Greetings everyone,

Welcome to yet another approaching Summer season, but what is possibly to be expected? As we all know, weather plays a highly important role in having safe and successful fireworks displays, and so it is necessary to pay attention to atmospheric conditions and report them - I'll get to what should be focused on a little later. In any case, first, let me say that this Spring has, so far, been incredibly disappointing, where we had long spells of cool weather (even during mainly sunny days), frost, as well as enduring periods of rainfall. Though this has been the common trend across most of Eastern Canada, Western Canada was dealing with Winter-like weather for most of the month of May, where large amounts of accumulating snow (yes, snow), sleet, freezing rain and obviously well below average monthly temperatures were observed in many regions. Though the West has improved over the last week, temperatures are expected to cool down and balance off with the East as we get into June. Therefore, I feel this unseasonably cool and unsettled trend may, overall, linger on for a little while longer throughout most of Canada before we see more consistent Summer weather. It is actually a possibility that this won’t occur until around mid-June, so I can’t really offer any positive news until around then. I have prepared an analysis that may help to explain this trend.

It is to my belief that the recent and persistent La Nina that was present during the Winter, while dwindling for most of Spring, is likely the primary force governing the overall dismal conditions we’ve witnessed this season. Cool sea-surface temperatures (SSTs) seen off of the Eastern equatorial Pacific are likely suppressing any significant warming, even in many parts of the U.S. Atmospheric circulation patterns are responding accordingly. If you examine synoptic weather maps throughout May, the polar jet stream has been, on average, following a fairly zonal, or latitudinal pattern, and so undulations in the form of amplified ridges (which usually flood in nice warm weather) were seldom present. In addition, the jet stream has been often located more towards the South than usual, which ultimately prevents warm moist air from circulating further North – hence the lack of consistent South to Southwesterlies in Eastern Canada. As such, I would theorize, then, that these average jet stream configurations and the subsequent delay in consistent warmer temperatures across the nation are likely the result of a temperature lagging effect in response to the current slowly changing SSTs in the Eastern equatorial Pacific moving towards a neutral state from the last La Nina.

Despite all this, I am still firmly holding onto the prediction that I stated earlier (in the Thunderstorm vs. Fireworks thread), where we should see a normal to slightly above normal Summer in terms of temperature, particularly in July. However, we'll have to be a little more patient for Summer-like conditions due to a possible temperature response lagging behind changing Pacific SSTs. Remember, though, that Summer doesn't officially start until the 21st of June. Precipitation itself should follow a similar trend, and, again, I’m still expecting fair activity in terms of thunderstorms this Summer, a few of which could reach strong to severe criteria (the average being 1-3 severe t-storms in Montreal per Spring-Summer). Both April and May have followed the precipitation forecast well in terms of being above normal, particularly May, though it is clear that May has been below the average with respect to temperature – our monthly average for May 2009 was barely 17 Celsius (this is cooler than even May 2000 and comparable to May 1997), and the norm is averaged at 19.5 C. Interestingly, this year, so far, has had a history of possessing a relatively large number of windy days, too.

So that’s the breakdown. To sum it up, a normal to slightly above normal Summer (similar to last year) should be in store for us in terms of both precipitation and temperature, mainly because of predominantly “neutral” conditions as well as a slowly building El Nino in the Eastern Pacific. El Nino should continue to develop into the Summer and Fall and persist for the months thereafter, meaning that we may be in for milder weather this coming Winter as compared to the last two harsh ones. With this sort of setup, I believe hurricane season will be fairly active as well – a tropical depression (Tropical Depression 1) recently developed in the Atlantic, even though the season doesn’t officially start until today, June 1st. A developing El Nino, however, may suppress high frequency down the line.

Other than that, I’m hoping for nice cooperating weather for the 2009 fireworks season. Please feel free to report any weather conditions in this topic as we approach fireworks days. However, as always, I recommend waiting at least 2-3 days in advance to make any statements, as things usually become increasingly uncertain any earlier (some exceptions, of course), especially in Summer. It’s always a good idea to report mainly wind speed and direction (remember that light Westerlies coupled with high moisture content is the worst combination for people viewing from La Ronde), precipitation if any, as well as humidity levels. Forecasting thunderstorms can often be trickier, but it’s always good to report the risk, especially for strong to severe t-storms. Finally, it’s also handy to keep an eye on the forecast during setup days. That said, again, I’m sincerely hoping for a perfect weather record this year, much like what was seen in 2004 for the 20th anniversary. Should bad weather affect any fireworks days, though, I’m sure that our 10:00 p.m. “weather barrier” will kick in, as it commonly does.

Trav.

Good afternoon,

Just to provide a small preliminary report, but as I'm sure you all are aware of, this week is going to be predominantly wet/cloudy and unseasonably cool with two low pressure systems moving towards Eastern Canada from the United States. By early Tuesday morning, enduring rains will likely fall as a warm front enters our area, making it an overall soggy day tomorrow. During late day Tuesday, we may actually encounter some sunny breaks, though this may invite thunderstorms in the late afternoon to evening hours and possibly into the overnight, especially as the cold front moves in. Wednesday will be more of a break with mostly cloudy skies along with some on and off isolated lingering showers (particularly in the morning) while still remaining cool. Into Thursday, another organized system may head in this direction and provide more periods of on and off rainfall and last into at least the first half of Friday.

Although continuing to be dismal, in general, this week for Eastern Canada, the reason I bring this up is because I was concerned about the setup for the opening show. When do preparations start? The good news is that, with respect to the regional models, high pressure is expected to settle in by this weekend, which should allow for more dry and seasonable conditions. I'm expecting things to gradually improve overall with respect to temperature by this coming weekend and onwards, especially as we move toward the official start of Summer. We'll keep an eye on that.

I'll provide a final update by Friday, but this is what we can typically expect for this coming week.

