Feb 20-21st LES Event Southern Ontario, Expect some LES to develop late Tues night and continuing into Thurs Options

[blizzardOf96]

I agree with most of what travis said, nice map! I just want to chime in and add a few of my thoughts on this event.

1. Wind alignment starts of as WNW before transitioning to NW and NNW later tonight and into tomorrow morning. Up to 40cm of snow may fall in areas along the shores of GB and lake huron with 850's crashing below -15c and favourable wind alignment aloft. Boundary level moisture will be present from 600 to 800mb with little to no wind shear throughout the region. All these parameters coupled with ice free lake huron and GB will allow for significant LES to set up across southern ontario.


2. I think the GB squall will be strongest and most extensive from midnight tonight through 8am tomorrow morning. This squall should extend into york region and the GTA in the early morning hours wednesday and thursday with accumulations up to 10cm in some spots. This band will weaken but continue to stay active across the barrie, meaford and wasaga areas into mid day wednesday. It should intensify again in the evening hours with significant impacts from meaford to collingwood stretching east to wasaga. I expect a re-intensification wednesday night into thursday morning with further impacts possible across york region again.

3. I am expecting the lake huron band to be stronger with several waves of snow squall activity from tonight into tomorrow afternoon with weakening by 1pm. This zone will set up from owen sound south to london including goderich, kincardine, walkerton, hanover, huron east and lucan. We are already seeing a first band of snow setting up across this region. Northern parts of this zone will get into the second heavy band from midnight to 4am. It should shift into the goderich and kincardine areas by 7am and lasting into the early afternoon. I think the most impacts on london will be from now until 11pm with a WNW flow dominating but they should avoid the second band for the most part. I think weaker but consistent bands of snow will continue to set up through wednesday afternoon and evening from blue water to kincardine. Another intense band should set up through the city of london wednesday night into thursday morning which will be their best chance at heavy snowfall from this event as the flow switches to NW. I am expecting the heaviest accumulations to stay NW of the city but 13-23cm in the city itself.

Here is my snowfall map for this event. In the GB and lake huron squalls i can see some 35cm accumulations locally but most accumulations should stay below 30cm in the dark purple zones.
 Screen_Shot_2013_02_19_at_7.45.08_PM.png ( 304.31K ) Number of downloads: 5


This post has been edited by blizzardOf96: Feb 19 2013, 07:47 PM

[Torontoweather]

I agree with most of what travis said, nice map! I just want to chime in and add a few of my thoughts on this event.

1. Wind alignment starts of as WNW before transitioning to NW and NNW later tonight and into tomorrow morning. Up to 40cm of snow may fall in areas along the shores of GB and lake huron with 850's crashing below -15c and favourable wind alignment aloft. Boundary level moisture will be present from 600 to 800mb with little to no wind shear throughout the region. All these parameters coupled with ice free lake huron and GB will allow for significant LES to set up across southern ontario.
2. I think the GB squall will be strongest and most extensive from midnight tonight through 8am tomorrow morning. This squall should extend into york region and the GTA in the early morning hours wednesday and thursday with accumulations up to 10cm in some spots. This band will weaken but continue to stay active across the barrie, meaford and wasaga areas into mid day wednesday. It should intensify again in the evening hours with significant impacts from meaford to collingwood stretching east to wasaga. I expect a re-intensification wednesday night into thursday morning with further impacts possible across york region again.

Not really seeing the NW wind until sometime tomorrow evening:


Looks like a nice WNW wind tonight though could extend a band from Huron into GTA as we saw a couple weeks ago:




This post has been edited by Torontoweather: Feb 19 2013, 07:48 PM

[blizzardOf96]

Not really seeing the NW wind until sometime tomorrow evening:


Looks like a nice WNW wind tonight though could extend a band from Huron into GTA as we saw a couple weeks ago:

I agree, i think we will see some accumulations across york and toronto tonight with possible re-development tomorrow night as the NW wind gets better established.

[Ryan45]

Puttin: It's my hobby grade RC car. It ain't one from Walmart! They are so cool! I built the plow myself!

[travis3000]

While some LES activity will occur tonight, the powerful NW/NNW flow will not be fully established until afternoon Wednesday. The bands will meander a tad and strengthen/weaken right through Thursday afternoon before things end. Winds will more WNW tonight and tomorrow morning. The bands under this wind alignment will not as strong nor will they last as long.


GB:
The WNW wind tonight will create flurries in the Midland/Orillia/Gravenhurst area and drop 4-10cm of snow in the process. The big 25-40cm amounts will be in a line from Blue Mountain/Collingwood and Wasaga SE to Creemore/Duntroon, Angus/Borden, Cookstown/Alliston, Tottenham/Beeton, SE to York Region. Newmarket will see the band affect them but it will be moving just to the west of the city, probably west of the 400 and 9 intersection. Parts of the GTA could easily get 5-10cm out of this, possibly more. Be on the lookout in the GTA starting tomorrow afternoon right into tomorrow night and early Thurs morning. Barrie will be on the eastern edge of the band but I am still forecasting about 10-20cm in Barrie with higher amounts to the west of the city. Once you go NE of Barrie, amounts will fall drastically.

