Peak Wind Gusts across the Washington D.C. Metropolitan Area
Source: NWS Washington DC (Preliminary Storm Report)
For a very informative report on the science behind a “derecho”, click here
Still frame radar images of the derecho racing east at nearly 70 mph
(courtesy: weatherunderground.com)
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.
Towering Cumulonimbus clouds can be seen on the visible satellite image across the Midwest (Satellite image above courtesy: NEXLAB College of DuPage)
A wider view of the MCS over Indiana and Ohio riding the strong jet stream aloft as it races southeast toward the Mid-Atlantic. (Satellite image above courtesy NEXLAB, College of DuPage)
A “Bow-echo” signature on this radar image above is indicative of a line of widespread damaging wind gusts in excess of 70 mph (Radar image courtesy RadarScope)
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 dew points and very high CAPE values (convective available potential energy) Severe Thunderstorm Watches may be issued across our region.
The “spark” to ignite the CAPE (gasoline) is moving this way. You have been warned, The Storm Prediction Center may issue a Severe Thunderstorm Watch for the Washington Region a bit later this afternoon.
