Subj : HVYRAIN: Excessive Rainfall Discussion To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Thu Feb 22 2024 08:11:20 FOUS30 KWBC 220811 QPFERD Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 310 AM EST Thu Feb 22 2024 Day 1 Valid 12Z Thu Feb 22 2024 - 12Z Fri Feb 23 2024 ....THERE IS A MARGINAL RISK FOR EXCESSIVE RAINFALL FOR PORTIONS OF THE OHIO VALLEY... During the morning hours there will be areas of heavy rain with embedded thunderstorms positioned north of a a weak warm front within a corridor of weak (<500 J/kg) MUCAPE. As the day progresses a surface low advance eastward with its associated cold front trailing southwest of the low. Aloft a strong upper level jet will be nosing into the region while increasing ascent along its path. Meanwhile precipitable water values are expected to peak in the 1.0 to 1.2 inch range across the Ohio Valley (standardized anomalies of +2) with 850 mb winds exceeding 50 kt at times within the warm sector. This environment could support the potential repeating and training of cells especially across eastern reaches of the Ohio Valley. The latest guidance depicts 1 to 2 inches for areal averages with the higher amounts focusing over eastern Ohio, West Virginia and western Pennsylvania. Peak rainfall rates of 0.5 to 1.5 in/hr. Relatively modest total precipitable water and weak instability (MLCAPE generally less than 500 J/kg, MUCAPE generally less than 1000 J/kg area wide) should limit the potential for a greater flash flood risk. The threat looks to wane in the 00-06Z time frame on Friday as the cold front sweeps through the Ohio and Tennessee Valleys. The Marginal Risk area that was carried over from the previous day issuance was trimmed back on the western bounds to account for the trend of less QPF over southeast Missouri and southern Illinois and was expanded a little further east into western Maryland and western Pennsylvania where there was an uptick in QPF signal. Campbell Day 2 Valid 12Z Fri Feb 23 2024 - 12Z Sat Feb 24 2024 The probability of rainfall exceeding flash flood guidance is less than 5 percent. Campbell 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!8PCiMrpOMcM3O_aY3JeX3Xn8TtGCZqOxHm75SQRwQ8N7= L4QC8-WKguoFiS0Xs94syWObzuVEuADmNR57nJUdEwPeo5o$=20 Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!8PCiMrpOMcM3O_aY3JeX3Xn8TtGCZqOxHm75SQRwQ8N7= L4QC8-WKguoFiS0Xs94syWObzuVEuADmNR57nJUdM2hw6tQ$=20 Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!8PCiMrpOMcM3O_aY3JeX3Xn8TtGCZqOxHm75SQRwQ8N7= L4QC8-WKguoFiS0Xs94syWObzuVEuADmNR57nJUdRvZ9wuc$=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) .