BBS: TELESC.NET.BR Assunto: HVYRAIN: Excessive Rainfall Discussion De: COD Weather Processor Data: Mon, 4 May 2026 15:45:48 +0000 ----------------------------------------------------------- FOUS30 KWBC 041545 QPFERD Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 1145 AM EDT Mon May 4 2026 Day 1 Valid 16Z Mon May 04 2026 - 12Z Tue May 05 2026 The probability of rainfall exceeding flash flood guidance is less than 5 percent. There is a non zero chance that some of the slow moving convection near the immediate coastline may lead to isolated flash=20 flooding/ponding, particularly near urban areas surrounding West Palm Beach. Easterly onshore flow into the afternoon may keep the southeast coast with the potential for locally heavy rainfall. Campbell Day 2 Valid 12Z Tue May 05 2026 - 12Z Wed May 06 2026 ...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF THE MID MISSISSIPPI VALLEY INTO THE OHIO VALLEY... Deep layer southwesterly flow leading into the start of the period will be drawing moisture into parts of the Plains and then downstream toward the Great Lakes and the Ohio Valley. That large scale picture has changed little but subtle run to run difference in the global models and convective allowing models continues to result in minor adjustments to the ERO. A mid- and upper-level trough will be amplifying over the central part of North America and a jet streak forms over the Southwest US and approaches the Plains...the chance for showers and thunderstorms increases along and ahead of a develops surface front. With precipitable water values of 1.75 to 1.9 inches embedded within a broader where precipitable water values of 1.5 to 1.75 are going to be more common...areal average rainfall is expected to be on the order of 1 to 1.25 inches. In general this will be beneficial rain. However there may be isolated areas where rain rates lead to local flash flooding. There was spread between model members with the ARW core favoring a western solution while models with an NMM core favored areas farther east. Given the synoptic pattern and with the support of the global models...the ERO was kept in general along and east of the Mississippi River. Bann Day 3 Valid 12Z Wed May 06 2026 - 12Z Thu May 07 2026 ...THE RE IS A SLIGHT RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF THE INTERIOR SOUTHEAST UNITED STATES... Maintained a Slight Risk of excessive rainfall introduced by the WPC Medium Range desk as shortwave energy drops out of Canada and across much of the central and eastern United States. The coverage and rainfall intensity should be increasing on Wednesday as the best dynamics and the best Gulf moisture coverage with a frontal boundary over the interior portion of the Southeast US. Deterministic QPF tends to cluster in the 1.5 to 3 inch amounts across part of the Tennessee Valley into the southern Appalachians from Wednesday into early Thursday due to the presence of surface dewpoints close to 70 degrees getting drawn northward from the Gulf. Whether or not the convection evolves into line will affect the amount of rainfall and any associated risk of flash flooding. Bann Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!_W2lej0--9OONnTqj1dOGylj1jRDbMygT_SYrNYOnClf= jp-yvf2Pekd8QEEThTnM33b28j8idXIs_AKk79wiQ59Aqy8$=20 Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!_W2lej0--9OONnTqj1dOGylj1jRDbMygT_SYrNYOnClf= jp-yvf2Pekd8QEEThTnM33b28j8idXIs_AKk79wiQvSdRPg$=20 Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!_W2lej0--9OONnTqj1dOGylj1jRDbMygT_SYrNYOnClf= jp-yvf2Pekd8QEEThTnM33b28j8idXIs_AKk79wiHZY-__M$=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]