SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1120 PM CST Fri Dec 19 2025 Valid 201200Z - 211200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated lightning flashes may occur near coastal sections of Washington today. ...Synopsis... A mid-level trough will progress across the eastern CONUS while upper ridging builds west of the Rockies, resulting in surface high pressure overspreading the Midwest as a surface trough impinges on the Pacific Northwest Coastline. Cooler temperatures aloft will overspread a marine boundary layer over the Washington coast, resulting in scant buoyancy, which may favor a few convective updrafts that may deepen enough to produce isolated lightning flashes. A weakening surface low will also drift southward across the southern Plains, promoting low-level moisture return inland from the western Gulf. However, considerable convective inhibition should limit convective development through the Day 1 period. ..Squitieri.. 12/20/2025
