
SPC 1200Z Day 1 Outlook

Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1227 AM CDT Mon Mar 17 2025 Valid 171200Z - 181200Z ...NO SEVERE THUNDERSTORM AREAS FORECAST... ...SUMMARY... Severe thunderstorms are not forecast. ...Discussion... Large-scale pattern has allowed significant offshore flow to develop along the Atlantic/Gulf Coasts as surface ridging settles deep into the Gulf Basin. While a few weak thunderstorms may develop beneath a cold mid-level trough along the Carolina Coast later this afternoon, a dearth of deep convection is expected east of the Rockies during the day1 period. Across the western CONUS, a seasonally strong upper trough will approach the CA Coast this afternoon as a 90kt 500mb speed max translates toward the southern part of the state. Very cold mid-level temperatures will overspread regions north of the jet such that profiles will steepen and weak buoyancy will develop, especially by peak heating. Forecast soundings exhibit a few hundred J/kg SBCAPE across the interior valleys of CA. Given the cold temperatures, stronger updrafts should penetrate levels necessary for lightning discharge. Instability appears inadequate for more than very small hail with this activity. ..Darrow/Moore.. 03/17/2025