Subj : HVYRAIN: Excessive Rainfall Discussion To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Feb 14 2023 08:13:59 FOUS30 KWBC 140813 QPFERD Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 313 AM EST Tue Feb 14 2023 Day 1 Valid 12Z Tue Feb 14 2023 - 12Z Wed Feb 15 2023 The probability of rainfall exceeding flash flood guidance is less than 5 percent. Hurley Day 2 Valid 12Z Wed Feb 15 2023 - 12Z Thu Feb 16 2023 ....THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS PORTIONS OF THE LOWER MISSISSIPPI VALLEY, WESTERN TENNESSEE VALLEY, AND LOWER OHIO VALLEY... Upper level jet streak and associated shortwave energy will round the base of the longwave trough on Wednesday, then lift northeast along the eastern periphery late Wed-Wed night as the the trough begins to phase with the northern stream shortwave. At the surface, the guidance is fairly well clustered with the lee-side low emerging across the TX Panhandle by midday Wed, and are now in more decent alignment with the track and timing through Wed night (GFS and NAM still a bit faster than the non-NCEP consensus, however both are trending closer to the ECMWF). Wed night into Thu morning, as the upper level jet streak and associated shortwave energy lift across the Central Plains and Lower MO Valley, the longwave trough will be nudging eastward across the southern High Plains. The increasingly difluent flow aloft, combined with the right-entrance region forcing from the upper jet streak to the north, will strengthen the low-mid layer moisture transport and deep-layer ascent across the outlook area Wed night into Thu morning. Per both the GEFS and SREF, 850-700 mb moisture flux anomalies climb between 3-4 standard deviations above normal between 00-12Z Thu, as 850 mb SSW flow increases to 40-50 kts. Increasingly favorable thermodynamic environment in evolving warm sector will also include PWs increasing to 1.5-1.6 inches and MUCAPE values between 500-1500 J/Kg. The dynamic and thermodynamic setup will favor 1-2" hourly rainfall rates Wed night underneath the stronger convective clusters, however at this point it appears there will be enough low-mid layer shear to maintain forward propagation, at least through 12Z Thu, especially over eastern portions of the outlook area. Because of this and overall later timing of the heavier rain (latter half of the outlook period/after 00Z Thu), will maintain the Marginal Risk from yesterday's Day 3 ERO with the anticipation of at most isolated/localized short-term runoff issues.=20 Hurley Day 3 The Day 3 outlook will be updated by 0830Z. Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!8bwtSuXkgc7D-xna6fFbt3FLRcq4dQo6PKLfwhK0vCcb= gGhKdXYtKawz37Df8dGHduW_oxep6GY8zHaHRbq3YRX30TA$=20 Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!8bwtSuXkgc7D-xna6fFbt3FLRcq4dQo6PKLfwhK0vCcb= gGhKdXYtKawz37Df8dGHduW_oxep6GY8zHaHRbq3fQC6rbY$=20 Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!8bwtSuXkgc7D-xna6fFbt3FLRcq4dQo6PKLfwhK0vCcb= gGhKdXYtKawz37Df8dGHduW_oxep6GY8zHaHRbq3AW60hdg$=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) .