Day 4-8 Outlook
Day 4-8 Convective Outlook NWS Storm Prediction Center Norman OK 0328 AM CDT Mon Sep 29 2025 Valid 021200Z - 071200Z ...DISCUSSION... Latest model output is not much different from prior runs concerning the continuation of generally low convective potential across the U.S. into and through the medium-range period. Guidance continues to suggest that an increasingly amplified regime across the mid-latitude eastern Pacific into western North America could lead to the evolution of a prominent blocking pattern late this week into next weekend. By early next week, this may include a building mid-level high over the northeastern Pacific, near the British Columbia/Pacific Northwest coast, flanked by a pair of evolving lows at somewhat lower latitudes, including one over the U.S. Intermountain West. Otherwise, the stronger westerlies may retreat to somewhat higher latitudes, and mid/upper ridging may build in the southern mid- to subtropical latitudes east of the Rockies and Mexican Plateau. Significant surface cyclogenesis still appears unlikely to the east of the U.S. Rockies, and low-level moisture return off the Gulf Basin may be slow to develop.
