Just What the Doctor Ordered
All the ingredients necessary for a heavy rain event are coming to fruition on Monday.
A widespread 1.5 to 2.5″ of rain will impact the National Capital Region… with the heaviest rain developing Monday afternoon and lasting through the overnight. Some locations could locally pick up 3 to 4″ of rain (between late tonight and Tuesday evening)!
Hydrometeorological Prediction Center (HPC) rainfall forecast, courtesy NOAA
- Rush hour Monday afternoon looks awful, so plan accordingly if you must use the interstates (95, 66, 270).
- Heavy rain will reduce visibility, cause water to pond on roads and underpasses, and increase the risk of hydroplaning.
3 Month Rainfall Deficit – 4 to 6 inches of rain is needed in the immediate Washington Area
Scattered thunderstorms will develop Tuesday afternoon as a cold front approaches the Washington Area.
After the much-needed, soaking, rain, Wednesday through Friday will feature partly to mostly sunny skies and seasonable temperatures.
Heavy Rain & Severe Thunderstorms Thursday
A warm front will pass through the Washington Area overnight Wednesday bringing with it a period of moderate to heavy rainfall with embedded thunderstorms. A cold front will move through the D.C. Area on Thursday afternoon possibly producing a severe weather outbreak across central Virginia. Rainfall totals across the Washington Area by Thursday evening will range between a half an inch and 1.25″! The drought relief continues and those of you who have been thirsting for a good thunderstorm may just get your wish.
North American Model (NAM) depicts heavy rainfall moving through the Washington Region at 3 AM Thursday morning. Darker colors indicative of possible embedded thunderstorms. (courtesy: weatherunderground.com)
North American Model (NAM) depicts heavy rainfall moving through the Washington Region at 6AM Thursday morning. At this time, the heaviest rain may push just east of the immediate DC Area for the beginning of rush hour.
Sunshine that breaks out Thursday late morning through the mid afternoon will aid in instability as a cold front approaches from the northwest during the late afternoon. The map below shows Convective Available Potential Energy, or CAPE. The more latent heat energy in the atmosphere the better the chance for thunderstorms that can produce large hail and damaging winds.
Very High CAPE depicted over Fredericksburg, the northern neck of Virginia, the central Shenandoah Valley... points south on Thursday afternoon ahead of an approaching cold front.
Right now the best chance for severe thunderstorms will be across the southernmost suburbs (Quantico, Stafford County, and Fredericksburg) the piedmont of north-central Virginia (Culpeper) the central Shenandoah Valley and central Virginia (Charlottesville and Richmond).
