News & Blogs
Heat and storms
By: SteveDa1 , 7:44 PM GMT on June 07, 2011
We are definitely in a summer pattern with cold fronts stalling once they get close to a line from Illinois to North Carolina. South of this line, high 80's to 90's and even 100's are pretty much going to be the norm for the next 3 months. Temperatures today are as high as 38C (100F) all the way north to central Minnesota and the Dakotas! Although, once you go not too far north to the southern Canadian prairies the temperatures are in the low to mid teens Celsius (50's and 60'sF) and this temperature difference is producing storms in between... A decent MCS formed over Southwestern Ontario early this morning and continued due south across western Pennsylvania and eastern Ohio but is now already breaking up.
This heat is heading east and the northeastern United States will experience the brunt of it with readings well into the 90's and some spots challenging 100. Even up here in Montreal, Quebec, where I live, I expect a high of 90F or 32C tomorrow with dewpoints of at least 20C or higher (mid to upper 60s or even 70 in the evening).
This extremely moist air will spawn strong Thunderstorms in and around the Laurentians of Quebec to the Great Lakes and beyond to the southwest into the United States on Wednesday. Wednesday night it will shift the the southeast and Thursday is another day capable of producing severe thunderstorms.
In fact, Thursday should be the worst of the two days because deep shear, which will be lacking on Wednesday, and upper-level support will contribute to a greater chance of damaging winds and an isolated tornado.
Official nearest weather station temperature (3:00pm EDT): 28.0C (82.5F) Dewpoint: 10.5C (51F)
My weather station's temperature at the exact same time: 30.1C (86F) Dewpoint: 7.0C (44.5F)
Earlier this morning the dewpoint at both stations was around 13-14C or 55-57F...
Definitely expected to be much more humid the next 2 days and as a result Environment Canada has just issued a High Heat and Humidity warning for the lower Ottawa river and St-Lawrence river valleys. The only time they publish such a warning is when they expect heat index values to be above 40C or 105F suggesting oppressive and even dangerous heat for some.
A humidex advisory is also in place for many areas of southern Ontario. Basically, everywhere except areas downwind of the lakes.
From Environment Canada
Humidex advisory for..
City of Toronto
Windsor - Essex - Chatham-Kent
Sarnia - Lambton
London - Middlesex
Simcoe - Delhi - Norfolk
Dunnville - Caledonia - Haldimand
Oxford - Brant
City of Hamilton
Halton - Peel
York - Durham
Huron - Perth
Waterloo - Wellington
Dufferin - Innisfil
Barrie - Orillia - Midland
Belleville - Quinte - Northumberland
Kingston - Prince Edward
Peterborough - Kawartha Lakes
Stirling - Tweed - South Frontenac
Bancroft - Bon Echo Park
Brockville - Leeds and Grenville
City of Ottawa
Prescott and Russell
Cornwall - Morrisburg
Smiths Falls - Lanark - Sharbot Lake
Renfrew - Pembroke - Barry's Bay
This is an advisory that maximum humidex values of 40 or higher are
forecast over most of Southern Ontario for Wednesday afternoon.
Hot and humid air over Southwestern Ontario will continue to flood
over all of Southern Ontario tonight and Wednesday morning in a brisk
west to southwesterly flow.
Except for areas down wind from the Great Lakes, daytime high
temperatures Wednesday afternoon are expected to peak above the
thirty degree mark over all of Southern Ontario with humidex values
near or higher than 40.
Day 2 (Wednesday) severe weather potential from the SPC / Day 3 (Thursday)
My expectations for a good storm when I classic summer setup like we have here is always too elevated and I end up being disappointed with the result. (a brief 15-min slightly gusty storm) So, this time, I'm going to conserve my excitement and hope for a brief measly storm so that if a strong one is on my doorstep I will be even more thankful!
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The weather is always interesting. - Jesse Ferrell
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