Expansive Severe Weather Threat Tuesday and Wednesday in the South, Midwest, East

Jonathan Belles
Published: February 26,2017
Another round of severe thunderstorms will wrap up the month of February and kickoff March beginning in the South and Ohio Valley Tuesday, and tracking to the East Coast Wednesday. This follows on the heels of a two-day episode of severe weather this past Friday and Saturday in the Midwest and East.
(MORE: Tornado Central)
A strong jet stream will pivot into the eastern half of the country, blasting atop a warm and increasingly humid air mass. A sharpening cold front will eventually sweep to the East Coast, as well.
(MORE: Signs of Spring Are Already Popping Up)

Moderate to strong wind shear, the change of wind speed and direction with height, will allow storms to grow and persist.
Dew points, a measure of moisture, in the low to mid-60s as far north as southern Indiana and Illinois will contribute fuel and instability for thunderstorms.

Forecast Timing

Here is a general outline of where and when we expect storms this week. Check back frequently for further details on weather.com.

Tuesday

• An expansive area of severe thunderstorms is possible both Tuesday and Tuesday night from the Ark-La-Tex region northeast into the Ohio Valley, perhaps as far north as the southern Great Lakes.
• Damaging thunderstorm winds, large hail, and a few tornadoes are possible.
• Cities: Little Rock |  Memphis | St. Louis | Louisville | Cincinnati

Tuesday's Forecast

Wednesday

• A moderate to strong cold front will sweep across the South, then head toward the East Wednesday and Wednesday night.
• One or more squall lines of severe thunderstorms are possible near and ahead of the cold front.
• Damaging winds will be the primary threat, though a few tornadoes can't be ruled out.
• Cities: Jackson, Mississippi | Birmingham | Nashville | Atlanta | Washington D.C.

Wednesday's Forecast

Very Welcome Rainfall

Along with the storms, locally rainfall amounts will be seen across parts of the South and Ohio Valley.
A swath from northern Louisiana to Ohio and West Virginia is expected to pick up 1 to 2 inches of rainfall. Localized amounts up to 3 inches are possible.

Forecast Rainfall

Much of the South remains in a severe drought that dates back to summer.
With just a few exceptions, the Southeast has seen below average rainfall since the beginning of February. Parts of Mississippi have seen less than 25 percent of their average February rainfall.
(MORE: 6 Unusual Things February Brought)
In fact, as of February 24, Spartanburg, South Carolina, Cedartown, Georgia, and a few other stations in the Southern Appalachians are having their driest February on record. Numerous sites across the Southeast are experiencing one of their top 10 driest Februarys.

Current Drought Monitor

How Much Severe Weather Does March Typically Bring?

As meteorological spring begins, on March 1, temperatures begin to increase and moisture makes more advancements from the Gulf of Mexico toward the north.
The contrast of late winter cold air from the northern tier of states and increasing heat and humidity from the Gulf of Mexico increases the frequency of severe weather events and reports by late March.

In the "possible" lighter red are locations that have a 0.10 percent probability of a tornado within 25 miles of a point by late March. The "most likely" pink shading is for locations that have a 0.60 percent probability of a tornado within 25 miles of a point by late March. Based on 1982-2011 averages.
(NOAA/Storm Prediction Center)

MORE: Severe Storms -- January 2017