Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon Jun 09 2025 03:17:46 AWUS01 KWNH 090317 FFGMPD VAZ000-NCZ000-090700- Mesoscale Precipitation Discussion 0406 NWS Weather Prediction Center College Park MD 1117 PM EDT Sun Jun 08 2025 Areas affected...South-central to Southeast Virginia... Concerning...Heavy rainfall...Flash flooding possible Valid 090315Z - 090700Z SUMMARY...Continued limited flash flooding risk continues for a few more hours as remaining training cells approach southeast VA and more susceptible urban environment.=20=20 DISCUSSION...GOES-E 10.3um and RADAR mosaic across the Mid-Atlantic shows a slowly stabilizing environment, particularly northward along the advancing occluded front from HGR/FDK MD into north-central VA toward the triple point near LKU. The warm front remains well defined cross the lower neck into Hampton Roads and out into the Atlantic through the mouth of the Chesapeake Bay.=20 RAP analysis shows a well of 1000-1500 J/kg of MLCAPE along and east of the slowly advancing cold front out near the slopes of the Blue Ridge across south-central VA into southeast VA. However, VWP shows mid to upper level trof is starting to slide away further northeast but 850mb winds remain mildly convergence as down-sloping becomes more westerly and into the 20-25kt range. As such, a few convective cells remain across south-central VA and while there are some indications of cold pool/outflow, there is some upstream redevelopment on that low level convergence to keep activity going. Deep layer flow remains a bit north of ideally parallel to the orientation of the ongoing convection but still remains suggestive of training/repeat component as the cells continue to drift east.=20 Total moisture of 1.75" and deep warm layer and flux for rainfall production helps to maintain solid efficiency for 1.5-1.75"/hr rates with length of training to support 1-2 hour duration for additional 1.5-3" totals over the next few hours. This is a the lower threshold of FFG values in the rural areas, however, if cells can maintain strength and tap remaining instability pockets, these rates/totals would pose a greater potentail for flash flooding across the urban locations from Richmond/Petersburg southeastward toward Norfolk and Hampton Roads. So while not the highest confidence it will given the stabilizing environment with loss of heating...the risk is sufficient for localized flash flooding to continue to be possible for the next few hours.=20 Gallina ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!51BV9I7SzZjyVQ3VKsMpcyrKrro_3Hrxdx8wnGGZ0JH4OgfvDf9kBSK-dYfHnLXB8_ki= YtsRcfwdUVnvu1lAofsMc08$ for graphic product... ATTN...WFO...AKQ...RNK... ATTN...RFC...ALR...RHA...NWC... LAT...LON 37857671 37637628 37077605 36847595 36567584=20 36327595 36397697 36557779 36587861 36767934=20 37157952 37427867 37637752 37747708=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) .