Subj : HVYRAIN: Excessive Rainfall Discussion To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Fri Nov 10 2023 00:26:04 FOUS30 KWBC 100025 QPFERD Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 725 PM EST Thu Nov 09 2023 Day 1 Valid 01Z Fri Nov 10 2023 - 12Z Fri Nov 10 2023 ....THERE IS A MARGINAL RISK OF FLOODING FROM THE ARKLATEX TO THE TEXAS GULF COAST... Realigned the Marginal risk area a bit...keeping the area outlook area in proximity to an area of low pressure over far eastern Texas and a cold front extending southwestward from there. In this alignment...the outlook area was focused where instability could support locally higher rainfall rates. In addition...the outlook area was extended a bit northward and the low and the front where instability was more elevated and the potential for training may locally offset the rainfall rates that are below 1- and 3-hour flash flood guidance. =46rom the central Texas coast northeastward into eastern Texas and a small portion of adjacent Arkansas...surface dewpoints of 65 to 70 degrees were common ahead of the front resulting in surface based CAPE around 1000 J per kg. This same area had precipitable water values were at or above 1.6 inches as of late afternoon/early evening. Latest runs of the HREF shows neighborhood probabilities for 1 inch per hour rainfall exceeding flash flood guidance was 5 to 10 percent along and west of the Texas coast near CRP where precipitable water values were closer to 2 inches. Given the potential for slow cell motion and training of cells...a few locations that have instances of convective training with 3+ inches of total rainfall just inland from the coast through the end of the period. This may also be enough for localized flooding concerns. Bann Day 2 Valid 12Z Fri Nov 10 2023 - 12Z Sat Nov 11 2023 Although there are currently no excessive rainfall risk areas at this time, the models agree that an axis of heavy convection will be just offshore the southern Texas Coast as the cold front and the surface low slowly pushes towards the south. There may be some instances of elevated convection that develops over portions of Deep South Texas, but the majority of the guidance suggests this would not be enough to cause any flooding concerns. However, if the frontal progression slows down and later model runs trend west, then a Marginal Risk area may eventually be needed, so this will continue to be monitored. Elsewhere, the latest CAM guidance indicates the potential for some slow moving storms off the East Coast of Florida over the Gulf Stream waters, but should remain far enough away from land to also keep this region clear of any risk areas for now. Hamrick Day 3 Valid 12Z Sat Nov 11 2023 - 12Z Sun Nov 12 2023 The probability of rainfall exceeding flash flood guidance is less than 5 percent. Hamrick Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!47DlazLl4I_90dqhLDcYGwXvgvAqwu9xO1LH4YBGu0Cr= wRmSJVTEFaiDxcDY3_mBlJhFpbGqnQZ5xOgKMMAT7f5EGTE$=20 Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!47DlazLl4I_90dqhLDcYGwXvgvAqwu9xO1LH4YBGu0Cr= wRmSJVTEFaiDxcDY3_mBlJhFpbGqnQZ5xOgKMMATHjK2Bwo$=20 Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!47DlazLl4I_90dqhLDcYGwXvgvAqwu9xO1LH4YBGu0Cr= wRmSJVTEFaiDxcDY3_mBlJhFpbGqnQZ5xOgKMMATTXPobUY$=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) .