Greetings,

First, let me say that I’m pleased to have recently become an official severe weather watcher volunteer member for Environment Canada. My job is simply to report any active (namely severe) weather on days where the potential exists for ominous conditions to develop. More specifically, it is important for me to look out for signs of severe weather well in advance of the main storm itself, should it occur, and report them using precise meteorological observations and data collection based on moisture, temperature and wind patterns, among other parameters. In short, I’m basically the eyes and ears for EC in my region, and since I already normally do some storm chasing in late-Spring to Summer, this task will be rather fun. I suppose my reports provided here on the forum will occasionally be supplemented by some of these observations in the event of a severe thunderstorm watch and/or warning occurring in conjunction on the days of fireworks displays, just so to make things a little more tenacious and accurate when making my assessment.

In any case, welcome to yet another Summer season, where it’s possible to witness periodic heat waves, thunderstorms of all types, long periods of fair/cool weather or just boring persistent low pressure systems. Interestingly, the moderate-strong La Nina that was present during this past Winter and Fall has weakened considerably since mid-March, as shown by the extensive warming recovery of the sea-surface temperatures off of particularly the NW coastal region of Peru. My prediction was for a generally prolonged delay in Summer-like temperatures, and this has, so far, been clearly the case with their absence throughout virtually all of May and so far for the first few days of June. I’m expecting the more warm-hot temperature threshold to slowly be attained as we get closer to mid-June (as what we will shortly be witnessing this coming weekend) and onwards, so I don’t think we’ll have to be anymore patient. Regarding storms, there is a fair chance that we could see some particularly vicious thunderstorms this season following mid-June (we’ve already seen one 3 days ago), and I am generally expecting a moderately active t-storm frequency up till September in Southern Quebec and Ontario due to the jet stream’s average configuration associated with a weak La Nina. La Nina itself is expected to continue to weaken and gradually reach a neutral state during the heart of Summer, suggesting the upcoming months to be near normal, or just slightly above normal in average temperature. This also means that precipitation will follow a below to near normal trend, which is again consistent with what has been going on during the month of May. Hurricane season is also expected to be an above average one.

Anyhow, I’m sincerely hoping that none of the 10 displays will be influenced by the risk of storms, heavy moisture (unless winds are at a favorable speed to take care of smoke accumulations), unfavorable wind direction, and persistent strong winds, although there tends to be at least one participant per year (with the exception of 2005) that fall victim to either of these situations. Even if the probability of precipitation is at a greater percentage rate, or if winds are expected to be strong on some presentation nights, perhaps our usual 10:00-10:30 p.m. “weather-proof barrier” will kick in until the show is over.

You’re all more than welcome to report weather conditions some time before the day of presentation of each display. However, I advise not to provide updates no more than 2-3 days preceding the performance date as things become increasingly uncertain prior to that time frame in the models. Be sure to sometimes pay attention to dewpoint (moisture) and wind speed/direction, in addition to temperature and the risk of precip.

And just out of interest, I'll be sure to share a picture of that funnel cloud extending from that supercell (severe t-storm) I spoke of from 3 days ago in the afternoon. The storm produced pea to marble sized hail with radically heavy rain and brief strong gusts of wind in excess of 90 km/h. The picture was taken from Southwestern Pierrefonds, which is in the West Island.

Now then, let the weather watch of Summer 2008 commence. I've got a feeling it's going to be an interesting year weather wise.

Trav.

I apologize for the delay of providing the photo of that funnel cloud that I had seen back on June 2nd. I just got my internet running again after some time moving into my new residence. Anyhow, here it is:

http://i18.photobucket.com/albums/b132/Rain12/DSC00839.jpg

*And here's a couple of photos of the mighty supercell that roared through a couple days ago:

http://i18.photobucket.com/albums/b132/Rain12/DSC00875.jpg

http://i18.photobucket.com/albums/b132/Rain12/DSC00874.jpg

Notice the stacked layered shelf cloud there - this is indicative of powerful updrafts, windshear and the possibility of a tornado touching down.

This storm produced hail as large as baseballs, flash flooding rains, frequent lightning, periodic wind gusts in excess of 110 km/h and an unconfirmed report of a tornado. We had it pretty strong in the West Island, but just not as powerful as what was seen in the South shore. I personally don't think the t-storm gave birth to a twister because based on what I saw to the Southeast, the winds were downbursting in a straight line as they pushed up the debris ahead of the rain core, so it is to my belief that this was indeed a microburst. Also, I didn't spot many sightings of distinctive lowering, nor of a wall cloud formation to suggest a persistent mesocyclone, although it's definitely possible that some may have developed later on as the storm tracked NE. In any case, large trees were snapped and there were many reports of property damage as a result of powerful winds. Large 50 foot trailer trucks were overturned on the Champlain bridge, too - some nearly falling into the river. Severe weather was also reported near the U.S border.

It seems that June is closely following the predictions I stated earlier, though the vicious thunderstorm appearances have started a little earlier than expected. Temperatures are following the expected trend as well, so far.

I'm sure there's still a few strong storms yet to come, as I had previously mentioned in my last post, so stay loose.

Trav.

Only FIVE DAYS before the launch of the 2008 competition! Of course, some displays are more anticipated than others, especially when a winning contestant is back. However, the opening one is always special for me, the first to be enjoyed after several months of deprivation.

Unfortunately, it appears that the cost for a contestant to start the competition is high: from 1992 to 2007, only one opening display (6%) has been awarded by a Jupiter, in opposition to 10 "closing" display (63%). This is what social scientists call a statistically significant difference.

About the weather, I just love the MétéoMédia forecast available this morning for next Saturday: sun with some clouds, 30%, 25 degrees. I cross my fingers that forecast will remain the same!

Fred

Hi Fred,

I, too, cross my fingers in hopes that the weather will remain fixed the way it currently is. Once that cold front comes through today (the 16th), a cool airmass will follow behind it and persist for the remainder of the week, as well as being unsettled. In the meantime we're under the risk of some pretty hefty t-storms for the next 12 hours. I am, however, expecting a returning South-Southwesterly flow by ending Friday and onwards with returning humidity, but at the same time this may run the slight risk of on and off thunderstorms on Saturday in both Ontario and Quebec as the warm moist sector of air advances into the region. We'll keep an eye on it, though, since the speed of this coming system is everything.

And yes, Fred, I, and everyone here I'm sure, am always in high anticipation when the competition is set to begin, as well as hearing that first boom. 10 months is much too long of a wait - virtually a year's time.

Trav.

Good day,

As I mentioned earlier, the weather forecasted for Saturday (the 21st) is a little tricky, but being consistent with my last post a few days ago, the risk of on and off rain showers still exists, as well as the isolated chance of non-severe thunderstorms.

What has been happening for the last little while and what will be occurring for the next few days is that the jet stream has produced a persistent "cut-off" low pressure system that has constantly been spawning low after low and subsequently creating trough waves one after the other, creating continuous instability, and hence the dreary weather - the clouds have been generally dark, low, dense and boring-like for the last while. This redundant pattern persists because the system is also being blocked off by high pressure to the Northeast, so it's almost as if this area of low pressure has been going nowhere - on the precipitation weather maps, it looks like a real mess in the East because lows are constantly replacing old ones in the same area.

Fortunately, for the most part, this will be widely isolated and hit and miss rain showers scattered all about on Saturday. Sunny breaks are certainly possible, but cloud will usually tend to interfere. Temperatures sharply rebound, though, compared to what they are presently and what they were for the last couple of days. However, with the sun out at times this weekend along with the warm moist Southerly flow returning, it will help provide enhanced instability needed for rain and even t-storms to develop ubiquitously. This is the kind of pattern we're dealing with, and it will persist throughout virtually all of Eastern Canada over the next 72 hours before it breaks. The only thing that's different is the warmer temperatures on the way.

My main concern is again later in the day on Saturday as the new system moves in this direction, so I'd like to still keep an eye on that. Either way, things will still be unsettled, but perhaps we'll get some breaks during the evening hours, or at least during 10-10:30 p.m, especially since we're dealing with isolated showers and storms. If anything is expected to occur during these hours, then I would estimate a 40-60% probability.

I'll provide more updates as we get closer to the day, but you get the idea of what the atmosphere is and will be like.

EDIT: Btw, tomorrow is the first official day of Summer. It arrives at 7:59 EDT.

Trav.

Good morning,

First, let me just wish everyone a happy first day of Summer. I noticed I forgot to add in the official time of its arrival in my edit, but it arrived at 7:59 p.m. EDT yesterday (the 20th of June). So, I welcome you all to the first full day of Summer, which entirely means that today has the longest daylight period of the year.

