Unsettled Wednesday Weather

Light rain is currently approaching the North Bay and will arrive by Wednesday morning, while a historic, record-deep 5,200-foot marine layer continues to trap an unseasonably cold, fall-like air mass over Northern California. Wednesday Morning Arrival: Light rain and pre-frontal coastal drizzle will push inland overnight and blanket the North Bay by tomorrow morning. The Second Wave (Wednesday Night – Thursday): A secondary weather disturbance will slam into the coast from the northwest tomorrow night, increasing light rain potential across the broader Bay Area by Thursday morning. Projected Rainfall Totals: North Bay Coastal Ranges: The highest terrain will see the heaviest totals, easily cracking 0.25 inches. Santa Rosa & Sonoma Valleys: Widespread beneficial wetting rain will total around 0.10 inches. San Francisco & South Bay: Rainfall amounts drastically drop off the further south you go, limiting impacts to patchy coastal drizzle. "Rare" Marine Depth: Evening weather balloons measured the marine layer at a staggering 5,200 feet deep. This deep moisture blanket is causing unusual cumulus clouds to pop up inside the fog deck, and will likely create a rare "double inversion" weather pattern tonight.