time. In the end, a weather "forecast" is nothing more than a prediction, and though it is correct most of the time, it never comes with 100% accuracy.

You're very welcome, and thank you for your kind comment. It will be a pleasure posting weather analyses once again this year.

Edit: I hope that everyone will be taken away by Italy's display.

Edit 2: It looks like the mostly cloudy conditions will slowly break later this afternoon into the evening with a few lingering cloudy periods - the clearing will briefly boost the temperature a little this afternoon from what they are currently (1:30 p.m). Everything else holds constant.

Trav.

As mentioned above, my only real concern is the possible lack of sufficient wind speeds this evening. Smoke obstructions would be more of an issue for those on Notre-Dame (sections farther away from the bridge mostly) due to direction, but with the borderline moderate-high humidity present, smoke buildup may be a problem for many viewers due to very light winds.

Trav.

Consistent Summer weather has returned. as expected. to Eastern Canada and is to stick around for some time. The changing patterns can be attributed to corresponding changes in the polar jet stream.

As a vigorous low pressure system advances Eastward into Ontario and Quebec for this weekend, a more Southerly flow will begin to emerge, causing a surge of heat and humidity to circulate from the Gulf of Mexico today (Friday) and particularly through to Saturday. As is the case with a hot and humid atmosphere, however, convective showers and thunderstorms are possible late day Saturday into early Sunday because of an increasingly buoyant airmass and principally due to the passage of a relatively strong cold front.

Running some of the latest models, most of these thunderstorms are non-severe in nature, but the possibility is there for some isolated severe cells to erupt late day Saturday in the later afternoon-early evening hours, especially taking into account that this front has had a history of producing severe weather. Temperatures Saturday evening are very likely in the mid 20s Celsius with high humidity (potentially very high - dewpoints 20 C or higher), making it feel into the low 30s C. Humidex values are closer to 40 C (highs quite possibly into the low 30s C) during the day, which could generate a humidity advisory (morning temperatures already into the low 20s C with moderate humidity). Skies will likely be partly cloudy in the evening with, again, the risk of thunderstorms. In the context of smoke, despite the humidity, I do not think rapid smoke accumulations will be a problem as winds are breezy at 17-21 km/h while coming from the South-Southwest (SSW) - SSW being an ideal direction since no major vantage point has to contend with smoke blowing towards them. With SSW winds, this means that smoke will be blowing mostly to the right of viewers stationed at La Ronde (left for those on De Lorimier/Notre-Dame).

I'll provide an update later on today or early Saturday once I receive newer model runs to work with. Rest assured that most of the day Saturday will in fact be nice, but it's the late afternoon-evening that I'd like to continue to monitor. Though storms are possible, I want to remind you that not everywhere will in fact see showers and storms, but rather that the risk is there for areas of Southern and Eastern Ontario as well as Southern Quebec during that time. With the isolated nature of the thunderstorms and showers, the chance is 40%. I also want to keep tabs on wind direction as a more Southwesterly tendency could blow the smoke to the extreme right end of the audience at La Ronde.

In the meantime, the UV index is high for both today and Saturday, so be sure to adequately protect yourself if you are expected to spend prolonged time outdoors.

Other than that, enjoy the upcoming weather.
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I thought it would be useful to provide a small table in helping to read dewpoint (moisture/humidity) values, in case you wanted to know:

Dewpoint of 11 C or lower: low humidity
Dewpoint of 12-15 C: moderate humidity (the case for Italy's performance)
Dewpoint of 16-19 C: high humidity
Dewpoint of 20+ C: very high humidity

Trav.

In accordance to the previous weather post, the newer model outputs from yesterday (Friday) do not deviate significantly from my analysis above. As such, I will post a recap of this evening's weather by extracting the key elements from the last message while providing some additional information where applicable.

Temperature/Humidity

Temperatures during this evening are likely into the mid 20s Celsius (as much as 27 C in the early evening to 24-25 C later on), while the high humidity will make it feel into the low 30s C. Even during the overnight hours, I doubt temperatures will drop below 20 C. Dewpoints (humidity) are also in the high range during the day itself (potentially very high), so humidex values are likely to be close to the 40 C threshold (not quite enough for a humidity advisory). Sticky.

Precipitation

With the contributing strong cold front that I spoke of earlier, it will be largely responsible for the isolated convective showers and thunderstorms erupting during the late afternoon-early evening period. As is common with cold fronts, bands of showers and thunderstorms (squall line storms) could very well form as well out ahead of the front. Through the course of the mid-late afternoon, daytime heating showers are possible, but as the cold front presses East to Northeastward later on in the afternoon, thunderstorms become increasingly possible. Chance for showers and storms is generally 40%, but I would raise the figure to at least 60-70% during the evening and early overnight period - surface air and air aloft are nearly saturated during the evening.

Please note, again, that some thunderstorms along and ahead of this cold front could be attaining severe limits in both Ontario and Southern Quebec - the reason being that there is a large amount of convective available potential energy ahead of the front and fairly good atmospheric instability during the late afternoon-early evening, as shown in various model runs. Daytime heating is also typically at its maximum during this timeframe. The threat of severe weather diminishes as we head into the overnight hours.

Wind

Winds are very likely from the SW to SSW, so smoke will be predominantly pushing towards the right for viewers at La Ronde (to the left for those on De Lorimier/Notre-Dame). Occasionally, however, there may be slight tilts from the SW, so smoke could sometimes blow towards the extreme right end of the La Ronde audience. Note that winds will be quite gusty for most of the afternoon with gusts reaching close to 45-50 km/h at times (sustained between 24-29 km/h). Winds should be settling by the evening, but nevertheless still breezy in the specified range above (17-21 km/h).
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Once more, the risk of showers and thunderstorms does not necessarily imply that we will indeed see unsettled conditions during the afternoon-evening hours, but rather that the "risk" is there for showers and storms due to a very unstable atmosphere - such is to be expected when weather becomes tropical-like. It's difficult to say what exactly will happen at 10-10:30 p.m, or for any specific time window for that matter, but I can safely say the risk is there for showers and storms. Best thing to do is to equipt yourselves with umbrellas.

That's the way the weather should generally behave this evening. With luck, the rain will hold off for the fireworks. Once that cold front clashes with the hot and moist airmass ahead of it, you will notice the temperatures gradually dropping (not too much) for Sunday (Father's Day) with lower humidity, although higher humidity values will pay a visit again during the work week.

