Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun Jan 29 2023 10:40:26 AWUS01 KWNH 291040 FFGMPD LAZ000-TXZ000-291638- Mesoscale Precipitation Discussion 0050 NWS Weather Prediction Center College Park MD 538 AM EST Sun Jan 29 2023 Areas affected...Southeast TX...Southwest to South-Central LA Concerning...Heavy rainfall...Flash flooding possible Valid 291038Z - 291638Z SUMMARY...Showers and thunderstorms will be developing and expanding in coverage and intensity this morning across southeast TX and into southwest to south-central LA. Some cell-training may occur, with sufficient rainfall for some flash flooding to be possible. DISCUSSION...The environment is expected to become conducive for areas of showers and thunderstorms to develop and expand in coverage over the next few hours across the northwest Gulf Coast region and including areas from the middle and upper TX coast northeastward into southwest LA. Increasingly favorable low-level convergence/forcing near and just inland of the coast will be coupling with right-entrance region upper-level jet dynamics and an improving thermodynamic environment for convection to expand in coverage and intensity. There is already a southerly low-level jet on the order of 30 to 40 kts yielding relatively strong moisture transport in off the Gulf of Mexico. Meanwhile, strong southwest mid to upper-level flow crossing Mexico with origins from the eastern tropical Pacific Ocean is fostering the transport of vort energy embedded within the subtropical jet along with a rather well-defined ribbon of subtropical moisture. The latest CIRA-ALPW data suite depicts this dual moisture transport regime with a convergence of moisture streams noted toward the northwest Gulf Coast region. There is a bit of uncertainty with where the strongest concentration of convection will be this morning, but the better overlap of forcing through the column relative to the stronger instability axis would favor the southeast TX coastal plain initially, but with gradually more expansion and organization in time into southwest to south-central LA. The 00Z/06Z HREF guidance support showers and thunderstorms capable of producing rainfall rates of 1.5 to 2 inches/hour with the aforementioned dual moisture feeds and persistent columnar transport of moisture supporting enhanced convective rainfall efficiency. Despite uncertainties in the latest CAM guidance on the placement of heaviest rainfall, the general expectation is that some locations near or along the upper TX and over into southwest LA will see as much as 3 to 4 inches of rain with locally higher amounts by late morning, and some of this will be reflective of at least occasional cell-training. Downstream areas of south-central LA may also see similar amounts closer to midday. Given the relatively moist soil conditions from the last heavy rainfall event a few days ago, these additional rains will favor sufficient runoff concerns for some flash flooding to be possible. The urbanized locations including the Houston and Beaumont/Port-Arthur metropolitan areas, and eventually Lake Charles will also be sensitive to enhanced runoff potential. Orrison ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!4H-TUxgzJtxR-gu7UQirzKOznpvm9zVNLLDtN1U9ohBS0l2VLZoIBXrr-cUL0nzAmdou= 22bu0islpZDqMDD4yxHOz-Q$ for graphic product... ATTN...WFO...HGX...LCH...LIX... ATTN...RFC...LMRFC...WGRFC...NWC... LAT...LON 30939287 30929203 30789140 30359111 29989117=20 29639164 29569254 29639351 29399463 29479517=20 29809566 30169556 30529498 30829396=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) .