Regarding the weather, everything what I had mentioned previously in my last post still stands firmly. Again, the day today will be predominantly fair since the showers and thunderstorms are widely isolated from now up till the overnight hours.

From now until the early part of the evening, we run the risk of light to moderate thunderstorms, but the reason as to why they are not forecasted in the evening, in general, is because we're losing daytime heating, so if anything does occur, it will be likely in the form of rain showers. Seeing that the sun has been out for some time, it will help develop those showers and storm sporadically. However, the more severe weather is expected and more confined in Southern Ontario due to lake breeze convergence.

The good news is that we will be getting some breaks this evening before the next system arrives from the SW. Further to the West and Southwest, there is a much greater risk of thunderstorms and showers this evening as the new low tracks East-Northeast, which is why I wanted to watch the evening forecast for Montreal. These showers and possibly light t-storms will near us during the overnight hours.

In any case, when there's the risk of thunderstorms or isolated showers, most of the day tends to be pleasant, but just know that they're out there. This evening should be alright with a nice temperature of 19-21 C along with a few cloudy periods and variable cloudiness - isolated showers are again still possible in the early evening, though, especially seeing that there's the risk in Ottawa and Cornwall. I'm expecting the thunderstorm risk to end towards the ending afternoon. Also note that it will feel more humid, thanks to the returning SW flow bringing in more moisture from the Gulf, and the winds should stay steady from the SW at 10-15 km/h. As I told Enkil, I'm confident that we'll surpass the daytime high of 22-23 C, mainly because of the warm and stronger Southwesterly flow. It's already just that out there currently.

You can always equipt yourselves with a small umbrella, if you've need of it, but we should be alright by the time 10 p.m rolls around.

Trav.

Thanks so much for the info Trav.

I'm sure we will do our collective best to fight off any rain once again this season!

Hello,

Just briefly, but I had wanted to state that there's the risk for isolated showers and thunderstorms for this coming Saturday as a merged low moves slowly from the West and Southwest - there's a fair circulation of moisture also coming in from the Gulf for the next little while. As the system pushes in this direction, it will generate instability throughout the day, but particularly later in it, so I'm finding myself waiting for the late afternoon-evening forecast yet again for this coming Saturday. If anything, I'm not really anticipating all day rains, just on and off showers and, as always, the possibility of thunderstorms due to daytime convection. On the other hand, it's still a tough call in some sense, too, since the jet stream is showing signs of slowing or altering the course of this complex system in the models.

In any case, regarding t-storms, at this point in time, I don't think they are expected to reach severe limits, but I'll know more on that as we get closer to the day.

Given the layout, however, most of the day should be pleasant when the risk of showers and storms are present.

Trav.

Good morning,

Being consistent with my last post about a couple days ago, this merged low pressure system is well on the way from Western and Southwestern Ontario. However, the low has become much better organized just recently and the jet stream is not doing so much in altering its course, mainly because of it being so enlarged after combining. In any case, as mentioned before, these will be predominantly widespread rain showers and thunderstorms for most of the day Saturday, but as we approach late day into the evening-overnight hours, we could see periods of rain and a better chance for thunderstorms as the associated cold front nears.

The only thing that sways away from my last post is that while the thunderstorms are mostly non-severe in nature, there is a good possibility that some among them could attain severe criteria as the cold front approaches later in the day, so we'll have keep an eye on that. Thunderstorm risk will persist in the evening-overnight regardless of the loss of daytime heating, merely because the cold front will continuously provide the instability needed.

The forecast itself is calling for a "soupy" airmass, where there will be quite a bit of humidity tomorrow, much like today and yesterday, and hence the risk of severe thunderstorms with the passage of the front. Most of the showers and storms will begin to develop in the afternoon with daytime heating convection. The majority of these are commonly associated with a 40-60% probability since they are relatively ubiquitous in nature.

The evening is where it gets tricky. During the evening, I'm anticipating anything from a 40% P.O.P to as much as a 70% since increasing cloudiness will develop by then and in the afternoon. Again, showers and storms are possible. I assure you that temperatures will be very warm, ranging from the mid to high 20s depending on how much sun we get heating the ground. Winds will be coming out from the SW and at times the SE before the front comes through. The speeds should be adequate to get rid of smoke accumulations - remember that there will be a lot of moisture, so we need favorable windspeeds.