I will be vigilant with radar and satellite imagery through the day.

***EDIT: In the event that severe weather threatens (I'm not saying that it will indeed occur, but if it does), I would then strongly advise seeking shelter immediately.

Trav.

With respect to tomorrow's weather (Saturday, the 26th of June), I'm picking up another area of low pressure developing towards the Southwest later tonight and pushing Northeast through the day Saturday. As such, this system will be bringing on a wave of instability to Ontario and Quebec, though conditions are not exactly favorable for thunderstorms to develop this time around. What is happening is that the polar jet stream has once again recently taken on a more zonal pattern, and this is permitting a train of systems to form and quickly move through much of the country over the coming week.

Temperatures for Saturday evening are on the cool side into the high teens (likely 17-18 C) with light winds (potentially very light) and moderate humidity. Models are demonstrating variable wind direction (usually the case when they are light in nature), but I will continue to monitor this as the current tendency is West-Southwest (WSW). I do not think the rains will be persistent through the day and there is the possibility for some partial clearing in the evening hours. Daytime highs in the low 20s C.

I'll provide a final update later this evening to confirm these conditions as I get newer model runs to work with.

Trav.

After assessing the newer model simulations, the weather conditions stated in my previous post still stands firmly for this evening. To provide an overview, here is what to generally expect.

Temperature/Humidity

Temperatures during the day should reach an unseasonably cool high of 22-23 C, though this would be attained later in the afternoon with the appearance of the sun. Later evening temperatures are likely 17-18 C (on the cool side), but pretty much holding steady at 20 C in metropolitan Montreal. Humidity levels are moderate, but will progressively be rising to higher standards later tomorrow into Monday. You may want to bring a light sweater for this evening.

Precipitation

Instability is being generated by a weak cold front associated with an area of low pressure sliding from our Northwest. As specified above, mostly cloudy skies are expected for the morning to early afternoon hours (some sunny breaks in between) with periods of showers - most of these bands are pushing South, however. Conditions are not favorable for severe weather, but enough instability for some periodic showers (30-40% probability due to scattered nature) and isolated embedded non-severe thunderstorms in the early afternoon (most of these, too, staying to the South into New York). Things, again, should increasingly improve by mid-late afternoon into the evening with some more clearing and therefore more sunshine, while most of the showers will have moved to our East and Southeast. Not a bad day overall.

Wind

Winds are likely variable from between the WSW and SW through the day, but more so from the SW during the evening, which means smoke will mostly be, as was the case for Taiwan's display, blowing towards the right of the audience of La Ronde (left for those on Notre-Dame). Also, like last week, smoke will occasionally push towards the right end of where spectators are seated in the park. Speeds are again light and ranging between 12-15 km/h (cooperative), but closer to 23-26 km/h (same direction) in the afternoon with some occasional gusts reaching closer to 35 km/h.

That's the way the weather should generally behave. To sum it up, a slightly cool evening with fairly light WSW-SW winds (mostly SW by evening) and moderate humidity levels under a few lingering clouds in a scattered fashion. Should be a mostly ideal night for the fireworks, just a touch on the cool side.
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Yet another low pressure system on the way for later tomorrow, though this is responsible for the warmer and more humid weather for both tomorrow and Sunday. Unfortunately, once this low pushes East, cooler air will sag Southward on its back end and, consequently, the last few days of June will end with relatively cool conditions. More Summer-like weather returning by end-week, however, as a nice building ridge from the West slowly pushes East.

Trav.

Trav, you're the best. Thank you very much!

Tyler, nice to hear from you! Please feel free to write up some reports if you saw any of the displays.

And now for Trav, from the Environment Canada website just now:

This watch is in effect from 03:50 PM to 08:00 PM EDT.

The sky has cleared over the regions between the Southern Témiscamingue and Montréal. The airmass over that area is very unstable and humid. A line of thunderstorms has formed over Témiscamingue and others have formed over parts of the area for which a thunderstorm watch is in effect. A funnel cloud has also been observed over Montréal's west island.


Paul.

Hi Paul,

Indeed, severe weather was observed in and around the island of Montreal, including, as you had quoted, a funnel cloud forming in the West Island of Montreal. Luckily, no touchdowns were reported as the funnel cloud did not make contact with the surface, and therefore becoming a tornado. To accompany the funnel were heavy rains, gusty winds and some grumbles of thunder here in the West Island.

I observed another developing severe thunderstorm cell coming in from the WNW just around since 7:10 p.m and this one is pushing towards the East End as I write this. A final line of strong storms/heavy showers is still moving in this direction within the next couple of hours (the risk should be over following 9:30-10:00 p.m). Following this, the air temperatures will begin to drop off slowly tonight and humidity levels will significantly be reduced in the process.

I was anticipating severe weather to develop today in Southern Quebec and Eastern Ontario, especially after seeing the sun make an appearance following noon. Humidity levels were VERY high and the air was quite unstable once the sun had appeared. The storms developing out there are being set off by a pair of cold fronts (the catalyst) coming in from the NW, which again will be giving way to unseasonably cool conditions for the final two days of June. As mentioned a couple of days ago, though, Summer-like weather will likely return for the first weekend of July as an amplified ridge forming out West slowly pushes Eastward.
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***EDIT: As I had expected, a defined line of strong thunderstorms and heavy rains came racing through Southern and Eastern Quebec by roughly 8:45 p.m. EDT as well as extending into Eastern Ontario. We lost electricity for about 20 minutes when the relatively strong downdrafts of the storm (nearly 80 km/h) drew near. For visual perspective, the following images represent composite radar imagery at 8:30 p.m. EDT depicting a classic squall line (a distinctive line consisting of numerous strong multicell thunderstorms) forming along and ahead of the secondary vigorous cold front. The first photo illustrates the full extent of the squall line with a spanning distance that is the equivalent of roughly 400-450 km from the Northeast to the Southwest. The red marker there indicates the approximate location of the West Island. Notice the slight curvature in the entire band, indicating some potentially damaging straight-line winds with some of the storms. The second shot shows a more zoomed in perspective of the same line taken at the same time.

http://i18.photobucket.com/albums/b132/Rain12/CIMG2835.jpg

http://i18.photobucket.com/albums/b132/Rain12/CIMG2833.jpg

Corresponding to the above images, here were the actual storms coming from the West-Northwest to Northwest. This first video shows the storm moving in. You can see some scud (low dark cloud usually developing under the storm's updraft area) forming there, which signifies strong downdrafts behind the shelf cloud (the elongated dark band of cloud). In addition, there were some signs of lowering beneath the shelf cloud, which may have suggested some brief rotation and funnel cloud formation - I kept my emphasis on this for a fair portion of the footage. Some thunder can be heard at times.

http://www.youtube.com/watch?v=knph1TRuZfc

The footage in the next video represents the storm overhead. In combination with the strong downbursts of wind, heavy lashing rains eventually came pouring down, as well as some pea-sized hail.

http://www.youtube.com/watch?v=1NSySUCjE3c

In any case, now that the storms have passed through and moved off into New York, the airmass is stable, the winds have shifted direction (now from the WSW to NW) and humidity levels are already proceeding towards lower values.