Trav.

Trav,

Thanks for the udpate! The first stage of the process, in-door, should be Tuesday and Wednesday. Then, the on-site setup should occur Thursday, Friday and Saturday. However, the schedule may be a little different (and begin early) as it is an off-competition display.

I hope to have enjoyable weather for this opening display!

Fred

Hi Fred,

Thank you very much for the information. Assuming this is in fact the schedule, then the rains that fell yesterday should not have interferred with the first stage of the setup process. The second phase shouldn't run into as many barriers either since Thursday's unsettled conditions shouldn't be much of a problem until mostly later in the day (that means a little more sunshine) and, again, up till at least the first half of Friday with on and off showers. That said, Friday would probably be the more iffy day to work with, but I don't think it will be as steady as yesterday's rainfall, if any precipitation should develop. I'm still expecting fair weather for Saturday. As always, a final report will follow on Friday to confirm everything. The only thing I'm really watching for Saturday right now are the winds, moreso the average speeds.

Given that we're a third into June exactly, I thought it would be appropriate to put our current average temperature into perspective, just to see where we stand. So far, in Montreal, the average temperature for this month is a mere 19.1 Celsius, and the mean for the first 10 days in June is closer to 24 C (about 23.6 C), which entirely implies that we are almost 5 C below the norm at this point. For those of you who recall the Spring-Summer of 2000 (the year without a Summer), well, May 2009 was actually a little cooler than May 2000 by about 1 degree Celsius. With respect to June, assuming we attain a high of 19 C today, it would be just enough to cause our average to drop a touch below that of the first 10 days of June 2000. Again, I blame this on slowly adjusting atmospheric patterns in response to the transitioned conditions of the central and Eastern Pacific from the last La Nina. The reason I make use of the year 2000 for comparative purposes is simply because it was one of the coolest Spring-Summer periods on record. The major difference between 2000 and 2009, however, is that in 2000, La Nina never vanished, even into the Summer, which is why I don't so much anticipate persistent cooling into this coming Summer as we saw in 2000. Let's hope I'm correct.

Trav.

Good evening,

Tomorrow's weather (Saturday) is expected to be predominantly pleasant along with a mix of sun and cloud with light and variable winds. Though mostly fair, there is, at the same time, an upper level disturbance developing in the atmosphere that will be present over much of Eastern Ontario and Southern Quebec, which will give way to a slight risk for showers (30-40% P.O.P and scattered in nature) in these regions for later tomorrow afternoon and the evening. Unfortunately, I thought instability would fizzle out by the evening, but it appears the disturbance is lingering in the region, which will continue to promote widespread cloudy periods and scattered showers. Highs reaching as much as 25 Celsius tomorrow, while evening temperatures should stay comfortable (not too cool as compared to what we've seen for much of this Spring) at anywhere from 16-18 C - you can always bring a light sweater if you find this a little chilly for your liking.

As for the winds, again, they will be relatively light at about 10-15 km/h during the evening hours. I am hoping for at least 15 km/h in order for adequate smoke clearance and particularly since moisture levels will be close to moderate tomorrow (slight smoke build up). A little change with respect to wind direction, though. As shown in some wind models, though still fairly variable across the island, between 8-11:00 p.m., wind tendency is in the form of Southwesterlies, which means the smoke will mostly be passing lightly to your right (for those of you in La Ronde). However, winds may occasionally shift to Westerlies, which may, at times, be a little inconvenient to La Ronde viewers since smoke would be blowing towards them in that respect.

In any case, that's the way the weather should work for the most part. Light SW to W winds with the slight chance for some late afternoon to early-mid evening showers due to an upper level low. I personally think that the atmosphere should behave itself in time for the fireworks, but it's good to be prepared, just in case. Overall, though, a pleasant day coming up, so enjoy it - it will be more and less identical to today. UV levels are high (8), though, so be sure to wear the proper protection if out for long periods in the sun.

Trav.

Hi guys,

Just one final update to supplement my previous report, but that upper level disturbance I spoke of should exit the region by mid-evening, so we should see a clearing trend by then with just a few lingering cloudy periods - most of the showers and steadier rainfall should stay to our South and East. The slight chance of showers still exists, but fortunately moreso in the late afternoon to early evening for us in Montreal. Temperatures should, as I said before, be comfortable during the evening at about 16-18 C, though I personally feel it will be closer to the 18 or even 20 C mark. Wind tendency is still in the form of light Southwesterlies (see 2nd paragraph in post above for more details).

With everything else holding constant, I believe this will be, as mentioned before, an overall gorgeous day accompanied by a pleasant night for the opening show.

Enjoy the display, everyone.

Trav.

After 1 year of patient waiting, oh glorious Notre-Dame Street here I come

Good afternoon,

Saturday's weather, the 20th of June (last day of Spring and the day holding the second longest daylight period of the year - I guess everyone knows that lol), is a little bit tricky to forecast, where there is a secondary low pressure system following closely behind this current one - the trajectory of this next low is a little less clear for the Eastern Ontario-Southern Quebec corridor for Saturday. The reason for the uncertainty is simply because of the position of the subtropical jet stream in our region at that time. If it migrates just slightly Northward, it will be increasingly unsettled, and if not, which are the current projections, rainfall and thunderstorms will stay just barely to the South into New York and travel towards Maine into the Maritime provinces for the weekend. With the average jet stream flow shown in the models, Southern Ontario and the Maritimes are pretty much going to be facing a predominantly wet or unsettled Father's Day weekend, regardless.

Most wind simulations for Saturday evening seem to be in agreement at this point in time with moderate North to Northeasterlies, which means the winds would be likely flowing in the complete opposite direction to what they were during Panzera's display (SW). With the current projection, things look to be fairly good with warm temperatures (as much as 25 C) and building humidity for Saturday, so the moderate winds are good in this respect. Skies should be variable to a mix of sun and cloud, though there is the possibility for convective showers.