Again, note that most of the day tomorrow will be fair with variable cloudiness with the chance of showers and storms. Also note that once the cold front comes through, it will do little to take away the humidity, and hence the continued warm temperatures following tomorrow. This trend looks to be continuing up till Canada Day, although, as is normal for that festive day, the risk of t-storms exists. Today (the 27th), the risk for storms is there as well, though this is the result of pure daytime heating.

Anyhow, I'll provide a final update sometime tomorrow morning, but this is the way the weather will likely work over the next 48-72 hours - there's a lot of available convective energy for storms to develop in this period. Of course, I very much recommend having your umbrellas at your disposal moreso than last week Saturday. As TRae said earlier, we'll do our best to fight off any rain threats this season!

EDIT: Just realized that I crossed over 2000 posts! Yahoo!

Trav.

Trav,

any chance you could do me a personalized forecast for Sunday 29th for Knowlton/Lac Brome? I'm putting on the Canada Day fireworks at 9:30pm in Lions Park - it will be a pyrodigital show for anyone that's interested in coming to see a show scripted by me

Paul

Paul,

The weather pattern for the Eastern Townships, including the area for where you're firing your display, is quite identical to that of Montreal and most of Quebec this weekend. As the low pressure system tracks into Quebec tomorrow, we will get the chance of showers and thunderstorms, some storms of which could be severe. There have been some pretty nasty storms near the Sherbrooke area over the course of the last week to two weeks.

With respect to Lac Brome on Sunday, most of the diurnal part of the day will be at times soggy and sticky with persistent rainfall and the risk of thunderstorms. Breaks of sunshine are also very possible, but this will tend to be interfered by clouds. Temperatures, however, will remain warm (mid to high 20s depending on how much solar heating reaches the surface) and it will be, like Montreal, humid there for the entire day, much like the way it has been for the last 48 hours. As the system continues to track towards the East-Northeast, there will be some lingering showers wrapped around on the back end of the low - these showers and storms are scattered all about during the evening hours, but there will increasingly be breaks in the clouds by this period in time before everything exits completely by the overnight.

Seeing the layout in the models, there's a better chance that you'll encounter breaks in the on and off rain showers during the evening compared to earlier in the day itself. Moisture levels are high, but winds will be light to moderate continued from the South-Southwest (could be a shift in direction in the early evening, though). Either way, you'll need your umbrella, just to be safe - hit and miss showers and storms are often hard to predict. If you require a latter forecast, let me know, but what I provided here is meant to give you a wide scope of the weather trend for Sunday in that region.

Anyhow, I think the majority of people living in Ontario and Quebec will be making good use of their umbrellas this weekend. Thankfully, it will be very warm, hazy and humid.

As for the display, it sounds really interesting, Paul. How long is it expected to last?

In the meantime, here in Montreal, tomorrow evening is a bit scary for Italy's show with that front closing in. Overall, tomorrow in its entirety is definitely a day to keep an eye on the sky - could even hear a crack of thunder when you wake up in the morning.

Trav.

Hey guys,

Nothing too much for me to report as everything I regurgitated in my posts over the last three days still stands firm. You'll notice the first bands of precipitation from the warm front moving in quickly from the Southwest bringing some steady rainfall along with some embedded thunder for the next few hours. Behind this cluster is what we call a "dry slot", so the sun may often make some brief appearances later this afternoon. However, this will energize the rising air currents as air molecules begin to collide frantically in response to solar heating.

Severe weather is still possible, but I'm expecting widespread watches and warnings to surface later this afternoon in Ontario and Quebec, especially if the sun gets the chance to shine.

To recap, a fair risk of showers and thunderstorms (possibly some reaching severe limits in the afternoon-evening hours). Temperatures will be warm, ranging from the mid to high 20's, especially if we get appearances of the sun, even if briefly. Dewpoints are high since moisture levels are soaring, but we should have light to moderate Southerly winds at 15-20 km/h - these winds can sometimes shift to the East. Finally, just to note, but when you read the probability of precipitation, such as 60-70%, this means that in any random area in the forecasted region, there's a 60-70% probability that there will be precipitation.

To close, let's just hope that we'll be alright by the time 10:00 p.m arrives, but the storms and rains will be out there all night tonight - it's just a matter of seeing them or not at that time. I'll keep a close eye on the various radar systems I typically use from now until I depart for the fireworks.

Trav.

Paul,

I noticed that there were some light rain showers and surrounding storms near the Sherbrooke area as the cold front went through around 9:00 p.m. Did the rain interfere with the display?

Trav.

