Issued at 901 AM PDT Fri Mar 13 2026
Locally foggy conditions along the coastline are beginning to dissipate with visibility to improve through the remainder of the morning. Increased cloud cover across the region has kept temperatures this morning a few degrees cooler than they were at this time yesterday. Still expecting highs today to be 10-15 degrees above normal with most interior locations in the mid to upper 70s. Minor HeatRisk is forecast across the CWA today which primarily effects those who are extremely sensitive to heat or without access to cooling/hydration.
, Issued at 1229 AM PDT Fri Mar 13 2026 (Today and tonight)
Cirrus clouds are moving over the CA coast associated with a sharp upper level trough over the Eastern Pacific. This feature is producing southerly winds that are pumping upper level moisture from the tropics to the West Coast. These clouds will likely remain trough the day as the trough slowly weakens and meanders a little closer towards the coast. This will help moderate the temperatures today, but the moderate strength upper level ridge will keep max temperatures similar to yesterday and around 10-15 degrees above normal.
..issued at 1229 AM PDT Fri Mar 13 2026 (Saturday through Thursday)
Saturday's temperatures will be similar to Friday, but for a different reason. The high clouds will clear, but a very weak disturbance will take a quick bite out of the ridge. 500mb heights are expected to drop from around 5850m on Friday to around 5770m on Saturday morning. That's still well above normal (5650m) for this time of year. The ridge starts to rebuild Saturday afternoon while surface high pressure builds over the northern Rockies causing the winds to veer offshore. This upper level ridge will continue to build through Tuesday, eventually becoming as strong as we ever seen in March. Some high clouds are likely to return Sunday before clear skies and unfiltered heat moves in for the peak of the heat wave starting Monday. Tuesday and Wednesday look like the hottest days before the ridge axis moves through. This will cause the temperatures to drop a couple degrees, but the heat wave will persist through the workweek. More noticeable relief will have to wait until the weekend, but temperatures may not return to normal for the rest of the month.
The guidance on the strength of this heat wave is remarkable. I'm going to cover it in detail here, but the bottom line is that I audibly gasped when I saw the ECMWF Extreme Forecast Index for maximum temperatures next week. I have never seen it anywhere near this aggressive with bright red painted across the state. That means the ECMWF ensemble members are showing a 99-100% chance of exceeding the maximum values of M-Climate (20-year database). The upper level support strongly points record breaking heat. There is a 75% chance that the 500mb height will break 5900m Monday evening (March record: 5885m). There is also a 75% chance the 850mb temp will break 20C Tuesday - Wednesday (March record: 19.2C). The 250 mb height is very likely to set a monthly record as well. All of this upper level support, combined with offshore winds, creates the perfect recipe for record breaking heat. As such, we expect a slew of daily records to be broken, and several monthly records are likely to go down as well. One final note on the upper level statistics before the hype train runs off the rails; these numbers are very high for March (near the lowest heights climatologically), but would be typical for early August. As such, expect next week to feel like early August, just without the marine layer.
So what does this mean for you? Temperatures will be warm but comfortable through Saturday with mid to upper 70s inland and upper 60s along the coast, roughly similar to what we saw on Thursday. By Sunday temperatures jump 5-10 degrees before another similar increase Monday. During the peak of the heat wave on Tuesday and Wednesday, most areas will be in the upper 80s and 90s, including many coastal locations thanks to the offshore winds. Temperatures will likely drop a couple degrees later in the week, but not nearly enough to end the heat wave. Much of the area will be under moderate HeatRisk. This level affects people sensitive to the heat, especially those without access to cooling and hydration. Keep in mind this is our first heat wave of the year and we haven't seen these temperatures since September.
(18z TAFS) Issued at 1043 AM PDT Fri Mar 13 2026 VFR is expected to prevail through the remainder of the day and evening hours for all terminals as high pressure continues to build offshore. Primarily chose a persistence approach with the drop in cigs/vis for the North Bay and Monterey Bay terminals, with the potential for IFR/LIFR well after midnight into the mid- morning hours of Saturday.
Vicinity of SFO, VFR is expected to prevail through the forecast period with only a slight chance of MVFR cigs around sunrise Saturday.
SFO Bridge Approach, Similar to SFO.
Monterey Bay Terminals, VFR for the remainder of today and this evening, with around a 50% chance of IFR cigs developing overnight and continuing through mid-morning Saturday at the latest, along with the potential of IFR/LIFR valley fog developing shortly before sunrise and mixing out by mid-morning, similar to today.
(today through Wednesday) Issued at 901 AM PDT Fri Mar 13 2026
Fresh to moderate north/northwest breezes will persist through the weekend. Periods of stronger winds will result in locally hazardous conditions. Both winds and seas will begin to ease late Sunday night into the beginning of next week.
Ca, None. PZ, Small Craft Advisory until 3 AM PDT Sunday for Pt Arena to Pt Reyes 0-10 nm-Pt Pinos to Pt Piedras Blancas 0-10 nm.
Small Craft Advisory from 3 PM this afternoon to 3 AM PDT Sunday for Pt Reyes to Pigeon Pt 0-10 nm.
Small Craft Advisory from 9 PM this evening to 3 AM PDT Sunday for Pigeon Pt to Pt Pinos 0-10 nm.
Small Craft Advisory until 9 PM PDT Sunday for Pigeon Pt to Pt Pinos 10-60 NM-Pt Arena to Pt Reyes 10-60 NM.
