Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon Mar 31 2025 07:13:41 AWUS01 KWNH 310713 FFGMPD MSZ000-LAZ000-ARZ000-311200- Mesoscale Precipitation Discussion 0099 NWS Weather Prediction Center College Park MD 312 AM EDT Mon Mar 31 2025 Areas affected...Northeast LA...Southern AR....Northern MS... Concerning...Heavy rainfall...Flash flooding possible Valid 310710Z - 311200Z SUMMARY...Favorable training profile for strong thunderstorms capable of 2"+/hr rates. Localized totals of 2-4" in 2-3hrs pose possible localized flash flooding over the next few hours. DISCUSSION...GOES-E 10.3um and regional RADAR mosaic has shown consistent strong development that has maintained itself across S AR, starting to spread downstream into NW MS, with additional upstream overshooting tops breaking through the cirrus canopy over north-central LA. GOES-E WV and AMV suite shows a strong speed max starting to round the southeast quadrant of a larger scale trof through the Ozarks providing solid divergence aloft. RAP forecasts are expected for the jet to further enhance the downstream right entrance region across the central MS Valley maintaining solid divergence across the lower Delta Region into N MS over the next few hours. At the surface, a slowly forming surface low along a stalled portion of the main front has locally backed surface to boundary layer flow tapping enhanced moisture and unstable airmass out of the MS Valley. Tds in the low 70s and MLCAPE to 1500 J/kg combined with the convergence downstream of the surface low will maintain inflow/flux convergence to further expand convective development over the next few hours. Veering mid-level flow above the boundary layer is also providing 850-700mb moisture flux from a pool of enhanced moisture upstream to increase rainfall efficiency and likely limit cold pool development. Deep layer steering is also generally parallel to the boundary to support moderately lengthy axis for training over the next few hours. As such, a streak of enhanced rainfall with 2-4" totals should extend from S AR into northern MS. This aligns with a localized minimum in FFG values along the river and northeastward where 1/3hr FFG values of 1.5-2" & 2-3" have a solid potential of been exceeded in spots along the training axis. In the longer term maintenance of the line of convection will be determined on upstream development over central LA and points south. If clusters develop, inflow/flux of moisture/unstable air is likely to be disrupted, but until then there is a good possibility of an incident or two of localized flash flooding through early morning. Gallina ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!5VrUXOTKumSFvhfkvikkPBun-IArAQjVjGr3cr4JLzCa_PXtafYErBxlZM1K4-z67cN7= HutoKbkwkHCH6iwdVu9KehI$ for graphic product... ATTN...WFO...JAN...LZK...MEG...SHV... ATTN...RFC...LMRFC...SERFC...NWC... LAT...LON 34858901 34268829 33388846 32878936 32679035=20 32589159 32609252 32819306 33349308 34369101=20 34729014=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) .