A very potent area of low pressure and associated cold front have been moving east over the past few days which has made few numerous bouts of severe weather. Numerous tornadoes produced heavy damage across portions of Illinois, Missouri and Kentucky. This included a possible EF-4 tornado with winds up to 170mph that went through the town of Harrisburg, Illinois. Unfortunately, these storms not only caused many injuries but also a number of fatalities as well.
- Storm Prediction Center Outlook for 2/29/12
The storm threat for the day has been primarily over Tennessee and Kentucky. Above is a look at the SPC's Severe Weather Outlook product which can also be found here with real-time updates. Notice how the yellow area dips to the south of the D.C. area. This is because of a warm front draped across our area keeping D.C. and its suburbs cooler and limiting instability. Even when the remnants of the storms get to the D.C. area from Kentucky they should weaken as they enter our more stable atmosphere.
Here are the storm reports so far today which have mainly been in the state of Kentucky. Yesterday's storm reports ranged from the Central Plains all the way to Illinois. The storm that eventually hit Harrisburg, Illinois happened at 4:56am this morning. This is possibly the worst time of day for this to happen while most people are still asleep. It's also February when people aren't accustomed to having severe weather which complicates things even more.
- Branson, Missouri tornado damage from Mark Cowsert
Check out this timelapse through the day of the radar imagery. You can see the front with the line of storms stretching from Southern Pennsylvania all the way to northern Louisiana. The low itself can be seen spinning over portions of Minnesota and Wisconsin. This has brought heavy snow and blizzard conditions to the Midwest with as much as 10 to 15 inches of snow over both Minnesota and Wisconsin.
The severe threat will finally come to an end late tonight as the cold front moves to the east out over the Atlantic. Just like that though the threat will return for more severe storms tomorrow and Friday over portions of the Mississippi and Tennessee Valleys. A few rumbles of thunder will even be possible on Saturday in the D.C. area as a strong cold front pushes through the region.