Trav.

Your Canada Day forecast:

In the wake of the severe weather triggered by Monday evening's (June 28th) strong cold front, cooler air has, as expected, settled into Eastern Canada from the Hudson Bay and is expected to last for a couple of days longer (today included) due to a sharp trough in the jet stream. As such, this trough does play a role in governing Canada Day's weather before Summer-like conditions make their graceful return. Here is what to generally expect in most of Southern Quebec for Canada's 143rd birthday:

Temperature/humidity:

With the trough persisting and with an area of strong high pressure advancing in, daytime highs will continue to struggle in surpassing 20 C, and overnight lows will likely hover around the mid teens (a little cooler in the the lower double digits towards the Eastern Townships during the late evening-overnight period). Temperatures are suppressed due to breezy Northwesterly winds, and the same holds true for humidity levels (low). Equipt a light jacket or sweater if you plan to be out long just before and following dusk - it will be a chilly, if not cool, night.

Precipitation:

Instability will continue to linger into Southern Quebec for Canada Day because of the wrap-around effect of the low pressure system situated (strengthened by the trough) over central Quebec, and so widely scattered showers (brief if you encounter any) during the afternoon hours are possible, particularly when advancing Eastward into the Eastern Townships and towards Quebec City - otherwise simply a mix of sun and cloud, much like today. As a result of high pressure moving in, though, the chance for instability becomes lower into the very late evening-overnight, and I thus believe there will be mostly scattered low to mid level cloud by that point in time. Saturation levels are low at the surface and aloft by late day, but a little higher as you head East and Northeast of Montreal during the very early evening/late afternoon, resulting in a continued slight risk (still at 30-40%) for scattered showers for these hours in those areas. Chance of showers for the day is 30% in most of Southern Quebec.

Winds:

As mentioned previously, winds are principally coming out from the Northwest to later West-Northwesterly (WNW) at speeds in the moderate range at 17-23 km/h, though diminishing to 12-15 km/h (same directional range) by late evening-overnight. With the low humidity, the winds will provide a little chill when they blow, especially considering the direction(s).

***If you plan on heading to Ottawa, weather conditions are similar to Montreal, and so the evening should be ideal for the fireworks there, just on the cool side.
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Two tornadoes were confirmed by Environment Canada with the squall line on the evening of June 28th, one of which touched down in the West Island in Saint-Anne-de-Bellevue (roughly 8 km Southwest of where I reside) and the other just to the North of Montreal in Mascouche, roughly 30-35 km North of the city. Both tornadoes were registered at F0 strength (the weakest), but though at the lowest end of the Fujita scale, winds are, most assuredly, powerful enough to do some damage to trees (some large) and property, which was indeed the case for both areas affected. Fortunately, no injuries or fatalities were reported. An F0 is capable of winds of up to 116 km/h.

There were apparently numerous observations of funnel clouds that evening and earlier in the afternoon in both Ontario and Quebec, though I suspect many of the these reports had mistaken them for scud formations. As previously explained in the above post, scud clouds are clouds that commonly develop underneath the shelf cloud due to the powerful downdrafts forcing the warmer, moister air ahead of the storm to rise and condense into additional funnel cloud-like formations. Because of their ominous appearances, and the way they hang or droop beneath the shelf cloud, they are often erroneously identified as funnel clouds. Scud, however, can sometimes point to rotation, and therefore the presence of mesocyclonic activity, if or when they exhibit circular motion below the base. Wind shear, which are winds that change in speed or direction (or both) with increasing elevation, was also quite high that day, which prompted many appearances of funnel clouds.
Here is a picture shot from Saint-Anne-De-Bellevue:

http://www.theweathernetwork.com/your_weather/details/620/2899137/3/ca qc0142?ref=ugc_city_thumbs

I'll be heading down there to survey the damage.

Edit: And Tyler, it's a real pleasure to see and hear from you again, my friend. No problem, as always, for the forecasts and analyses.

Trav.

Saturday's weather for Portugal's highly anticipated display is expected to be fabulous and Summer-like. As stated several times previously, Summer weather is returning to much of Eastern Canada, and this will be giving way to some very warm temperatures over the course of the weekend and onward - there is a strong surge of warm, moist air circulating from the Gulf of Mexico with the ongoing atmospheric setup.

If the wind direction plays out the way I think it will, then surely this will be the "perfect" Summer's evening for the fireworks - at this point in time, it may be only the right end of the audience at La Ronde occasionally contending with smoke, but there is a fair possibility of smoke predominantly missing the audience altogether. Wind speeds are moderate from 16-19 km/h. Temperatures are the main story in being very warm to possibly hot standards with high humidity present, making it feel into the mid 30s C (high 30s-low 40s by Sunday and onward). Temperatures Saturday evening hovering around 24-25 C with continuing high humidity, feeling like the low 30s. For a change, I don't have any instability to speak of.

I'll have a final update by tomorrow evening, but I honestly doubt things will deviate too much.

Edit: Welcome to the hottest month of the year.

Trav.

To elaborate on the information presented in the above post, here is what to expect for this evening, the 3rd of July.

Temperature/humidity:

With an existing strong pressure gradient between high pressure to the South and low pressure to the West, a strong Southewesterly flow will be ushering in a warm, moist airmass into much of Eastern Canada. As such, temperatures will be achieving very warm to hot standards in Southern Ontario and Southern Quebec with daytime highs attaining 28-29 C (possibly striking 30 C), including here in Montreal. Humidity levels are borderline moderate-high, making it feel into the mid 30s C. Late evening temperatures likely still as high 25 C, but feeling like the low 30s with the humidity. More oppressive humidity will gradually settle in by tomorrow (Sunday) and onward (potentially accompanied by some high heat, humidex and smog advisories).

