Issued at 921 PM PDT Wed May 27 2026
We have been able to continue to benefit from the upper level disturbance that has been slowly churning overhead the past couple of days with beneficial rainfall in the bumper portion of our transition into the dry season. Most locations that have received some rainfall got less than a tenth of an inch, but numerous locations in the Myacama's, Diablo Range and Santa Lucia's have seen 0.25"-0.50" or more the past 48hrs. The Santa Cruz Mountain are likely to catch up somewhat overnight into Thursday as the upper low ends its retrograde and starts to exit to the east on Thursday morning. Portions of the Santa Lucia's and Santa Cruz mountains will see more rainfall tomorrow with ensembles indicating a roughly 30%-50% chance of exceeding 0.50" of rainfall by sunset tomorrow across those areas.
, Issued at 1215 PM PDT Wed May 27 2026 (This evening through Thursday)
We have already seen showers and an isolated thunderstorm develop late this morning across the Eastern Santa Clara Hills and in the Mountains of San Benito County. As daytime heating continues, we are expecting convection to fire up in the East Bay Hills, Eastern Santa Clara Hills, the Santa Cruz Mountains and the Central Coast (County of Monterey/San Benito) this afternoon and evening. This is as the atmosphere becomes more unstable with CAPE values between 100-400 J/kg. However, vertical wind profiles don't favor organized convection, with little to no 0-6km wind shear. Therefore, probabilities for thunderstorms remain less than 10% through the afternoon and early evening. Any stronger cell (shower and/or thunderstorm) that develops over any one given location has the potential to produce 0.25"-0.50" per hour of rainfall.
The mid/upper level low will begin to retrograde back over the Pacific tonight into early Thursday morning and begin to pull in PWAT values of around 1.00". This will increase rain chances offshore late tonight and then will move onshore along the Central Coast through Thursday morning. However, with the loss of daytime heating, the thunderstorm threat will lessen. Forecast rainfall amounts have increased in the Santa Cruz Mountains and Santa Lucia Range now having a greater than 60% probability of seeing more than 0.25" through Thursday afternoon (this would include rainfall from today). These probabilities of seeing greater than 1.00" (40%-75%) remain confined to the Santa Lucia Range.
Conditions begin to dry out from north to south during the day Thursday as the mid/upper level low shifts further inland. However, rain showers look to linger over the Central Coast through the early evening.
..issued at 1215 PM PDT Wed May 27 2026 (Thursday night through next Tuesday)
Cannot rule out rain showers to linger across the North Bay late Thursday night into early Friday morning as deeper moisture (PWAT values approaching 1.00") move across this region. In wake of the exiting trough, a warming and drying trend will kick off by Friday afternoon with temperatures gradually returning to near average this weekend as zonal flow develops over the region. Temperatures are currently forecast to warm above seasonal averages by Sunday and into the middle of the upcoming week.
(06z TAFS) Issued at 957 PM PDT Wed May 27 2026
Scattered showers are expected to arrive tonight becoming widespread rain by early morning. Rain generally continues through late morning/early afternoon before conditions dry out. There is some potential for isolated thunderstorms to develop again during the day. Any t-storms that develop would likely impact MRY and SNS with the highest thunderstorm probabilities across the interior Central Coast. Breezy onshore winds are expected again during the afternoon/evening before winds ease tomorrow night. Confidence has increased in widespread MVFR CIGs tonight with most sites seeing MVFR conditions through late morning. Temporary decreases in visibility are possible if a stronger shower moves directly over the airport.
Vicinity of SFO, Shower chances are expected to increase overnight and continue through late morning. Winds remain relatively light overnight before breezy onshore winds return during the afternoon/evening. MVFR CIGs generally expected overnight with CIGs rising to the MVFR/VFR border overnight. Winds ease tomorrow evening/night with some potential for MVFR CIGs to return.
SFO Bridge Approach, Similar to SFO.
Monterey Bay Terminals, Shower chances increase through 10Z with widespread rain returning afterwards through much of the day. There is some potential for thunderstorms to develop during the day. The highest chances for thunderstorms are to the south of MRY and SNS but cannot rule out the potential for a stray storm or two moving through the Monterey Peninsula (particularly during the morning into the early afternoon). Winds remain breezy during the afternoon/evening before starting to ease overnight. Winds at SNS are tricky with LAMP guidance highlighting strong valley winds during the early morning. For now put gusts to around 15 knots during the early morning but LAMP guidance seemed a little high with 20+ knot gusts.
(tonight through next Tuesday) Issued at 921 PM PDT Wed May 27 2026
Winds diminish and waves abate across the coastal waters tonight with a moderate northwest breeze expected late morning through Friday. Strong to near gale force northerly winds return over the weekend and continue into next week. Wave heights build as winds restrengthen with wave heights between 10 to 12 feet expected this weekend into early next week.
Ca, Beach Hazards Statement from 9 AM PDT Thursday through late Thursday night for CAZ006-505-509-529-530.
PZ, Small Craft Advisory until 3 PM PDT Thursday for Pt Arena to Pt Reyes 10-60 NM.
Small Craft Advisory until 3 AM PDT Thursday for Pigeon Pt to Pt Pinos 10-60 NM.
