Issued at 910 PM PDT Tue Mar 17 2026
No update to the forecast necessary this evening with this impressive heat wave in full swing. Numerous daily records were set today, however no monthly records were set. As overnight lows continue to warm as the dome of high pressure keeps building, we may see more monthly records fall over the coming days. Stay hydrated, seek shad or AC during the day and check on family, friends, and neighbors. Also, don't leave kids or pets in vehicles, even for a short time.
, Issued at 149 PM PDT Tue Mar 17 2026 (This evening through Wednesday)
We are well on our way to break more record high temperatures this afternoon with some all time monthly (March) records at risk of being broken (please see the CLIMATE below). This is as the center of the mid/upper level high pressure positions itself over the Central Coast today. Temperatures are forecast to reach into the upper 70s to mid 80s near northwest facing coastal locations and upper 80s to lower 90s across the interior and Santa Cruz area.
Overnight temperatures are forecast to cool into the low to mid 50s across the valleys, upper 50s to low 60s elsewhere, and mid 60s to low 70s in the higher elevations. Where radiational cooling is most effective, a few upper 40s cannot be ruled out. Downtown San Francisco may remain the lower 60s into Wednesday morning.
The center of the mid/upper level high will shift over the Desert Southwest by Wednesday and strengthens to 595 decameters (dam) with 850 MB temperatures approaching or exceeding 20 degrees C by Wednesday. Thus, temperatures may be a few degrees warmer than today in areas.
..issued at 113 AM PDT Tue Mar 17 2026 (Wednesday through Monday)
Wednesday through Friday feature similar conditions to today, with temperatures far above the seasonal averages, widespread Moderate HeatRisk, sunny skies, and light winds as the associated upper level ridge crawls across California. A slight warming trend will continue with portions of the Central Coast, including the Ben Lomond-Boulder Creek area, the Morgan Hill-Hollister corridor, and the southern Salinas Valley, seeing temperatures rising into the upper 90s. A couple of favored patches will even see Major HeatRisk, corresponding to a high level of danger for heat-related illnesses for the general population. Notable regions for Major HeatRisk impacts include the ridgelines of the Santa Cruz Mountains, Carmel Valley, and the foothills of the Gabilan Range east of Salinas. The Heat Advisory in effect for the entire forecast region remains in place through Friday evening at the earliest.
For the upcoming weekend, the ridge begins to break down as it crawls eastwards across the Desert Southwest. This will give us a gradual cooling trend, but will also promote an strengthening pressure gradient, leading to stronger winds and an elevated risk for grass fires across the region. The extreme heat of the last few days will dry out a lot of fine fuels across the region, and pulses of offshore flow are possible Friday into the weekend, especially in the South Bay and Central Coast. There are a couple of mitigating factors. The first is that live fuels remain rather moist as the peak growing season continues. The second is that the larger scale pattern is for winds to remain onshore, especially in the North Bay. As for the temperatures, they will gradually cool around 5-10 degrees per day starting on Saturday, and by the early part of next week, temperatures might only be slightly higher than the seasonal averages.
(00z TAFS) Issued at 449 PM PDT Tue Mar 17 2026
No major changes to the forecast as VFR conditions prevail and a few high clouds pass overhead. Winds generally remain light and around 10kt or less, with winds easing overnight. Similar conditions are expected for Wednesday.
Vicinity of SFO, Winds have become onshore for nearly all Bay Area terminals and will remain that way through the evening, peaking around 10kt or so. Diurnally driven winds ease tonight, becoming light and variable or weak and offshore. A similar forecast is expected tomorrow, with winds becomes onshore mid to late afternoon.
SFO Bridge Approach, Similar to SFO.
Monterey Bay Terminals, Similar to above, no major changes to the forecast. Winds are onshore at roughly 5-10kt with isolated gusts up to 14kt for the the Monterey Bay Area terminals for a few hours. Winds will gradually ease and become offshore tonight with onshore
(tonight through next Sunday) Issued at 449 PM PDT Tue Mar 17 2026
Moderate NW breezes will prevail offshore, with gentle breezes within 10NM. Seas are moderate from a combination of wind waves and a low southerly swell. Similar conditions will persist through Thursday before winds increase to a strong NNW breeze with rough seas from Friday through Sunday.
(Tonight through next Monday) Issued at 910 PM PDT Tue Mar 17 2026
Moderate northwest breezes persist across the outer waters, with gentle breezes over the inner waters. Relatively calm waters will persist through Thursday and then begin building again on Friday into the weekend.
Ca, Heat Advisory until 8 PM PDT Friday for CAZ006-502>506-508>510- 512>518-528>530.
PZ, None.