Huron:
Again amounts of 25-40cm are very likely. First off, the northern part of Lake Huron from Owen Sound to Kincardine and areas inland about 50KM will see a solid 5-10cm of snow overnight and tomorrow morning from a strong WNW flow. Another band from just south of Goderich towards Kitchener will also pick up 10-15cm tonight with the W/ WNW flow. As the day goes on tomorrow, the winds become NNW and the bands shift south to Goderich and extend SE from there through Lucan, Exeter, London, and Grand Bend. If you live anywhere within a 40KM line from Goderich to Lucan you will see a solid 10-20cm of snow. Within this band, where the band stalls... amounts of 30-40cm are very likely.

This post has been edited by travis3000: Feb 19 2013, 10:10 PM

[Ryan45]

Wicked stuff...I love squalls over Huron!

[travis3000]

My final map, including the WNW squalls tonight.

 final_map.jpg ( 431.16K ) Number of downloads: 8


This post has been edited by travis3000: Feb 19 2013, 10:26 PM

[snowgeek93]

Looks nice. Would be nice to have some more snow after today, although most of my my snow pack remained after the warm up so this would be a welcome addition. To think, only a month left to spring...

[kitfoxflyer]

I don't see 20 to 40 cms - would be nice but i think i will keep it under 20 cms for the 3 day splurge here. If these winds were over warmer water and more open water more would be likely.

I am talking London city

[Ryan45]

snowing nicely here in Burlington - looks like I will be out plowing my driveway later. ; )

Attached File(s)

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[TriC]

I don't see 20 to 40 cms - would be nice but i think i will keep it under 20 cms for the 3 day splurge here. If these winds were over warmer water and more open water more would be likely.

Lake Huron is almost all open water.. still tons of heat energy for LES.

In London here the Exeter radar is not showing very much but its really coming down time to time in London.. would say about 10 on the ground all ready in the north end of the city! Hard to get a real total because its blowing around so much.

This post has been edited by TriC: Feb 20 2013, 01:52 PM

[kitfoxflyer]

Lake Huron is almost all open water.. still tons of heat energy for LES.

In London here the Exeter radar is not showing very much but its really coming down time to time in London.. would say about 10 on the ground all ready in the north end of the city! Hard to get a real total because its blowing around so much.

Where is all this snow guys?

maybe I will eat crow in the AM but so far it not me eating crow

This post has been edited by kitfoxflyer: Feb 20 2013, 07:30 PM

[travis3000]

The LES outbreak has not been nearly as powerful as it should have been. All signs pointed to a stronger outbreak. Even EC downgraded their accumulations from 15cm per 12 hours to 5-15cm per 12 hours. The NNW flow has taken longer to form. Winds look to become more northerly tonight shifting the bands off GB to the south and west. I do not see 30-40cm in any location. At best a few locales may pick up 20cm. That's the thing about LES, very hard to predict. The temps of the lakes are very cold (about 1-2C) meaning the LES events aren't as intense as if this event were to occur in late November or December. I believe we are seeing this now.

Bands have been persistent today across Midland to Orillia and Wasaga Beach to Barrie. Some locales in here have picked up 10-15cm today or will by midnight tonight.

This post has been edited by travis3000: Feb 20 2013, 08:35 PM

[blizzardOf96]

Here We Go!
 Screen_Shot_2013_02_20_at_10.48.11_PM.png ( 45.6K ) Number of downloads: 1

[horsdoobers]

The LES outbreak has not been nearly as powerful as it should have been. All signs pointed to a stronger outbreak. Even EC downgraded their accumulations from 15cm per 12 hours to 5-15cm per 12 hours. The NNW flow has taken longer to form. Winds look to become more northerly tonight shifting the bands off GB to the south and west. I do not see 30-40cm in any location. At best a few locales may pick up 20cm. That's the thing about LES, very hard to predict. The temps of the lakes are very cold (about 1-2C) meaning the LES events aren't as intense as if this event were to occur in late November or December. I believe we are seeing this now.

Bands have been persistent today across Midland to Orillia and Wasaga Beach to Barrie. Some locales in here have picked up 10-15cm today or will by midnight tonight.

However, that turned into one heck of strong band...got like 2 inches in a half an hour. Too bad its on the move.



This post has been edited by horsdoobers: Feb 20 2013, 10:46 PM

[horsdoobers]

Here We Go!
 Screen_Shot_2013_02_20_at_10.48.11_PM.png ( 45.6K ) Number of downloads: 1

Pretty hefty band!!!!!

[TriC]

Lake Huron bands starting to shift to the south now as well.