Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Thu Jun 22 2023 17:45:01 AWUS01 KWNH 221744 FFGMPD VAZ000-NCZ000-222345- Mesoscale Precipitation Discussion 0561 NWS Weather Prediction Center College Park MD 144 PM EDT Thu Jun 22 2023 Areas affected...North Carolina...Southeast Virginia... Concerning...Heavy rainfall...Flash flooding possible Valid 221745Z - 222345Z SUMMARY...Clusters of thunderstorms moving northward with a lifting warm front may contain rainfall rates up to 2-2.5"/hr and create a localized risk for flash flooding through the late afternoon/early evening. DISCUSSION...Recent radar and satellite trends depict a well-defined warm front extending across far southeastern VA, with a widespread area of showers and thunderstorms located to the south over eastern NC. These storms have contained 1.5-2" rainfall rates according to radar and MRMS estimates, but have been progressing eastward enough to limit the flash flood threat. However, going into the mid-afternoon hours these storms should lift north and focus along the aforementioned frontal boundary as it pushes northward into southeastern and central VA. Even though storm motions will remain rather fast within the 30kt mean 850-300mb flow (up to 40kt at 850mb), the combination of uniform southerly flow aloft, increasing storm coverage, and surface frontogenesis could allow for a brief period of training storms and localized flash flooding. PWs throughout the region are in the 1.8-2.0" range, which falls within the 75th-90th percentile according to the 12z GEFS. So plenty of moisture is available for current and ongoing storms, with instability limited to areas within the warm sector. SBCAPE of 2000-3000 J/kg per SPC's mesoanalysis is located over northeast NC and is forecast by the RAP to advect northward while weakening over the next several hours. Outside of the broad area of locally heavy rain associated with the lifting warm front, recent radar trends depict a small developing MCV over central NC that is forecast by recent HRRR runs to lift northward into central VA by 22z. This area will be outside of the better instability, but will have better forcing near sfc-925mb fgen to maximize rainfall totals up to ~2-3" by 00z. Additionally, 12z HREF neighborhood probs of 20-35% for 3"/3-hr by 00z exists across southeast VA. 3-hr FFGs are as low as 2-3" across this region of VA, leading to the potential for localized flash flooding concerns. Areas across northeast and north-central NC may see soils saturated enough during current rainfall to lead to a localized flash flood concern by 20-23z as storms develop just to the east of the stationary front extending from northeast to southwest and parallel to the mean flow. Snell ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!_zSxHvStMMsiS8Hz4kdH2Ezt9EIeBM7B0LbS3O5c05Fo4yxSXaC-7jQ33eU_3_sV2fhl= J7ILMT9_1Wcbtr7kUR2v3k4$ for graphic product... ATTN...WFO...AKQ...MHX...RAH...RNK... ATTN...RFC...MARFC...SERFC...NWC... LAT...LON 38007702 37547614 36187683 35617790 35907890=20 37017900 37847831=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 3.14-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .