textproduct: San Francisco Bay Area

KEY MESSAGES

Updated at 135 PM PST Sat Feb 28 2026

- Cooler Sunday with very light rain across the North Bay and Pacific Coast

- Above normal temperatures with elevated winds and offshore flow next week

- Potentially hazardous marine conditions next week

LONG TERM

Issued at 135 PM PST Sat Feb 28 2026 (Sunday night through next Friday)

MUCAPE needed for lightning appears that it'll remain confined to extreme northern parts of the East Bay and a 20% chance for thunderstorms seems reasonable. While PoPs average between 40%-60%, rain amounts are anticipated to remain largely under one- tenth of an inch. Higher end amounts suggest that areas that would approach one-tenth of an inch (or greater) are most probable across the North Bay terrain (namely Coastal Ranges/Hills). PoPs, while probably a little broad-brushed, extend as far south as the Big Sur Coastline where RRFS output suggest the potential for a few showers. Onshore flow should encourage orographic ascent across the coastal ranges and there will be a potential for drizzle along the Pacific Coast (and across some of the higher terrain in the East Bay).

Rain chances fall down to near zero Monday afternoon with a predominately rain-free forecast (outside of the mid-week time frame). On Wednesday, an amplifying trough with an attendant front will slice through the area. The latest guidance does paint a 20-30 PoP across the North Bay, however, there does remain some spread in this portion of the forecast. Taking a look at the multi-model ensemble clusters reveals that 75% of the guidance offers a more northern track to this upper trough which would mean a lower chance for rain across the North Bay. However, the remaining quarter of the multi-model ensemble (including the deterministic ECMWF) does offer a more southern trek for the mid- week system. This would equate to a larger PoP footprint as far south as the Golden Gate strait. For now, NBM PoPs seem reasonable and I didn't make any deviations here and rain chances are limited to the North Bay during this time. QPF during the mid- week system is also anticipated to be predominately a few hundredths of an inch.

The primary weather headline in the long term will be the potential for increased northerly winds, particularly across the higher terrain as well as across the marine environment. Overall, the blended guidance seems to offer a reasonable wind gusts forecast given where it is (over 72 hours out). As surface pressures rise in the wake of the aforementioned trough/front, the MSLP gradient between building high pressure and the surface coastal trough will tighten. This is a common pattern that result in winds overachieving, particularly across the complex terrain. As a result, wind gusts across the mountain zones have been adjusted upward closer to the higher end of the NBM envelope. It should be noted, the position of the trough as discussed earlier, will modulate just exactly how the winds manifest themselves across the higher terrain. As noted before, any fire ignitions may pose some growth potential in dead/dormant vegetation. The marine environment, however, seems more likely to experience wind gusts in excess of 30-35 knots. Similar to PoPs, the blended guidance may have a broader than reality wind field, but hazardous marine conditions do appear that they'll transpire. For more details, see the marine section below.

AVIATION

(06Z TAFS) Issued at 920 PM PST Sat Feb 28 2026

Widespread VFR lasts into the night with high clouds continuing to build. Expect winds to reduce into the night with MVFR/IFR CIGs flowing through the area. Some of these CIGs will be inconsistent. CIGs thin in the late morning and early afternoon on Sunday, with lingering mid-level clouds. Expect more moderate winds to build into Sunday afternoon. Light rain and drizzle affect the North Bay and the immediate coast into Sunday evening. These chances for light precip will be accompanied by IFR/MVFR CIGs, that look to become widespread into Monday morning.

Vicinity of SFO...VFR lasts into the late night. Expect light to moderate northwest winds into the night before winds turn more westerly. Winds reduce slightly as MVFR CIGs fill around the SF Bay. Moments of IFR CIGs look to affect the terminals in the early to mid morning on Sunday. CIGs erode into the late morning. West winds reduce early Sunday night a drizzle begins to affect the area with IFR CIGs building later that night.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...VFR lasts through the late night. Winds become light into the late night as MVFR/IFR CIGs begin to fill around the bay. CIGs last through much of Sunday morning, but look to lift and scatter into that afternoon. IFR CIGs arrive into Sunday evening with drizzle later into the night around MRY.

MARINE

(Tonight through next Friday) Issued at 846 PM PST Sat Feb 28 2026

Moderate northwesterly swell lingers through Sunday with wave heights and swell periods gradually decreasing. Chances for showers and isolated thunderstorms return late Sunday into Monday morning for the northern waters, which will bring rougher seas, heavy rain, lightning, and erratic seas. Seas continue to abate until about mid- week. Thereafter, conditions will deteriorate as a series of stout strong systems usher in Gale Force wind gusts and steep seas over 12 feet.

MTR WATCHES/WARNINGS/ADVISORIES

CA...None. PZ...None.