Subj : HVYRAIN: Excessive Rainfall Discussion To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Apr 18 2023 15:05:01 FOUS30 KWBC 181504 QPFERD Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 1103 AM EDT Tue Apr 18 2023 Day 1 Valid 16Z Tue Apr 18 2023 - 12Z Wed Apr 19 2023 The probability of rainfall exceeding flash flood guidance is less than 5 percent. Jackson Day 2 Valid 12Z Wed Apr 19 2023 - 12Z Thu Apr 20 2023 ....THERE IS A MARGINAL RISK FOR EXCESSIVE RAINFALL FROM THE CENTRAL PLAINS TO THE UPPER MISSISSIPPI VALLEY... Showers and thunderstorms are expected to fire up across the Central Plains and the Middle/Upper Mississippi Valley today. The latest guidance continues to depict a Southwest to Northeast orientated QPF axis spanning from eastern Kansas to northern Michigan while favoring the higher totals to setup over eastern Kansas to southern Iowa as this is where the best alignment of deep layer moisture and CAPE values are upwards of 2000 J/Kg may occur. Some of the hi-res guidance is suggesting that hourly rainfall rates may range from 1 to 2 inches over this part of the country. While KS will have the most instability, antecedent conditions are most favorable for flash flooding in Wisconsin due to recent snowmelt and added snowmelt from the current winter storm in the western half of the state. A Marginal Risk that was already in effect from eastern Kansas to Wisconsin was expanded further southwest across eastern Kansas and north/east across Wisconsin and Michigan to reflect the latest WPC forecast and model QPF trends. Campbell Day 3 Valid 12Z Thu Apr 20 2023 - 12Z Fri Apr 21 2023 ....THERE IS A SLIGHT RISK FOR EXCESSIVE RAINFALL FROM THE SOUTHERN PLAINS TO THE OZARKS... Gulf moisture will continue to advect northward and pool across the central U.S. ahead of an advancing cold front. During this time PW values of 1 to 1.5 inches (approximately 1 to 1.5 Sigma) will be nearly parallel to the frontal boundary, which will be conducive for storm tracks to repeat along with some backbuilding of convection. With this in mind, the Slight Risk area was expanded further into northeast Texas and than further northeast into western Kentucky/Tennessee. These part of the region could have areal averages of 1 to 3 inches with locally higher amounts. QPF amounts across the Middle/Upper Mississippi Valley/Great Lakes region will likely be closer to the 1 to 2 inch range, although FFG will remain lower due to recent rains and snowmelt, thus keeping an elevate threat for locally heavy rain and flooding concerns. The Marginal Risk are spans from eastern Texas to northern Michigan. Campbell Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!5EI4RMnlVBzgyz7YyXJUHxHHd3nIfREnVgRWAyfdeQwh= 91dyyz7sbchVjwEXYhkEOnpR0VAMk_g1hUAlolhKv2c0zYQ$=20 Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!5EI4RMnlVBzgyz7YyXJUHxHHd3nIfREnVgRWAyfdeQwh= 91dyyz7sbchVjwEXYhkEOnpR0VAMk_g1hUAlolhKv_p72oM$=20 Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!5EI4RMnlVBzgyz7YyXJUHxHHd3nIfREnVgRWAyfdeQwh= 91dyyz7sbchVjwEXYhkEOnpR0VAMk_g1hUAlolhKuWnb1vI$=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) .