AWUS01 KWNH 062316 FFGMPD FLZ000-ALZ000-MSZ000-070410- Mesoscale Precipitation Discussion 0137 NWS Weather Prediction Center College Park MD 715 PM EDT Sun Apr 06 2025 Areas affected...Coastal MS...Southern AL...Western FL Panhandle Concerning...Heavy rainfall...Flash flooding likely Valid 062310Z - 070410Z SUMMARY...Training bands of showers and thunderstorms will continue through the evening hours which will include locally significant and life-threatening flash flooding concerns from extreme rainfall rates. DISCUSSION...GOES-E IR satellite imagery shows an extensive axis of cold-topped convection impacting portions of coastal MS through southwest AL. This corridor of heavy shower and thunderstorm activity is embedded within a divergent flow regime aloft with a combination of right-entrance region upper jet dynamics and shearing vort energy interacting with a moist and unstable south-southwest low-level jet. The latest area VWP data shows a convergent low-level jet on the order of 30 to 40+ kts with some of the strongest moisture convergence magnitudes situated across coastal MS/AL and the far western parts of the FL Panhandle. MLCAPE values of 1500+ J/kg are noted across this region with relatively strong shear parameters (effective bulk shear of 40+ kts) still favoring organized updrafts and a sustainable axis of convection. Significant concerns for cell-training will exist through the evening hours as this convection tends to maintain itself out ahead of a cold front slowly approaching from the west. While the overall instability may begin to slowly decrease in magnitude, there will likely still be sufficient low-level forcing/convergence and modest jet support aloft for convection to continue over the next several hours albeit perhaps occasionally in a broken fashion. Smaller scale bands of training convection are expected to continue though locally. Given the thermodynamic and kinematic environment, and level of moisture transport off the Gulf, the rainfall rates will continue to be locally extreme in nature, with rates as high as 2 to 4 inches/hour. Already areas around the Mobile, AL metropolitan area and adjacent suburbs have been seeing these high rates over the last couple of hours. In fact, just in the last hour, the Downtown Mobile (KBFM) ASOS reported 3.17 inches of rain! The latest HRRR guidance suggests high-end rainfall potential going through the mid to late-evening hours, with additional rainfall totals of 4 to 6 inches possible, with isolated heavier amounts. The 12Z ARW/ARW2 solutions of the HREF suite have a similar footprint, but are likely a bit too far to the north considering the latest observational trends. Given these solutions and the latest radar and satellite trends, it seems rather likely that some portions of southwest and southern AL in particular, and the far western parts of the FL Panhandle will have a period of extreme rainfall over the next few hours at least. Consequently, flash flooding is likely to continue through the evening hours, including potentially significant and life-threatening impacts. Orrison ...Please see www.wpc.ncep.noaa.gov for graphic product... ATTN...WFO...BMX...LIX...MOB...TAE... ATTN...RFC...LMRFC...SERFC...NWC... LAT...LON 31878642 31848563 31178560 30548641 30208782 30138870 30438895 31008836 31618709