SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 1130 PM CST Wed Dec 31 2025 Valid 011200Z - 021200Z ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF SOUTHERN COASTAL CALIFORNIA... ...SUMMARY... Locally damaging winds, and a perhaps a brief weak tornado, could occur along a portion of coastal southern California. ...Southern CA... Latest water-vapor imagery depicts a well-defined upper low about 300 mi WSW of Lompoc CA ejecting ENE in line with latest model guidance. This feature is forecast to shift inland as a 500mb speed max translates across the Channel Islands toward southern NV by early evening. Left-exit region of this jet will overspread the southern interior valley with seasonally cool 500mb temperatures noted north of the jet. Even so, forecast instability is expected to remain weak as MUCAPE values should remain generally less than a few hundred J/kg. Midlevel lapse rates are also not expected to be particularly steep and this is reflected in the sparsity of lightning currently noted with convection beneath the offshore low. Latest thinking is scattered weak convection will be the primary concern with the frontal zone early in the period, and much of this activity may struggle to generate lightning despite the maritime influences that will prove instrumental for this activity. While some risk for gusty winds, and perhaps a brief weak tornado exists, the majority of convection will remain sub severe. ..Darrow/Squitieri.. 01/01/2026