Is the Spanish team setting up anything on-site today? I'm just wondering because we're dealing with on and off periods of rain for most of today up till tomorrow (Friday) morning (afternoon-evening should be alright).

Finally, recall that I had mentioned "building humidity" on Saturday or for the Father's Day weekend, in general. This is because the subtropical jet stream is flowing close to the Canadian-U.S border for the first time, but more importantly, because of a defined ridge in the stream that is developing out West and pushing Eastward. Consequently, once this ridge moves over our region, I believe this will likely allow for typical Summer temperatures (possibly in excess of 30 C in some cases) and the chance for oppressive humidity to flow into Eastern Canada for particularly the work week next week. How appropriate for Summer to officially begin. Summer, btw, officially arrives on June 21st at 1:45 a.m. EDT.

Oh yes, just for the heck of it, I wanted to share some photos that I took of some individual storm cells that developed around the island of Montreal three days ago (on the 15th):

http://i18.photobucket.com/albums/b132/Rain12/CIMG1371.jpg

http://i18.photobucket.com/albums/b132/Rain12/CIMG1373.jpg

http://i18.photobucket.com/albums/b132/Rain12/CIMG1380.jpg

The main storm that principally affected the East End, starting with its preliminary stage:

http://i18.photobucket.com/albums/b132/Rain12/CIMG1385.jpg

http://i18.photobucket.com/albums/b132/Rain12/CIMG1390.jpg

Until eventually: http://i18.photobucket.com/albums/b132/Rain12/CIMG1406.jpg

And here's some large congestus clouds gathering together - this photo depicts a good visual of the definition of atmospheric instability:

http://i18.photobucket.com/albums/b132/Rain12/CIMG1365.jpg

Edit: I'll have a final update either later tomorrow of early Saturday to follow up what was stated here, if necessary.

Trav.

Greetings, everyone,

Virtually everything that was mentioned in my last post concerning today's weather (Saturday) still holds firmly. The secondary low that I briefly mentioned above is still going to be affecting Southern and parts of Eastern Ontario with a good deal of rainfall, and, at the same time, will be bringing variable to mostly cloudy skies for Southern Quebec today, particularly following lunch time.

I don't anticipate any steady rainfall from this system in our region because, as the models still depict, the system will be steered just to our South and then East by the subtropical jet. Any precipitation that should develop will be accompanied by a slight chance in the form of widely isolated convective showers (30% P.O.P). With relatively mild convective activity, I believe the best chance for isolated showers would be in the afternoon hours. Though mostly overcast, mild humidity will build in for the day and we could hit a high of 25 to maybe even 26 C, depending on the number of sunny breaks we receive - otherwise closer to 23-24 C. Evening temperatures should remain comfortable at about 21-22 C in the downtown area (almost similar to last week). As for the winds, they are still expected to be moderate overall at anywhere between 15-25 km/h and still mostly coming out from the Northeast. There is also some indication of wind tendency in the form of North-Northeasterlies, but regardless, you'll likely notice the smoke heading toward the bridge and to some folks on the Western banks of the river just South of the bridge. Mostly cloudy skies along with a slight chance for showers (nothing too significant, if any) are expected to linger for the evening hours as well.

That's the way the atmosphere should generally behave. Looking at the bigger picture, it seems like the weather is setting the stage for Spain to fire their highly anticipated display. I hope everyone enjoys Igual's performance tonight!

Trav.

Greetings,

Putting everything together for tomorrow (Saturday), most of the day will remain unsettled with some on and off lingering scattered showers (risk of a thundershower or even thunderstorm) due to an upper level trough moving in from the West. However, I believe the instability should exit Southern Quebec by the evening-overnight hours before the next system arrives for Sunday, and I think we will be seeing some periods of sunshine and variable cloudiness throughout the day as well. Temperatures should remain warm at close to the mid 20s (Celsius, of course) while humidity levels should remain mild to near-moderate (nothing oppressive like yesterday).

The winds, to be honest, are a little bit tricky to forecast due to the positioning of a surface low pressure system in close proximity to Southern Quebec to the South or Southwest on Saturday. Consequently, winds are variable throughout much of the region (because of being close to the center of the low) as well as being relatively light in nature, which may be some concern. With the position of the low at this point in the model simulations, winds seem to be coming out from the East (therefore moving towards those on Notre-Dame) for the Eastern and central portion of the island of Montreal during the late afternoon-evening hours. I'll have an update on this later on when things fall better in place.

And, as I had mentioned about a day ago, powerful thunderstorms did indeed erupted in Ontario and Quebec (some impressive ones around and in parts of Montreal as well) on Thursday. I'm expecting decent to strong storm activity to continue to develop in an isolated fashion through tonight (some impressive cells on radar to the NW), mainly because the atmosphere is still so full of moisture (dewpoints still holding steady at close to 20 C at this hour ). Spoke to some fellow storm chasers in Indiana, Ohio and New York earlier and they reported some good storms as well in parts of those states. Scattered thunderstorms, some severe, may continue to develop into Eastern Ontario and Southern Quebec today (Friday) as well, though this time because of an upper level disturbance and not so much because of a cold front. Moisture levels are still good, too, so that provides a little extra buoyancy to the atmosphere. Most of the storms we had seen yesterday were more in the form of multi-cell thunderstorms, that is, storms that develop from other storms' downdraft winds (forcing warm air upward). These are quite common along and ahead of a strong cold front. I'll probably later post some video of some nice cloud to ground strikes that I caught around the island.

I'll post a final update later today or early tomorrow to verify everything for Saturday.

Edit: Forgot to add, but if you're awake, you can gaze to the Northwest skies to see lightning illuminating the cloud there.

Trav.

