Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun Jun 08 2025 02:45:53 AWUS01 KWNH 080245 FFGMPD MSZ000-LAZ000-ARZ000-TXZ000-OKZ000-080800- Mesoscale Precipitation Discussion 0395 NWS Weather Prediction Center College Park MD 1044 PM EDT Sat Jun 07 2025 Areas affected...Southern AR...Northern MS... Adj Northwest TX/Southwest OK... Concerning...Heavy rainfall...Flash flooding possible Valid 080245Z - 080800Z SUMMARY...Training, back-building thunderstorms within axis of enhanced moisture capable of 2-2.5"/hr rates and localized totals of 3-4" pose possible incident(s) of localized flash flooding overnight. DISCUSSION...GOES-E 10.3um EIR and Regional RADAR mosaic depict a west to east band of thunderstorms with a few cells starting to expand and cool below -65C. Cells are developing within a very favorable moisture/instability axis south of the main front. A surface Td gradient is well denoted with mid to upper 70s Tds within the higher theta-E axis from the Red River Valley across S AR into N MS/AL (while being 10 degrees cooler downslope of the Ozark Plateau in central AR. CIRA LPW also notes mid-level layers are at the trailing end of stronger shortwave over the Ohio Valley but the upstream wedge brings an axis of 2" total PWats through the area of concern. In the wake of the shortwave in IL, height-falls are starting to encroach from the northwest further tightening the gradient of moisture/instability and given cyclonic curl of weak (15-20kt) LLJ out of central TX has resulted in a solid confluence axis coincident providing deep layer convergence for convective development. Flow is fairly unidirectional parallel to the moisture/instability gradient to support some training/repeat potential. However, the weaker inflow from the west suggests, convergence will be stronger along the upwind side of deeper convective clusters/cells to support back-building/flanking line development. Propagation vectors, including Bunker's right mover vectors, suggest clusters will deflect just south of due east though enough overlap should exist for some training/repeating cells. Much like the convergence, the best instability air remains upstream across the OK/TX Red River Valley propagating into the clusters mainly in SW AR. MLCAPE values of 2500-3000 J/kg will remain available slowly expanding east into S AR over the next few hours. So strong updrafts and flux should support efficient rainfall production with 2-2.5"/hr rates possible. Given flanking development, potential for pockets/clusters of 3-4" totals are probable through the overnight period, with an isolated 5" total possible. Hydrologically, the area of concern has been able to recover better than points north and NASA SPoRT LIS 0-40cm soil moisture has returned to average in all but far northern MS.=20 Most values range in the 50%-60% saturation, so FFG values have also increased back to normal ranges, generally about 2.5-3"/hr and 4"/3hrs (2.5-3" in N MS). Given this, incidents of flash flooding are likely to be localized and widely scattered through the axis (though guidance/trends suggest SW AR as best potentail) and is considered possible. Gallina ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!686R-YDvXgqUdtFCEo0klNkTomWyFD5muHgprm_vlVh7XoTLfrnBSIp8w2avC4Phny32= baTHzD5nzJ_2B_AL3amshnM$ for graphic product... ATTN...WFO...JAN...LZK...MEG...SHV... ATTN...RFC...ALR...ORN...TUA...NWC... LAT...LON 34909034 34798888 34288823 33418841 32958944=20 32899195 32999383 33599495 33999507 34239482=20 34519393 34639283=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) .