Subj : HVYRAIN: Excessive Rainfall Discussion To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Tue Apr 23 2024 00:03:17 FOUS30 KWBC 230003 QPFERD Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 803 PM EDT Mon Apr 22 2024 Day 1 Valid 01Z Tue Apr 23 2024 - 12Z Tue Apr 23 2024 The probability of rainfall exceeding flash flood guidance is less than 5 percent. Orrison Day 2 Valid 12Z Tue Apr 23 2024 - 12Z Wed Apr 24 2024 The probability of rainfall exceeding flash flood guidance is less than 5 percent. Roth/Kleebauer Day 3 Valid 12Z Wed Apr 24 2024 - 12Z Thu Apr 25 2024 The probability of rainfall exceeding flash flood guidance is less than 5 percent. ....In and near OK... Guidance continues to show an area of convective development across central and eastern OK within a low-level convergence field associated with a stalled boundary over the southern plains north of the Red River. Modest instability located over the region due to active return flow regime will aid in the convective pattern and create an environment capable of low-end flash flooding concerns, especially within any training cells within the confines of the stalled front. All guidance, to some degree has a QPF maximum focused between north-central OK over into the Lower Mississippi Valley which correlates well with recent ML guidance placement, as well as CIPS historical analogs within a similar synoptic evolution. The conundrum becomes a two fold issue of QPF magnitude, as well as agreement within the deterministic on where the best threat will lie. Spread within the latest NBM and GFS/ECMWF ensemble suites remains high with the lower and upper quartile outputs a solid 1-1.5" apart with a slightly higher skewed mean closer to the 75th percentile. This lends credence to potentially a MRGL risk implementation in later forecasts, but there was not enough consensus to warrant an upgrade at this time when factoring in higher FFG indices in place over the areas in question. Considering the setup, this is likely a better case of short term upgrades in the D1/2 periods as CAMs enter the equation and can provide some answers on the convective placement, and QPF footprint when incorporating hi- res ensembles. Have maintained the nil forecast as a result. Kleebauer Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!8SuPVvvxMgeIvzM2Fd_gsgUgNMxnOXFOYnptHgUVkkPm= 7v4ZQQQcvkGuah1hhI80AcTEmHq0KyMx-jbc4KPh_xFuipk$=20 Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!8SuPVvvxMgeIvzM2Fd_gsgUgNMxnOXFOYnptHgUVkkPm= 7v4ZQQQcvkGuah1hhI80AcTEmHq0KyMx-jbc4KPhQ31XEmg$=20 Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!8SuPVvvxMgeIvzM2Fd_gsgUgNMxnOXFOYnptHgUVkkPm= 7v4ZQQQcvkGuah1hhI80AcTEmHq0KyMx-jbc4KPhi0x9N8k$=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) .