Subj : HVYRAIN: Excessive Rainfall Discussion To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun Mar 10 2024 15:39:50 FOUS30 KWBC 101539 QPFERD Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 1139 AM EDT Sun Mar 10 2024 Day 1 Valid 16Z Sun Mar 10 2024 - 12Z Mon Mar 11 2024 ....THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF COASTAL MAINE... ....16Z Update... No changes were made to the inherited forecast. Steady rainfall continues to push into coastal Maine, changing over to snow in the interior of the state, with the dry slot evident on radar across far southwestern coastal Maine, including Portland. The dry slot will be the end of any steady rainfall, as colder, drier air moves in. The rain will end from west to east through the day today, ending the excessive rainfall threat accordingly. Much of the high-resolution model data suggest the steadiest rain will exit far eastern Maine between 20-22Z (4-6pm). A special update to remove the Marginal is planned to be issued around that time, assuming the weather follows recent guidance trends. In the meantime, reports of thunderstorms and locally heavy rainfall to 1 inch per hour requires the continuance of the Marginal into the afternoon. Wegman ....Previous Discussion... Continued trend of recent EROs in trimming the western boundary of the Marginal Risk area along and near coastal Maine given persistent signals from the latest suite of QPF guidance. Areal average rainfall within the Marginal was on the order of 1 to 1.25 inches...enough that there could be isolated problems from flooding/ponding given the antecedent conditions over the past few weeks. Used deterministic snowfall amounts from WPC's winter weather desk to minimize the overlap of the ERO with snow areas.=20 Conditions generally improving from west to east later today and this evening. Bann Day 2 Valid 12Z Mon Mar 11 2024 - 12Z Tue Mar 12 2024 The probability of rainfall exceeding flash flood guidance is less than 5 percent. Bann Day 3 Valid 12Z Tue Mar 12 2024 - 12Z Wed Mar 13 2024 The probability of rainfall exceeding flash flood guidance is less than 5 percent. Bann Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!4mN9KrtYG-HhxzY3Wz1U-qkpjZFWQNGt_srMMAE2FTpB= 02_TVv3itS3gxGICSKGAkVReM3Nnz_zCMEJ9IXlWt5RgiT8$=20 Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!4mN9KrtYG-HhxzY3Wz1U-qkpjZFWQNGt_srMMAE2FTpB= 02_TVv3itS3gxGICSKGAkVReM3Nnz_zCMEJ9IXlWwYG3Vys$=20 Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!4mN9KrtYG-HhxzY3Wz1U-qkpjZFWQNGt_srMMAE2FTpB= 02_TVv3itS3gxGICSKGAkVReM3Nnz_zCMEJ9IXlWGXI62RQ$=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) .