Area Forecast Discussion
Issued by NWS San Francisco Bay Area, CA
Issued by NWS San Francisco Bay Area, CA
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556 FXUS66 KMTR 081803 AFDMTR Area Forecast Discussion National Weather Service San Francisco CA 1103 AM PDT Sat Jun 8 2024 ...New AVIATION, MARINE... .SYNOPSIS... Issued at 242 AM PDT Sat Jun 8 2024 Cooler temperatures and breezy afternoon onshore winds last through the weekend. Another warm up is expected towards the beginning of next week. && .SHORT TERM... (Today and Sunday) Issued at 242 AM PDT Sat Jun 8 2024 Temperatures at this time of night are running anywhere from 5 to 10 degrees cooler than this same time yesterday for inland regions, with areas closest to the coast and covered by stratus running about 1 to 2 degrees warmer than yesterday. Looking at current air temperatures across the CWA, the spread between the coast and inland areas is very little, with largely uniform temperatures in the mid 50s. That being said, the cool off continues today as a weak trough moves through. High temperatures generally reach into the low to mid 80s for most inland locations today, perhaps a few upper 80s in the favored warm spots in the far southern Salinas Valley, and northern Sonoma and Napa counties. High temperatures at the coast will reach into the upper 50s and low 60s. Breezier onshore winds will return this afternoon, with gusts nearing the 25 mph range in the East Bay and Delta region, but will ease into the nighttime as the gradient eases. Largely a rinse and repeat for Sunday. One thing worth noting for today`s forecast is the inclusion of haze in the forecast for select locations. With recent ridging and compression of the atmosphere, particulate matter including smog, smoke, dust, and sea salt (the latter being lofted up by winds) have largely been confined close to the surface with nowhere to go. A look at area METAR reports the past few days shows reduced visibilities in the early evenings and reports of haze. Therefore have included the potential for haze in today`s forecast. However, expectations are that as the weak trough moves through later today, this allowance for rising air and breezier onshore flow should help to move particulate matter out of the region, therefore decreasing the appearance of hazy skies into Sunday. && .LONG TERM... (Monday through Friday) Issued at 242 AM PDT Sat Jun 8 2024 Starting Monday, another warm up begins as slight ridging develops once more. High temperatures reach into the high 80s and lower 90s for inland regions, with the warmest spots achieving temperatures in the mid 90s. Tuesday, temperatures increase a few degrees more with mid to upper 90s expected for the warmest spots. A few spots reaching into the low 100s namely in the eastern most portion of our CWA are not out of the question. Meanwhile, temperatures at the coast will maintain in the mid 60s. Warm temperatures persist into Wednesday, but begin to drop by a few degrees. Despite the warmer temperatures, NWS HeatRisk is currently largely only in the minor category, impacting those extremely sensitive to heat (ill, elderly, pregnant, or young children) as overnight low temperatures in the mid 50s will provide good overnight relief for all. Small pockets of moderate heat risk are possible in the warmest areas nearest to the Central Valley. Nonetheless, its never a bad idea to make sure you are staying adequately hydrated during times of warmer temperatures, taking breaks in the shade if working outdoors, and to check in on loved ones who perhaps fall into the demographics of those most sensitive to heat. Additionally, if planning to visit the coast or a body of water to cool off, make sure you wear a life jacket, swim ideally near a lifeguard, and be aware of the risks of cold water shock. Towards Thursday of the week next week, high temperatures take a dip and begin to cool off as troughing resumes. A cutoff low hanging off the coast of southern California will lift out to our northeast, inducing the cool-off. All for now, but stay tuned for updates as we near the warming event. Have not issued any heat-related products at this time. && .AVIATION... (18Z TAFS) Issued at 1032 AM PDT Sat Jun 8 2024 Coastal stratus is eroding and VFR conditions will prevail through the remainder of the day. Moderate SW winds will prevail in the North Bay, with NW winds at SJC and westerly winds elsewhere. MVFR-IFR stratus will return to most terminals overnight. Vicinity of SFO...VFR under high clouds. WNW winds will be moderate to strong this afternoon, and will remain fairly consistent once they get started. The big question at SFO is if ceilings will return overnight. The TAF keeps it clear for now, but there is a 20-30% chance of a low MVFR ceiling in the early morning hours Saturday, similar to what was observed this morning. OAK has a better chance, and MVRF ceilings were included in the TAF from 13-17Z Sunday. SFO Bridge Approach...The bridge approach will likely stay clear of low clouds, even if SFO and OAK develop ceilings Sun morning. Monterey Bay Terminals...MVFR ceilings are lingering, but the visible satellite loop shows they will soon break at both MRY and SNS. VFR conditions are likely for about 9-12 hours before the stratus returns this evening. GFSLAMP shows a 15% chance of LIFR ceilings developing around 12Z at MRY, and with subtle compression expected in the marine layer, the ceilings may drop lower than they were this morning (OVC006). Otherwise, moderate onshore winds will persist through the TAF period. && .MARINE... (Today through Thursday) Issued at 1032 AM PDT Sat Jun 8 2024 The gradient between subtropical high pressure and lower pressure over the SW US is supporting a moderate to fresh NW breeze. As the high pressure slowly encroaches towards the coast, the pressure gradient will tighten, causing the wind speed to increase through the weekend. A fresh to strong NW breeze will persist through next week with the potential for gale force winds by next weekend. Significant wave heights will mostly be dominated by wind driven waves, though there is a moderate NW swell and a low SW swell mixed in. && .MTR WATCHES/WARNINGS/ADVISORIES... CA...None. PZ...Small Craft Advisory until 3 AM PDT Sunday for SF Bay N of Bay Bridge. Small Craft Advisory until 9 AM PDT Monday for Pt Arena to Pt Reyes 0-10 nm-Pt Arena to Pt Reyes 10-60 NM. Small Craft Advisory until 3 AM PDT Monday for Pt Reyes to Pigeon Pt 0-10 nm. Small Craft Advisory from 3 PM Sunday to 3 AM PDT Monday for Pt Pinos to Pt Piedras Blancas 0-10 nm. Small Craft Advisory from 3 PM this afternoon to 9 AM PDT Monday for Pigeon Pt to Pt Pinos 10-60 NM. && $$ SHORT TERM...AC LONG TERM....AC AVIATION...Flynn MARINE...Flynn Visit us at www.weather.gov/sanfrancisco Follow us on Facebook, Twitter, and YouTube at: www.facebook.com/nwsbayarea www.twitter.com/nwsbayarea www.youtube.com/nwsbayarea