textproduct: San Francisco Bay Area

KEY MESSAGES

Updated at 142 PM PDT Sat Apr 4 2026

- Warmer temperatures continue today and tomorrow before a cooling trend begins next week

- Beneficial rain chances increase mid to late next week

SHORT TERM

Issued at 142 PM PDT Sat Apr 4 2026 (This evening through Sunday)

Another warm weekend remains on track. Interior highs today are largely in the low 80s while coastal areas remain in the 70s. This should keep most sites below their daily high temperature records but some coastal sites may come close to (or break) their daily records. Another warm day is expected on Sunday with temperatures rising by a few degrees compared to today. This does not change the overall forecast too much between Saturday and Sunday - inland highs remain in the low to mid 80s while coastal highs stay in the 70s. Winds remain light and offshore tonight through tomorrow morning before switching onshore again during the afternoon/evening. In terms of the larger synoptic pattern, a pattern change remains on track to begin next week but we see the first indications of this transition Sunday. This weekend, upper level ridging and high pressure have been able to build over California, resulting in temperatures warming up and our marine layer being compressed/mixed out. Sunday afternoon/evening, the upper level ridge begins to progress eastward as weak upper level troughing builds in from the Pacific. This will allow the marine layer to redevelop Sunday night and bring in a return of stratus and an increased potential for coastal drizzle.

LONG TERM

Issued at 142 PM PDT Sat Apr 4 2026 (Sunday night through next Friday)

A pattern change is expected next week with cooler temperatures and some light, beneficial, rain mid to late week. As mentioned in the short term, a weak, shortwave trough arrives Sunday into Monday before transitioning to more zonal flow (horizontal/stable) Monday into midweek. This will kick off a cooling trend with inland temperatures dropping into the 70s and coastal temperatures into the 50s to 60s. Inland areas will still be running a few degrees above normal but coastal temperatures will be fairly seasonal and right around average for this time of year. Out in the Pacific, a cut-off low is expected to break off from a deep upper level trough further north (closer to Alaska). This cut-off low looks to linger over the Pacific until Wednesday and is part of the reason we see a more zonal pattern early next week. By Wednesday, the cut-off low looks to reabsorb into the synoptic pattern and reaches the West Coast as part of a deep upper level trough. It will bring some moisture with it (PWAT values around 0.8" to 0.9") but the bulk of the moisture will be located farther south. Light rain is expected across the Bay Area and Central Coast Wednesday and Thursday with some potential for scattered showers Friday. It is low confidence but there is a nonzero chance for thunderstorms to develop with this system. In terms of temperature, temperatures drop into the 60s across the board Thursday and Friday with the warmest locations reaching the low 70s.

The real question about next weeks forecast comes from small variances in both the strength and location of the trough as it moves onshore. Cluster guidance presents two predominant forecasts: the low will be reabsorbed into the larger pattern but still maintain some elements of a cut-off low as it lingers offshore mid to late week, or, it will fully merge with the upper level trough and move onshore fairly progressively. Cluster guidance is split between these two scenarios with each presenting slightly different outcomes for this week's forecast. If the cut-off low does fully merge with the trough and moves inwards quickly, we could see offshore winds develop in the wake of the system depending on the orientation of the trough. If it maintains elements of a cut-off low after merging, the potential for thunderstorms increases slightly across the Central Coast. If the cut-off low remains stationary offshore (i.e. doesn't progress inland quickly) then we could see a longer duration of moisture transport inland resulting in additional light rainfall (largely over the Central Coast). Whatever way you slice it, the overall picture of next week remains the same: cooler, more seasonal temperatures and light, beneficial rain mid to late week. Make sure to stay up to date on the forecast as next week approaches and models come into a better consensus on the finer details of this system.

AVIATION

(00Z TAFS) Issued at 428 PM PDT Sat Apr 4 2026

High confidence of VFR with high level cloud cover through the TAF period. Winds remain generally offshore in the interior regions, with a coastal breeze developing at the immediate coast beginning to spread inland through the afternoon. Winds diminish overnight with light winds through early Sunday morning, when offshore breezes develop across the interior before a coastal breeze sets up in the afternoon. Beyond the TAF period, monitoring a potential return of marine layer stratus Sunday night through Monday morning.

Vicinity of SFO... High confidence of VFR with high level clouds through the TAF period. Breezy northwest winds will set up shortly and continue into the late evening hours, becoming light overnight before the onshore flow resumes Sunday afternoon.

SFO Bridge Approach... Similar to SFO.

Monterey Bay Terminals... High confidence of VFR with high level clouds through the TAF period. Breezy southwest winds persist at MRY, while the offshore flow should soon turn northwesterly at SNS. Winds will diminish in the evening with drainage flow overnight. At SNS, the southeast winds will pick up early Sunday morning before turning northwest late in the afternoon, while at MRY, onshore flow develops in the afternoon hours on Sunday.

MARINE

(Tonight through next Thursday) Issued at 428 PM PDT Sat Apr 4 2026

Light to moderate northerly winds continue into next week with the development of a coastal jet bringing locally fresh to strong gusts along the Big Sur Coast midweek. A low pressure system over the Pacific will approach the region by the middle of next week bringing a chance of rain, fresh to strong gusts across the northern waters, and moderate seas.

CLIMATE

Issued at 110 PM PDT Fri Apr 3 2026

The following are the record high temperatures at the long term stations for April 4th and April 5th.

Location April 4th April 5th

Santa Rosa 88 in 1961 90 in 1939 Kentfield 85 in 1957 88 in 1924 San Rafael 86 in 1960 87 in 1957 Napa 86 in 1985, 1960 86 in 1989, 1957 Richmond 89 in 2011 83 in 1989 Livermore 87 in 1959 84 in 1989, 1916 San Francisco 84 in 1985 88 in 1989 SFO Airport 82 in 1985 84 in 1989 Redwood City 86 in 1960 87 in 1989 Half Moon Bay 77 in 2011 74 in 2016 Oakland Museum 85 in 1985 85 in 1989 San Jose 87 in 1960 89 in 1989 Salinas Airport 86 in 1989, 1960, 1952 95 in 1989

MTR WATCHES/WARNINGS/ADVISORIES

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