BBS: TELESC.NET.BR Assunto: HVYRAIN: Excessive Rainfall Discussion De: COD Weather Processor Data: Fri, 8 May 2026 00:23:01 +0000 ----------------------------------------------------------- FOUS30 KWBC 080022 QPFERD Excessive Rainfall Discussion NWS Weather Prediction Center College Park MD 822 PM EDT Thu May 7 2026 Day 1 Valid 01Z Fri May 08 2026 - 12Z Fri May 08 2026 The probability of rainfall exceeding flash flood guidance is less than 5 percent. Orrison Day 2 Valid 12Z Fri May 08 2026 - 12Z Sat May 09 2026 ...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL FROM SOUTH TEXAS GULF COAST THROUGH THE LOWER MISSISSIPPI VALLEY... The synoptic pattern on Friday will characterized by the return of deep moisture as a previously stalled front, lingering along the Gulf Coast begins to lift northward as a warm front. Near the front, PWs are forecast to approach 1.8-2 inches (near the 99th climatological percentile) from South Texas through the lower Mississippi Valley, providing an ample reservoir for heavy rainfall. This moisture, along with an upper level low moving into West Texas and downstream shortwave are expected to support numerous showers and storms with the potential for heavy rates. However, the exact placement of the heaviest rainfall within the broad QPF footprint on Friday remains nebulous, with several separate rounds of thunderstorms possible throughout the Day 2 period. When considered with high 1-3 hour FFGs across much of the region, the Marginal Risk was left intact for this cycle. An embedded Slight Risk remains possible in subsequent updates should a focused signal for heavy rainfall emerge over a more sensitive area. Asherman/Pereira Day 3 Valid 12Z Sat May 09 2026 - 12Z Sun May 10 2026 ...THERE IS A MARGINAL RISK OF EXCESSIVE RAINFALL ACROSS PARTS OF THE LOWER MISSISSIPPI VALLEY AND THE CENTRAL GULF COAST... The previously noted upper-level low moving across Texas on Day 2 will continue to eject eastward toward the central Gulf Coast -- de-amplifying as embeds within the base of a broad upper-trough centered over the Upper Great Lakes. Deep moisture lingering ahead of the wave and associated stationary front will fuel shower and storm development capable of producing heavy rainfall. Similar to Day 2, however, confidence was lacking for any upgrades beyond a Marginal Risk within the broad precipitation footprint. However, should the models start to move into better agreement, an upgrade may be warranted in future updates -- especially if the guidance begins to show a growing signal for heavy amounts across areas impacted by recent heavy rains. For now, modest adjustments were made to the Marginal Risk area to account for the potential overlap of heavy rainfall in portions of central AL. Asherman/Pereira Day 1 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/94epoints.txt__;!!DZ3fjg!8fMT3VsE0X_Q4j7tRgLbNJUzMLJ3YUlOYbOnPJzPGC6Z= XfjVIoSnAm8JBaAJS311_UcrAhzd5xNNvINSGbkO0ZXruPg$=20 Day 2 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/98epoints.txt__;!!DZ3fjg!8fMT3VsE0X_Q4j7tRgLbNJUzMLJ3YUlOYbOnPJzPGC6Z= XfjVIoSnAm8JBaAJS311_UcrAhzd5xNNvINSGbkO92mBzg8$=20 Day 3 threat area: https://urldefense.com/v3/__https://www.wpc.ncep.noaa.go= v/qpf/99epoints.txt__;!!DZ3fjg!8fMT3VsE0X_Q4j7tRgLbNJUzMLJ3YUlOYbOnPJzPGC6Z= XfjVIoSnAm8JBaAJS311_UcrAhzd5xNNvINSGbkOag_bij0$=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]