BBS: TELESC.NET.BR Assunto: DAY48SVR: Nws Storm Prediction Center Norman Ok De: COD Weather Processor Data: Sat, 28 Mar 2026 08:58:07 +0000 ----------------------------------------------------------- ACUS48 KWNS 280858 SWOD48 SPC AC 280856 Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0356 AM CDT Sat Mar 28 2026 Valid 311200Z - 051200Z ...DISCUSSION... A return to a more seasonal upper-level regime will promote strong/severe thunderstorm chances beginning D4/Tuesday and potentially persisting into the upcoming weekend. A well-anticipated upper-level regime shift remains likely late this weekend and into early next week as an upper ridge over the south-central CONUS de-amplifies and shifts east. The return to mean troughing over the West will promote persistent lee troughing and southerly return flow into the Plains and lower MS Valley. Long-range guidance depicts several upper disturbances propagating across the northern and central U.S. through late week, which may each support some risk of strong/severe thunderstorms. ...D4/Tuesday... A low-amplitude upper wave is forecast to traverse the U.S./Canadian border and into the Great Lakes region Monday into Tuesday. Northeastward moisture return ahead of an intensifying surface cyclone and trailing cold front will likely establish a fairly broad warm sector from the Ozarks into the Midwest/Great Lakes region. Thunderstorm development along the cold front is expected by late afternoon with most deterministic and ensemble guidance showing strong QPF signals. Any severe weather threat will likely be focused from central IL northeastward into northern IN/southern MI where deep-layer wind shear will be stronger in proximity to the upper jet and shear vectors should be more orthogonal to the front. While some solutions depict favorable MLCAPE and shear for organized convection (e.g. the 00z GFS), ensemble consensus shows muted probabilities for a highly favorable convective environment (e.g. recent GEFS depicts less than 20% probability for SCP values above 3). This suggests that even though some severe threat will likely materialize, considerable uncertainty remains regarding the quality of the convective environment. ...D5/Wednesday and D6/Thursday... Tuesday's cold front is expected to stall roughly along or south of the OH River by the afternoon of D5/Wednesday. This will maintain a moist warm sector across the southern Plains eastward to the TN Valley. Strong to severe thunderstorm potential may emerge on D5/Wednesday and D6/Thursday as an upper disturbance propagates across the southern Plains and into the OH Valley and supports ascent along and north of the stalled frontal zone. Given the relatively focused nature of the wave and attendant mid-level jet, widespread severe convection seems improbable, though a favorable buoyancy/shear environment is possible in the vicinity of the stalled front each afternoon. ..Moore.. 03/28/2026 = = = 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]