Subj : MESO: Nws Weather Prediction Center College Park Md To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Fri Jan 05 2024 10:22:29 AWUS01 KWNH 051020 FFGMPD TXZ000-051618- Mesoscale Precipitation Discussion 0001 NWS Weather Prediction Center College Park MD 519 AM EST Fri Jan 05 2024 Areas affected...portions of the Middle & Upper TX Coast Concerning...Heavy rainfall...Flash flooding possible Valid 051018Z - 051618Z Summary...Showers and thunderstorms have been developing within a saturating air mass and showing increasing hourly rain totals where cells train. Hourly totals to 1.5" with local amounts to 3" are anticipated, which could lead to isolated flash flooding issues. Discussion...Showers and thunderstorms have been developing over the past few hours across portions of the Middle and Upper TX coast along an inverted trough of pure wind convergence extending north-northeast of a pair of surface lows near the TX coast and near a front that connects the two. Hourly rain total estimates are exceeding 1.2" in southern Jackson County in an area along a stationary front between two discrete surface lows. Precipitable water values have risen quickly towards 1.5" per GPS data.=20 Effective bulk shear of 30-40 kts is leading to some cell organization and short bouts of cell training, which have yielded ~2" of rain so far southwest of Austwell, per radar estimates. MU CAPE is minimal but increasing as the lows slowly deepen. The expectation in recent RAP runs is for the two lows to consolidate between now and 15z, which when it occurs, could end the training convective threat. Possible mesocyclones and cell mergers would also aid heavy rain production. In the meantime, the signal in the 06z HREF is for a strong signal for 2" and a non-zero chance for 3", which is extremely close to area flash flood guidance values. The 06z HREF has been too far east with its rainfall signal so far, placing it at the coast or offshore rather than inland. Patches of this region have seen 300%+ of their average weekly rainfall, so some degree of soil saturation has occurred. With the expectation of hourly rain totals peaking in the 1.5" neighborhood and local amounts of 3" expected, flash flooding is expected to be isolated within the MPD area. Roth ....Please see https://urldefense.com/v3/__http://www.wpc.ncep.noaa.gov__;!!= DZ3fjg!9ky0zrPEdiKqBS8aEACF75o9b4ZvQR-nPgtMC5NsWvdZjfNYPtZK-6KA-N5YG7i0mQ9J= sz-orzugJKxcBVqPgVaMPPg$ for graphic product... ATTN...WFO...CRP...HGX...LCH... ATTN...RFC...WGRFC...NWC... LAT...LON 30249478 29539431 28989516 28239645 27639728=20 28769698 29969593=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) .