Precipitation:

I am usually used to providing much detail in this section, but again, there are virtually no unsettled conditions to report this time around. Skies will be mostly clear with a few mid level altocumulus clouds.

Wind:

This is where I would like to keep a watchful eye. I was carefully reviewing some of the later model runs today, and with the way isobars (lines of equal pressure on a synoptic weather chart) are closely aligned with each other, this suggests to me gusty conditions for much of the day today, particularly between 2:00-5:00 p.m, with gusts of up to 45-48 km/h while sustained between 30-33 km/h at this time period. Winds should subside somewhat by the evening hours, but still moderate at 22-25 km/h with occasional gusts close to 35 km/h. Gusty winds are the result of the moister airmass rushing in. Wind directional tendency remains from the Southwest during the day and the evening hours as well, so I suspect that smoke will mostly be blowing towards the right end of the audience at La Ronde.

That's the way the weather should generally play out. In essence, a typical Summer evening, but fairly breezy/windy as well. I will continue to monitor the windy conditions, especially since the winds are exhibiting a tendency to blow towards the right portion of the audience at La Ronde. If necessary, I will provide a brief update later today regarding wind speeds.

UV levels are expected to be very high for today and the following next few days, so be sure to adequately protect yourselves if you plan on staying outdoors for prolonged periods of time.

Trav.

Corresponding to the wind section above, though wind speeds are somewhat subsiding from what they are this afternoon into the evening hours, I am still detecting sustained speeds around 14-16 knots (26-30 km/h) with occasional gusts from 35-40 km/h for this evening in and around the island of Montreal until at least 11:30 p.m. Because of the Southwesterly tendency (pushing towards right portions of the audience at La Ronde, and potentially towards central sections at times), I am concerned about delays as possibly gusty winds would not be ideal for the fireworks to be set off safely if winds persist in the specified range. It is possible that there are points where suitable wind speeds are present in between the general wind flow (which is sometimes the case), however, so we may have a break at 10:00 p.m., though I cannot guarantee anything.

For all other weather conditions, please refer to the above post as everything stated there still holds truthful.

Trav.

Now we have a divergence in the forecast for Saturday:

Environment Canada: Saturday Periods of rain. High 22.
Meteo Media: Saturday Cloudy with sunny breaks High 27
Weather.com: Saturday Morning showers. Highs in the low 80s

So it's two-to-one for good weather versus bad.

Trav: we're relying on your for the final word!

Paul.

Following the heavy convective showers and thunderstorms associated with the cold frontal wave duo for today (Friday) in both Ontario and Quebec, I'm calling for partly cloudy conditions to prevail with the risk of some lingering (very) early morning widely scattered showers for Saturday (a little more sun as the day progresses). It should be noted, however, that even with the passage of these cold fronts, because they are not quite as powerful, humidity will not completely vanish, and so it will continue to feel into the high 20s C during Saturday evening with borderline moderate-high humidity present (mid 30s C for the day with the humidity). Temperatures are similarly staying steady into the high 20s C during the day (I believe 28 C during the day) while remaining around 23-24 C for the evening hours (as much as 25 C in the Metropolitan area). I am a little more glued to winds because of the tendency, but I still need to ascertain both the wind speed and direction. I can safely say that winds will be light (7-10 km/h), but when high pressure is present, direction typically becomes a little more erratic - models indicate, so far, variability between the South-Southwest to straight Westerlies (Westerlies and West-Southwesterlies seem to be the dominant tendencies outside Montreal). As such, the potential is there for the smoke to be blowing towards portions of the audience at La Ronde.

I'm a little surprised with Environment Canada's current forecast for Saturday (today is fine), though I suspect they will soon alter the conditions enough so that they resemble what the other forecasts are stating. Relative humidity/saturation values at the surface and aloft are quite low for much of Saturday, and this is attributed to an area of high pressure gradually moving in behind the cold fronts from the West, suppressing precipitation. Available energy for thunderstorms is also quite low, and that is to be expected with high atmospheric pressure.

Although very warm temperatures coupled with high humidity are expected to continue for the upcoming week, the cold fronts coming through today will certainly be enough to put an end to this extreme heat wave, even though it saddens me greatly to see it go (that may come across as sounding crazy). To qualify as a heat wave, temperatures must attain 32 C (regardless of humidity) or more for at least three consecutive days. Clearly, we have more than met those standards this past week across many areas of Eastern North America (record-breaking in some cases), and the models did a fantastic job predicting the heat wave nearly a week in advance (around the time when I had first identified its existence).

In any case, showers and thunderstorms are possible today (some of these t-storms again could become quite severe in Ontario and Quebec despite the cold fronts not being as strong). In that respect, it is interesting to note how a (nearly) similar atmospheric setup is occurring almost a year after Hong Kong/China's performance.

I will finalize these conditions later this evening (especially for winds), but what was stated here should serve as a general guideline.
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Here are some photos of some distant thunderstorms that I took yesterday (the 8th of July). The first shot (notice the anvil/hammerhead) is looking roughly 60 km Southeast, and the second is towards the Northwest at about the same distance. All storms are moving at 30-35 km/h from the Southwest to the Northeast. The third photo is from the day before, where a thunderstorm affected the extreme Western portion of the West Island and Vaudreuil (we received some showers with that here). Needless to say, the airmass is quite unstable.

http://i18.photobucket.com/albums/b132/Rain12/CIMG2851.jpg

http://i18.photobucket.com/albums/b132/Rain12/CIMG2853.jpg

http://i18.photobucket.com/albums/b132/Rain12/CIMG2840.jpg

Trav.

Hey guys,

At 12:56, my area recieved such powerful rain and thunder. I'm working at 3 and I'm still unsure how I will be getting there.

It's weird how, for about four consecutive days, the weather has been extremley hot (30-35 degrees if not more in some locations). Global warming is seriously taking huge effect on our weather this year. I still look outside, people complain about the weather, and there's always traffic. If they are took their bikes to work like alot of people do, then we'd have nothing to complain about.. Well I hope the rain stops, the thunder seems to be getting louder and louder and it feels like the earthquake we recently had not long ago. Hope everyone is safe from floods in the regions of the storm.

