Central California Weather Update

Current Conditions

The Eastern Pacific High, currently sitting at 1,033 millibars, has shifted westward, approaching the International Date Line. This movement has significant implications for Central California, as it opens the door for incoming storms. Residents can expect blustery and wet conditions to persist through Tuesday.

Upcoming Weather Patterns

Tuesday to Wednesday Transition

As we transition from Tuesday to Wednesday, forecasters predict a shift to dry conditions. The Eastern Pacific High is expected to move eastward toward the Central Coast, marking a significant change in the weather pattern.

Cold Front on Saturday

A cold front linked to a surface low of 992 mb near Cape Mendocino is set to sweep through the Central Coast on Saturday morning. This will bring strong to gale-force southeasterly winds, ranging from 25 to 38 mph, with gusts reaching up to 45 mph. Expect periods of heavy rainfall as this system moves through.

• Rain Forecast: Total rainfall projections for Saturday range from 0.75 to 2.0 inches, with higher amounts likely in the Santa Lucia Range and Coastal Mountains.

As the day progresses into the afternoon and night, winds will shift, calming to levels between fresh and strong (19 to 31 mph), and rain will taper off into scattered showers.

Sunday Showers and Winds

On Sunday, the remnants of the cold front will continue to influence weather patterns. An upper-level trough will produce fresh to strong southerly winds in the morning, decreasing in the afternoon. Scattered rain showers are expected, with total rainfall around 0.33 to 1.0 inches, especially along the coast.

Monday and Tuesday Outlook

A new cold front will approach the Central Coast later on Monday, again bringing increasing southerly winds and rain showers. This system is anticipated to cross through San Luis Obispo and Santa Barbara counties Monday night into Tuesday morning.

• Forecasted Rainfall: Rainfall amounts for this period will likely total between 0.75 to 1.50 inches, along with the possibility of thunderstorms.

Mid-Week Expectations

Following the cold front’s passage, the merging of the Eastern Pacific High with a steep pressure gradient will lead to moderate to fresh gale-force northwesterly winds later on Wednesday and into Thursday.

• Wind Speeds: Expect winds from 32 to 46 mph, with gusts potentially reaching 50 mph, which will usher in a colder airmass. High temperatures will decline into the 50s across the Central Coast, with overnight lows dropping to the high 30s in inland valleys and to the low 40s along the coast.

Frost Advisory

With the arrival of colder air, widespread frost is expected during the overnight and morning hours on Thursday and Friday.

Fog and Stratus Conditions

High pressure building over the Great Basin may lead to the development of gusty Santa Lucia winds starting Friday into the following week. While skies will be largely clear during the day, night and morning dense valley fog and stratus clouds could blanket areas over the Santa Lucia and coastal mountains.

Weekend Surf Report

• Saturday Waves: A 6- to 8-foot southerly sea and swell is forecast, increasing to 9- to 11 feet on Sunday.
• Water Temperature: Sea surface temperatures, usually around 56°F this time of year, have recently risen to about 61°F.

Special attention is advised for potential coastal flooding due to high westerly swells combining with elevated water temperatures.

Historical Weather Highlights

Reflecting on significant weather events, notable historical weather occurrences on this date include the devastating flood in 1910 that washed out railway lines and the record low for Hawaii in 1961.

For the latest updates and further details on local weather, following meteorological reports will keep you informed on changing conditions.

For inquiries or more localized weather information, reach out to John Lindsey at PG&E’s Diablo Canyon or connect on Twitter at @PGE_John.