Swell Matrix

Area Forecast Discussion

National Weather Service San Francisco CA

955 pm PDT Mon Mar 23 2026

Short Term

, Issued at 113 PM PDT Mon Mar 23 2026 (This evening through Tuesday)

The heat wave is over but temperatures continue to run 10-15 degrees today, some elevated interior locations may see highs 20 degrees above normal by the end of the afternoon. The ridge that brought the record breaking heat last week has shifted to the southeast over the desert southwest, however it continues dominate our pattern and daily forecast. The ridge axis will continue to build back up over California for the remainder of today and tonight, then pivot eastward Tuesday. Tuesday will be slightly warmer than today, but barely noticeable. Overnight lows will also run 5-10 degrees above normal for most locations, tonight and through the remainder of the extended forecast. The stable environment will provide pleasant weather with mostly clear skies, especially away from the coast. Weak onshore flow will result in pockets of marine stratus overnight along the coast, but will struggle to move very far inland with the ridge still firmly in control.

Long Term

..issued at 113 PM PDT Mon Mar 23 2026 (Tuesday night through next Sunday)

A progressive trough will weaken the western periphery of the H50 height field through the middle of the week, with only slight declines in daytime highs Wednesday and Thursday. The marine layer quickly increase late Tuesday night through Wednesday morning as the progressive trough tracks inland. The ridge rebounds on Thursday and starts to build back offshore bringing back warmer temperatures and compressing the marine layer once again Friday. The offshore troughing expected as the longwave pattern becomes more amplified will result in the reemergence of the marine layer over the weekend into next week. There is a signal for some rainfall the first half of next week, but confidence is low that it will bring much in the way of wetting rainfall for our area.

Aviation

(06z TAFS) Issued at 946 PM PDT Mon Mar 23 2026

Currently VFR at all terminals. High confidence in VFR and diurnal winds prevailing. Low probability for sub-VFR conditions to return tonight, with the relatively greatest chances at HAF, MRY, SNS, and STS. If sub-VFR conditions do develop, it will likely be brief and/or intermittent around the 12Z timeframe. Haze will reduce slant range visibilities.

Vicinity of SFO, Currently VFR with westerly flow. High confidence in VFR and diurnal winds prevailing.

SFO Bridge Approach, Similar to SFO.

Monterey Bay Terminals, Currently VFR with southwesterly flow at MRY and VFR with northerly flow at SNS. High confidence in VFR and diurnal winds prevailing.

Marine

(tonight through next Sunday) Issued at 946 PM PDT Mon Mar 23 2026

Moderate to fresh northwesterly breezes and moderate seas will prevail through Tuesday. Strong to near gale northerly winds will develop Wednesday into Thursday with gale force gusts expected for the inner waters and outer waters. Rough to very rough seas will build as a result. Conditions improve by Friday.

Watches, Warnings, Advisories

Ca, None. PZ, Small Craft Advisory from 3 PM to 9 PM PDT Tuesday for Pt Pinos to Pt Piedras Blancas 0-10 nm.

Small Craft Advisory from 9 AM to 9 PM PDT Wednesday for Pt Arena to Pt Reyes 10-60 NM.

Gale Watch from Wednesday evening through Thursday afternoon for Pt Arena to Pt Reyes 10-60 NM.

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