Hello everyone,

Just so to reflect upon what I had stated above, mostly everything that was described should still serve as a fair guideline for today and this evening's weather. Looking at some hourly synoptic charts, the upper level trough and its surface low are going to be a little more persistent for Saturday as they are being blocked off by an area of high pressure in the Atlantic. With this in mind, along with some fairly decent levels of convective energy, scattered showers and pop-up thundershowers/t-storms will develop sporadically in Southern, Eastern Quebec and New Brunswick for Saturday morning into much of the afternoon. However, the system appears to be dematerializing as we progress into the early evening when it finally moves Southeastward over the NE states. Consequently, this will reduce the energy available for thunderstorms and showers, and therefore diminish the risk of them occurring during the evening, though mostly later in the evening. Since a cold front isn't involved, the loss of daytime heating with the onset of the evening will also suppress significant precipitation development.

The winds are still a bit of a problem. I ran quite a bit of wind simulations for pattern/tendency and speed, but, for the most part, winds are looking to be relatively light to at times nearly non-existent during the evening hours, in particular. In opposition to what was mentioned above, though, winds tend to be flowing principally out from the North-Northwest to Northwest, but there are signatures of variability between the West and Northwest from 8-11 p.m, so this may at times be detrimental for viewers at La Ronde and particularly those on the bridge overlooking the park depending on predominant directional tendency at the time. However, with the lack of sufficient wind and the presence of moderate atmospheric moisture content, accumulating smoke may become a problem for all viewers.

So, to sum it up, we're going to be dealing with temperatures ranging between 19-21 C in the evening along with about moderate levels of humidity (dewpoints around 15 C). Skies should be partly cloudy with a slight chance (30%) for showers, while the risk for more defined showers and thunderstorms (nothing too strong) exists during the morning-afternoon period. Winds are mostly calm (occasionally light) and variable between the W and NW during the evening. The occasional maximum speed would likely be measured at no more than 9 km/h. If I see any differing tendencies showing up in the newer model outputs, I'll let you all know well before the display, but if not, then everything mentioned here still remains true.

That's the way the weather should pretty much behave. The long range is pretty much unsettled, though with mostly seasonal temperatures as we end June and begin the hottest month of the year, July.

Trav.

Hi guys,

Just a brief final update, but I would advise having your umbrellas handy for this evening, since, as I mentioned above, there is still the slight chance for showers and even a stray light t-shower. It is still a possibility that precipitation can develop and move into the area, mainly because moisture levels are pretty high. Otherwise, again, it will be overall partly cloudy. To correct the information above, a dewpoint of 15 C is actually regarded as high - currently readings are at 18.

Winds are still showing up in the models as the same as what I had mentioned above. There is some slight indication of light Southerlies towards 11:00 p.m for the Southern half of the island, so, with a little luck, though still light in nature, we may see those during the display. The predominant direction is still variable between the West and the Northwest to Northerlies. Either way, direction may not be so much of an issue tonight as the winds are generally calm to light anyway.

For everything else, please refer to my post above.

Trav.

well SMOKE, you were unfortunately very right - there was sooooooooooooo much SMOKE, it is incredible - just got home - I am very upset - we feared the rain all day and got rain all day, and tonight, bingo, barely any rain - but what we must fear these days, really, is the wind conditions, or lack of wind and the SMOKE SMOKE SMOKE

I will download my images - pretty sure I have close to nothing but will try to salvage a few

Sleep well everyone - tomorrow is another day !!!

Your Canada Day forecast:

I thought it would be appropriate to synthesize a weather forecast for Canada's 142nd birthday, especially considering that fireworks are a common event for Canada Day!

Wednesday's forecast is expected to be widely unsettled, as is the case for a good portion of this week - in fact, this is the scenario for much of the country, and for similar reasons. In Eastern Canada, a pesky upper level low is hovering over the region and remains almost stationary because of blocking high pressure settled out over the Atlantic, just East of Newfoundland. Consequently, this disturbance will bring about prolonged unsettled weather and seasonal to slightly below seasonal temperatures. When I say "unsettled" for this week, it doesn't necessarily imply that it will rain all day non-stop for tomorrow and nearly everyday for the rest of the week - rather it simply means that atmospheric conditions are conducive to the development of convective showers and thundershowers in the forecasted region.

Given the layout, the surface low is stationed directly below that of the upper level, so there are no frontal systems involved, which is, in part, why thunderstorms, if any, aren't expected to reach severe criteria in general. Instead, we'll see typical convective showers and thundershowers/t-storms developing in particularly Southern Ontario and Southern Quebec in a ubiquitous fashion, and with the position of the surface low, bands and isolated preciptation will be coming out from the South-Southeast direction. Moisture levels are still high, so it would feel humid despite the temperature range, which is pleasant at anywhere from 24-27 C, depending, of course, on how much sunshine is present. Evening temperatures still holding steady in the low 20s. Winds are likely coming out from the East to Southeast and will be mostly light at 10-15 km/h.

If you're heading to Ottawa for the big display there, expect identical conditions throughout the day, though winds are behaving in a somewhat lighter fashion while having a tendency of being in the form of gentle East-Southeasterlies (ESE). Either way, you should walk with an umbrella, just in case. Thundershowers should mostly die out (though still possible) in the evening with the loss of daytime heating.

------------------------------------------------------------
Hi Rachel,

As was the case last week, I am very sorry to hear that the viewing conditions were so poor in your position relative to the site. Yes, unfortunately, wind patterns did behave accordingly to what I had seen in the models almost the entire time, though, unlike what I had stated previously, directional influence still very much played an important role in this display despite the presence of calm to light speeds at the time. Winds were behaving in mainly a Northerly fashion with a slight tilt change coming out from the Northeast seen later on in the display - this observation is based on to what extent the bridge was covered up Westward. As this continued, my mind turned to you and the folks around you in what was likely being seen in that area.

