Swell Matrix

Area Forecast Discussion

National Weather Service San Francisco CA

408 am PDT Wed jul 1 2026

Short Term

, Issued at 1146 PM PDT Tue Jun 30 2026 (Tonight through Thursday)

Longwave trough over the western CONUS will remain in place through Wednesday, with weak bouts of energy passing through the flow at 500 hPa. This pattern has been persistent over the last week, which has allowed the marine layer to be locked in place and kept temperatures below seasonal norms along the coast. As has been seen over the last few days, temperatures will continue to be in the upper 50s to 60s along coastal communities, with those inland in the 70s to mid 80s. Marine layer will slowly erode along coastal areas from north to south by midday, especially for areas north of the Monterey Bay Area. Although, communities located along Monterey Bay should largely remain locked under the marine layer through much, if not all, of the day. Some breaks in the clouds may allow the Sun to break through briefly at times. We will also continue to see breezy conditions through the afternoon as weak bouts of energy continue to pass through the broad upper trough.

Long Term

..issued at 1146 PM PDT Tue Jun 30 2026 (Thursday night through next Tuesday)

We will continue to fall under the influence of the long wave trough on Thursday, bringing another day of cool and breezy conditions under the marine layer along the coast. Warmer temperatures and mostly clear skies will remain inland.

Friday onward, we will start to see this long wave pattern break down over the area. We will also start to see some weak ridging develop going into the weekend. Thus, we will start to see a gradual warming trend through the weekend. Temperatures for communities along the coast will largely remain in the mid 60s to near 70, with more notable warming noted for inland areas. This will be especially true for inland areas south and east of the Monterey Bay Area where temperatures in the upper 80s to low 90s will be seen. As a result, HeatRisk along the coastal communities will remain low (green), while inland areas will be minor (yellow). As was mentioned in the last forecast package, guidance is hinting at the potential for another long wave trough to develop over the western CONUS. Although, CPC continues to highlight the area under favorability for above normal temperatures into the middle of next week, potentially bringing more summer-like weather to the area.

Aviation

(12z TAFS) Issued at 408 AM PDT Wed Jul 1 2026

Stratus /MVFR-IFR/ continues to develop while onshore winds also continue. Stratus mixes out by late morning and early afternoon otherwise VFR prevails today. Coastal stratus redevelops tonight and Thursday morning.

Vicinity of SFO, VFR. West wind 5 to 15 knots.

SFO Bridge Approach, Similar to SFO.

Vicinity of SJC and OAK, San Jose Airport VFR, southeast wind holding near 13 knots through morning, diminishing to light and variable wind 21z today. Northwest wind 5 to 10 knots in the afternoon and evening then shifting to southeast at 10 to 12 knots tonight and Thursday morning. Oakland Airport stratus /MVFR/ mixing out to VFR by late morning. Southwest to west wind 5 to 12 knots.

Monterey Bay Terminals, Stratus /MVFR-IFR/ mixes out to VFR by late morning and/or afternoon. Stratus /MVFR-IFR/ redevelops and moves inland tonight and Thursday morning. West to northwest winds 5 to 15 knots with afternoon gusts to 20 knots in the Salinas Valley.

Marine

(today through Monday) Issued at 355 AM PDT Wed Jul 1 2026

A gale warning continues for the northern outer waters while weaker, yet still gusty winds affect the rest of the waters. Gale force gusts across the northern outer waters will ease by late week. Moderate northwest breezes will prevail elsewhere. Rough to very rough seas will continue in the outer waters today and tonight before abating to become moderate to rough Thursday into Friday.

Watches, Warnings, Advisories

Ca, None. PZ, Small Craft Advisory until 3 AM PDT Thursday for Pigeon Pt to Pt Pinos 10-60 NM-Pt Arena to Pt Reyes 0-10 nm.

Small Craft Advisory until 9 AM PDT this morning for Pt Reyes to Pigeon Pt 0-10 nm.

Gale Warning until 3 AM PDT Thursday for Pt Arena to Pt Reyes 10- 60 NM.

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