####018002039#### AWUS01 KWNH 181413 FFGMPD MSZ000-LAZ000-ARZ000-181812- Mesoscale Precipitation Discussion 0161 NWS Weather Prediction Center College Park MD 1012 AM EDT Thu Apr 18 2024 Areas affected...northern Louisiana, southern Arkansas, and western Mississippi Concerning...Heavy rainfall...Flash flooding possible Valid 181412Z - 181812Z Summary...A band of convection has deepened very near the Arkansas/Louisiana border region over the past hour. These cells are oriented favorably for training and heavy rainfall, potentially posing a spotty flash flood risk through 18Z. Discussion...The combination of confluent/convergent low-level flow (in the 850mb layer) and a stout shortwave trough across northeast Texas was contributing to development of robust convection along the AR/LA border region over the past hour. The cells are oriented favorably parallel to mid/upper steering flow for training, and while rain rates so far are peaking at around 0.5 inch/hr, ~2000 J/kg SBCAPE and 1.5 inch PW values should eventually support higher rain rates especially as convection continues to train across the area. Observations and SPC Mesoanalyses suggest that this axis of convection could persist for a few hours as 1) the mid-level wave providing ascent continues to approach the area and 2) convergence on the nose of a 35kt 850mb low-level jet upstream across southeast Texas both contribute to ascent for deep convective development through 18Z or so. An isolated flash flood risk is expected especially where convective training can boost rain rates into the 2-2.5 inch/hr range. FFGs are in the ~2.5 inch/hr range, and may be exceeded in a few spots as storms mature. Cook ...Please see www.wpc.ncep.noaa.gov for graphic product... ATTN...WFO...JAN...LZK...MEG...SHV... ATTN...RFC...LMRFC...NWC... LAT...LON 33989137 33959011 33588961 32948967 32369123 32229317 32589377 33189367 33609325 33889245 ####018000701#### PENA01 KWNH 181200 @UHPISF000CN MPDSUM@V2.0@0101700060@12180424@@0NMCGPHMPD DP@!' `' ` @ & B7)p&PNAM02@@/~||zz}|}||}}~~~~~@@@@@@0161 @@d&MESOSCALE DISCUSSION SUMMARY GRAPHIC @@d& OF ALL VALID MESOSCALE DISCUSSIONS AT @@d& TIME OF PRODUCT CREATION:@@d& ISSUED 04/18/2024 1413Z @@ dNOAA/NWS/NCEP@@d WEATHER PREDICTION CENTER @@d FOR COLOR VERSION SEE: @@d WWW.WPC.NCEP.NOAA.GOV @