SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0650 AM CST Sat Dec 21 2024 Valid 211300Z - 221200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Isolated thunderstorms are possible this morning into early afternoon across parts of coastal Oregon and northern California. ...Coastal OR/northern CA... A potent mid to upper-level shortwave trough will move ashore the northern CA/OR coast and continue northeastward into the southern Canadian Rockies/northern Rockies vicinity through late tonight. Weak thunderstorm activity embedded within a warm-air advection rain shield will continue moving into the coastal range mountains this morning before outrunning the inland penetration of scant instability. The corridor of thunderstorms will probably shift north along the coast into OR by midday into the early afternoon in association with the mid-level cold pocket encroaching on the OR coast. Elsewhere, quiescent weather or stable conditions will preclude thunderstorm development over the remainder of the contiguous United States. ..Smith/Goss.. 12/21/2024