Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Jan 03 2023 16:26:34 AWUS01 KWNH 031626 FFGMPD TNZ000-ALZ000-MSZ000-LAZ000-032225- Mesoscale Precipitation Discussion 0012 NWS Weather Prediction Center College Park MD 1125 AM EST Tue Jan 03 2023 Areas affected...Areas of the Mid-South down to the central Gulf Coast Concerning...Heavy rainfall...Flash flooding likely Valid 031625Z - 032225Z SUMMARY...Heavy showers and thunderstorms will be tending to grow upscale over the next several hours across the Mid-South and toward the central Gulf Coast. Multiple rounds of convection are expected, and this will likely drive areas of flash flooding. DISCUSSION...An active afternoon is expected across many areas of the Mid-South and toward the central Gulf Coast as widespread areas of heavy showers and thunderstorms develop and expand in coverage gradually off to the east with time. The activity will be strongly facilitated by the arrival of additional shortwave energy/jet forcing rounding the base of the deep layer trough over the Midwest and lifting northeast across the South. This energy along with rather strong shear profiles will be working in tandem with a very moist and robust southwest low-level jet reaching 50+ kts and the pooling of a moderately unstable boundary layer (MLCAPE values increasing 1500+ J/kg) for organized convection capable of repeating/training over the same area. The PWs are running as much as 1 to 2 standard deviations above the mean with values of 1.5 to 1.75 inches. Already the latest GOES Visible satellite imagery shows a highly agitated CU/TCU field across areas of central/eastern LA and through southern MS with expanding cloud street activity and suggestive of imminent upscale growth of convection. The combination of excellent low to mid-level moisture transport, the persistence of it, and degree of instability should favor enhanced rainfall rates reaching as high as 2 inches/hour with the more organized convective cells. The 12Z HREF guidance favors this and supports localized swaths of rainfall totals reaching as high as 2 to 4 inches by late afternoon. However, locally higher amounts will be possible, and there are some concerns that the morning model guidance may be under doing the rainfall threat across areas of southern MS through central/southern AL where there is stronger forcing and instability compared to areas farther north. Overall, areas of flash flooding are likely heading through the mid to late afternoon time frame as these clusters of showers and thunderstorms expand in coverage and locally repeat/train over the same area. Orrison ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!_sG7ea5JGXp0y9CRfC-n0_RqCq6ohb4nQreAUVOXmM_SQL8o_nJ2BnSWWycWLXIqRIM6= yMxEdI45W8K3GbLhecJkUNI$ for graphic product... ATTN...WFO...BMX...HUN...JAN...LCH...LIX...MEG...MOB...OHX... ATTN...RFC...LMRFC...SERFC...NWC... LAT...LON 35288683 34758576 33038552 31438697 30168943=20 30069085 30399183 31209189 32759033 33968920=20 34958791=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 3.14-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .