Severe weather threat Tuesday and Wednesday
A series of disturbances tracking from northern Plains to the Ohio Valley over the next 36 to 48 hours will lead to pockets of severe thunderstorms with damaging winds, hail and flash flooding.
As is always the case this time of year, the timing and strength of these disturbances will be a challenge to forecast.
It appears that the main threat for severe thunderstorms on Tuesday will be from southeastern Saskatchewan and extreme southern Manitoba to Wisconsin and Michigan. See image below.
By Wednesday, the threat area shifts eastward, extending into southern Ontario and then down into the Ohio Valley. I think the greatest threat for severe weather in Ontario on Wednesday will wait until late in the afternoon or evening. I will have more detail on this tomorrow.
Speaking of Wednesday, I will be flying into Toronto during the afternoon (hopefully no delays) in preparation for a short talk I will be giving at the Hyatt Regency in downtown Toronto Thursday morning. I will be talking about AccuWeather Enterprise Solutions and SkyGuard warnings. I will also be covering severe weather (both winter & summer) climatology and impacts in Canada.
Extreme weather pattern shaping up by the weekend
The jet stream will once again become highly amplified (more like a rollercoaster, rather than a flatter, west to east flow) by the end of this week and especially into next week. What does this mean? It means that we can expect another round of extreme weather from west (hot/drier) to east (wet) across the U.S. and southern Canada.
I drew up the image below to show the basic pattern that is expected to set up starting this weekend and through a good chunk of next week....
This type of pattern could bring a spell of hot/dry weather into extreme southern interior of BC and then into Alberta next week. On the other side, a south-southwest flow from the Gulf of Mexico and Caribbean will likely deliver moist (humid), unstable air right up the eastern seaboard and into eastern Ontario/Quebec and the Maritimes, leading to widespread, daily showers and thunderstorms and the threat for flooding rainfall in some areas. When its not raining it will be like a steam bath in the East.
In between these extremes, cooler, less humid air will spread south into the Midwest U.S. next week.
Clearly the worst of this heatwave will be across the interior West of the U.S. with record high temperatures, drought and possible fires. Not a pretty site.
You can also interact with me on my twitter as I cover the severe weather @BrettAWX
Any questions....feel free to email me right here.
Latest clues to the long range into October.
Some needed rainfall for southern Ontario this week.
Mild air masses likely to outnumber the chilly air masses for a good part of October.
Jet stream pattern across North America will become amplified across North America into next week, which means more extremes in weather.
Warm weather will dominate in the eastern half of the country for the next week. Pattern change possible during the last week of September.
The jet stream will strengthen from the Pacific across southern Canada over the next 1-2 weeks which will keep any sustained chilly/cold air masses up across western Alaska and eastern Siberia.