FXUS66 KMTR 210102 AFDMTR Area Forecast Discussion National Weather Service San Francisco CA 602 PM PDT Fri Mar 20 2026 ...New CLIMATE... .KEY MESSAGES... Updated at 107 PM PDT Fri Mar 20 2026 - One last day of record-breaking heat today with Moderate HeatRisk across the region. - Elevated potential for grass fires today with fire concerns easing into the weekend. - Gradual cooling trend begins this weekend and lasts through the next week. && .SHORT TERM... Issued at 107 PM PDT Fri Mar 20 2026 (This evening through Saturday) The end is in sight... but not quite yet. Today should mark the last of several days of record-breaking heat across the region. As a note for the weather geeks out there, this morning's 12Z (5 AM PDT) sounding at Oakland reported a temperature of 23.4 C at the 850 mb level (around 5000 feet above sea level). This not only breaks the record for the hottest 850 mb temperature in March (which was itself set by the 00Z/5 PM PDT flight yesterday afternoon), it would also set the record highest 850 mb temperature for the month of April. With such high temperatures, it should not be a surprise to learn that as of noon today, downtown San Francisco, Oakland Museum, Redwood City, San Jose, and Salinas Airport have all broken their daily records. Widespread Moderate HeatRisk is expected today, corresponding to a medium risk of heat-related illnesses for sensitive populations, including children, the elderly, pregnant women, people with chronic diseases, and people who live or work outside without adequate shelter or cooling. Given the abnormally hot conditions for the middle of March, a Heat Advisory remains in effect for the Bay Area and Central Coast through 8 PM tonight. Follow these tips to protect yourself, your loved ones, and your animals. -Stay inside in an air conditioned environment between 10am and 7pm. -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 vest, 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. Later today through Saturday, the ridge that has given us these record-breaking temperatures begins to break down and crawl eastwards, allowing for a more zonal (east-west) upper level pattern, a gradual cooling trend, and a slight expansion of the marine layer to begin for the weekend. Low temperatures on Saturday morning hover in the lower to middle 50s for the lower elevations, and the lower to middle 60s for the higher elevations. Highs on Saturday will range from the lower to middle 80s for the inland valleys, the middle to upper 70s close to the Bays, and the 60s along the Pacific coast. && .LONG TERM... Issued at 107 PM PDT Fri Mar 20 2026 (Saturday night through next Thursday) The gradual cooling trend continues into the early part of next week. Despite the more zonal flow regime across the region, the upper level heights continue to stay above the seasonal averages, and a ridge develops across the Desert Southwest towards the middle of the week, keeping the temperatures near or slightly warmer than the seasonal averages. High temperatures will settle around the upper 70s to middle 80s inland and the lower to middle 60s along the coast, and lows will generally hover in the middle 40s to lower 50s in the lower elevations, up to the middle 50s for the higher elevations. The inland valleys of Monterey and San Benito Counties remain rather warm with highs in the upper 80s to lower 90s possible. For those people who are still holding out for a heroic late-season rainstorm, the 7-day forecast shows nary a drop of rain. The CPC outlook for the 8-14 day period does show a lean towards precipitation values closer to the seasonal average, but for downtown San Francisco, that seasonal average only translates to a little above a half an inch of rain. && .AVIATION... (00Z TAFS) Issued at 446 PM PDT Fri Mar 20 2026 Currently VFR at all terminals. Moderate to high confidence on the return of sub-VFR conditions to HAF, MRY, and SNS with low confidence on the return elsewhere. With high pressure, a compressed/shallow marine layer will yield IFR-LIFR ceilings/visibilities primarily for the immediate Pacific Coast. Low stratus will stick close to the coast tomorrow afternoon once VFR is achieved. Onshore winds will prevail. Vicinity of SFO...Currently VFR with northwesterly flow. High confidence in VFR through the TAF period with a low probability (20%) for sub-VFR conditions to return to the terminal tonight. If sub-VFR conditions were to materialize, they will likely be LIFR- IFR. Low stratus can be expected along the Pacific Coast with moderate confidence on it sneaking through the Golden Gate Gap with a San Bruno Gap intrusion unlikely due to the compressed nature of the marine layer. Westerly winds will prevail. SFO Bridge Approach...Similar to SFO. Monterey Bay Terminals...Currently VFR with northerly flow at MRY and VFR with northwesterly flow at SNS. Moderate to high confidence on sub-VFR conditions returning to the terminals tonight. Highest confidence in MRY which is also expected to have the poorest flight conditions. Low stratus will stick to the Pacific Coast tomorrow afternoon. Westerly winds will prevail. && .MARINE... (Tonight through next Wednesday) Issued at 446 PM PDT Fri Mar 20 2026 A cold front will approach the coastal waters tonight and passing through on Saturday. As a result, northwesterly winds will increase tonight through the weekend. The strongest winds will be gales over the northern waters Saturday into early Sunday. Hazardous seas with steep fresh swell will develop due to strengthening winds. && .CLIMATE... Issued at 557 PM PDT Fri Mar 20 2026 The following are the UPDATED record high temperatures at the long term sites for March 20th. Location Mar 20 Santa Rosa 91 in 2026 San Rafael 89 in 2026 Kentfield 88 in 2026 Napa 90 in 2026 Richmond 87 in 2026 Livermore 87 in 1915 San Francisco 90 in 2026 SFO Airport 89 in 2026 Redwood City 93 in 2026 Half Moon Bay 75 in 2010 Oakland Museum 91 in 2026 San Jose 88 in 2026 Salinas Airport 94 in 2026 The following are the UPDATED record high temperatures at the long term sites for the entire month of March. Location Santa Rosa 92 March 19, 2026 San Rafael 89 March 19 and 20, 2026 Kentfield 91 March 28, 1923 Napa 92 March 17, 1914 Richmond 88 March 18, 2026 Livermore 90 March 25 and 26, 2025 San Francisco 90 March 20, 2026 SFO Airport 89 March 20, 2026 Redwood City 93 March 17 and 20, 2026 Half Moon Bay 83 March 31, 2000 and March 17, 2004 Oakland Museum 91 March 20, 2026 San Jose 89 March 14, 2015 Salinas Airport 94 March 20, 2026 && .MTR WATCHES/WARNINGS/ADVISORIES... CA...Heat Advisory until 8 PM PDT this evening for CAZ006-502>506- 508>510-512>518-528>530. PZ...Small Craft Advisory until 3 PM PDT Saturday for Pt Arena to Pt Reyes 0-10 nm-Pt Arena to Pt Reyes 10-60 NM. Gale Warning from 3 PM Saturday to 3 AM PDT Sunday for Pt Arena to Pt Reyes 0-10 nm-Pt Arena to Pt Reyes 10-60 NM. Small Craft Advisory from 3 AM Saturday to 3 AM PDT Sunday for Pt Reyes to Pigeon Pt 0-10 nm. Small Craft Advisory from 3 PM Saturday to 3 AM PDT Sunday for Pigeon Pt to Pt Pinos 0-10 nm. Small Craft Advisory from 9 AM Saturday to 3 AM PDT Sunday for Pt Pinos to Pt Piedras Blancas 0-10 nm. Small Craft Advisory until 3 AM PDT Sunday for Pigeon Pt to Pt Pinos 10-60 NM. && $$ SHORT TERM...DialH LONG TERM....DialH AVIATION...Sarment MARINE...MM Visit us at www.weather.gov/sanfrancisco Follow us on Facebook, X, and YouTube at: www.facebook.com/nwsbayarea x.com/nwsbayarea www.youtube.com/nwsbayarea