BBS: TELESC.NET.BR Assunto: HVYRAIN: Excessive Rainfall Discussion De: COD Weather Processor Data: Thu, 26 Mar 2026 15:50:06 +0000 ----------------------------------------------------------- FOUS30 KWBC 261549 QPFERD Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 1149 AM EDT Thu Mar 26 2026 Day 1 Valid 16Z Thu Mar 26 2026 - 12Z Fri Mar 27 2026 ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL FOR PORTIONS OF=20 OHIO THROUGH NORTHERN WEST VIRGINIA AND WESTERN PENNSYLVANIA... ...16Z Outlook Update... 12Z guidance depicts banding of elevated convection generally=20 along an axis from northern/central Ohio to western Pennsylvania.=20 While predicting specific locations of this axis(es) is a=20 challenge at this timeframe (several hours out from convective=20 initiation), some risk of flash flood guidance exceedence will=20 exist - most likely where the recently added Slight Risk was drawn. Locally sensitive terrain exists in this region, and 3-hour FFGs=20 thresholds are in the 1-2 inch range, supportive of the increase in FFG exceedence probabilities. The remainder of the outlook is on track, with a broad Marginal Risk area extending from Illinois to southern New York state. See the previous discussion below for more information. Cook ...Previous Discussion... A strong cold front tracking south out of the Great Lakes and Canada will provide the primary forcing for a line consisting of several segments of severe thunderstorms this evening through the overnight period. Working against flash flooding remains the very fast movement of any individual cells of heavy rain, the progressive southward movement of the cold front, average soil moisture (which usually can stand to soak in lots of rain before the rest converts to runoff), and average PWATs (around 1.25 inches) and instability (between 1,000 and 1,500 J/kg of MUCAPE). Working for flash flooding is the several urban areas which locally lower FFGs and have more flood-prone areas, good potential for training storms, and into portions of southwest Pennsylvania, upslope potential against the mountains. Into Illinois, ongoing slow moving showers and storms are locally saturating soils in east-central portions of the state and into western Indiana. Rainfall forecast amounts have increased a bit across Ohio and southwest Pennsylvania. This moves the threat up into the higher- end Marginal risk category (10-15% chance of exceeding Flash Flood Guidance). Thus, any further increases in the rainfall amounts may require a targeted Slight later today anywhere from Illinois to southwest Pennsylvania, generally along I-70. Wegman Day 2 Valid 12Z Fri Mar 27 2026 - 12Z Sat Mar 28 2026 The probability of rainfall exceeding flash flood guidance is less than 5 percent. Wegman Day 3 Valid 12Z Sat Mar 28 2026 - 12Z Sun Mar 29 2026 The probability of rainfall exceeding flash flood guidance is less than 5 percent. Wegman Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!8k1ezYaW4yWVFMwjU0xKMVOkVW6qxkM0XZlmALsaL3u7= Is4VepdMpAgA9jdQJ_BehD2Ck1X1QA0IN4wVkcqYRYoSC04$=20 Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!8k1ezYaW4yWVFMwjU0xKMVOkVW6qxkM0XZlmALsaL3u7= Is4VepdMpAgA9jdQJ_BehD2Ck1X1QA0IN4wVkcqY75DqZA4$=20 Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!8k1ezYaW4yWVFMwjU0xKMVOkVW6qxkM0XZlmALsaL3u7= Is4VepdMpAgA9jdQJ_BehD2Ck1X1QA0IN4wVkcqYAGAm7zE$=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]