Subj : HVYRAIN: Excessive Rainfall Discussion To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Jan 28 2025 00:44:32 FOUS30 KWBC 280043 QPFERD Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 743 PM EST Mon Jan 27 2025 Day 1 Valid 01Z Tue Jan 28 2025 - 12Z Tue Jan 28 2025 The probability of rainfall exceeding flash flood guidance is less than 5 percent. Chenard Day 2 Valid 12Z Tue Jan 28 2025 - 12Z Wed Jan 29 2025 The probability of rainfall exceeding flash flood guidance is less than 5 percent. Hurley Day 3 Valid 12Z Wed Jan 29 2025 - 12Z Thu Jan 30 2025 ....THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF NORTH TEXAS AND SOUTHERN OKLAHOMA... ....1930 UTC Update... Only minor changes do the Day 3 ERO, based on the latest guidance/trends, including 12Z global ensembles and 06Z EC AIFS. Hurley Discussion below.. An upper level cutoff low ejecting out of the Southwest into the Plains will provide the forcing for ascent for a developing low over North Texas Wednesday and Wednesday night. Return flow of Gulf moisture ahead of the low will advect north into Texas and Oklahoma along with increasing instability. The typical diurnal increase of the LLJ Wednesday night will greatly increase the coverage and intensity of storms along the developing low's cold front, while the warm front locally increases lift into Oklahoma. Since the upper level low will be slow-moving (though increasing in forward speed with time), this will allow the storms that form to train over the same areas. Soils in the area have been drier than normal, meaning most of the rain will be beneficial, however where storms train over more flood-sensitive areas and urban areas, localized flash flooding is possible. Ensemble guidance have increased in the areal coverage of at least 1 inch of rain, though the pattern is much more favorable to narrow streaks of much heavier totals where the storms track. Thus, confidence has increased enough to introduce a Marginal Risk area. The more significant flash flooding risk will be largely north and east of the Day 3 Marginal Risk area going into D4/Thursday. Wegman Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!9Ej3T1LrvxKfO9vm9ODTFZ104Nrtcj4KrvcOz6lDFs0l= Itt8bvg7CYC7kTPIa8hVssijpHb2-k401acUZsVc1LbolZ0$=20 Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!9Ej3T1LrvxKfO9vm9ODTFZ104Nrtcj4KrvcOz6lDFs0l= Itt8bvg7CYC7kTPIa8hVssijpHb2-k401acUZsVcUKORsws$=20 Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!9Ej3T1LrvxKfO9vm9ODTFZ104Nrtcj4KrvcOz6lDFs0l= Itt8bvg7CYC7kTPIa8hVssijpHb2-k401acUZsVcyqZbRlY$=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 3.20-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .