Issued at 758 AM PDT Tue May 12 2026
Satellite imagery shows extensive stratus coverage across the valleys with high clouds aloft, with the Bodega Bay profiler showing an marine layer around 1500-2000 ft deep this morning. Stratus should gradually pare back to the coastal regions through the day with some inland development expected this evening. Gusty onshore winds this afternoon and evening will contribute to the potential for elevated fire weather threat in the farthest interior regions of Monterey and San Benito Counties, particularly the areas adjacent to the Central Valley where daytime relative humidities are low and overnight recoveries are poor. Although the threat is not widespread enough for fire weather products, any well-aligned grass fires that start may take hold and spread quickly. People in these interior regions should take care to properly dispose of cigarettes and matches and avoid using equipment that creates sparks.
DialH
, Issued at 1216 AM PDT Tue May 12 2026 (Today and tonight)
The pattern shift discussed on yesterday's AFD is upon us. A quick snapshot of the longwave pattern over the West shows a ridge sneaking off to the east and settling over the Desert SW and knocking on CA is an upstream upper trough and associated cut-off low. Onshore flow plus lower 500 mb heights equals a deep marine layer presences this morning. Satellite fog product shows a decent marine layer with way more inland intrusion than 24 hours ago. Marine layer depth will vary from 1000-1500 feet this morning. Light mist or drizzle will be possible along the immediate coastline through this morning.
Deeper marine layer and onshore flow will lead to a later clearing time of inland stratus for Tuesday. The coast on the other hand may not see much in the way of clearing today. Noticeable cooldown for Max Temps today bringing readings closer to seasonal averages. Max Temps 60s to 70s coast/bays and 70s to lower 90s interior.
If we follow the trend is your friend logic: the upstream upper low has been trending more north and continues to do so. As such, the chance for widespread drizzle and/or light rain has now been removed from the forecast late Tuesday night into Wednesday. That being said, still expecting another push of marine stratus overnight.
..issued at 1216 AM PDT Tue May 12 2026 (Wednesday through Monday)
The upper low will sweep through Oregon during the day on Wednesday. While the forecast has trended drier temperatures will still be on the cool side. Wednesday will be coolest day of the forecast. Additionally, expect some breezy onshore winds through out the day. Winds will be strongest along the coast and inland gaps/passes.
Quiet weather returns for the second half of the work week and into the weekend with zonal flow, warming temps, night/morning clouds.
(18z TAFS) Issued at 1059 AM PDT Tue May 12 2026
A deep marine layer produced widespread stratus across the region this morning. Stratus is receding with all sites except HAF and MRY likely to clear by 19/20Z. Winds strengthen by the afternoon/evening with gusts to around 20-30 knots expected along the coastline. A dry cold front will push through tonight with moderate confidence in the timing of cloud cover arrival. Currently kept a later stratus arrival (09/10Z) for most sites but LAMP guidance shows some potential for stratus to return closer to 05/06Z. This cold front will also result in widespread gusty winds along the coast and across the bay shoreline early tomorrow morning. For now, kept tomorrow morning's gusts limited to HAF, OAK, and SFO but gusts are expected to pick up at the remaining airports after 18Z tomorrow.
Vicinity of SFO, Stratus is receding from SFO and should dissipate by 19Z. Gusts are expected to pick up by late this morning with the site to remain gusty through the end of the TAF period. Bumped up the afternoon/evening gusts to 30 knots with around a 10% chance of stronger gusts to 35 knots. We do expect gusts to ease slightly overnight (20-25 knots) but gustier winds (30-35 knots) are expected to return tomorrow afternoon/evening. Moderate confidence that stratus will return around 09Z with some potential for stratus to return as early as 03-06Z. Stratus should clear by late tomorrow morning with VFR conditions through the end of the TAF period.
SFO Bridge Approach. Generally similar to SFO. Expect stratus to fill in over the bay this evening and linger through late tomorrow morning. Similar to SFO, gusty winds are expected over the bay with the potential for sustained winds around 20 knots and gusts between 30-35 knots tomorrow afternoon/evening.
Monterey Bay Terminals, VFR at SNS through early this evening. IFR- LIFR CIGs are expected to persist at MRY through the TAF period with a continued stream of stratus onshore making it unlikely for MRY to clear this afternoon. Moderate confidence in IFR-LIFR CIGs developing again tonight with LIFR CIGs becoming more likely by early tomorrow morning. Breezy onshore winds are expected this afternoon/evening with gustier onshore winds to develop late tomorrow morning and continuing through the evening.
(tonight through next Sunday) Issued at 949 PM PDT Mon May 11 2026
Occasional strong gusts continue through tonight across the far northern outer waters. Otherwise, a moderate to fresh northwest breeze will continue over the waters through midweek. Seas subside but remain moderate with 4 to 6 foot seas through midweek. Winds increase and seas build starting mid-week with gale force winds and wave heights in excess of 10 feet likely starting Friday and continuing through the weekend.
Ca, None. PZ, Small Craft Advisory from 9 AM to 9 PM PDT Wednesday for Mry Bay.
Small Craft Advisory from 3 PM this afternoon to 3 AM PDT Thursday for Pt Arena to Pt Reyes 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm.
Small Craft Advisory from 9 AM Wednesday to 3 AM PDT Thursday 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.
Small Craft Advisory from 3 AM Wednesday to 3 AM PDT Thursday for Pt Pinos to Pt Piedras Blancas 0-10 nm.
