Issued at 737 AM PDT Wed May 6 2026
Extensive stratus coverage was observed across the Bay Area with patchy coverage in the Monterey Bay region and interior San benito County, but the latest satellite imagery shows a progressive clearing of the cloud cover over western and central Contra Costa County and areas near the San Pablo and northern San Francisco Bays. Expecting more stratus clearing to continue through the morning and early afternoon hours today. Will monitor the expected development of a distinct marine layer inversion through the day as the larger scale pattern turns to ridging over the West Coast.
DialH
, Issued at 1235 AM PDT Wed May 6 2026 (Today and tonight)
Cool temperatures and cloud cover left over from the recent 500 mb low continue to linger. Tuesday evening's Oakland upper air sounding showed ~ 25th percentile temperatures at 925 mb (2500 feet) and 850 mb (5000 feet) for early May, just below a newly developed temperature inversion aloft. The temperature inversion is an early sign of newly warming air aloft with 500 mb high pressure beginning to advance in across the forecast area. With clearing by late morning and afternoon, daytime highs will climb to the 60s coastside and bayside to the 70s to 80 well inland. In areas that received recent rainfall, lingering surface to lower level water vapor availability combining with peak daytime surface heating may cause mainly small cumulus clouds to develop today as well.
For tonight, post sunset cooling will diminish any small cumulus clouds while lower level temperatures steadily warm, strengthening the lower level temperature inversion. Coastal stratus clouds return tonight, capped underneath the lower level temperature inversion. The SFO-SAC pressure gradient remains onshore through today, near 3 mb by late afternoon then decreases to 1 mb by early Thursday. Onshore winds will usher stratus inland tonight. Low temperatures tonight in the 50s and 40s.
..issued at 1235 AM PDT Wed May 6 2026 (Thursday through Tuesday)
A 500 mb high pressure ridge moves in from the west and northwest during this time, the ridge flanked on each side by strengthening troughs assisting in dynamic strengthening (meridional north-south wave strengthening). Lower to mid level thermal ridging will move in across the forecast area as well. 500 mb heights will increase to above normal Thursday through Tuesday, peaking over the weekend to early next week. By Sunday, Monday and Tuesday recent ECMWF forecasts show 850 mb temperatures warming up to 20 to 23 Celsius which is right around the max moving average on Oakland soundings for the time of year. This means surface temperatures will become warm to hot, daytime highs in the 80s to 90s away from any marine influence. Early next week a few spots in the southern interior may also reach 100F. We may also get close to a few record highs at the long term stations. If planning to be outdoors please keep in mind that moderate HeatRisk will be developing for inland areas Sunday, Monday and Tuesday.
There have been recent positive anomalies observed in the subtropical jet stream winds (stronger than usual) entering the southwestern states. Global models, particularly the GFS shows strength maintaining in both the polar jet stream and subtropical jet stream winds crossing the Pacific during this forecast period. The larger scale pattern may nudge eastward the aforementioned high pressure system a little quicker to our forecast area. This means that late week including Saturday for example may warm up a little faster than currently forecast. Something to keep in mind. Please stay tuned to the latest updates.
(18z TAFS) Issued at 1012 AM PDT Wed May 6 2026
Low clouds have been clearing out quickly by mid-morning and expect VFR conditions the remainder of the day and evening. Marine layer and associated low stratus will begin its push inland later this evening with MVFR ceilings expected for all terminals through the overnight hours with clearing beginning by mid-morning Thursday, likely VFR for all terminals by Noon Thursday.
Vicinity of SFO, Steady fetch of onshore flow through the TAF period with VFR conditions for the remainder of this afternoon and early evening, and a return of MVFR cigs later this evening. MVFR cigs will persist through the overnight hours with clearing expected to begin by mid-morning Thursday, and VFR expected by Noon Thursday.
SFO Bridge Approach, Similar as SFO.
Monterey Bay Terminals, VFR conditions this morning through the afternoon accompanied by moderate WNW winds. Low MVFR ceilings from the coastal stratus deck are expected to move onshore this evening impacting MRY first. Overnight around 09Z Thursday, moderate confidence that conditions will transition into IFR as the stratus marine layer becomes more defined. These lower ceilings will begin to lift and mix out by late morning Thursday.
(today through Monday) Issued at 1012 AM PDT Wed May 6 2026
A building ridge of high pressure over the eastern Pacific will continue gentle to moderate northerly breezes across the coastal waters this afternoon. Expect increasing northerly breezes by Thursday afternoon that will persist through the weekend with building rough seas, resulting in dangerous conditions for small crafts.
Ca, None. PZ, Small Craft Advisory from 9 PM Thursday to 3 AM PDT Saturday for Pt Arena to Pt Reyes 0-10 nm.
Small Craft Advisory from 3 AM Friday to 3 AM PDT Saturday for Pigeon Pt to Pt Pinos 0-10 nm-Pigeon Pt to Pt Pinos 10-60 NM-Pt Arena to Pt Reyes 10-60 NM-Pt Reyes to Pigeon Pt 0-10 nm.
Small Craft Advisory from 9 AM Thursday to 3 AM PDT Saturday for Pt Pinos to Pt Piedras Blancas 0-10 nm.
