Subj : HVYRAIN: Excessive Rainfall Discussion To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sat Apr 08 2023 08:22:25 FOUS30 KWBC 080822 QPFERD Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 421 AM EDT Sat Apr 08 2023 Day 1 Valid 12Z Sat Apr 08 2023 - 12Z Sun Apr 09 2023 ....THERE IS A MARGINAL RISK FOR EXCESSIVE RAINFALL FROM THE CENTRAL GULF COAST TO THE CENTRAL CAROLINAS... The potential for excessive rainfall lingered across parts of the Gulf Coast this morning as an area of showers and thunderstorms continued to make its way east in association with a broad mid- and upper-level trough. It appears that the back-edge of the area of rainfall will still be lingering over portions of Mississippi at the beginning of the Day 1 period...so adjusted the position a bit westward from where it was depicted as yesterday's Day 2 Excessive Rainfall Outlook. Despite some reports of 1+ inch per hour rates still being reported during the overnight hours...much of the instability to support intense rainfall rates has been shunted off-shore ahead of a cold front. Considering that a surge of instability back into the region is not expected...opted to maintain the outlook area as a Marginal with the expectation that any flooding concerns would be confined to urban areas and regions of poor drainage. Focus then shifts into the Carolinas where latest numerical guidance was consistent with previous runs showing some 2 to 2.5 inch rainfall amounts in the Day 1 period.=20 Felt a Marginal was still adequate here given the prolonged period during which that amount of rain falls...implying that any flooding would be more urban and/or areal flooding in nature and less flash flooding. In addition...the 40 km neighborhood probabilities did not indicate even low probabilities for rainfall rates of 1 inch per hour or greater in the area of greatest QPF.=20 Latest guidance suggests most of the rain should be pushing off the Carolina coast line very late in the period. And the latest suite of CAM guidance still supported the idea that thunderstorms over northern Florida may produce rainfall rates at or even slightly greater than 0.5 inch per hour between 20Z and 01Z...so did not make any changes there. Bann Day 2 The Day 2 outlook will be updated by 0830Z. 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!4xXb3dgj6WZnj0Ium2lYEEddJ61damsqnPW-y0we00ox= 9woylDkuJQbaT8LjZ14mmFu5Xa6xCUHnsqJ-D4V3IShFav4$=20 Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!4xXb3dgj6WZnj0Ium2lYEEddJ61damsqnPW-y0we00ox= 9woylDkuJQbaT8LjZ14mmFu5Xa6xCUHnsqJ-D4V3M0jy8aY$=20 Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!4xXb3dgj6WZnj0Ium2lYEEddJ61damsqnPW-y0we00ox= 9woylDkuJQbaT8LjZ14mmFu5Xa6xCUHnsqJ-D4V3_2oYwvw$=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) .