Sunday Severe Weather Threat Zones Refined for Tornado and Flood Threats

Areas that could see tornadic thunderstorms today are shaded in green. Image: NWS/SPC

The National Weather Service’s Storm Prediction Center (SPC) and Weather Prediction Center (WPC) have both drastically refined their previously identified areas of tornado risk and flash flood risk for today. Due to a variety of atmospheric ingredients that evolved differently than initially projected, both the SPC and WPC have scaled back areas where very bad weather was initially expected to occur today and tonight.

Thunderstorms are possible in any shaded region, with green, then yellow, then orange being greater risk zones of severe storms. Image: NWS/SPC

While thunderstorms are still likely across the Northeast, Mid Atlantic, and Ohio River Valley, the greatest risk of tornadic cells will remain over portions of Virginia and North Carolina and a portion of western Kentucky and southern Indiana and Illinois. According to the SPC, a cluster of strong to severe storms will continue to impact far southeast Virginia vicinity through early afternoon. Otherwise, a relatively moist and potentially unstable air mass is present to the west of these early day storms. The SPC adds that forecast soundings suggest sufficient deep-layer shear for convective organization and perhaps a supercell or two today. Overall, with most thunderstorms in the eastern U.S. today, locally damaging winds are the main threat through the early evening.

The area shaded in green could see exceptionally heavy rain and areas of flash flooding later Sunday into Sunday night. Image: NWS/WPC — The WPC initially felt that the area shaded in green could see exceptionally heavy rain and areas of flash flooding late Sunday into Sunday night. However, this is no longer the case. Image: NWS/WPC

The precipitation potential has also dropped from previous forecasts. At this time, the WPC does not believe showers will be heavy enough to reach flash flood criteria in the northeast. Yesterday, they believed there could be a flash flood threat around portions of New Jersey, Delaware, Connecticut, Rhode Island, Massachusetts, and eastern Pennsylvania and Maryland, but that is no longer the case. While heavy rain could fall from scattered storms today and tonight, the risk of flash flooding from those showers should remain low.