
Day 4-8 Outlook

Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0350 AM CDT Tue Mar 18 2025 Valid 211200Z - 261200Z ...DISCUSSION... ...Friday/Day 4 to Saturday/Day 5... On Friday and Saturday, a shortwave mid-level trough will move eastward from the Great Plains to the Eastern Seaboard, as a long fetch of west-northwest flow develops over much of the continental U.S. Isolated convection may develop ahead of the trough, but instability will likely be insufficient for a severe threat. In the wake of this system, low-level moisture return will begin along the western Gulf Coast. By Saturday, surface dewpoints are expected to be the upper 50s and lower 60s F over the Texas and Louisiana Coastal Plain. ...Sunday/Day 6 to Tuesday/Day 8.... On Sunday, moisture advection is forecast to increase over eastern parts of the southern Plains into the Ark-La-Tex. A mid-level trough is forecast to move across the central U.S. Ahead of the trough, moderate instability is forecast to develop across much of a moist airmass located from the southeastern third of Texas northeastward into the Ark-La-Tex. On Sunday, thunderstorms with a threat for isolated large hail and severe gusts are expected to develop along the northern edge of the moist sector, with a complex of storms moving southeastward across the Sabine and lower Mississippi Valleys overnight. On Monday and Tuesday, the mid-level trough is forecast to move into the eastern U.S., as a cold front advances southward to near the Gulf Coast. Although isolated storms could develop in the southern Gulf Coast states, limited large-scale ascent is expected to be problematic concerning an organized severe threat.