An outbreak looms

Unseasonably warm temperatures have embraced the Eastern United States. While many people are undoubtedly basking in the warm sunshine, there are probably a few people out there thinking “this isn’t quite right!” One of those people is Mother Nature, who is preparing a dose of reality over the weekend.

A broad upper level trough in the northern Plains is starting to move incrementally eastward, and over the weekend, there is going to be a bit of a repetitive pattern at the surface, with a low developing in the southern Plains and shifting towards the Great Lakes. The first such system has already developed and is halfway through it’s course, with some showers and storms in the mid-Mississippi Valley and snow in the Upper Midwest.

As soon as Saturday morning, the next area of low pressure will crop up around the Oklahoma Panhandle and start moving to the east northeast. This version will have a little bit more upper level support, which means more cold air pulled in from the north and more moisture drawn in from the Gulf of Mexico. Given the warmth that is seated in the east and southeast, that’s a recipe for, you guessed it – severe weather.

This is an outlook for day 3, or Saturday, featuring a very large “slight risk” though I suspect by the time Friday morning rolls around, there will be a red “moderate risk” from about Memphis to Shreveport.

The central low pressure is in the colder part of the system, and the tornado threat won’t be extreme, but strong straight line winds seem like a sure thing.

This is going to be the first wide spread severe event of the year, and it is the always underrated squall line variety. While tornadoes cause a great deal of devastation, they often do so in isolated locations. Squall lines like the one expected this weekend touch a lot more lives, even if they don’t necessarily produce the destruction a twister would.

Oh, and on the northwest end of this feature? We’ll be looking at a late season snow storm for the Upper Midwest, with some locations looking forward to a foot of snow over the weekend, on top of the 3-6″ they are seeing tonight with the first wave.