BBS: TELESC.NET.BR Assunto: DAY48SVR: Nws Storm Prediction Center Norman Ok De: COD Weather Processor Data: Fri, 27 Mar 2026 08:55:31 +0000 ----------------------------------------------------------- ACUS48 KWNS 270855 SWOD48 SPC AC 270853 Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0353 AM CDT Fri Mar 27 2026 Valid 301200Z - 041200Z ...DISCUSSION... An uptick in severe thunderstorm potential is expected through the upcoming work week and heading into next weekend. Long-range ensemble guidance continues to show a strong signal for a return to mean troughing across the western to central CONUS as a long-wave ridge gradually de-amplifies and shifts east. This upper-level flow regime will promote steady lee troughing/cyclogenesis along the High Plains, which in conjunction with the placement of a surface high off the East Coast, will promote moisture return northward into the Plains and MS Valley. Strong to severe thunderstorms appear possible multiple days next week as ascent associated with upper disturbances embedded within the mean flow regime overspread the moisture plume. ...D4/Monday - Upper Mississippi Valley... A low-amplitude upper wave is forecast to traverse the U.S./Canadian border during the D4/Monday to D5/Tuesday time frame. As this occurs, surface cyclogenesis is expected across the northern Plains. A broad swath of isentropic ascent with in the warm conveyor of the developing cyclone will likely support showers and isolated to scattered thunderstorms across portions of the upper MS Valley late Monday. A few deterministic solutions, notably the recent 00z ECMWF, hint that the convective environment will be conducive for organized convection, including the potential for elevated supercells. However, ensemble agreement regarding this potential is limited. ...D5/Tuesday - Lake Michigan Vicinity... Confidence is gradually increasing in a regional severe weather threat across parts of the upper Great Lakes for D5/Tuesday. Over the past 24 hours, model guidance has come into somewhat better agreement regarding the timing and evolution of the northern Plains surface low through as it translates east and intensifies across the Great Lakes region Tuesday into early Wednesday. Above-seasonal moisture return northward into the Great Lakes region is anticipated by late Tuesday, which should support adequate buoyancy for deep convection. Thunderstorm development appears likely along a trailing cold front as it pushes southeast into the Midwest and MS Valley. Based on ensemble guidance, the best convective environment may reside across the Lake Michigan vicinity where mid/upper-level flow should be stronger in vicinity to the upper jet and may be more orthogonal to the front and supportive of more robust convection compared to locations further south. Despite the trend towards a more consolidated solution, notable discrepancies remain pertaining to the propagation speed of the upper wave and surface low, which introduces uncertainty in how favorably timed the strongest ascent will be with peak heating/destabilization and potential storm modes. These uncertainties preclude probabilities at this time, but highlights will likely be introduced as model consensus improves. ..Moore.. 03/27/2026 = = = 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]