We were incredibly lucky - there was about 1 minute of light raindrops around 6:30pm and then, despite lightning on the horizon and threats of strong winds, we started the display at about 9:27 - just in time as the wind became too strong about 5 minutes after showtime. We'd just finished cleaning up at around 11pm and then torrential downpours started - and it kept raining for at least two hours. So we were really really lucky! I may upload a video of the display later, but I was rather too close to film it properly.

Paul

Paul,

It looks like mostly everything played out accordingly, as expected.

Yeah, I was assuming that there would be some close calls around that time. I spotted the clusters of showers and storms moving in from the Southeast at least 2 hours before they pushed in your direction, so I got a bit nervous. However, it's good to hear that everything went well despite the fact. This is why it's often difficult to predict precisely where showers and storms will develop along a cold front, only until clusters of cells begin to form and push towards the given area within a small time frame, and hence the issuing of risks of steady rains and heavy thunderstorms in all of Southern Quebec.

It would seem that you faced quite the weather scenario - lightning in the far distance, strong winds and torrential downpours, but again I'm happy things worked out for the best. I'm not really expecting anything of the sort for this coming weekend since, at this point in time, a gorgeous high pressure ridge is building in, ushering in mild humidity, warm temperatures and fair skies. Assuming the models continue to cooperate with this trend, then I wouldn't have much to cover for the weekend for the first time this season. In the meantime, showers and storms along yet another cold front will make their appearances much later tomorrow evening-overnight into Thursday.

Anyhow, I hope to see the display on your video that you took!

Trav.

Hello,

Compared with the last two weekends' volatile weather, as briefly mentioned in my last post, there's really nothing too much for me to cover, besides the odd cloudy period, for this coming weekend as a beautiful high pressure ridge will virtually dominate Southern Ontario, Southern Quebec and most of the Maritimes once this approaching cold front comes through later tonight and through half of the day tomorrow - could be some early morning cracklers (just a little heads up in case lol).

Highs in the mid 20s, fair skies with gentle Southerlies and a steady flow of moderate moisture should do it justice for Saturday night's display. The only thing I'd like to keep a watchful eye on is the wind speed during the evening. In short, a nice weekend is well on the way, so get out there and soak up that sunshine.

Trav.

Hi guys,

Everything in my last post still holds true for tonight. Highs in the high 20's with some mild humidity and moderate Westerly-Southwestely winds at 15-25 km/h will be the story. Dewpoint (moisture) levels are not expected to be extremely high, as this will kick in moreso on Sunday and through the week. Thus there shouldn't be too much in the way of thick smoke accumulations compared to last week. Winds themselves should be agreeable, as they will maintain their W-SW status during the evening at about 15-20 km/h, while under mainly clear skies and temperatures keeping warm at, I'd say, 22-24 C by the time 10 p.m. rolls around - virtually perfect weather.

Again, a beautiful weekend in most of Eastern Canada, but we're running the risk for thunderstorms by the time Monday-Tuesday moves in.

Notice that this weekend didn't require much updates for weather. This is all courtesy of the large high pressure ridge, thus making me having to cover much less compared to the last two volatile weeks.

Enjoy the show, although I will be in Ontario for today, so I'm not entirely positive if I'll be able to attend. We'll see what happens, but at least I can leave you guys with some great weather conditions.

Cheers,

Trav.

^^^^^

One more thing I forgot to point out, in addition to the above, is that the UV index is rather high this weekend (about 9), as is common with high pressure. So, if you plan to be out there for extended periods, please protect yourselves accordingly from the sun. Light long sleeves tend to do it justice, but if you're using sun block directly, be sure to use an SPF of 30 or more.

Trav.

Saturday's weather in Southern Quebec looks to be promising. However, a well developed "Prairie low" (currently in the making) will be consistently tracking Eastward toward Eastern Canada. For the most part, this system will be moving in a East-Northeast pathway, but its cold front will be covering a large area further South, eventually affecting virtually all of Eastern Canada at some point from Saturday through to ending Monday.

The front is expected to move through Southern, Southwestern Ontario and the U.S Midwest, during the afternoon hours on Saturday, bringing the risk of showers and heavy thunderstorms (perhaps some cells reaching severe criteria) in its wake. The good news is that I do believe, based on the model simulations, that these preliminary bands of precipitation will reach our good city by later overnight as opposed to the evening hours, but I'd still like to keep a watchful eye on the speed of the system altogether before I give a final update. The front itself is responsible for the showers and thunderstorms we will be receiving come Sunday.

