SPC 0700Z Day 2 Outlook
Day 2 Convective Outlook NWS Storm Prediction Center Norman OK 1253 AM CST Wed Dec 31 2025 Valid 011200Z - 021200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS IN COASTAL SOUTHERN CA... ...SUMMARY... Locally damaging winds and a brief tornado are possible along a portion of coastal southern California on New Year's Day morning. ...CA and the Southwest... Guidance continues a decidedly northward trend to the evolution of the compact shortwave trough, currently west of southern CA. Latest indications are for this wave to reach the San Joaquin Valley around midday Thursday, before slightly dampening over the southern Great Basin. Thunderstorm potential appears greatest on Thursday morning with isolated to scattered thunderstorms possible across southern CA. Despite the early time of day, activity along the coast should be surface-based along the periphery of low 60s dew points. Buoyancy/instability will remain meager, given the expected northerly track of the wave and attendant mesoscale cold core displaced from the richer moisture plume. But guidance is consistent with the depiction of 40-50 kt 700-mb flow across the Transverse Ranges through midday. With some low-level hodograph curvature and several CAMs suggestive of at least one rotating cell in the LA Basin vicinity, have opted to include a small level 1-MRGL risk for wind and tornado. Confidence remains low in the degree of thunderstorm potential farther north and east. Lower-level moisture east of CA should be greater across AZ, but this may remain displaced too far south of the latest consensus for the mid-level cold core. It is plausible that much of the convection from the Central Valley to AZ will remain low-topped, with thunderstorm probabilities around 10 percent or less. ..Grams.. 12/31/2025
