Hello everyone,

As we have (quickly) arrived in the month of June, I thought that it would be appropriate to post the weather thread.

As always, weather reports/updates will be posted prior to each fireworks night, including some preliminary details from as far as two days in advance. The reason for this is that there is often too much uncertainty to provide more meaningful forecasts beyond two days ahead for a specific time frame. Reports will include temperature, humidity (moisture), wind speed and direction, and, if necessary, the risk for precipitation (rainfall/showers). I will try to keep details brief and concise, but if/when the potential for severe weather exists, a little more elaboration and additional updates, as needed, will be provided. Everyone is also more than welcome to share any information.

I continue to regularly post weather updates on my Facebook profile, largely when extreme weather is likely. If you would like to follow me there from time to time, please feel free to visit my profile:

https://www.facebook.com/travis.moore.5074?ref=tn_tnmn

For those that are interested, my Spring-Summer 2013 weather outlook (posted on St-Patrick’s Day) can be found here:

https://www.facebook.com/notes/travis-moore/winter-2012-2013-and-a-loo k-ahead-to-spring-summer-2013/10151528552166346

In summary, I am anticipating a very humid end-Spring to Summer period for 2013, with an enhancement in the number of thunderstorm/severe thunderstorm days. Temperatures should generally be slightly above normal for each of the warmer months, though the number of days reaching 30 C or more could be slightly reduced relative to what was observed in 2010, 2011 and 2012. Precipitation should follow near to above normal tendencies, but locally well above normal patterns will occur due to the nature of thunderstorms.

Here’s hoping for ideal weather conditions for all of our participants of 2013!

Trav.

Mother Nature may have decided to play a role as soon as with the inaugural display of the season. I am looking forward to read your weather forecast, especially specific information for late night.

Fred

First, let me welcome everyone to the first official day of Summer (it arrived early this morning - June 21st - 1:04 a.m. EDT).

A warm front will gradually migrate into E. Ontario to S. Quebec during the day Saturday (June 22nd), producing widespread rainfall across these regions ahead of it. Current and recent model runs have come more into an agreement concerning the overall nature and timing of the front, and the associated rainfall coverage. Given the timing of the warm front, periods of rain are most likely to occur during the late-morning through to the afternoon hours, followed by mainly cloudy conditions for the late-evening period. General cloudiness and rainfall will act to maintain near-constant maximum temperatures of 20-22 C throughout the afternoon period. It will likely feel sticky, as well, and temperatures should hover between 18-20 C during the evening hours.

What is possibly more concerning to me, however, is the combination of high humidity and light winds shown for the evening hours, especially following the afternoon showers/periods of rain, when the air is more saturated. At this point, winds are projected to be coming out from the NE/NNE at about 8-11 km/h during the late-evening, so this could prompt smoke to be moving gently to the left of the audience at La Ronde. This would affect those on the bridge in sections over Notre-Dame, and over the river while, at times, obstructing the view for those stationed at the Old Port.

I would still like to analyze the newer model runs from tonight as they come in to confirm the above information, so I will provide another update early tomorrow. Once the warm front lifts farther North with time, a heat wave (in the technical sense) may emerge for many areas of E. Canada, beginning on Sunday (June 23rd).

I apologize for the delayed initial update, as I was awaiting for the models to show a consensus concerning the risk of precipitation for tomorrow.

Trav.

The newest model runs from this morning (June 22nd) have recently arrived and follow general trends shown by previous runs. However, the new data presented does warrant some revisions to the above mentioned information for precipitation coverage and timing for today, and, to some extent, maximum temperatures. As such, here are the most likely conditions to predominate for today:

Temperature/Humidity

Maximum temperatures will likely reach 23-24 C during the afternoon, owing to some pockets of afternoon solar heating. Evening temperatures in the metropolitan area should be anywhere from 20-21 C. Humidity will be high throughout the day, and borderline high-very high by the late-afternoon/evening, making it feel like 27-28 C during that time frame.

Precipitation

As mentioned previously, periods of rain/showers are still expected to occur. However, the newest model runs indicate that most of this rainfall should take place by through most of the morning hours, largely around and after dawn. Into the afternoon, mainly cloudy conditions should prevail, but because of the potential for some brief, isolated breaks of solar heating, combined with increased moistening, there will be a slight risk for isolated air mass thunderstorms and/or convective showers. Into the late-evening, convection should cease, and skies will remain mostly cloudy with some clear breaks.

Wind

Wind speeds remain light from the ENE to eventually NE (late-evening to overnight) at 9-12 km/h (slight change from 8-11 km/h). As such, winds will be “gently” pushing the smoke to the left of and away from the audience at La Ronde and instead affect viewers on Notre-Dame/de Lorimier street, as well as those on the bridge overlooking those streets. This may occasionally affect viewing at the Old Port, as well. Note that periods of smoke accumulation could occur due to the high humidity and generally light winds.

If necessary, I will provide another update well before the display today.

Trav.

MeteoMedia has just updated tonight forecast, increasing probability of showers from 30% to 60%-70%.