May I remind you that most of the day Saturday will be very warm, as well as mostly sunny with some later variably cloudy conditions (because of the approaching front). A returning flow of moderate to high humidity is also expected (even by Friday), and therefore constant Southerlies and Southwesterlies will prevail - it's actually a very nice Saturday overall. Highs are expected to be reaching the high 20's and possibly even crossing that 30 Celsius threshold during the afternoon.

In essence, I'll be paying attention to two things - one is the speed of the front, and two are the actual wind speeds during the evening hours, especially considering that the air will be reasonably moist. Count on the winds being continuously from S-SW, though, even during the evening.

I'll provide a final update, if needed, by sometime Friday when things fall better together.

Trav.

Greetings,

I felt it was necessary to provide another update since the system has sped up in the last 12-18 hours. Most of what I said in my previous post still remains true, but now that the front is approaching at a faster rate, the risk for rain showers exists further back into the late evening hours. However, I still believe that we will miss the showers and simply be faced with the expected variable cloudiness (as stated before) to mostly cloudy skies along with some clear breaks. You'll notice the clouds themselves moving in and increasing in number later in the afternoon with the front approaching.

I'm confident that winds will pick up as we get closer to the evening from anywhere between 15-25 km/h from the S-SW because again of the front, so I don't believe we will have to worry about smoke accumulations, despite the mild-moderate humidity present at the time. Clouds will most certainly increase with the cirrus (high level) as well as the alto-cumulus (mid level) variety. Temperatures will be, again, very warm ranging in the very high 20's, possibly crossing 30 C. Humidity is not expected to be very high, but it will be mild to moderate (humidex of 32-35 C) before the cold front completely comes through. At the time of presentation, temperatures will hold steady at 23-24 C.

It's an interesting low, I mean for this time of year. The system itself is something to behold because of its uncommon low central pressure (983 millibars - surface pressure is normally 1013). We call this a "weather bomb" because central pressure within the center of the system has dropped over 24 millibars during the course of 24 hours. If this system came through a given region in the Winter, that region would easily get an upwards of 30+ cm of snow. This system is also responsible for the severe weather in the Canadian Prairies as well as in the United States, namely parts of Minnesota.

In any case, once more, I personally think that the main rains will hold off just passed 10:00 p.m. towards 11:30 and onwards, but I would still advise to have a small umbrella on standby since some introductory brief passing showers are possible in the lateevening. I'm saying this because places like Ottawa and Cornwall are both expected to receive steady precipitation on their doorsteps by as early as 8 p.m. Other than that, don't worry, a light jacket is certainly not required, unlike tonight.

Finally, the UV index is once again very high (reading of 9 by 1:00 p.m) for most of the afternoon Saturday, so protect yourselves accordingly if you're planning to be out there for extended periods.

As for Sunday, showers and isolated/embedded thunderstorms (some vigorous) are the backdrop for most of the day, including while we sleep tomorrow night.

Trav.

Those "introductory showers" I spoke of also should not be affecting us, so there's no need for an umbrella at all. The system has again slowed somewhat and will thus delay any precipitation we receive. Once again, you will notice the skies becoming mostly cloudy, as well as the winds picking up early this evening from the S-SW. Everything else I said before still holds true, including the fact that Ottawa and Cornwall have the risk for thunderstorms this evening, although now until 10:00 p.m., so that's reassuring for us here in Montreal. In this sense, please enjoy the warm weather we will be witnessing this evening, as well as the wonderful display the Portuguese have prepared for us!

As for tomorrow, the rains and storms should subside by the later afternoon hours - some storms could be rather heavy.

Cheers,

Trav.

Good day,

The atmosphere is, much like yesterday, is going to behave in an unstable manner for the next week or so thanks to constant areas of low pressure moving in from the West-Southwest and thus dominating the Eastern part of the country. Out of interest, notice that this previous/current cold front did not do so much in the way of taking away the humidity. This is because there's one area of low pressure one after the other - think of it as an express.

Now, this weekend, including Saturday, is expected to be predominantly pleasant, though again moderately humid along with highs likely attaining the high 20's. However, we're running the risk of thunderstorms to develop on Saturday as a result of pure daytime heating and not because of a cold front, like what was seen racing through late last Saturday night into Sunday. Because of the lack of a lifting mechanism, such as a cold front, I don't really anticipate much in the way of anything reaching severe criteria, nor of t-storms developing passed dusk this coming Saturday.