That said, it is thanks to the slight Northeasterly tilt that viewers from La Ronde likely got the most ideal viewpoint for England's performance, for this served to direct the smoke just lightly towards the bridge and slightly Southwest. However, this appeared to hold true for the second half of the display, as I noticed in the first half of Paul's video, and towards the end, that smoke accumulations were causing the mid to high level shells to be faint. On the other hand, the slight Northeasterly angle meant that the right end of the display was at times marred by quickly building smoke for us on Notre-Dame, though mostly at mid to high level. It was also beneficial to those at La Ronde and Notre-Dame that the display was not so constantly active simply because this gave the smoke a chance to clear out a little. It was likely that those viewing on the bridge adjacent to the park had to quickly displace themselves since the smoke, once arriving there, was not moving too much - you can imagine how that feels! The Southern end of the park, from our viewing perspective, almost completely vanished 13 minutes into the display.

Wind and humidity, like last year, seem have been a problem for our first competitors. Things should be different for Australia's performance, but I'll have more on that towards the end of the week, so stay tuned.

Trav.

THANKS Smoke for your reviews - they are way too technical for me - all I want to know is if I am going to get lots of smoke on a particular evening - two weeks in a row with all the smoke is enough to make me stop suffering and going out there - but I will be positive and hope that next weekend, we will have perfect weather, just as we did on opening night

Anyways here are my images from the England show.

http://www.pbase.com/rachelita/england2009

If any of you happen to live in the greater Montreal area or even in Laval, chances are that you have encountered some very wild weather on Canada Day around dinner time. Flash flooding rains, marble sized hail, gusty winds and frequent loud crackles of thunder were the story from a severe thunderstorm that rolled through many parts of these areas. This gentleman posted a video on YouTube of what the storm was like in his vicinity:

http://www.youtube.com/watch?v=979FGW7nTVw

Though I was not so much expecting severe weather to erupt, in general, on Canada Day, I didn't rule out the possibility of it occurring altogether. I was actually tracking many of the cells displaying high reflectivity on radar coming in from New York, including the one that affected Montreal. It wasn't long after that Environment Canada issued the watch, and eventually a public warning.

Thunderstorms have died down now due to, as mentioned, the loss of daytime heating, though they will fire up again today in the same scattered fashion and pushing up from the South- Southeast. Some of these storms can, again, reach severe standards, especially if the sun is able to remain out for prolonged periods, much like earlier yesterday. All of this unsettled/active weather is, once more, due to a persistent upper level disturbance. This brings me into Saturday's weather.

At this point in time, I think this disturbance will still be plaguing extreme Eastern Ontario, Quebec and the Maritimes for a fair portion of this weekend before finally clearing. Being on the back end of the low at that point, cooler air will flood into much of Eastern Canada (highs barely reaching the low 20s), and unsettled conditions may remain for much of Saturday, although t-showers/t-storms should come to an end. Winds could be another problem, though not in the same context as last Saturday. Rather, the directional tendency is likely Westerly to Northwesterly, which could be affecting folks on the bridge just behind and adjacent to La Ronde as well as possibly those in the park itself - I'll keep an eye on that. Winds look to be light in nature, but should have much higher speeds than what was seen the last time. Temperatures are likely cool, so I think you'll need your jackets. All that said, I hope the showers and thunderstorms aren't interferring with Foti's setup too much.

I'll have a final update later on tomorrow (Friday) or early Saturday. I leave you with a video I took of a full rainbow arc seen in the distance when the sun came out from behind and projected its light towards the storm cloud at the Southeast (the one that dumped all that rainfall and hail). If you look carefully, you'll also see the much fainter secondary bow, who's color order is the reverse of that of the primary.

http://www.youtube.com/watch?v=XtF0xKldne4&feature=channel_page

Edit: I also caught this photo when the storm was in development:

http://i18.photobucket.com/albums/b132/Rain12/CIMG1544.jpg

These are called "Mammatus" clouds and sometimes form beneath the anvil of a thunderstorm. Though they are amongst the most beautiful, striking and captivating cloud formations for photographers and weather watchers alike, they commonly warn of a vigorous storm, so take precaution if you ever encounter them.

Rachel, sorry for the technicalities - just have a habit of being as specific as possible, I suppose. I'll try to condense/simplify things, however, for future reports, but at least you have some idea for wind direction this coming Saturday. I'd still like to keep an eye on overall patterns, though.

Trav.

Hi guys,

Everything that was mentioned in my post above regarding Saturday's weather (the 4th of July) still holds true, though I'd like to add a couple of things as I make my summary.

Firstly, though still unsettled, I think most of the rains should conclude by late tonight into the morning hours tomorrow, leaving us with cloudy to partly cloudy skies for ending Saturday into the evening-overnight. The chance for lingering showers still exists, but precipitation development should taper off by later in the day altogether. If you recall what I mentioned above, as we will be clearly on the back end of the low for tomorrow, cooler air will invade much of Eastern Canada (it's already in the process of doing so), and so temperatures will be quite unseasonably cool for tomorrow (again, struggling to strike the 20 C mark), particularly into the evening-overnight period (hovering around 16-18 C), so you'll find yourselves needing to equip either a light sweater or light jacket (yes, in July, I know ). Humidity levels will also drop off gradually later on tomorrow.

Winds are more of something to keep an eye on. Because of the cooler air descending from the North, winds have been picking up recently and will continue into the afternoon tomorrow, reaching a peak of up about 35 km/h (gusting to 45 km/h) in parts of the island by around 2:00-3:00 p.m. As the afternoon progresses, winds should still stay at moderate speeds, but I'm expecting them to diminish by the evening down to light standards. Wind tendency is still a little difficult to predict during the evening, but right now I'm still detecting W to WSW. Winds overall are light, nevertheless, at that time, but unlike last Saturday, they should be at much higher speeds at anywhere between 9-16 km/h.

