Area Forecast Discussion
Issued by NWS San Francisco Bay Area, CA
Issued by NWS San Francisco Bay Area, CA
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146 FXUS66 KMTR 080946 AFDMTR Area Forecast Discussion National Weather Service San Francisco CA 246 AM PDT Sat Jun 8 2024 ...New SYNOPSIS, SHORT TERM, LONG TERM, 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. && .UPDATE... Issued at 853 PM PDT Fri Jun 7 2024 The short term forecast is in good shape with just some minor tweaks to overnight wind grids for some of the East Bay Hills/Mountains, as well as across coastal waters (including the northern part of the San Francisco/San Pablo Bay areas). Flow this evening along the shoreline remained quite brisk, especially along the Marin Headlands up toward Bodega Bay. In fact, the Bodega Bay Profiler indicates around 35 knots of flow around 1km. Whether or not this momentum mixes down to the surface is a little uncertain, however, some of the short-term guidance (e.g., HRRR) suggests this is a possibility. Winds across some of the coastal waters---from Bodega Bay down through the Golden Gate Gap were adjusted upward to the 75th NBM percentile. Winds appear that they`ll channel through the Golden Gate Gap and accelerate through portions of the SF and San Pablo Bays, as well as the west Delta. East Bay Hills and Mountains may also be recipients of this accelerated flow. The 75th percentile NBM numbers translate to 20 to 30 mph wind gusts later tonight into the pre-dawn hours on Saturday morning. The impact will be rough boating conditions for small craft as well as an increased potential for any loose outdoor articles (trash cans, lawn furniture) to be blown about in the wind. The rest of the forecast remains in good shape and updated products have been transmitted. && .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... (06Z TAFS) Issued at 1127 PM PDT Fri Jun 7 2024 MVFR and IFR CIGs are moving inland affecting most of the TAF sites overnight and into Saturday morning with some areas along the coast and in the Monterey seeing CIGs into Saturday afternoon. Pockets of haze look to continue to affect the region through much of Saturday in spite of moderate to breezy winds through the afternoon and evening. Winds reduce into Saturday night as stratus moves slightly inland once again. Vicinity of SFO...MVFR lasts through the late morning. Winds stay moderate through the night and begin to increase into Saturday afternoon as CIGs dissipate, with gusts peaking around 25 kts. Portions of the SF Bay may still be affected my reduced visibility from haze, but it becomes less likely into the afternoon. Expect winds to reduce in the late evening, but stay moderate through Saturday night. SFO Bridge Approach...Similar to SFO. Monterey Bay Terminals...IFR-LIFR CIGS are expected through he late morning before CIGs lift to MVFR levels into the afternoon before dissipating. Winds stay light to moderate overnight with some pockets of mist and drizzle affecting the terminals. Winds increase in the mid afternoon as VFR returns, but haze could still affect local visibility. Weaker winds and lower clouds return Saturday evening. && .MARINE... (Today through Thursday) Issued at 242 AM PDT Sat Jun 8 2024 Chances for patchy fog and light drizzle continue through the morning, within the Monterey Bay and along the Big Sur Coast.Breezy to gusty northwesterly winds will develop over the waters through the weekend. Significant wave heights build throughout the weekend with wave heights peaking between 12 to 14 feet. Elevated wave heights and gusty conditions will create hazardous conditions for small crafts that will continue through the weekend and into the following work week. && .MTR WATCHES/WARNINGS/ADVISORIES... CA...None. PZ...Small Craft Advisory from 9 AM this morning to 3 AM PDT Sunday for SF Bay N of Bay Bridge. Small Craft Advisory from 9 AM this morning to 3 AM PDT Monday for Pt Arena to Pt Reyes 0-10 nm. Small Craft Advisory until 3 AM PDT Monday for Pt Arena to Pt Reyes 10-60 NM-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 3 AM PDT Monday for Pigeon Pt to Pt Pinos 10-60 NM. && $$ SHORT TERM...AC LONG TERM....AC AVIATION...Murdock MARINE...Murdock 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