Pat

What is stated in my above post still stands firmly, though I will be a little more descriptive about wind tendency. To reiterate the information from the previous post, here are the conditions that I believe will be mostly prevalent today (Saturday) and during the evening.

Temperature/humidity

Following a possible record-breaking heat wave, temperatures will very likely continue to reach the very high 20s Celsius today (I again believe about 28 C, though this depends on how much sun is present), while evening to late evening temperatures should stay steady around 23-24 C (as much as 25 C in the Metropolitan area). Humidity levels are leaning more in the "high" category, so it will continue to feel more like the mid 30s during the day to very low 30s C by late evening. I don't believe overnight lows will drop below 20 C. Temperatures will eventually head back into the low 30s C through the week, potentially generating another heat wave, though not to the same extent as what we just experienced. Heat waves have also been present in parts of Europe and China.

Precipitation

As expected, heavy convective showers and thunderstorms (many of which were severe, which generated isolated flash-flooding) have raced through much of Southern Quebec yesterday, including here in Montreal (have a look at some of the footage I took way below). As the principal cold front has now advanced further East, an area of high pressure is migrating from the West, permitting for gradually more fair conditions. As a result, we should see a little more sunshine as the day progresses with continuing partly cloudy skies. Available potential energy is actually abundant for t-storms, but that is only because the air is still so humid. Relative humidity values, by contrast, are low both aloft and near the surface, so I do not anticipate precipitation development today and this evening - the further East/Northeast you advance, the chance becomes greater.

Wind

The complete opposite of last week. Winds are, as mentioned above, exhibiting very light speeds (such is to be expected under the influence of high atmospheric pressure), which does not bode too well when relatively high humidity is present. Newer wind model simulation runs from yesterday and this morning suggest speeds of 4-7 km/h this evening, and it seems that directional tendencies are variable from between the West-Southwest to Southwesterlies, so smoke may at times be affecting central areas of the audience at La Ronde, as well as those towards the right end, in particular, as the smoke often blows very slowly in that direction. Rapid smoke accumulation may sometimes become problematic typically when the display starts to increase in pace at any given level if the winds remain in the specified range combined with the high humidity. Winds are generally variable in both speed and direction in and around the island of Montreal (i.e Westerlies for the Western portion of the island, Southwesterlies towards the Eastern parts and Southerlies towards the Eastern Townships), but are very light during the evening hours regardless (a little more breezy during the afternoon at 10-13 km/h).

That's the way the weather should generally behave for both today and this evening. To sum it up, we should be witnessing an evening that possesses high humidity, very light winds and partly cloudy skies.
-----------------------------------------------------------------
It's weird how, for about four consecutive days, the weather has been extremley hot (30-35 degrees if not more in some locations). Global warming is seriously taking huge effect on our weather this year.

Temperatures have consecutively been at or above 30 C for about a week, though the more oppressive humidity started flooding into Ontario and Quebec as of Monday, prompting, as I suspected, high heat alerts, humidex advisories as well as smog advisories. Overnight lows this past work week have also accomplished an incredible feat of not dropping below a value of 24-25 C for four consecutive days. Although it is not uncommon to witness heat waves in Southern Quebec, this particular one comes across as being unique due to its intensity, endurance and consistency, not only with respect to daytime highs, but overnight lows as well. A heat wave of this magnitude, technically, was not experienced since July of 1987 (though I believe we slightly surpassed that heat wave), just before the Great Flood that July.

Global warming is seriously taking huge effect on our weather this year.

The effects of global warming/climate change in terms of temperature increases cannot distinctively be detected in an individual year-by-year basis as there is often too much variability at this scale level - if that were the case, then last year's overall cool Summer and previously harsh Winter would not be consistent with this interpretation. Climate change (namely recent climate change), rather, can be manifested in a longer established period of time, such as during decadal cycles or multi-decadal to century cycles, where a more defined trend can be visualized while having inter-annual variability (but the overall trend is demonstrating warmer temperatures). However, it is to my belief that global climate change will increase the number of El Nino events (as well as the number of moderate-strong ones) in the years to come, which is conducive to warmer Summers and particularly warmer Winters.

I still look outside, people complain about the weather, and there's always traffic.

Just wait until Winter arrives and see their reaction.
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Here are a couple of photos I took during the storms (one being composite radar imagery) as well as some complementing video. Grumbling/vibrating thunder can be heard occasionally in both videos, but you can certainly hear the winds and the heavy rains. We had some sparse flooding here in the West Island.

Radar imagery:

http://i18.photobucket.com/albums/b132/Rain12/CIMG2884.jpg

Storm entry:

http://i18.photobucket.com/albums/b132/Rain12/CIMG2879.jpg

Videos:

http://www.youtube.com/watch?v=wJ267_bX-ng

http://www.youtube.com/watch?v=zqZTm7AHGpg

Trav.

Trav, thanks for the weather reports! I measured 68mm rain fall during the three storms we had where I live - pretty extreme for what was probably less than 60 minutes of rain!

What's the URL you use for the radar overlay on the bing maps?

Paul.

Hi Paul,

Indeed, the total rainfall amounts recorded at many weather stations in Southern Quebec yesterday afternoon were most impressive. Though Environment Canada has reported roughly 41-42 mm of rain from the afternoon-evening period, there were undoubtedly locally much larger accumulations, as was the case for both our areas. I experienced five storms yesterday afternoon in my area, all of which dumped incredible amounts of rain (the videos being indicative of that). Funnel clouds were also reported (some good wind shear present), but no tornado touchdowns confirmed this time around. The flooding was the biggest concern with these powerful thunderstorms, especially because they were heavy multi-cell thunderstorms - one storm after the other.

Here are the radar imagery URLs that I commonly employ:

http://www.theweathernetwork.com/weather/maps/caqc0142?ref=topnav_weat her_maps

http://www.weatheroffice.gc.ca/radar/index_e.html

^^^
Both can also be used for lightning detection.

NOAA's variety of radar maps are also very useful (especially Doppler radar) as they provide more advanced options in the ability to track relative storm/system speeds and direction and assess more accurate reflectivity measurements, which are read in "DBZ" units - DBZ being decibels (DB) as a function of the radar reflectivity factor (Z), where the higher the "Z" value, the greater the initially emitted beam of energy from the radar is being scattered by the target (precipitation) before returning as a form of echo to the weather station for analysis. Potentially strong thunderstorm activity and heavy rains are indicative when this energy is highly scattered, and therefore showing up on radar as the red color values displayed in the legend there:

http://www.nws.noaa.gov/radar_tab.php

No problem for the weather reports. Always a pleasure.