Friday (tomorrow), on the other hand, could be more of a dilemma. A vigorous low pressure system is on the way from Southern Ontario, making its entrance very late today and into tomorrow. Along the warm front, steady bands of rain and quite possibly some powerful thunderstorms (as what is happening currently in Ontario) are developing. This is not to say that this will be all day rains and storms, but is certainly to acknowledge that the high potential is there for large storms and for steady rainfall at times to form (huge amounts of moisture associated with this). I'm bringing this up out of concern because it may pose some occasional problems for the Australian and La Ronde crews in setting up the display for Saturday.

And just to note, the jet stream is and will be relatively zonal across the country for the next 48 hours, so this simply will allow systems to travel fairly quickly, which is in part why things will be consistently unstable.

I'll provide an additional update either later tomorrow or early Saturday depending on how well organized the models become, but things look to be alright for Saturday evening at this point in time despite the instability present.

Trav.

Anybody enjoy the storms this morning, or did they awaken you from your beauty sleep? Some of us over here lost electricity in the West Island, as well as seeing some pretty extensive flooding, but nevertheless, this is what I meant by powerful storms for today in my previous post! I got some good footage of it as well - I'll be uploading it later today. VERY loud cracks of thunder were heard and we did receive marble-sized hail mixed in with the torrential downpours.

The storms are moving towards the Eastern Townships presently and are exiting the area here, leaving moderate rainfall behind them. I'm expecting storms (many reaching severe criteria) to fire up sporadically all over the place once more with daytime heating throughout the day - there's just so much moisture to work with.

Trav.

Consistent with my last report, the newly developing showers and thunderstorms won't be affecting Southern regions of Quebec until the later overnight hours into early Sunday, in which case, Sunday will offer another round of volatile weather. This has been a typical July week, most notably for today.

Ahem...The evening hours for tomorrow will bring about simply cloudy periods to variable cloudiness (these are introducing the upcoming warm front from our new system), and very warm temperatures will dominate, despite this current cold moving through. In terms of dewpoint (moisture), there will be some mild humidity still in force throughout the day into the evening-overnight hours and the temperatures will hold steady from 23-25 C. Winds are expected to be relatively calm as both Westerlies and Northwesterlies at about 5-10 km/h - this may cause some occasional smoke build up because of the lingering humidity.

For the most part, the weather should be setting the stage nicely for the Australian performance, but I'll still be keeping a watchful eye on those winds since this could pose some periodic problems in smoke build up. Also, I hope that the rains today did not do much in disrupting the setup schedule.

That's the way the weather should work, so the Montreal skies are yours, Australia.

Trav.

Again, everything looks alright for this evening, but once more my only concern is the periodic lack of wind this evening. They will certainly be variable from between the West and the North, which may occasionally gently blow some of the smoke inconveniently towards the audience at La Ronde. There will also be mild moisture levels present, and so this is why I'm providing this final update.

And as I had mentioned with my post from the 17th of July, don't be surprised if you hear cracks of thunder or the odd rainfall this afternoon into the early evening - this is because of pure instability. Expect this pattern to persist for the next few days.

Everything else is good, so enjoy the show, and hopefully the winds won't be as tranquil during the 10-10:30 p.m. period.

Trav.

The computer weather models have been quite busy today! The good news is that the winds are expected to gain some speed during the evening (10-15 km/h) while maintaining their variable status between the West and the North. The bad news is that the risk of thunderstorms is extending itself through the entire night. I'm not surprised in the least since the air is so unstable - I spotted a storm moving through either the East end or Dowtown itself in the distance moving towards the Southeast just about an hour ago.

Please have your umbrellas on standby, and again, hope the winds are adequate enough, which they should be. Storms and convective showers are hit and miss, but let's hope it is a miss. The storms have been out there since noon developing on radar like popcorn. I personally think that we should be alright by the later evening hours following 8 p.m, though, especially with the loss of daytime heating, but then again you can't rule out the risk since the air is still moist.

I apologize for the late notice.

Trav.

Trav (and other weather maniacs), apologies if you already know this, but there's a great website with realtime radar images of the entire continent integrated with google maps - it has a resolution down to blocks of about 1km x 1km - it was easy to see the rain cells that affected La Ronde on Saturday that didn't touch the surrounding areas. Anyway, for those who don't know try: http://itsweather.com

The search function only works for US cities but it's easy enough to zoom in on Montreal (unless one is geographically challenged).

