After recent dry spells, the Bay Area is bracing for some needed rainfall starting this week. NWS San Francisco has forecasted light rain beginning yesterday, in the North Bay, with chances spreading to the rest of the Bay Area and the Central Coast later in the week. As reported by NWS, "Light, generally beneficial rain is expected to begin Tuesday December 16 in the North Bay," setting the scene for a moisture-rich period leading into the holidays.
Ahead of a potentially disruptive holiday storm series starting Sunday, December 21, the rain this week is viewed as a positive to alleviate the parched conditions. NWS San Francisco has noted, "Confidence is increasing for a series of storms beginning Sunday, December 21 and continuing through the Christmas holiday period." However, they caution that "Holiday travel is likely to be impacted across the West Coast." The forecast is still being finalized, but early indications suggest that travelers should stay informed about the evolving weather conditions.
According to an Area Forecast Discussion issued at 304 AM PST on December 17 by the National Weather Service, San Francisco, CA, the Bay Area can expect "beneficial, light rain showers today into tomorrow." The higher terrain could see up to a quarter of an inch, while the rest of the Bay Area might get a sprinkle, with the Central Coast anticipating mostly drizzle. The short-term outlook promises no adverse impacts from the impending precipitation.
More widespread rain is on the docket for Friday and Saturday, attributed to a conveyor belt of moisture powered by competing high and low-pressure systems. "The 80 member ensemble mean from the GEFS and ECMWF ensemble IVT forecast depict values near 500 kg/ms with a gradient to near 250 kg/ms for the Central Coast," the NWS San Francisco noted. Yet, they advise, "Uncertainty begins to creep in Saturday with some global ensemble members depicting that there may be a break in the rainfall." San Franciscans should thus make preparations by Thursday, securing loose items and ensuring gutters are clear.
The forecast beyond this week becomes increasingly complex and uncertain as various global models present differing scenarios for the Christmas holiday. NWS warns of potential cumulative impacts from the prior rainfall and stresses the importance of monitoring updates, especially if traveling during this period.
