607 FXUS66 KMTR 070912 AFDMTR Area Forecast Discussion National Weather Service San Francisco CA 212 AM PDT Thu Aug 7 2025 ...New SHORT TERM, LONG TERM... .KEY MESSAGES... Updated at 210 AM PDT Thu Aug 7 2025 - Patches of Moderate HeatRisk Friday through Monday for interior East and South Bays. - Seasonally warm conditions through the early part of next week. - Elevated fire weather concerns given the warming and drying trend coupled with daily afternoon/evening breezes. && .SHORT TERM... Issued at 210 AM PDT Thu Aug 7 2025 (Today and tonight) No major changes from the last discussion. Broad troughing sits over the majority of the West Coast this morning, with the closed low swinging into the PacNW today. To our east, the upper level ridge over the Four Corners will continue to flatten. Temperatures for interior locations today may climb a couple degrees higher while most locations will be similar to yesterday. As noted before, could still see some haze/smoke nudge into interior San Benito from the Gifford Fire to the south on Thursday. && .LONG TERM... Issued at 210 AM PDT Thu Aug 7 2025 (Friday through Wednesday) Upper level troughing slides to the east late Thursday into Friday, as the eastern Pacific high builds into the region. This will hold through the weekend and into early next week. The only real change noted in the forecast period is that the warmer weather looks to hold through Monday. Patches of Moderate HeatRisk are expected for portions of the East, South, and North Bay while Minor HeatRisk is expected elsewhere. For those who have to work in or are looking to enjoy the outdoors, be sure to practice heat safety. Wear sunscreen, take breaks, hydrate, and look before you lock your vehicle. && .AVIATION... (06Z TAFS) Issued at 945 PM PDT Wed Aug 6 2025 The areal extent of marine stratus continues to fluctuate this evening. This translates to low to medium confidence in the 06Z TAF package. Nighttime satellite reveals several large patches of stratus with an eddy across Monterey Bay. Mid-level troughing is expected to encourage stronger onshore flow during the pre-dawn hours on Thursday. This should mean an reasonable opportunity for IFR (at KHAF) to MVFR cigs at just about all Bay Area TAF sites; the exception is KLVK. Cigs will be intermittent at KSTS and KAPC, with a more continuous period of MVFR stratus at KOAK. I cannot rule out a brief period of IFR cigs, but confidence is too low to include at this time. While MVFR is currently not advertised at KSJC, there's some guidance that suggest it is a possibility around 15 UTC. KHAF may carry a cig through much of the valid TAF cycle, with brief periods of VFR. Most of the afternoon is expected to be VFR at the remaining terminals. MVFR cigs are anticipated to return late Thursday into Saturday, though confidence is low in the current TAF timing. Vicinity of SFO...VFR with intermittent MVFR Thursday AM and breezy to windy conditions. Impacts are possible to the morning push, if it is busier than usual due to clouds. Elevated winds of 15 knots will continue this evening, with gusts abating through the mid-morning hours. The window for MVFR and potential loss of VAPS is between 1200 and 1600 UTC. There may be a brief window for light/variable winds, but onshore flow/westerly flow will be the predominant wind regime. Winds increase to near 20 knots with gusts as great as 30 knots on Thursday afternoon. All indications are that gusts will subside by 0600 UTC, along with a return of MVFR stratus near/during the evening push. SFO Bridge Approach...Loss of VAPS potentially between 1200-1600 UTC Thursday. VFR in the afternoon with MVFR/possible loss of VAPS around 0300 UTC Friday. Monterey Bay Terminals...An eddy continues to churn through the bay which has helped to dissipate stratus that moved onshore. It may take some time for stratus to re-develop across Monterey Bay, but short-term guidance continues to advertise this potential. The latest TAF set adjusts the onset of IFR cig with brief windows of LIFR cigs/visibility. Confidence is low to medium. A window of VFR is anticipated late morning/early afternoon on Thursday. If little to no stratus develops prior to sunrise, it's possible that both terminals will remain VFR until late Thursday afternoon. During this time stronger onshore flow is anticipated and is expected to translate into an increased potential for IFR Thursday evening/night. && .MARINE... (Tonight through next Tuesday) Issued at 853 PM PDT Wed Aug 6 2025 Widespread fresh to strong northwesterly gusts will continue tonight into Thursday. A coastal jet off of Point Reyes and off of the Big Sur coast will bring near gale force gusts. Winds ease beginning Friday with a gentle to moderate breeze prevailing through the weekend. Moderate seas persist through the forecast period, with a brief period of 10 to 12 foot wave heights in the northern outer waters on Friday. && .FIRE WEATHER... Issued at 937 AM PDT Wed Aug 6 2025 After coordination calls this morning with fire partners we'll be hoisting a headline for the afternoon fire weather forecast. The headline will mainly focus on the increasing temperatures coupled with the lower humidity Friday and over the weekend. The greatest areas of concern will be the higher terrain and interior locations. Low elevations will see better humidity recovery, but higher terrain will be persistently dry. Daily sea breeze pushes occuring during peak heating will also elevate concerns. Taking a look at the Hot Dry Windy index also highlights concerns pushing values into the 95th percentile later in the weekend and early next week. MM && .MTR WATCHES/WARNINGS/ADVISORIES... CA...None. PZ...Small Craft Advisory until 9 PM PDT this evening for Pt Arena to Pt Reyes 0-10 nm. Small Craft Advisory until 3 AM PDT early this morning for Pt Reyes to Pigeon Pt 0-10 nm. Small Craft Advisory until 3 AM PDT Friday for Pigeon Pt to Pt Pinos 10-60 NM-Pt Pinos to Pt Piedras Blancas 0-10 nm. Small Craft Advisory until 3 PM PDT Friday for Pt Arena to Pt Reyes 10-60 NM. && $$ SHORT TERM...KR LONG TERM....KR AVIATION...Bain MARINE...JM 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