Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun Mar 16 2025 21:59:01 AWUS01 KWNH 162158 FFGMPD VAZ000-NCZ000-170400- Mesoscale Precipitation Discussion 0074 NWS Weather Prediction Center College Park MD 558 PM EDT Sun Mar 16 2025 Areas affected...Northeast NC...Southeast VA Concerning...Heavy rainfall...Flash flooding possible Valid 162200Z - 170400Z SUMMARY...Continuation of stronger cells capable of 1.5-2"/hr rates with upstream redevelopment probable resulting in possible streets of 3"+ totals and localized flash flooding conditions. DISCUSSION...RADAR mosaic depicts a cluster of stronger elongated updrafts in proximity to the I-95 corridor tracking through an area that had already seen an earlier round wetting the grounds with spots of .75-1.5" as far north as Petersburg/Wakefield, VA. These cells are aided by a divergence maxima rounding the cyclonic edge of a fairly laminar upper-level jet. This pattern is expected to remain similar with a very slow eastward progression; as such, 500-1000 thickness ridge resides along/just east of the I-95 corridor and with solid 45-50kts of moist 850mb flow, there is ample potential for additional upstream redevelopment.=20=20 Alignment of the moisture axis and instability axis appears to be fairly stable in placement as well with upstream well of 1000-1500 J/kg of MLCAPE to the west and 1.5 to 1.75" of total PWats eastward. Solid deep layer confluence is providing the upstream convergence to allow for back-building/redevelopment. However, the updraft strength is offset a bit being on the gradient of the instability axis, resulting in inconsistent, narrow updrafts but stronger cloud base moisture flux allows for efficient loading to support 1.5-2"/hr rates. Lengths of the updrafts should allow for an hour or so of training for streaks of 1.5" with each pulse/round of convection moving northward. Stronger convergence along the cold front as the base of the trof drifts eastward is likely to occur after sunset and likely spell=20 the last round, this may be after 04z (the end valid time of this message) and trends will need to be continually monitored for additional training and longer duration totals of 3-4" when all is over earlier tomorrow morning. Area has been fairly dry and FFG values are high (especially further east in the Coastal Plain); however, given each round slowly infiltrated and saturates the upper soils reducing it for the next round. While, an incident or two of flash flooding is possible, it is more likely to be isolated, lower-end with greatest risk of higher magnitude of flooding in urban locations such as Raleigh, Rocky Mount, Emporia, Petersburg and the Hampton Roads vicinity of SE VA.=20=20 Gallina ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!5iY5coMLNs81Tr5eQT0UFxE04VIqjH8-mHIs9W4KB6MNGOWjJEA0ZHVJVXa-ktQ6kJzE= XvY4ZQOIjalgGcDRcMqw_Sc$ for graphic product... ATTN...WFO...AKQ...MHX...RAH... ATTN...RFC...MARFC...SERFC...NWC... LAT...LON 37897661 37867619 37297617 36797596 36597603=20 36207647 35347760 35007846 35417909 36347852=20 37367736=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) .