Bay Area on Alert for Upcoming Shift to Wet Weather as Pacific Systems Gear Up

Bay Area on Alert for Upcoming Shift to Wet Weather as Pacific Systems Gear UpSource: NWS Bay Area
Eileen Vargas
Published on December 11, 2023

According to the National Weather Service's Bay Area unit, we're in for some wet weather as we move further into the month, with above-average rainfall expected. The NWS Bay Area advises residents to prepare for the rainy conditions ahead, though specific details on the amount, timing, and intensity of the rain are still uncertain.

The current weather forecast for this week promises mild days and cool nights in the Bay Area. However, the focus is on early next week, when a pattern change is expected to bring wet and unsettled conditions. The NWS San Francisco notes in its forecast discussion that a quiet spell will precede this change, with a return to wet weather on the horizon.

As the pleasant weather wraps up, an upper-level high-pressure ridge will flatten out, making way for an incoming shortwave trough from the Pacific Northwest. This will turn winds onshore and bring moisture to the coastal areas by this evening. Coastal stratus and patchy fog are expected, with temperatures reaching around 60 degrees during the day and dropping to 30–40 degrees at night.

Looking ahead, the region will experience the influence of a Desert Southwest upper-level low and a Pacific jet stream, bringing subtropical moisture. Rain chances are predicted from Saturday into next week, with the potential for an Atmospheric River setup. While details on rain amounts and intensity are still uncertain, the NWS advises residents to stay updated on weather forecasts.

For aviation enthusiasts, mostly clear conditions are expected, with visibility concerns at some terminals due to mist and fog, which should improve by afternoon. Mariners are also advised to be on alert, as high-pressure dominance over the waters will give way to a new storm system approaching next weekend. Gusty winds and potential showers are in the maritime forecast as the week progresses.