Overview

• Tuesday morning sees a sharp temperature drop across the Bay Area, with inland highs struggling to reach 70°F and coastal areas remaining in the 50s.
• Dense fog and possible drizzle are forecast for San Francisco and other coastal areas, with patchy fog extending into the North Bay valleys.
• A low-pressure system off the California coast is driving the cooldown, accompanied by humid southerly winds and increased cloud cover.
• Subtropical moisture transported by the system may fuel isolated thunderstorms in the Sierra Nevada and brief showers in parts of the Bay Area, particularly near the South Bay foothills.
• Regional microclimates vary significantly, with cooler, foggy conditions dominating coastal and northern areas, while the South Bay may see pockets of sunshine and slightly warmer temperatures.