Edit: Speaking of thunderstorms, there is the slight risk of one (pop-up, not frontal) this afternoon, only because of the large convective available potential energy still present. The evening is still safe, however.

Trav.

Severe weather once again threatened many parts of Southern Quebec late this afternoon, including one powerful t-storm that mostly affected the South shore of Montreal and skimmed the Southern part of the island. Though the storm did not affect us directly here in the West Island, we were certainly still faced with strong winds (I recorded gusts of up to 67-71 km/h) coming from the powerful downdrafts of the cumulonimbus (thunderstorm), enough that electricity was cut in our area for one hour's time - it became quickly chaotic on the roads as traffic lights were down in a ubiquitous fashion. The core of this severe thunderstorm was located about 15 km to the SE of my residence and was moving slowly at about 30 km/h from the SSW to the NNE.

Here is a video I took of the storm, which mostly depicts the strong winds:

http://www.youtube.com/watch?v=OybNofP_57A

And some photos:

http://i18.photobucket.com/albums/b132/Rain12/CIMG2920.jpg

^^^
This was taken around the time the storm was beginning to lose its energy, but the strongest of storms were centered roughly 60 km to the NW and WNW along the Quebec-Ontario border - the line of thunderstorms there consists of severe multi-cell thunderstorms forming ahead of a cold front (which still has not completely gone through yet - hence the continued risk for tomorrow).

http://i18.photobucket.com/albums/b132/Rain12/CIMG2906.jpg

^^^
The above photo illustrates the flanking line of the thunderstorm. Flanking lines are lines of massive cumulus clouds that develop along the outflow boundary as a result of convergence between warm, moist air ahead of the storm and the dense, cold air descending rapidly from the storm's core towards the warmer air, creating a distinctive boundary - the outflow boundary. Flanking lines have a tendency to also form when the moisture/humidity content (dewpoint readings) near the surface are particularly high. The series of cumulus clouds associated with the line tend to feed on the warm updrafts of the storm, and the stack/tower of clouds forming closest to the parent storm eventually grows taller on the vertical (more mature) and gradually merges with it (see the following picture). Cumulus clouds along the flanking line can also become separate thunderstorms with time, forming a cyclic multi-cell thunderstorm complex.

http://i18.photobucket.com/albums/b132/Rain12/CIMG2908.jpg

http://i18.photobucket.com/albums/b132/Rain12/CIMG2909.jpg

^^^
This is a picture of the turbulent updraft area of the storm. Precipitation scarcely falls from this region of the thunderstorm because the rapid (sometime violent) upward motion of air currents keeps rain droplets suspended. Turbluent skies indicate powerful updrafts. Mammatus clouds also later appeared on the underside of the anvil, as shown in the following picture. Mammatus clouds are commonly associated with severe thunderstorms, but have been known to appear with regular storms as well. Mammatus clouds, though the most captivating to weather watchers and photographers alike, often warn of a vigorous storm, and indicate that the thunderstorm has reached optimal maturity. They commonly form through a process called "reverse-direction convection", in which moist air (usually from the updrafts) of the storm convects into the cooler, drier air beneath the anvil often through turbulent eddies, forming these brief magnificent and distinctive globules of cloud beneath the anvil:

http://i18.photobucket.com/albums/b132/Rain12/CIMG2915.jpg

And finally, the anvil crown showing off in all its glory as the storm departed:

http://i18.photobucket.com/albums/b132/Rain12/CIMG2918.jpg

Tomorrow afternoon (July 13th), as well as this coming Friday, are when we need to keep a watchful eye on the weather as the potential for severe thunderstorms exists (not a certainty, but rather that conditions are ideal for them to develop) - the reason being similar in that cold fronts are colliding with the hot and humid airmass ahead of them while there is a fairly large amount of energy available for thunderstorms. July-like temperatures and humidity will continue to persist regardless.

Trav.

To touch on my closing paragraph above, a very active cold front is currently moving towards Eastern Ontario and Southern Quebec into the very early morning hours tomorrow (Friday) and through to the mid-afternoon period, bringing with it possibly heavy convective showers and scattered bands of thunderstorms (some of these could very well reach severe criteria). Once the front moves through by late day, humidity levels will drop somewhat, but very warm temperatures will persist as a returning Southwesterly flow gradually moves in.

The area of low pressure affecting tomorrow (Friday) will also play some role for Saturday as well, as it is exhibiting signs of slowing due to an area of blocking high pressure stationed over the Labrador Sea. As such, though the cold front will have already gone through, I believe showers and single-cell scattered thunderstorms could develop during the early morning to mid-afternoon hours - the scattered nature of these storms is typically accompanied by 30-40% P.O.P. Things should, however, gradually improve later in the day and into the evening with partly cloudy skies, although I still want to keep a watchful eye as there is still a fair amount of available energy present for convective showers, as well as fairly high relative humidity values from the surface to the air aloft. Air temperatures during the late evening are likely 24-25 C (as much as 25 C in the metropolitan area) with borderline moderate-high humidity, making it feel into the very high 20s and very low 30s C.

I'm keeping a watchful eye on the winds as they could be reaching close to strong standards (sustained and gusts) both Friday and Saturday (primarily Saturday afternoon) due to a steep air pressure gradient between high pressure over the Atlantic (a typical Bermuda High) and this area of low pressure centered over central Quebec. I believe that winds should subside somewhat by the evening hours Saturday, but still relatively breezy nonetheless. I would like to, however, still examine the later model simulations when they become available so to monitor evening tendencies. Regardless, winds are likely out from between the West-Southwest and Southwest, so smoke will typically move towards right, and at times central sections of the audience at La Ronde.

I'll provide a final update later tomorrow evening to finalize these conditions.

Trav.

What was stated in my above message still holds mostly truthful for tomorrow (Saturday), but I will now provide some additional details after revising the later weather prognostics. Here is what to generally expect for tomorrow through the day and into the evening hours.

Temperature/Humidity

Although the cold front has moved through just recently setting off heavy rains and thunderstorms, a secondary front is slowly advancing Eastward associated with the same low, which has slowed down. Consequently, temperatures will continue to be sustained into the very high 20s (possibly hitting 31 C) for daytime highs Saturday while remaining in the mid 20s for late evening (again, about 25 C in the metropolitan area) while humidity levels will continue into high to potentially very high standards, and so it will feel like the high 30s C during the day (potentially 38 C) and the low 30s during the evening hours (likely 30-31 C). Once the next cold front passes tomorrow evening, moderate humidity levels will take over for Sunday.

