Upper-Level Ridge Fuels Warming on Central Coast; Morning Drizzle Possible in Far North

Overview

• Meteorologist Jim Castillo says a rebuilding upper-level high is starting a multi-day warming trend across San Luis Obispo and Santa Barbara counties, with a cloudy start and a slight chance of early-morning drizzle in extreme northern San Luis Obispo County.
• Daytime highs are expected in the 60s near the coast now with overnight lows in the mid-to-upper 40s and inland valleys capable of reaching the low 80s as the warming strengthens.
• Model guidance shows increasing offshore northeasterly gradients later in the week that could push highs into the upper 70s to low 80s even along the immediate coast while lowering relative humidity.
• Forecast uncertainty centers on wind gust strength because mid-level wind support is currently light and gusts will depend on the pressure gradient between the Great Basin and the Central Coast, especially on exposed ridges in the Los Padres National Forest.
• Local factors will modulate conditions: air sinking down the Santa Lucia and Santa Ynez ranges causes compressional heating while mountain radiational cooling keeps inland nights cool and offshore flow tends to suppress the low-level marine stratus.