textproduct: San Francisco Bay Area

KEY MESSAGES

Updated at 1201 AM PDT Fri Oct 16 2026

- Above normal temperatures continue into Saturday before cooler, below normal weather returns Sunday into next week

- Critical to near critical fire weather conditions continue across the higher elevations of the Bay Area and Central Coast due to very dry conditions and offshore flow through Saturday

- Pattern change expected early to mid next week with periods of breezy onshore winds and light, accumulating rain

SHORT TERM

Issued at 1201 AM PDT Fri Oct 16 2026 (Today and tonight)

A Red Flag Warning remains in effect through 11 AM Friday for the North Bay Interior Mountains due to moderate offshore winds and critically dry conditions overnight. Minimal to no overnight humidity recovery is expected with humidity values between 15 to 25% expected. Winds across the North Bay Interior Mountains have picked up across the highest peaks and will spread into the remainder of the NB Interior Mountains tonight. Offshore gusts are expected to peak between 20 to 30 mph with stronger gusts possible across the highest ridgelines. Gusts between 40 to 60 mph have been observed across the highest peaks (3500+ ft) in northern Sonoma and Napa counties. As offshore winds pick up across the rest of the NB Interior Mountains, humidity values will drop with rapid fire spread possible should a fire start. Winds are expected to decrease by late morning with the Red Flag Warning set to expire at 11 AM. Although the winds will have decreased, very dry conditions (RH 10-20%) will persist through the rest of the day with poor overnight recoveries expected Friday into Saturday. As such, near critical fire weather conditions will continue across the higher elevations of the Bay Area and Central Coast through Saturday. If you are participating in any activity involving flames outdoors, be very careful and do not allow sparks/embers to escape. Listen to all guidance from local officials.

Upper level ridging continues with widespread above normal temperatures and Moderate HeatRisk peaking today. Minimal relief is expected along the coast due to upper level ridging mixing out the marine layer. Interior highs peak in the upper 80s to low 90s with coastal highs in the 70s to low 80s. Portions of the Santa Cruz Mountains and the southern Santa Clara Valley may reach the upper 90s. Expect hot conditions and patchy Moderate HeatRisk to continue into Saturday although a few degrees cooler than on Friday. If you're not a fan of hot weather, you're in luck as a pattern change is expected Sunday into next week (see Long Term discussion).

LONG TERM

Issued at 1201 AM PDT Fri Oct 16 2026 (Saturday through Thursday)

Temperatures return to more seasonal temperatures by Sunday as upper level ridging is replaced by broad troughing. High temperatures cool into the 70s to low 80s across the interior while the coast drops back into the 50s to 60s thanks to the return of the marine layer. Upper level troughing impacts become more pronounced over the course of the next week as a deep upper level low becomes cut-off from the jet stream and lingers along the Central/Southern California coastline through late next week. At the same time, a surface low pressure system originating from the Gulf of Alaska will move southwards along the California coast next week. This system will bring a much cooler airmass into the region and see a return of fall temperatures in the 60s to 70s and morning lows in the 40s to low 50s. Recent guidance has trended towards the low staying offshore rather than moving onshore next week. The current forecast shows the highest rain totals along the Santa Lucia Range and Santa Cruz Mountains where totals are between a quarter to half an inch. For the lower elevations expect up to a tenth of an inch across the Bay Area and up to a quarter of an inch across the Central Coast. Periods of gusty onshore winds are likely along the coast, the higher elevations, and across mountain gaps/passes next week. Winds don't look to be widespread enough to necessitate a Wind Advisory but favored windy locations (Altamont Pass) will definitely be gusty. Another item to watch is the potential for thunderstorms with this system. NBM guidance has consistently maintained a low chance (<15%) of thunderstorms across the region. In favor of thunderstorms is the fact that this is a cold core low which is bringing in cooler air and may be more favorable for ice crystal development/eventual lightning development. Anti-thunderstorm development is the new more offshore track of the low which keeps the best MUCAPE and CAPE values offshore. This may be a setup where we see some sort of convective activity over the marine environment but it doesn't make it onto land (if the current track holds).

Bottom line: expect a pattern change to occur next week with below normal temperatures, potential for light rain, breezy to gusty onshore winds, and a low potential for thunderstorms.

AVIATION

(12Z TAFS) Issued at 451 AM PDT Fri Oct 16 2026

Another night of VFR conditions as the picture from space is clear over the Bay Area and Central Coast. The challenge for this TAF cycle is capturing the winds, with offshore flow setting up this morning. Along the coasts, we should see a push of diurnally driven onshore winds for a few hours this afternoon. Winds may be more light and variable in some spots tonight, though weak offshore winds are expected to return. As noted by the prior meteorologist, we'll need to keep an eye open for KHAF tomorrow morning. In these offshore flow set ups winds can sometimes align for the E to NE and increase as they surface toward the ocean.

Vicinity of SFO...No major changes as offshore winds set up this morning, generally around 10kt or less. Then this afternoon, onshore winds return lingering into the evening. Tonight, winds may be more light and variable.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...Offshore winds are expected for through the morning with onshore winds by late morning or early afternoon. Onshore flow should continue through the early evening, before another round of offshore winds returns late evening and into early Saturday morning. VFR conditions will prevail.

MARINE

(Today through Wednesday) Issued at 258 AM PDT Fri Oct 16 2026

Gentle to moderate northerly breezes will prevail over the coastal waters today and become moderate to fresh on Saturday. These winds hold into the early portion of the week. The increasing winds will bring a fresh swell and steeper wind waves.

FIRE WEATHER

Issued at 451 AM PDT Fri Oct 16 2026

The Red Flag Warning for the North Bay Interior Mountains remains in effect this morning due to moderate offshore winds and very dry conditions. This included the very poor overnight humidity recovery between 13 and 23 percent. The Red Flag Warning is set to expire at 11AM, as winds decrease. Conditions will remain very dry, with RH values around 10-20% forecast for the rest of the day and poor overnight recoveries tonight into Saturday. These conditions, combined with warmer weather, will lead to near critical weather conditions for the higher elevations of the Bay Area and Central Coast through Saturday. We will begin to see a reprieve in conditions Saturday into Sunday, as the upper level pattern shifts to broad troughing. Temperatures become more seasonal and we should start to winds become onshore, improving RH conditions as well.

MTR WATCHES/WARNINGS/ADVISORIES

CA...Red Flag Warning until 11 AM PDT this morning for CAZ504.

PZ...None.