2 days Ago By Tony Ng
The National Weather Service San Francisco has indicated a shift in the Bay Area's weather pattern, setting the stage for a series of rainfalls starting tonight and extending into the upcoming week. According to NWS updates, the region's dry conditions, with temperatures falling below seasonal averages, will soon give way to wetter conditions. However, there is still some uncertainty surrounding the potential development of an atmospheric river, particularly regarding the amount of rainfall and subsequent impacts this weather phenomenon could bring.
Residents and visitors can expect cloud coverage to increase today as a precursor to the incoming precipitation. The first signs of change will be the warm frontal rain processes starting this evening over marine zones, which spread eastward then overnight, bringing measurable precipitation to regional areas. Despite the anticipation of rainfall, NWS has noted considerable uncertainty, specifically affecting the southern coastal regions.
In a somewhat atypical development so close to the event, the predictability of an atmospheric river forming hovers with ambiguity. To fully grasp this complexity, one might consider how the ensemble models are split, with some indicating brief periods of atmospheric river conditions and others forecasting none at all.After this initial rainfall, the intensity is expected to lessen by Sunday afternoon, with a resurgence following cold frontal processes commencing by Sunday night.
Although the rain might start strong, the overall forecast for rainfall amounts has been adjusted downward, marking a northwest-to-southeast gradient with an anticipated range of 1.50 inches in the North Bay Mountains to as little as 0.05 inches in the Interior Central Coast, as stated in the NWS discussion.
Gusty winds accompanying the rainfall are also expected to be a factor, with gusts exceeding 20 mph and potentially reaching up to 45 mph in coastal areas, high terrains, and through certain passes.For aviation, VFR conditions will be the norm for most of today, shifting to moderate southerly breezes and light rain by Sunday morning. This change in weather conditions will likely lower ceilings to MVFR by mid-morning Sunday.
Mariners should prepare for transitioning conditions as well. "High swell continues to diminish through the day with moderate seas expected through the weekend. An approaching warm front will bring a strong southerly breeze Sunday morning," outlines NWS San Francisco.
Rough seas are set to make a comeback Tuesday due to a low-pressure system stirring up a strong NW breeze that will persist through mid-week.No immediate advisories or warnings have been declared for the California coastline, but mariners should take note of the Small Craft Advisory in effect for several zones beginning Sunday morning, as indicated by the National Weather Service. The advisory signals the potential for hazardous conditions for smaller vessels, so caution is urged.
.
