Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0142 AM CST Tue Dec 09 2025 Valid 111200Z - 121200Z ...NO THUNDERSTORM AREAS FORECAST... ...SUMMARY... The risk for thunderstorms appears negligible across the U.S. Thursday through Thursday night. ...Discussion... Downstream of an increasingly prominent, blocking high building near and to the north of the Aleutians during this period, models indicate that strong flow will take on an increasing northwesterly component across southern British Columbia and adjacent portions of the Pacific Northwest into portions of the Canadian Prairies and northern U.S. Great Plains. It appears that a significant short wave trough near the leading edge of this regime will begin to reinforce broad mid-level troughing extending downstream into the western Atlantic. While mid-level flow is likely to remain cyclonic as far south as the Gulf Coast states into the southern mid- to subtropical latitudes of the western Atlantic, heights across the south are forecast to begin to rise, as a prominent perturbation accelerates rapidly east-northeast of the lower Great Lakes region through the Canadian Maritimes. The primary surface front, trailing an evolving cyclone across the Canadian Maritimes, may stall across the southern Atlantic coast through Tennessee Valley, while progressing slowly southward through the lower Missouri Valley and central Great Plains by late Thursday night, in advance of much colder air beginning to nose southward to the lee of the Canadian/northern U.S. Rockies. As a remnant preceding front becomes more diffuse across the central through northwestern Gulf Basin, Gulf boundary-layer modification may gradually continue, as a weak southerly return flow begins to develop across the Texas coast. However, beneath relatively warm and dry lower/mid-levels, it does not appears that this will contribute to appreciable destabilization during this period. ..Kerr.. 12/09/2025Read more
