, Issued at 218 PM PDT Tue Sep 8 2026 (This evening through Wednesday night)
Temperature's early this afternoon are running 5-10 degrees warmer than they were at this time 24hrs for most locations across our area, including the coastal communities. A weak fetch of offshore flow aloft with a weaker unorganized signal at the surface is still holding back the marine layer influence from penetrating farther inland. Decided to start the Heat Advisory this afternoon instead of Wednesday morning due to warmer than normal temperatures overnight beginning tonight along with the warmer than normal daytime temperatures. With a shallow, unorganized marine layer persisting through tonight and Wednesday, decided to increase temperatures slightly for Wednesday to lineup more with current trends. Along with a lack of a well organized marine layer, PWATs are expected to gradually increase between now and Wednesday afternoon. As noted in the previous forecast, we'll approach values that come close to daily climatological records for this time of year. Although, some high cloud cover is expected, we're not expecting enough to significantly impact daytime max temperatures. That added moisture will make for higher RH values with the warmer temperatures, making for a muggy day and more heat related health impacts.
Please remember these tips to help mitigate impacts from heat exposure:
-Suspend unnecessary outdoor activities during the extreme heat, but if you must be outdoors, take frequent breaks in the shade or AC and drink cool water. -Know the signs and symptoms of Heat Exhaustion vs. Heat Stroke! Heat Stroke can be deadly if not treated immediately by a medical professional. Call 911 if you suspect someone is suffering from Heat Stroke. -Wear a life jacket, swim near a lifeguard, and check conditions before entering the water if going to a river or ocean to cool off. Rivers and the ocean are extremely cold, and Cold Water Shock can turn into paralysis and drowning if you are not careful. -Use a cool and damp towel on your body if you do not have AC and are feeling hot. Or, take a cool shower or bath. -Do not leave kids or pets in a parked car. -Ensure pets and livestock have access to shade and water.
..issued at 218 PM PDT Tue Sep 8 2026 (Thursday through next Monday)
The pattern change from high heat to cooler will highlight the challenge going in to the long term forecast. Confidence is high that the pattern change will occur and we'll see a notable cool down. However, there may be some room in the forecast for the end of the weekend into the beginning of next week for temperatures to be higher than currently forecast depending on how progressive an upper level system across the Great Basin moves inland and suppresses the top of the ridge currently producing the warm temperatures.
(06z TAFS) Issued at 945 PM PDT Tue Sep 8 2026
Widespread mid-upper clouds will overspread the airspace tonight. Still expecting VFR all terminals. Some HZ/BR may occasionally drop vis 5 to 6 at HAF. Onshore flow will bring gusts Wednesday afternoon/evening.
Vicinity of SFO, VFR. Gusts up to 20 kt Wednesday afternoon.
SFO Bridge Approach, Similar to SFO minus the gusts.
Monterey Bay Terminals, VFR. Still a 20 percent chc for some CIGs SNS by AM, but not high enough to included TAFs yet.
(tonight through next Monday) Issued at 945 PM PDT Tue Sep 8 2026
High pressure off the Pacific Northwest and low pressure over California maintain gentle to moderate northwesterly breezes through Wednesday. Northerly pressure gradients increase leading to fresh to strong breezes Thursday afternoon into the weekend. Slight to moderate seas will prevail, building to become rough in the outer waters Friday into Saturday.
Ca, Heat Advisory until 10 PM PDT Thursday for CAZ006-502>506- 508>510-512>518-528>530.
Coastal Flood Advisory until 1 AM PDT Thursday for CAZ006-506- 508-529-530.
PZ, None.