That's the way the weather should operate for the most part. In summary, we're looking at a cool, mostly cloudy/slowly clearing evening with fairly light winds (with some occasional breezes). It's going to be an overall dismal greyish kind of day, but at least providing pretty much ideal conditions for the fireworks.

*I'd like to keep an eye on wind direction still simply because it still may concern folks at La Ronde, so I'd like to see how things play out before I state anything. If things come into more of an agreement, I'll let you know in advance.

Trav.

Thanks, Trav. I met dark clouds and heavy rain this afternoon as I was on the Aut. 20 between Quebec and Montreal. We are very lucky because it looks that once again, tomorrow, we will avoid rain for the fireworks and the waiting time just before it. I look forward to wear just shorts and t-shirts, but the most important is to not have a rainy night. Some wind would be welcomed also, especially with the massive display I expect from Foti, with all these nautical shells.

It is nice to have our in-house meteorologist. Do you study in that field?

Fred

Hello everyone,

I have prepared a short analysis of the winds tonight in what we could possibly expect. The models are still reading wind tendency coming out from anywhere between the Northwest to West (not so much the occasional SSW any longer). The average direction, I believe, will be in the form of North-Northwesterlies (NNW), so smoke may be, at times, blowing towards folks at La Ronde (moreso towards the left end of the seating area) and even towards the bridge thanks to the occasional Northwest tilt. It sounds like the display will be rather active, so smoke could sometimes become more of a problem in that respect. Note that winds have been Westerly all day. Winds should, again, diminish to lower speeds from what they currently are this afternoon (9-16 km/h). Humidity levels have dropped off to moderate.

Though there is some clearing this evening, there's still the slight chance for some lingering rain showers during this time (nothing enduring, if any), much like what has been seen in parts of the island this afternoon with some brief isolated showers along with the partly cloudy conditions. There are still some bands of showers to the Northwest (clouds moving to the Southeast). Nevertheless, expect overall partly cloudy conditions this evening. Temperatures are quite cool and I think they will be closer to the 16 C mark than 18 C this evening.

For everything else, please refer to my post above.
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Hi Fred,

I was actually tracking the cells in Eastern and Southern Quebec yesterday, and I spotted the huge cluster of steady rains on Aut. 20 and the 40 between the two cities, so I'd imagine that you would encounter such an event there at the time.

Though the winds should be ideal in terms of speed, the direction may, at times, be inconvenient to some of those seated at La Ronde and the adjacent bridge, especially since this display is likely going to be so active at many points. For the most part, I think we should be ok in terms of rain, but there's still the slight risk for some isolated showers in the evening. If there are showers, however, I don't anticipate them to be enduring. Overall, though, partly cloudy conditions should dominate the evening skies.

Don't worry. You'll likely get the chance to get out your shorts and t-shirts this coming work week as temperatures gradually rise back up to more July-like.

And, indeed, I'm working to become a professional forecaster. I've been studying meteorology for many years now, and the fascination first triggered since I was about 3-4 years of age.

EDIT: Enjoy the show, guys, and KEEP WARM!

Trav.

Hi Trav,

Following Paul's exciting interview with Pyromagic crew, I think that we are due for a weather update. I hope that the display will not be impacted by poor weather conditions and that the Ferris Wheel will run in the evening, allowing me to take some pictures of this particular setup. However, I'm afraid: MétéoMédia projects showers and thunderstorms for Saturday, 80%, with about 20mm of precipitations. It doesn't look good.

Fred

MétéoMédia projects showers and thunderstorms for Saturday, 80%, with about 20mm of precipitations. It doesn't look good.

I noticed the same thing this morning Fred. If the weather is that bad I would not be opposed to postponing the display until Sunday where MétéoMédia is calling for nice weather and strong enough winds. I won't worry to much until Travis tells me to.

Tyler

MétéoMédia is notoriously pessimistic this summer- in fact, apart from Trav, all the mainstream forecasts have been way off base and the weather has been nowhere near as bad as they have predicted. Only Pascal Yiacouvakis on RDI/CBC Daybreak tells it like it is!

Paul.

p.s. as far as I understand, the only reason a display will be postponed is excessive wind, not rain - let's hope this isn't put to the test

For the past weeks, MeteoMedia was pretty accurate on the hour the rain would stop. They predict 20h for this coming saturday... but still let's keep our finger crossed all !

Mylene.

Mylene Salvas is right. It won't last all day. The latest is that the thunderstorm will end by early evening and so by 10pm, the sky will be partly cloudy, but this could change, of course! At the moment, it looks like it's some crazy thunderstorm that will passby during the day. Travis would know!

Why not postpone it until Sunday. Already the attendance at La Ronde has been very low due to the poor weather, like last year, and Saturdays haven't been so great! What a bad luck!

Hi everyone,

It would seem that we have some concerns here, but I can certainly understand the feeling with respect to the forecast you're all seeing. Let me make sense as to what we could be dealing with.

As a general overview, this is a vigorous surface low pressure system that has been affecting much of the Western portion of the country over the last 3 days, and is expected to move through parts of Eastern Canada in the same manner. The associated cold front will be responsible for the unsettled weather for Saturday (as I briefly mentioned before in Rachel's Australia thread) over Ontario and Quebec as it clashes with this warmer and mildly moist air mass. Once this front passes through, temperatures will drop off by about 5 C from what they will be tomorrow for daytime highs by Sunday and Monday through to Tuesday.

