Map Porn: Decaying Squall Line Forms Near-Perfect Cane Over Midwest
Satellite images over the past few weeks have been anything but boring, and last night's thunderstorms were no exception. A weakening squall line moving through Illinois and Missouri formed into almost a perfect cane shape as the northern end wrapped around a strengthening low west of Chicago.
The squall line — consisting of storms that dropped copious amounts of hail and even a few tornadoes in Missouri yesterday afternoon — marched out ahead of a cold front that stretched from Illinois to Texas, while the northern part of the line of showers and storms attached themselves to a warm front. The distortion between the main squall and the storms along the warm front made for the cool effect on satellite imagery.
Here's what the weakening line of storms looked like on radar imagery around the same time as the above satellite shot:
The cold and warm fronts are pretty easy to spot using a model analysis map from the Rapid Refresh model from last night. The product, called "Surface Theta-E," has a pretty wonky technical definition, but it allows users to pick out frontal boundaries more easily than using a temperature or dew point analysis alone.
On the below surface Theta-E analysis from the same time as the above satellite and radar pictures, I've drawn on the cold and warm fronts to make them easier to pick out.
And just for the hell of it, here's a screengrab of the radar out of Kansas City, Missouri just as the cold front passed by the radar site yesterday afternoon. The sharp edge of the cold front is clearly visible as a line extending from bottom-left to top-right, and it's the clear culprit behind the formation of the nasty thunderstorms northeast of MCI.