Paul.

Hi Paul,

Normally, on most radar imagery that I utilize from the Weather Channel and other major meteorological organizations when providing short term forecasts mainly deal with the actual trajectory of individual cells or bands/clusters of precipitation associated with frontal systems, and inconveniently lack the capability of zooming into a very large scaled perspective to get important details, as offered in the integrated google maps you've introduced.

So no, I was not aware that the google maps now integrated precipitation cell intensity signatures from low pressure systems, and seeing that these maps already are capable of viewing at such a large scale, it makes them rather useful in both tracking storm movement to some extent as well as especially seeing precisely which regions will, or are being affected by them. I commonly use similar radar imagery that tracks the relative motion/speed of any form of precip. on an interval of every 5-10 minutes or so, but the integral radar images combined with google maps are quite advantageous in predicting precisely which areas would be hit whenever cells come into close proximity to whatever localized area. Not only this, but looking closely at the structure and potential growth of the more severe isolated cells, or along squall lines, allow us to see if tornadic supercells are emerging (seen often as a hook shaped cell formation on a large scale), even though this is not designed to detect windshear with height. It's also handy in getting a broad picture of the strength of an updraft in thunderstorm development, and therefore identifying characteristics such as lightning intensity or hail potential.

Other than that, it coincidentally came in useful in my weather watch for today in detecting a storm earlier in where it was moving. I was expecting strong thunderstorms to develop all over, but a cell had closed into the Southeastern portion of the West Island of Montreal and had nearly produced a weak tornado near the airport this afternoon (you may hear it pop up in the news). I've also reported funnel clouds developing in the late afternoon as well towards the South shore.

As for the storms that hit the metropolitan area as well as the East end moreso than the West Island on Saturday, I had also spotted them on radar. However, although I had a clear picture of where the cells had hit, it still couldn't tell me precisely which areas these cells were affecting within these regions, or where the heaviest of the precipitation was located - this is where this kind of radar map comes into play.

A fine tool to add to the weather watch and forecasting arsenal indeed! Thank you very much for this, Paul - I'm treating it as a birthday present. I've got a feeling that I'll be making much use of it from here on out.

Now onto my report for Wednesday!

Trav.

Atmospheric instability still yet continues to dominate Eastern Canada with much moisture and a steady South-Southwesterly flow ushering very warm and humid air. The result is consistent developments of early morning sporadic showers giving way to the possibility of light to moderate thunderstorms for the afternoon and evening hours tomorrow (Wednesday).

Looks like yet another evening to have your umbrellas handy. Temperatures will easily remain mild in the low to mid 20's during the evening, while mild humidity will continue to persist. Winds should be at more of a favorable speed, and South-Southwesterlies would mean that smoke shouldn't be so much of a dilemma for the audience in the park this time around.

We'll keep a close eye on the rain/t-storm patterns as they develop through the day since the sun will be out for a fair portion of the time.

Trav.

Being on track with my last update, the forecast model projections remain the same as a merged low pressure system creeps up into Southern Quebec and most of Southern Ontario progressively through the late morning hours and gradually through to the rest of the day. As a result, the provided instability will cause scattered to isolated showers to develop in a very ubiquitous pattern (as always), along with thunderstorm cells developing throughout the afternoon and into the evening - again, most of these are light to moderate cells, but some among them can easily reach severe criteria in the afternoon to early evening due to the persistent amount of moisture readily available in the atmosphere. For the remainder of the evening, thunderstorms are still very well possible, and this will eventually give way to steadier rain bands (and embedded t-showers) coming in from our S-SW late evening and especially the overnight.

To break it down once more, there's a fair possibility that we'll hit a high reaching about 24-25 Celsius, depending of course on how long the sun endures for the day. Evening temperatures will persist into the very low 20's, and at times the air may feel a little on the cool side, so you may want to think about carrying a light sweater or jacket, in addition to the umbrella.

Finally, checking the models, because of the positioning of the system during the day and through the evening, it would suggest that winds should be blowing gently from the East-Southeast, which is again ideal in terms of direction. With respect to speeds, we should be seeing relatively light to possibly occasional moderate winds at 10-15 km/h (occasional small gusts passing just over 20 km/h).

This is quite a risky forecast, but, as always, let's hope for the best - I'll be paying close attention to the models and radar imagery today. Why is it that Canada always has these threats? It has almost always been this way since 1995.

Trav.