A Mesoscale Convective System (MCS) is racing east-south-east across Ohio and is rapidly approaching the West Virginia and Maryland borders… Look out Washington… The Weather will go down hill in a hurry this evening!
A mesoscale convective system is a complex of thunderstorms that becomes organized on a scale larger than the individual thunderstorms but smaller than extra-tropical cyclones and normally persists for several hours or more.
As these storms approach the mountains and it becomes more certain that they may survive the trip (I don’t see why they would dissipate given a strong jet stream aloft, the record heat outside, high dewpoints and very high CAPE values (convective available potential energy). The “Spark” to ignite the CAPE (gasoline) is moving this way. *You have been warned* The National Weather Service and Storm Prediction Center may issue a Severe Thunderstorm Watch for the Washington Region a bit later this afternoon.