BBS: TELESC.NET.BR Assunto: HVYRAIN: Excessive Rainfall Discussion De: COD Weather Processor Data: Tue, 5 May 2026 08:27:47 +0000 ----------------------------------------------------------- FOUS30 KWBC 050827 QPFERD Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 427 AM EDT Tue May 5 2026 Day 1 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 had drawn Gulf moisture into parts=20 of the Plains and then downstream toward the Great Lakes and the=20 Ohio Valley. The resulting showers and thunderstorms today will be=20 able to tap into an atmosphere that generally has 1.5 inch=20 precipitable water or greater extending as far north as Ohio by the overnight hours. The southeastward adjustment of the Marginal Risk area still looks good and spans the placement of the 2 inch=20 contour shown by a handful of ARW-core and NMM-core ensemble=20 members. So few changes were needed and were not made due to a=20 fundamental shift in forecast reasoning. Bann Day 2 Valid 12Z Wed May 06 2026 - 12Z Thu May 07 2026 ...THERE IS A SLIGHT RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF=20 THE INTERIOR SOUTHEAST UNITED STATES... Maintained the slight southward shift of the previously issued Slight Risk area introduced a couple of days ago. The coverage and=20 rainfall intensity should be increasing on Wednesday as a large scale trough over the northern Plains continues to amplify and=20 result in a 140 kt to 160 kt upper level jet over the Tennessee Valley during the latter part of the period. The resulting upper divergence, steepening mid-level lapse rates and increasing=20 moisture and instability should result in convection capable of=20 producing heavy rainfall rates and embedded areas of rainfall=20 amounts of 3 to 5 inches as suggested by the latest run of the=20 RRFS. There is a fairly wide spread in the north/south placement of that heavier axis. As a result...the Slight area was expanded=20 somewhat and tended to cover the greatest overlap of higher QPF and exceedance probabilities. Thinking is that there are some=20 probabilities supportive of a higher-end slight risk embedded=20 within the broader Slight. The continued amplification of the upper trough should keep the convection moving southward with time=20 during the overnight hours.=20 Bann Day 3 Valid 12Z Thu May 07 2026 - 12Z Fri May 08 2026 ...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL OVER PORTIONS OF THE GULF COAST REGION TO THE SOUTHEASTERN UNITED STATES... Showers and thunderstorms along and ahead of a surface cold front will be lingering into Thursday from parts of the Gulf coast region northeastward into parts of Georgia and South Carolina. At this point...rainfall rates look to be decreasing as the better upper=20 level dynamics pull off to the northeast and low level flow becomes directed along...rather than normal...to the front. Maintained a=20 Marginal Risk area where there could be overlap with areas somewhat higher soil moisture content from recent rainfall. Overall the=20 rainfall looks to be more beneficial than not. Bann Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!-IdF5gnciVApUszmOx83FGBBA5QiAkj_sQ4slAufPXOB= W1rUuF-boXTFkQQrIVpcXYvjAXXGE5XVKDHRRLjskdV9Nzs$=20 Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!-IdF5gnciVApUszmOx83FGBBA5QiAkj_sQ4slAufPXOB= W1rUuF-boXTFkQQrIVpcXYvjAXXGE5XVKDHRRLjsXUbFI98$=20 Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!-IdF5gnciVApUszmOx83FGBBA5QiAkj_sQ4slAufPXOB= W1rUuF-boXTFkQQrIVpcXYvjAXXGE5XVKDHRRLjsVfXzMg8$=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]