Fig. 1-3: HRRR model projects radar depictions of today’s Mid-Atlantic squall line which produces a tornado risk.
Discussion: A TORNADO WATCH is in effect for the Mid-Atlantic States to 2PM EDT. A new watch for this afternoon extending across the northern Mid-Atlantic States is likely! The HRRR model identifies the axis of the squall line across west-central Virginia to far northeast South Carolina at 10AM (Fig. 1). The squall line produces a tornado risk, wind gusts to 6-65 mph, heavy rain and moderate lightning frequencies. By 1PM EDT, the squall line reaches the Baltimore/Washington to Richmond stretch (Fig. 2). The duration of the weather event averages 90 minutes. By 4PM EDT, the squall line remains intense in eastern Pennsylvania stretching through Delaware to Norfolk (Fig. 3). As the squall line reaches the coast, weakening is generated. A second less intense squall line develops and moves to Washington, DC to Richmond, VA around 5-6PM. A third squall line moves across the DCA/BWI area late this evening.