Precipitation

In reference to the cold frontal wave passing through for the day tomorrow, convective showers and thunderstorms are certainly possible. Additionally, because the air is so buoyant, typical scattered single-cell airmass showers and storms (as mentioned previously) are possible earlier in the afternoon with an increased risk during the mid-late afternoon as the front draws closer. There is a good amount of energy available for thunderstorms during the late morning to early evening hours, and relative humidity values are reasonably high at 60-70% over the course of this timeframe, so the risk is there for the early evening period as well. I would accompany the showers and thunderstorms with a 30-40% P.O.P due the scattered nature (60% by mid-late afternoon). ***Please also note that some thunderstorms could reach severe standards due to the atmospheric dynamics. A reminder that this setup does not necessarily imply that the entire day is a washout (most of the day will actually be pleasant), but rather that conditions are conducive to the development of showers and storms – in fact, some areas may get away without seeing a drop of rain, whereas others will witness loads of it.

Wind

Wind tendencies are nearly similar in both speed and direction as what was experienced today, just a little stronger. The windy conditions are persisting simply because again the same low pressure area is slowing down, so we’re still under that tight pressure gradient. The strongest of winds will endure through the afternoon hours at sustained speeds as high as 32-35 km/h and wind gusts of up to 55-58 km/h (particularly between 2:00 and 6:00 p.m. EDT). Speeds should subside to 19-22 km/h by the early evening and progressively less thereafter. With respect to direction, Southwesterlies will continue to grip the afternoon hours, but I believe there will be a gradual shift from the WSW by the late afternoon-evening period (due to the front), and so smoke will principally head variably towards right and central sections of the audience at La Ronde.

That’s the way the weather should generally behave. To recap, breezy WSW winds along with high humidity and temperatures at or close to the mid 20s C (feeling like the low 30s C) for Saturday evening. Risk of showers and thunderstorms, mostly for the early evening period (30-40%). I’ll continue to monitor wind speeds for the evening hours and provide an additional update if necessary, but if I don’t, everything should be alright. For the most part, if things play out the way I think they will, wind speeds should be at safe standards in time for the fireworks and the showers and storms will have moved to the East by that time as well.
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And here is some footage depicting the "heavy convectional showers/t-storms" I spoke of for today - this was a late-afternoon brief thunderstorm that went through, and man, the resulting rains were the true definition of "heavy".

http://www.youtube.com/watch?v=5xeE-27lEg0

Storm entry:

http://i18.photobucket.com/albums/b132/Rain12/CIMG2945.jpg

Storm departure (move away from your screen a little to fully appreciate the first two shots):

http://i18.photobucket.com/albums/b132/Rain12/CIMG2951.jpg

http://i18.photobucket.com/albums/b132/Rain12/CIMG2947.jpg

http://i18.photobucket.com/albums/b132/Rain12/CIMG2958.jpg

Trav.

As I suspected, a severe thunderstorm watch was appropriately issued for much of Southern Quebec, including here in Montreal until early this evening (which is consistent with the available energy I was detecting from this morning stretching towards early this evening). The cold front is still showing signs of slowing, so although I do indeed believe that most of the bands of showers and thunderstorms (including those that are severe) will have passed by the time the fireworks are set to start, there is still time for the possibility of lingering scattered showers and the odd t-shower to persist for the duration of the evening (30%) until the front completely passes through towards the East and Southeast - otherwise, partly cloudy skies. Regardless, have an umbrella handy in case of anything.

Winds should still be subsiding by the early evening, though again sustained between 10-12 knots (19-22 km/h) with occasional gusts of up to 31-35 km/h (as compared to the 55-58 km/h gusts this afternoon). Later in the evening, winds should be more in the 16-19 km/h range, which is moderate.

For more details, please refer to my above post. I was also most delighted to see that my above video was shown briefly on TV on The Weather Network this morning!

In any case, typical July weather for today.

Trav.

Thank you, Trav, for this relevant update.

I haven't seen your video on the Weather Network, but we will maybe see you there to deliver us the fireworks forecast on air. I remember from a previous post that you have graduated this year (congratulations!). What are your next projects? I suppose that you would like to work at Environnement Canada or something like that, would you?

Fred

Un couple de Montréal a été brutalement frappé par la foudre, samedi soir, a confirmé Urgence-Santé.

L'homme, qui a subi un arrêt respiratoire, était toujours dans un état grave à la fin de la soirée, sa compagne a subi de sérieuses brûlures.

L'homme et la femme dans la quarantaine s'étaient réfugiés sous un arbre à l'angle des rues Notre-Dame et Frontenac pour se protéger de l'orage alors qu'ils se préparaient à assister aux feux d'artifice.

Le drame est survenu vers 19h45.

Plusieurs résidants du quartier ont donné les premiers soins aux victimes qui ont été transportées dans deux hôpitaux différents.

Cyberpresse

Hi Fred,

It's no problem that you were unable to catch my video while it was on the air on The Weather Network two days ago. If your images/videos are selected, they are briefly displayed between 47-49 minutes past the hour, before the national forecast every half hour, or sometimes appearing during the weather news segment, which are 10 and 40 minutes past the hour. Your videos or pictures are also usually shown either during the day in which you took them or early into the next day. All images/videos need to be a little rushed in order to stay within the allocated two or so minutes in these segments, but they do briefly highlight the important aspects that were specified in your accompanied description(s). Speaking of which, more of my footage and images (which I'm about to share here below) were briefly displayed on TV both yesterday morning and afternoon. The on-air presenter simply stated: "Not surprisingly, we received more footage from Trav today (now yesterday) showing the severe weather on Saturday that went through his area in Montreal's West Island". That was a little unexpected.

I remember from a previous post that you have graduated this year (congratulations!). What are your next projects? I suppose that you would like to work at Environnement Canada or something like that, would you?

Indeed, I have graduated this past Spring (the convocation falling nicely on the first day of Summer ). I am planning on pursuing a Master's degree in climatological studies so that I may conduct and organize research down the line, but I will likely soon work as a climatologist and/or forecaster (perhaps as an on-air presenter, or simply preparing weather forecasts behind the scenes) for Environment Canada or The Weather Network in the very near future. Working in a meteorologically-oriented field also opens avenues in environmental planning and management, so I may consider those as well. Finally, I am additionally thinking strongly on joining a storm chasing team, not just for the pleasure of it, but for research purposes as well.

