
Day 4-8 Outlook

Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0356 AM CDT Sun Mar 16 2025 Valid 191200Z - 241200Z ...DISCUSSION... ...Wednesday/Day 4 to Friday/Day 6... A mid-level trough is forecast to move northeastward into the upper Mississippi Valley on Wednesday. Ahead of the trough, a narrow axis of moisture and weak instability is forecast from the western Great Lakes into the lower Ohio Valley. This corridor of low-level moisture will be the favored location for convective development Wednesday afternoon. Surface dewpoints along the moist axis are only expected to be in the 40s to lower 50s F. In spite of this, the exit region of the mid-level jet is forecast to overspread the region during the mid to late afternoon. This will provide strong lift and deep-layer shear, sufficient for an isolated severe threat. Any severe threat should remain marginal. On Thursday, the trough is forecast move eastward through the Ohio and Tennessee Valleys, as a cold front advances to near the Atlantic Seaboard, from the eastern Carolinas into the Mid-Atlantic. Isolated severe storms will again be possible along or ahead of the front during the mid to late afternoon, but any threat is expected to be marginal. On Friday, a mid-level trough is forecast to move eastward into the central states, where isolated convection will be possible. However, moisture return is expected to be confined to the Texas Coastal Plain, which will be a severe threat limiting factor. ...Saturday/Day 7 and Sunday/Day 8... On Saturday, the trough is forecast to de-amplify and move into the northeastern U.S. as a broad low-amplitude cyclonic flow pattern develops over much of the U.S. Moisture return is expected to take place over the western Gulf Coast on Saturday and across the southern Plains on Sunday. Some models suggest that a trough will take shape in the Great Plains on Sunday, with a cluster of storms forming ahead of the system Sunday afternoon. These storms would develop along the northern edge of the stronger instability from Oklahoma into Arkansas, expanding Sunday evening across the lower to mid Mississippi Valley. If this scenario where to verify, then a severe threat would be possible with the stronger storms within the MCS. However, at this extended range, the magnitude and spatial extent of any severe threat remains considerably uncertain.