Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0354 AM CST Wed Feb 26 2025 Valid 011200Z - 061200Z ...DISCUSSION... Severe weather potential will be low to start the period with northerly flow across the Gulf on D4/Saturday. On D5/Sunday, a compact mid-level low will translate east across the Southwest which will result in lee cyclogenesis in the southern/central High Plains. As surface high pressure across the Midwest translates east, favorable low-level trajectories and strengthening flow across the Gulf and southern Plains will initiate significant moisture return across Texas. The initial mid-level low will weaken as it moves across the Plains and into the Mid-Mississippi Valley on D6/Monday. However, lee cyclogenesis will likely strengthen Monday afternoon as a larger scale trough approaches the southern Plains. Shortwave ridging will likely keep the dryline capped on Monday with continued moistening beneath the capping inversion as low-level moisture advection continues. ...D7/Tue - East Texas into the Mid/Lower Mississippi Valley... By 12Z Tuesday, moisture recovery across the western Gulf should be complete with 70F dewpoints forecast by both GFS and ECMWF ensembles. Aloft however, there is significant disagreement regarding the amplitude of the larger scale wave on Tuesday. The less amplified GFS seems to be the outlier, with a more amplified solution preferred by most other extended range guidance. However, even the GFS would pose a severe weather threat across parts of East Texas into the Mid-Lower Mississippi Valley. The inherent uncertainty in a Day 7 forecast and the modest spread regarding the mid-level trough evolution make specific factors such as severe hazards and storm mode nebulous at this time. However, there is enough confidence in at least mid-60s dewpoints well inland with an ejecting large scale trough, to introduce broad 15% severe weather probabilities on D7/Tuesday from East Texas to the Mid-Mississippi Valley region. ...D8/Wed - Carolinas into the Southeast... Some severe weather threat will likely exist on Wednesday ahead of a squall line that may be ongoing along or ahead of the cold front. Uncertainties in the mid-level pattern on Tue/D7 will be further exacerbated on Day 8. In addition, it is unclear whether full moisture recovery will occur across the eastern Gulf ahead of the cold frontal passage. This will have significant implications on the moisture quality ahead of the front on Wed/D8 and thus the instability available.
