There is a tornado watch ongoing this evening from southeastern Tennessee to northeastern Alabama. The threat is localized to the region, and while significant for the region, it doesn’t qualify as an outbreak. Today’s feature is born of a lower level, cut off area of low pressure that doesn’t have a lot of juice to keep it sustained.
Later this week, a more formidable feature is forecast to emerge in the Plains. A sharp area of low pressure that also threatens too become cut off will develop with a little bit more jet support over Oklahoma, Kansas and other nearby states. The sharply cut off low will have a shortwave and a resulting rapid propagation, and as a result will diminish fairly quickly in the Ohio Valley.
Still, even on Day 5 (Sunday), the Storm Prediction Center already has a splotch on the map to be monitored for severe weather. The likely turning in the atmosphere, and the clashing airmasses of a changing season make tornadoes a strong possibility.
Another thing that will usher this shorter — but still active — wave out of the Plains is another, strong, longer waved trough that, even though it is still a week out, the SPC is concerned about. The surface low is forecast to be much more ferocious, with strong winds, rain and perhaps even more thunderstorm activity in the Plains.
This is going to be a very fall like feature, which means windy and rainy in the Upper Midwest. Further to the south, there will be tornadoes in a similar region as on Sunday, but gusty straight line winds will be a problem as well. A well defined cold front will sweep through the southern Plains, which usually means lines of thunderstorms rather than supercellular tornadic storms.
Nevertheless, I would expect the severe picture to clear up as models get better and we get closer to time. An initial instinct for me is that the zone for severe weather will include portions even further north by next Tuesday and Wednesday, perhaps as far as South Dakota. For now, here is the map:
It’s been a very quiet year for severe weather of the traditional variety, but it looks like October will change things. Not only will the next week change our fortunes, it will also change our weather. Don’t be surprised if next Tuesday’s storm is the one that ushers a real dose of autumnal air.