BBS: TELESC.NET.BR Assunto: HVYRAIN: Excessive Rainfall Discussion De: COD Weather Processor Data: Sat, 28 Mar 2026 08:09:28 +0000 ----------------------------------------------------------- FOUS30 KWBC 280809 QPFERD Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 409 AM EDT Sat Mar 28 2026 Day 1 Valid 12Z Sat Mar 28 2026 - 12Z Sun Mar 29 2026 The probability of rainfall exceeding flash flood guidance is less than 5 percent. We will keep an eye on south FL, where convection is likely this afternoon into tonight. However, at this time the flash flood risk looks low. Initial convective development along the east coast of FL should move off to the southwest, limiting rainfall rate=20 duration. Additional development this evening into tonight near and post frontal passage should generally stay transient in nature,=20 with a downward trend in CAPE also expected overnight. The 00z HREF and REFS neighborhood probabilities of exceeding 3" are over 50%, but generally focused over inland areas of south=20 FL...and 5" exceedance probabilities from the HREF are zero. For a Marginal risk we would like to see the higher 3" probabilities=20 focused across the coastal urban areas and/or significantly higher=20 5" probabilities. Thus will continue with no risk area. Chenard Day 2 Valid 12Z Sun Mar 29 2026 - 12Z Mon Mar 30 2026 The probability of rainfall exceeding flash flood guidance is less than 5 percent. Additional showers and thunderstorms are expected across southeast=20 FL, with a stream of activity potentially focused near the urban=20 corridor. However, most model instability forecasts are below 1000=20 j/kg, and thus currently not expecting rainfall rates to be high=20 enough for flash flooding, but we will continue to monitor. Chenard Day 3 Valid 12Z Mon Mar 30 2026 - 12Z Tue Mar 31 2026 The probability of rainfall exceeding flash flood guidance is less than 5 percent. There is a non-zero risk for minor urban and small stream flooding across portions of MI, northwest PA and western NY Monday into=20 Monday night. There is a notable increase in instability, with=20 values exceeding 1000 j/kg. This is anomalous for the time of=20 year, especially over portions of MI where the ECMWF EFI for CAPE=20 is over 0.9. Combine this CAPE with above average PWs and strong=20 moisture transport and we would expect there to be a potential for=20 heavy rainfall rates. At the moment, not really seeing enough of a=20 consistent model QPF signal to justify introducing a risk area, but we will have to continue to monitor trends, especially as we move=20 more into the high res model timeframe. Chenard Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!7RFAvq65xuPGXI9r1EOJ_9oJzKUwg_oCUABAVUSaAK8O= snzGwTWJvsFbC_WakouER_6VA57-nSbefodGOA_txQGGt4c$=20 Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!7RFAvq65xuPGXI9r1EOJ_9oJzKUwg_oCUABAVUSaAK8O= snzGwTWJvsFbC_WakouER_6VA57-nSbefodGOA_tycxpj4I$=20 Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!7RFAvq65xuPGXI9r1EOJ_9oJzKUwg_oCUABAVUSaAK8O= snzGwTWJvsFbC_WakouER_6VA57-nSbefodGOA_tUuH9vBc$=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 3.28-Linux * Origin: Capitol City Online (1:2320/107) ----------------------------------------------------------- [Voltar]