With the front's average speed and nature shown in the computer models, I'm predicting that isolated cells and lines of cell clusters along the front won't be (at this point in time) affecting Southern Quebec until about lunch time and thereafter, especially as daytime heating begins to reach its peak (assuming we get enough sun). Convective showers and thunderstorms are possible in the late afternoon to the evening period, and possibly won't completely clear out until the early overnight hours. This cold front also has a history of producing severe thunderstorms, so I wouldn't be surprised if some of the storms manage to reach severe limits. However, I'm still a little doubtful about severe t-storms forming in the region, simply because there isn't a great deal of moisture to work with. Because this is a cold front, many thunderstorms won't really die or fizzle out rapidly, even with the onset of the evening-overnight, and so showers and thundershowers/t-storms are still possible until the front finally passes through late evening-overnight. Just to be clear, again, "unsettled" generally signifies that conditions are favorable to the development of showers and thunderstorms, and therefore holds that there is a greater portion of cloud cover (due to instability) with the "risk" for stormy weather - the entire day wouldn't be a washout and it doesn't necessarily mean that everywhere in the forecasted region will in fact see showers and storms - that is where the current forecasts are a little misleading. We should encounter some sun during the day, although this drives storms to develop. I would establish the risk at 40-60%, particularly since we're dealing with thunderstorms.

The winds are behaving a little different than the previous weeks. For Saturday, as expected, wind tendency is typically out from the South (slight SSE tilt) and later coming out from the SW. They may become quite gusty passed lunch time (gusting up to possibly *50 km/h), but slowly dropping in speed by the evening. It will remain fairly windy at moderate speeds of close to 25 km/h and coming out from the SW during the evening. There is also some indication of a Westerly shift in the late evening, like last week, which suggests that the front may completely come through by that time, though this isn't ideal for La Ronde viewers due to wind direction. I'll keep tabs on this.

As for a show being canceled, as Paul stated, it is likely that enduring strong winds would cause this course of action (which is what almost happened for England in 2003). However, a severe thunderstorm in the area, much like the case for England 2007, could also call for a delayed show until conditions improve. It was disclosed to me on this forum that, as a safety measure, a display cannot be fired safely unless winds are constantly below the 40 km/h threshold, or even 35 km/h. Though it is likely moderately windy Saturday evening, I don't think we can expect winds reaching that level.

All that was mentioned here should serve as a fair idea in what we can expect for this Saturday, but I'd really like to keep an eye on things before providing confirmation of these conditions, especially with an atmospheric setup such as this. As new model runs come in, I'll have a better idea in what's likely in store for the evening.

I'll have a report by later tomorrow or early Saturday to finalize things.

EDIT: Temperatures will be more comfortable compared to last week.

Trav.

Good evening,

All that was stated in my previous post still stands firmly, though I'd like to make some small adjustments with respect to a number of variables.

Firstly, with respect to wind tendency, as stated yesterday, it will be mainly in the form of Southerlies for the majority of the day, but you will notice the SW shift by late afternoon-early evening. Wind speeds will maintain their moderate status throughout the day, and will likely reach a peak of about 30-35 km/h (gusting, at times, up to 45 km/h) not long following noon, particularly in the East End - the strongest of winds will be concentrated in the Eastern Townships. With some gradual weakening in the late afternoon to early evening, we should see speeds of closer to 22-25 km/h (again from the SW by that time) and then closer to 20 km/h by late evening. The wind direction seems to be behaving in a SSW to SW manner during the evening hours, so for folks at La Ronde, you will notice the smoke typically moving off to your right this time. However, with the possible Southwesterlies in between, I'm thinking that this will, at times, blow the smoke to the extreme right end (not sure of the section name) of the seating area at La Ronde, so avoid that part for viewing if you can.

Now, for the thunderstorms and rainfall. Most of the models are still projecting strong instability into the evening hours. This is not to say that it will rain all evening, but rather that the conditions are still favorable to the development of showers and storms. Once more, I'm thinking that the greatest likelihood for unsettled weather will be just around lunch time and onwards with mostly cloudy skies in between. I was checking in with Ottawa and SW towards Morrisburg, and it would seem that there will be improving conditions by around 8:00 p.m. in both areas. Given the average speed of the cold front and the distance from here to Ottawa, I don't think we'll be completely out of the risk until sometime around 11:30 p.m. here in Montreal. Looking at the big picture, I personally think that things should somewhat improve, in general, by the time we hit 9:00 p.m., but the chance for lingering precipitation will still be with us for the next couple of hours or so. As a precaution, I would recommend having an umbrella handy. It's difficult to say what exactly will happen at 10:00-10:30 p.m., or for any specific narrow time window, but I can safely tell you that the risk for showers and even t-storms exists (40%).

*Also take note, again, that some storms out there could reach severe standards tomorrow afternoon - a good amount of convective potential energy is present. Moisture levels are also decent and the air is unstable. The likelihood for severe thunderstorms would increase depending on how much sun we receive through the day. Before the front moves through, though, a trough will also trigger scattered non-severe thunderstorms. The cold front is responsible for the severe weather, though that will come later in the afternoon.

That's the way the atmosphere should generally behave. In summary, we're looking at a fairly breezy evening along with temperatures holding steady at about 18-20 C (much more comfortable than last week in that respect) and moderate humidity. Showers and thundershowers/t-storms are also possible (I think 40% by 10:00 p.m.). Once that cold front clears out, you guys will notice the cool, windy and dry weather on Sunday into the next few following days.

EDIT: I'll be keeping a track of radar and satellite imagery throughout tomorrow.
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Fred and Tyler,

The main reason as to why you're seeing large measurable rainfall in the forecast(s) is simply because precipitation is mainly associated with thunderstorms, and t-storms, particularly heavy to severe t-storms, can bring locally massive amounts of rain in a very small amount of time. The storm on Canada Day is a good example of that.

Enkil,

I don't think it will rain all day either, but as I mentioned, it will remain mostly cloudy for most of the day, particularly following lunch time. The greatest chance for severe weather is in the latter part of the afternoon.

Trav.

