Subj : HVYRAIN: Excessive Rainfall Discussion To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Mon Apr 14 2025 19:12:27 FOUS30 KWBC 141912 QPFERD Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 312 PM EDT Mon Apr 14 2025 Day 1 Valid 16Z Mon Apr 14 2025 - 12Z Tue Apr 15 2025 ....THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF WEST VIRGINIA, SOUTHERN OHIO, AND EASTERN KENTUCKY... Based on latest model guidance, the Marginal Risk area has been expanded to include most of West Virginia and portions of southern Ohio and eastern Kentucky. The CAMs continue to show the potential for training this afternoon and evening as an ENE-WSW oriented cold front moves through the region with easterly storm motion. This could result in localized QPF values reaching up to 1.5-2.5+ inches. Additionally, the ingredients will be in place for stronger storms to produce rainfall rates greater than 1 inch per hour, with an axis of high moisture ahead of the front with PWAT values 1.25-1.5 inches and MLCAPE greater than 1000 J/Kg. Given recent rainfall and saturated soils, FFGs are quite low in this region, and there is a chance they could be exceeded, leading to isolated to scattered flash flooding concerns. Dolan Day 2 Valid 12Z Tue Apr 15 2025 - 12Z Wed Apr 16 2025 The probability of rainfall exceeding flash flood guidance is less than 5 percent. Dolan Day 3 Valid 12Z Wed Apr 16 2025 - 12Z Thu Apr 17 2025 ....THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF NORTHERN CALIFORNIA AND WESTERN NEVADA... An upper level low is forecast to slowly drift east towards the=20 California Coast on Wednesday, which will result in decreasing=20 heights and cooling upper levels over California and Nevada.=20 Instability will increase across this region as lapse rates=20 steepen, and there will likely be enough large scale ascent to=20 support showers and thunderstorms across portions of northern=20 California and the Sierra Nevada. PWATs are expected to increase=20 ahead of the low, reaching 2+ standard deviations above normal with values up to 0.75-1 inches in some locations. There should be=20 enough moisture and instability for locally moderate to heavy=20 rainfall in thunderstorms, which supports a Marginal risk area. The dominant precipitation type will be rain, but some precipitation=20 is expected to fall as snow in the Sierra Nevada, mainly above 8000 ft with the best snow potential above 10000 ft. Snow melt could=20 contribute to flooding concerns where rain falls on top of snow,=20 but this should have limited impacts. Some rain may make it east of the Sierra into western Nevada, but there is uncertainty as to how much.=20 Dolan Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!-FKF_ZXIcyFJo3xeJKBAZju2qRW1PxV85MWdjRjc2naJ= ixeUBDpyCsoMvUwoft-e0ACthmYiaW0PBc5WCaGc6Dla084$=20 Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!-FKF_ZXIcyFJo3xeJKBAZju2qRW1PxV85MWdjRjc2naJ= ixeUBDpyCsoMvUwoft-e0ACthmYiaW0PBc5WCaGcbQwywgQ$=20 Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!-FKF_ZXIcyFJo3xeJKBAZju2qRW1PxV85MWdjRjc2naJ= ixeUBDpyCsoMvUwoft-e0ACthmYiaW0PBc5WCaGcFmMGpU0$=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) .