SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook NWS Storm Prediction Center Norman OK 0127 PM CST Mon Dec 22 2025 Valid 241200Z - 251200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS MUCH OF COASTAL CALIFORNIA AND PORTIONS OF THE CENTRAL VALLEY... ...SUMMARY... Isolated strong to occasionally severe thunderstorms are possible on Wednesday and Wednesday night across portions of California. ...Synopsis... A pronounced upper ridge will remain anchored over the central and eastern US while strong troughing persists over the West Coast. A series of embedded impulses will move onshore Wednesday and Wednesday night, coincident with their attendant deepening surface lows. A cold front and persistent southwesterly low-level flow should support isolated thunderstorms over much of the West Coast through early Thursday. ...California... As troughing deepens over the eastern Pacific, several embedded disturbances will propagate eastward overspreading modest low-level moisture from the CA coast to the central valley. Robust forcing for ascent and cold temperatures aloft (-24 to -26 C) overspreading 50s F dewpoints will likely support weak buoyancy along the southern CA coast and central Valley. A prolonged period of scattered showers and episodic periods of isolated thunderstorms are possible Wednesday morning and afternoon. Of these storms, sufficient CAPE, strong flow aloft and locally enlarged hodographs may allow for a few semi-organized/weakly rotating storms to mature. Sporadic damaging gusts, small hail and a brief tornado would be possible with the strongest storms before convection weakens into the evening and first part of the overnight hours. Additional low-topped linear storms/localized squalls are also possible ahead of the advancing cold front near the immediate coastal portions of central and northern CA primarily late Wednesday into Wednesday night. A few strong gusts are possible, though instability should quickly decrease inland. Elsewhere across the US, the prominent ridging will favor dry and unseasonably warm conditions with little potential for thunderstorms. ..Lyons.. 12/22/2025