Thank you, Trav, for all these details. I now prefer to take a look on your posts than MétéoMédia, since we have some personalized info for our needs! It looks that the wind will push the smoke toward the VIP section, as it happens most of the time. Not too bad: most (or all) these people don't personnally pay and I suppose that they are often more interested by the free adult beverage and by the opportunity to chat together than by the display! Hopefully, this wind will not detract the anticipated letter effects.

I will leave Quebec City in mid-afternoon. I suppose that the bus may travel through some thunderstorms. I would prefer to see there by the windows along the 20 highway than tonight at La Ronde.

Fred

SEVERE THUNDERSTORM WARNING for the MONTREAL METROPOLITAIN AREA AND TORNADO WARNING FOR LAVAL AT 8:43 p.m (no confirmed touchdown as of yet). Please take precaution out there! Tornado warning has just been ended for Laval.

Trav.

Hi Fred,

Your comment is much appreciated on my part. Though I find most of the main forecasts to be reasonably accurate in giving you a basic idea of how the weather will most likely turn out on a given day, I personally feel that the key to giving a good forecast is to be as open-minded as possible, and that means to consider all meteorological parameters efficiently. A good method that I employ is simply running individual model simulations of, say, wind, cyclonic tendency, and temperature, and then coming out with my own forecast while simply using my own intuition regarding certain things. I then compare my own predictions and findings with those established by the major Canadian (and American) meteorological organizations, such as Environment Canada, and then make an assessment. Following that point, if I happen to be reasonably close in my analysis, I will produce my predictions with a good level of confidence and later make any adjustments if necessary (models aren't perfect since they assume ideal atmospheric conditions). Making a localized weather prediction is where it gets tricky, for micro scale weather patterns can deviate from those of the macro scale due to geographical disturbances, but I have ways of working around that. In essence, I simply try to put the pieces together and then later share my predictions with you guys.

I also sometimes make use of the "steady state" method in predicting weather events, especially with respect to fronts. In this way, I was able to successfully predict the timing of the first line of storms on Saturday at lunch time and to similarly anticipate the estimated time when the storms would completely exit the area Saturday night, which was just past 11:30 p.m. All that said, a forecast isn't perfect, but it should attempt to try to explain the weather as accurately as possible for the general public.

This coming Saturday's forecast is a little tricky, but I'm certainly not expecting a similar atmospheric setup as what we had seen on July 11th, although we may see storms developing on late Wednesday into Thursday as higher levels of moisture flows into the region. More details later on this week.
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In other weather related news, if any of you happen to remember my Summer prediction this past June, I stated that an El Nino should develop during this Summer and persist likely into next year. As it turns out, I was correct in making this statement as scientists have recently confirmed the presence of an El Nino just three days ago. They are also expecting it to gradually strengthen. Should that be the case and assuming it holds strong during the Winter, it may signal, as I mentioned before, that this coming Winter will be milder than those of the last two years. Depending how warm temperatures get, it will prevent large amounts of snow as well. If a strong El Nino persists into Summer 2010, I feel that it will be a very hot one as we had similarly seen in 1999 and 2005. This also likely means a decrease in the number of hurricanes or tropical storms forming in the Atlantic this Summer-Fall.

Though I was successful in predicting El Nino, temperatures this Summer were clearly not normal or above normal as I had initially stated (no sign of the usual Bermuda High in the Atlantic). Thunderstorm frequency has been fair so far, though, and rainfall above normal. If an El Nino is present, it may have more positive implications for the end of this month into August, as well as granting us an Indian Summer. Thunderstorm frequency would pick up if that's the case, especially in August.

Let's just say that El Nino has a tendency to make North American weather much more exciting.

Trav.

Good day,

With regards to Saturday's (July 18th) weather for Argentina's display, it's a little complex to explain the setup, but I'll do my best to simplify things. Unlike last week Saturday's wild weather, this time it's a fairly strong, blocked upper level low that we'll have to contend with following today's (Friday) fair weather. This disturbance aloft is showing signs of strengthening as it pushes Eastward, and so it will bring about mostly unsettled weather until at least the first half of Sunday. Now, there are also two surface lows converging, which is, in part, why there is so much moisture associated with the entire merged system. Given the speed of the low and the jet stream configuration, I suspect that the bulk of the rain will fall overnight Friday up until close to lunch time Saturday. Following that point, rains will give way to on and off periods of showers into the afternoon and evening (still want to keep an eye on the evening hours, though). The air at upper levels is close to saturation throughout the day and into the evening as well. Before the system comes in, though, we could see some thunderstorms fire up into very late afternoon and early evening hours (For Friday) before the relatively steadier rains arrive overnight. Chance of showers in the evening would be anywhere from 40-60% P.O.P on Saturday.

I'm also watching the winds. You will notice their overall directional pattern to be quite variable duirng the first half of the day Saturday, while being light in nature. I am expecting them to pick up in speed rapidly during the afternoon, however, and could become rather breezy at times. Latest and recent model runs project winds to be mainly in the form of Southwesterlies to SSW in the evening while holding speeds of about 20-25 km/h (higher in the extreme West end of the West Island at this point). This wind tendency would mean that smoke should be moving rapidly to the right for those stationed at La Ronde, though, again, it's best to avoid the extreme right end of the seating area due to Southwesterlies.

Maximum temperature values during Saturday evening is 20 Celsius, though I think it will be hovering around 17-18 C by 10 p.m. Humidity levels will remain close to high standards, but temperatures are unseasonably cool this weekend. As mentioned in my last post, I'm expecting that pattern to break in the closing week of this month into August due to, in part, El Nino.

I'll have a final update either later this evening or early Saturday to confirm these conditions, but this should serve as a basic guideline.

Trav.

P.S. Hope you all liked the storm this evening - it mainly came through the West Island and Southern Laval before dying once it reached downtown. A separate storm hit the South Shore as well. This is what I meant when I said we could see some good storm activity last night!