I thank you very much for your kind wishes. And, as always, it was no problem in providing the weather reports.

Hi Enkil,

Thank you, once again, for sharing that article. While parked on De Lorimier, we saw two ambulance trucks racing across the street, not knowing that they were likely headed for that awful incident that had occurred closeby to where we had been stationed. I just pray that the affected couple (both in their late 40s, as was recently disclosed) will make a quick recovery.

I cannot emphasize it enough that people should never, EVER, seek shelter underneath a tree during a thunderstorm. The way a CG (cloud to ground) lightning discharge typically works is that its generated path (the invisible stepped leader) follows a channel of least electrical resistance once the insulating layer in the atmosphere is broken down after the electrical field is sufficiently built. Consequently, this suggests that lightning often targets elevated objects because the channel created between these objects and the cloud is shorter and requires less air to travel through (and therefore less energy to take form), leaving taller objects obviously quite vulnerable during thunderstorms. More importantly, when the charge buildup between the cloud and the surface becomes progressively larger, the positive charges distributed along the surface, which follow the storm like a shadow, commonly tend to move up along taller objects, making a potential strike much more likely at these points.

The safest place to be during a thunderstorm, regardless of severity (all thunderstorms are characterized by having at least one lightning discharge, after all), is an enclosed building (preferably with plumbing and electrical wiring that would conduct the electricity efficiently) or your vehicle (also must be enclosed with a metal frame). Contrary to popular belief, the car's tires play a very little role in ensuring your safety - rather, it's the conductive outer metal frame that administers the protection, where the electric current will likely be diverted around the passenger area through the metal covering of the vehicle and safely into the ground. In order for a lightning discharge to take place, an unbelievable amount of charge buildup between opposing charges is required since again the atmosphere is a very good electrical insulator. With this in mind, since a lightning bolt is fully capable in overcoming the highly electric-resistant properties of the atmosphere, it can undoubtedly overcome the resistance of a few inches of rubber.

***I will happily go over all basic lightning safety tips if anyone requests them, but I'm sure that everyone here is a fair understanding of them all. Even though lightning typically goes for elevated objects for the reasons described above, there is no guarantee that you will be safe from lightning even if you are well away from them as lightning possesses a very capricious nature. Simply put, as long as you can hear thunder, you are always at risk of being struck by lightning if outdoors. The lightning strike in Montreal was not the only lightning-related incident as, tragically, a 25-year old man was killed while at a water park in Ontario the same day, and a firefighter also suffered some injuries.
---------------------------------------------------------------------- ------------------
And the video footage I took (I realize that they're lengthy, but I will highlight the main features and where to find them):

Cloud to ground strikes of the evening storm Saturday before I departed for the fireworks (when you get to 3:43 and 4:28, try pausing the video to see the spectacular form of those discharges).

http://www.youtube.com/watch?v=FBW9BFZWThM

Thunderstorm just past lunch time (thunder can be heard throughout, but lightning strikes can be seen from four minutes into the video and onwards):

http://www.youtube.com/watch?v=GmHBDHfJNq0

Another storm later that afternoon (very haeavy rains start around 4:20 with marble-sized hail pelting on the window by 6:20):

http://www.youtube.com/watch?v=-Sq4Gir6G_g

Loud thunder (zoom to 40 seconds to hear it):

http://www.youtube.com/watch?v=jeYDqSbHUvE

Some photos (evening storm):

http://i18.photobucket.com/albums/b132/Rain12/CIMG2991.jpg

http://i18.photobucket.com/albums/b132/Rain12/CIMG2999.jpg

http://i18.photobucket.com/albums/b132/Rain12/CIMG2997.jpg

Multi-cell thunderstorm to the Northwest (notice the principal storm with newly developed cells side by side in the first photo, the one on the right being a new mature cell):

http://i18.photobucket.com/albums/b132/Rain12/CIMG2983.jpg

http://i18.photobucket.com/albums/b132/Rain12/CIMG2988.jpg

Heavy rains (notice the sewer there cannot handle the rain):

http://i18.photobucket.com/albums/b132/Rain12/CIMG2977.jpg
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Slight risk for thunderstorms this evening - heavier storms depending on how much sun is present this afternoon, but I do not anticipate anything of the sort that we had seen Saturday.

Edit: An F0 tornado was also confirmed by Environment Canada near St-Jerome that day.

Trav.

Showers and thunderstorms are a possibility for tomorrow (Saturday, July 24th). An area of intensifying low pressure is slowly moving Eastward from Ontario and progressively for Southern Quebec for later today and through to Saturday. For today, the system's warm front will bring us some periods of showers and isolated embedded t-showers later in the day today, while the associated cold front will be affecting Southern Quebec mid-late Saturday, bringing with it isolated bands of convective showers and thunderstorms, some t-storms of which could be reaching severe standards in the later afternoon hours and early evening (my principal focus) partly due to the large amount of available convective potential energy present. The system has also had a history of producing severe weather. Things should begin to improve by early Sunday morning with some lingering showers, though brisk WNW winds will develop later in the day. Temperatures Saturday evening still maintain the mid 20s C (nearing 30 C for daytime highs) and likely 24-25 C in the metropolitan area, but the humidity will be high to potentially very high standards until the cold front passes through. Preliminary showers and storms are possible into the afternoon as well following lunch time ahead of the frontal wave, but the chance would go up slightly as the afternoon progresses

Winds are still something that I'd like to monitor, but the average direction is Southwesterlies through the day with a possible shift to South-Southwesterlies by late day, which would be ideal as smoke would move to the right of the audience at La Ronde. I will continue to watch directional tendency as the system's motion/speed can change in the next 24-36 hours. Speeds are light regardless, though a little more breezy during the day itself.

I will, as always, provide a final update to confirm these conditions this evening.
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Here is some video I wanted to share of last night's thunderstorm, which was a rather pleasing way to end off my birthday.

http://www.youtube.com/watch?v=L2kvsuxi_cU&feature=related

http://www.youtube.com/watch?v=3fHpcLk6wL0&feature=related

And a nice forked lightning I captured:

http://i18.photobucket.com/albums/b132/Rain12/CIMG3068.jpg

Trav.