Dense Fog — East Bay Interior Valleys, California

2019-12-09 · East Bay Interior Valleys, California

Event narrative

Concord Airport ASOS recorded visibility down to a quarter mile on and off during this time period.

Wider weather episode

Residual low-level moisture from recent rainfall in combination with longer December nights and a stable airmass allowed for the formation of dense fog across the North and East Bay Valleys as well as along the San Francisco Bay shoreline. Multiple airports recorded visibility down to a quarter of a mile or less.

Source: NOAA Storm Events Database, event_id 864884. Narrative written by the NWS forecast office that issued the report.