Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Fri Jun 27 2025 01:54:38 AWUS01 KWNH 270154 FFGMPD MDZ000-VAZ000-DCZ000-270450- Mesoscale Precipitation Discussion 0524 NWS Weather Prediction Center College Park MD 952 PM EDT Thu Jun 26 2025 Areas affected...Northern VA...Eastern MD Concerning...Heavy rainfall...Flash flooding possible Valid 270150Z - 270450Z SUMMARY...Thunderstorms will continue across portions of northern VA and eastern MD for a few more hours. Hourly rainfall rates up to 2"/hr are possible with urbanized areas most prone to flash flooding. DISCUSSION...Outflow boundaries emanating from several different afternoon thunderstorm complexes have collided over northern VA, while a cold front races in from the DelMarVa Peninsula. This cold front is helping to ignite thunderstorms near Annapolis while the outflows have triggered storms from the southern Capital Beltway on west to the south of Interstate 66. The 00Z IAD RAOB shows depicts a more tropical air-mass aloft, highlighted by PWs of 2.34" and MUCAPE >3,500 J/kg. This atmospheric setup is resulting in tropical-downpour rainfall rates with MRMS 15-minute radar-estimated rainfall rates ranging between 0.5-1.0" within the storms stretching from Routes 28 & 17 on east towards the MD Eastern Shore. The lack of vertical wind shear should ultimately lead to these cells dissipating within the next few hours. However, these storms are packing quite the punch with >2.0"/hr rainfall amounts likely to be realized in some of these areas. The flash flood threat continues across northern VA on east to the MD Eastern Shore this evening with the more urbanized communities within the "DMV" most at-risk for flooding should storms ensue over more densely populated locations. Mullinax ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!-3uVZE8jo8fpOXVfUcofGTXdgVnK-OgMeMcVQbJm7ATeJrEqQF5NbhcCbTw4m8SkDQZ1= nCxzP2WssMx6sm3QhsL_Q30$ for graphic product... ATTN...WFO...AKQ...LWX...PHI...RNK... ATTN...RFC...RHA...NWC... LAT...LON 39157657 39157618 38967600 38677591 38467602=20 38137631 37907662 37577726 37427752 37337803=20 37397831 37517855 37707882 37827904 38027932=20 38357925 38597901 38807864 38977821 39117766=20 39127715=20 =3D =3D =3D To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM. --- SBBSecho 3.20-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .