Subj : HVYRAIN: Excessive Rainfall Discussion To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Thu Jan 26 2023 08:26:14 FOUS30 KWBC 260826 QPFERD Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 325 AM EST Thu Jan 26 2023 Day 1 Valid 12Z Thu Jan 26 2023 - 12Z Fri Jan 27 2023 The probability of rainfall exceeding flash flood guidance is less than 5 percent. Kebede Day 2 Valid 12Z Fri Jan 27 2023 - 12Z Sat Jan 28 2023 The probability of rainfall exceeding flash flood guidance is less than 5 percent. Kebede Day 3 Valid 12Z Sat Jan 28 2023 - 12Z Sun Jan 29 2023 ....THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF THE SOUTHERN PLAINS AND LOWER MISSISSIPPI VALLEY... A shortwave impulse will break from an upper trough in the East Pacific and propagate into the Southern Plains on Sunday night. Surface low pressure will develop within an area of upper divergence in southern Texas and lift into the Gulf Coast. This new low pressure system will become the focus for heavy rainfall and thunderstorms across the region beginning Sunday night and continuing through early next week. Southerly mid-level flow between 30-40kts will transport Gulf moisture, with PWATs between 1.5-1.75", into the eastern Texas and the Gulf Coast. Another low pressure system propagating southward through the midsection of the country will aid in pulling moisture northward into the Ohio Valley and Northeast. Some of the latest guidance suggests the potential of another QPF maxima occurring over portions of the northern Arkansas, presumably due to the influence of the northern stream shortwave and its southward propagating surface front. The focus for Saturday's Marginal risk area will be portions of eastern Texas and the Lower Mississippi Valley. Soil moisture is fairly high over the Lower Mississippi Valley and the central/Texas Gulf Coast following recent heavy rainfall, but some drying may occur before rainfall begins again on Sunday. The anticipated recovery of soils and relatively high FFGs support the Marginal risk area as drawn, but isolated instances of flash flooding are still a possibility, especially along the Mississippi River where flooding has caused those soils to be especially vulnerable. Considering that the onset of heavy rainfall will be late Saturday night, any slowing in future guidance may kick impacts of this heavy rain threat into the Day 4 (12z Sunday -- 12z Monday) time frame. Kebede Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!6dPYp_i-2Tzl-pJr6bV_JSqZqV5IjDffiGhkRatfBvLa= 7f4M_wO4GH2_QPzuJA67r90skWtk3u2PfY92wwg0_GK7zeI$=20 Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!6dPYp_i-2Tzl-pJr6bV_JSqZqV5IjDffiGhkRatfBvLa= 7f4M_wO4GH2_QPzuJA67r90skWtk3u2PfY92wwg0367Q4q4$=20 Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!6dPYp_i-2Tzl-pJr6bV_JSqZqV5IjDffiGhkRatfBvLa= 7f4M_wO4GH2_QPzuJA67r90skWtk3u2PfY92wwg0JKTs2eU$=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) .