It's a shame that few people will likely attend the Australian debute display.

Fred

I'm still optimistic that the bulk of the rain will be over around 5/5:30pm.

So long as there is a bit of wind, we should be fine tonight.

Paul.

Just to provide an additional update, periods of rain/showers should largely come to a close following dinner time (near 7:30 p.m. EDT) this afternoon (June 22nd), with the bulk of the precipitation coming to a close shortly. This means that the risk for (deep) convection will be minimal later this afternoon, and temperatures will remain closer to 18-19 C, coupled with continued borderline high/very high humidity. Persistent rains throughout the afternoon are the result of the aforementioned warm front becoming more quasi-stationary, allowing precipitation to linger for an extended period of time. Edit: Skies will remain mostly cloudy this evening.

As per my previous postings, the combination of high humidity and very light winds (recent projections of 6-9 km/h) could generate conditions for periods of heavy smoke accumulations and may deteriorate viewing, especially for those positioned on Notre-Dame street (and nearby streets) - winds are expected to be more from the East to ESE, so the smoke should be very slowly moving away from the audience at La Ronde (and occasionally "slightly" to the right) later this evening, though it will build up quickly, especially from low-level effects. These conditions will also be accompanied by more saturated surface and near-surface air following the morning-afternoon rain/showers.

Trav.

If it is not too late, I would suggest having the umbrellas handy (or some form of head covering) for the evening, as the degree of lift, as well as the near-saturated nature of much of the lower atmosphere, is supportive for continued scattered precipitation development throughout the evening (despite what recent projected radar imageries have shown). Otherwise, it will be mainly cloudy, as was originally stated.

All other conditions remain constant.

Trav.

Trav: I need a forecast for Knowlton for Saturday evening. Environment Canada and MeteoMedia have divergent forecasts right now - the former says rain and 19C and the latter 40% chance of thundershowers and 26C - quite the difference. I'd like warm, dry and sunny please for my Canada Day show Plus it would be good if it's dry at La Ronde on Friday evening for Team England's debut in the competition.

Cheers,

Paul.

Weather conditions for England's display this Friday (the 28th) are generally expected to be unsettled. A broadening upper-level trough will likely be developing across Ontario and Quebec by tonight (June 27th), allowing for a developing area of low pressure in the U.S. to travel North along the jet stream.

Latest model guidance is somewhat divergent, but there has been some agreement that the bulk of the associated rainfall for Friday will occur during the early-morning hours (slight risk of non-severe thunderstorms at this time) through to the mid-afternoon, which will be followed by mainly overcast skies into the late-afternoon/evening hours. However, a few lingering showers are still possible for the evening due to continued lift.

With the lack of daytime heating, and because of wet conditions and gusty NE winds, temperatures will be restricted from rising to seasonal/above seasonal values. Instead, maximum temperatures could only reach 17-18 C and will drop slightly by the evening to 15-16 C. Winds will continue to be breezy into the evening hours from the NE, making it feel chilly (enhanced by cool evening temperatures). As such, light jackets will likely be required for many (something that bothers me to say at the end of June). Humidity should remain at moderate levels throughout Friday. Breezy NE winds should generally push smoke quickly to sections of Notre-Dame street nearest to the bridge (and affecting those on the bridge near and overlooking the street). For those positioned at La Ronde, the smoke should predominantly be moving to your left and away. Wind speeds may be marginally strong into the early-evening, so that is something to be monitored in the newer model runs.

Another update to follow later today/early tomorrow.
-------------------------------------------
Hi Paul,

For Saturday evening/late-evening in Knowlton, temperatures are expected to hover around 18-19 C (afternoon high of 24-25 C), along with relatively high humidity. A few convective showers and scattered non-severe thunderstorms will also be possible along a stationary front that will affect locations mostly East of Montreal. Latest model guidance, however, suggests that convection will be most active during the afternoon hours. Skies should remain partly cloudy during the evening, and winds could become very light from the WSW at 4-7 km/h.

If necessary, I will provide another update as the newer model runs become available.

Trav.

Thank you for this forecast, Trav, and we stay tuned for updates as we may experience severe weather conditions tomorrow.

For sure, that would be a nightmare for many people - including Paul, who must be at Knowlton Saturday - but I wonder whether we are going to experience a premiere in the Montreal International Fireworks Competition history. Meteomedia predicts winds around 30 km/h for Friday evening, with gusts reaching 50 km/h. Specific forecast is not available to distinguish early and late evening, and we have often experienced more severe winds in early than in late hours.

There hasn't been any cancelled or postponed show since 1985. While Six Flags had, a couple of years ago, a policy to postpone a show to the next day in case of poor weather conditions, I think it has been dropped because too difficult to implement given the number of organizations involved in the event (police, fire service, public transportation system, etc.). Now, the policy is that fireworks are displayed rain or shine, but may be postponed for security reasons.

So I think that we must be alert for any cue from the organizers today and tomorrow morning. They may have to take a tough decision.

Fred

I'm sure that by 10pm tomorrow night thing will be fine. Funny that it's always England that experiences bad weather in their participations (recalling the strong winds during the last Kimbolton display a few years ago that lead to a the latest ever start).

I think things will be better for me on Saturday (I hope!). Every year it's the same thing: eyes glued to the radar!

Paul.

I'm sure that by 10pm tomorrow night thing will be fine. Funny that it's always England that experiences bad weather in their participations (recalling the strong winds during the last Kimbolton display a few years ago that lead to a the latest ever start).

Yeah, that was in 2003. Paul, you wrote this in your report:

Weather became the dominant issue for this display. The team lost half a day of setup due to heavy thunderstorms. Then it was hot for a day, then grey and humid. The weather threatened to do its worst but it appeared everything would be OK. Suddenly, at 9:30pm, very strong wind came out of nowhere. So strong that it was difficult to hear the announcements for a while. Unfortunately, the wind was blowing directly at the audience. Then the thought that the unthinkable could happen: cancellation. As the time inched towards 10pm, the wind didn't diminish. Everyone waited nervously. Then an announcement that the display would be delayed by 25 minutes until the wind, as confirmed by the meteorologists at Dorval airport, would subside enough to allow the display to be fired safely. Just after 10pm, the wind died down a lot. Darryl Fleming came to see me at 10:20 and commented that I would have something interesting to write here! Then the wind increased and once again diminished. Finally, an announcement that the display would start. Expectantly people awaited the countdown from 10. But nothing, just silence. Then a slow handclap from the audience. A minute passed. Would it be canceled? The wind seemed to be picking up again. But finally, the countdown took place and the display started at 10:27. At around 10:40, heavy rain started, frustratingly because the period from 10:00 until 10:30 was completely dry. I put a small umbrella over my notebook and battled on regardless, trying to write even though I couldn't see, both because the notebook was covered, and my eyes got ash and rain in them. But after about 10 minute, the rain more or less stopped and it didn't detract from the display too much. What a way to celebrate my 100th display!

And I clearly remember the (false) announcement that the display was going to start, as the famous "Que tombe la nuit, que la fête commence" was pronounced. Following a moment of silence, the incredible Michel Lacroix catched the movie theme of that display and resumed with these words: "Nous vous avions promis Une soirée au cinéma, alors prise 2! Que tombe la nuit, que la fête commence! 10, 9..."

Fred

Canadian displays also had their share of bad weather in the past, but it is quite the coincidence that England is expected to potentially face a near-similar scenario to a decade ago. Still, I believe the strongest of the winds will occur during the afternoon hours, and, unlike 10 years ago, the winds are not projected to be directed toward the audience at La Ronde, but rather closer to those on the bridge, and those on Notre-Dame street. Overall wind speeds for the evening, however, are still questionable. Rainfall during the late-morning to mid-afternoon hours will likely be abundant.

I will have another update prepared for later on.

Trav.

A strengthening area of low pressure moving in from the South is expected to bring copious rains and strong winds to S. Quebec. As such, here are the most probable weather conditions for Friday, June 28th for the Montreal area (and surrounding locations).

Temperature/Humidity

Temperatures throughout today will remain unseasonably cool across much of S. Quebec due to ongoing NE/NNE winds, thick cloudiness, and rainfall. Maximum temperatures will likely only reach 17-18 C, with evening/late-evening temperatures cooler at 13-14 C. Humidity levels will be moderate. Please dress warmly.

Precipitation

Periods of rain are still expected to occur throughout today, with the heaviest of rain occurring from the mid-morning to early-afternoon period. Following this, mainly cloudy conditions will persist into the late-afternoon to the evening, with scattered showers lingering for the late-afternoon. By evening, overcast skies should prevail, with the continued possibility for scattered showers (mostly for the early-part of the evening).

Wind

Winds will be gusty from the NE to NNE through most of the day, with highest speeds occurring during the late-morning to mid-afternoon period. Top gusts and sustained winds during the this time will be between 48-52 km/h and 28-33 km/h, respectively. Into the late-afternoon to evening period, wind speeds should diminish progressively and significantly, especially into the evening, with general speeds closer to the 11-14 km/h range by late-evening and overnight. Dominant wind direction has recently been shown to shift a little counter-clockwise by the late-evening, however, due to a progressive retrograde motion exhibited by the associated area of low pressure. As such, winds should be coming out more from the North to NNW by late-evening, causing the smoke to move towards the adjacent bridge, and to the left of those at La Ronde. Some periods of smoke accumulation will be possible due to saturated air, but the winds should typically be strong enough to frequently push away the smoke.

That’s the way the weather should generally work. In summary, mainly cloudy conditions should dominate for the late-evening, with the continued possibility for lingering scattered showers, especially for the early part of the evening, so have an umbrella (or some form of adequate head covering) handy. Though winds will diminish, they will still be enough to chill the air, so also bring a jacket for the evening.

I will provide an additional update, if necessary, should wind and/or precipitation tendencies show significant changes for the evening (especially since some model divergence still exists for this time frame).

Trav.