Area Forecast Discussion
Issued by NWS San Francisco Bay Area, CA
Issued by NWS San Francisco Bay Area, CA
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329 FXUS66 KMTR 180414 AFDMTR Area Forecast Discussion National Weather Service San Francisco CA 914 PM PDT Fri May 17 2024 ...New UPDATE, MARINE... .SYNOPSIS... Issued at 108 PM PDT Fri May 17 2024 Quiet weather persists. Widespread stratus coverage dissipating by mid-to-late morning with breezy, clear conditions developing by the afternoon. Heading into the weekend, stratus coverage will be diminished with stratus primarily confined to coastal regions and down into the Salinas Valley. && .UPDATE... Issued at 914 PM PDT Fri May 17 2024 If you`ve been following the weather these past few days, you know what`s coming: Satellite imagery is showing marine layer stratus building from the coast and flowing into the interior, expected to expand in coverage through the night. The clouds are expected to retreat to the coast in the morning, with onshore flow developing into the afternoon and clear skies expected through the day across the interior. No changes to the forecast at this time. DialH && .SHORT TERM... (This evening through Saturday) Issued at 108 PM PDT Fri May 17 2024 Low clouds continue to erode across most inland areas as of early afternoon, but are still hanging on around the Monterey Bay region and adjacent valleys, Santa Cruz Mountains, and coastal areas of the North Bay. Tonight, expecting less inland penetration of stratus across the North Bay and the greater San Francisco Bay Area. However, stratus will spread back inland and down into the Salinas Valley (and adjacent valleys). Where stratus does develop, drizzle will remain possible again tonight into Saturday morning. Morning cloud cover will retreat back to the coast by mid-to-late morning or early afternoon. Saturday will be seasonably cool with temperatures near the coast in the upper 50`s to mid 60`s and mid 60`s to upper 70`s inland across the far interior. && .LONG TERM... (Saturday night through next Friday) Issued at 537 PM PDT Fri May 17 2024 An upper level trough develops over the West Coast later in the weekend, the first in a series of upper level troughs expected to impact the western United States through the next week. The troughing pattern will cool 850 mb temperatures to around the mid to upper 50s. Coincidentally, sea surface temperatures as currently observed are also around this range, and an old rule of thumb is that stratus decks don`t typically develop whenever the 850 mb and sea surface temperatures are close to each other. The end result of all of this: a potential for more enhanced mixing out of the marine layer next week, with a consequent warmup for the inland regions in the early part of the work week. Temperature forecasts for next week are low confidence at this time. The current expectation is for highs to range from the mid 70s to the low 80s in the inland valleys, with coastal regions remaining cool near the upper 50s to lower 60s. CPC products show a lean towards temperatures below seasonal averages, and precipitation above seasonal averages, through the end of May. && .AVIATION... (00Z TAFS) Issued at 505 PM PDT Fri May 17 2024 A discontinuous marine layer continues to hug the coast this evening with MVFR cigs impacting MRY and SNS. Once the sun sets do expect the marine layer to move inland, but inland impacts are lower confidence especially inside SF Bay and East Bay. Any Saturday morning cigs will erode back to the coast with VFR expected at all terminal Saturday afternoon. Additionally, there is a 20-30% of fog impacting MRY and SNS Saturday morning. Vicinity of SFO...Breezy NW winds will persist through the evening rush. Cigs will linger in the gap this evening, but not expecting cigs at SFO. SFO Bridge Approach...Some cigs around 1500 feet have a chc of impacting the approach during the Saturday AM rush. Conf is 50-60%. Monterey Bay Terminals...Despite a SW wind at MRY cigs remain. TAFS were update to keep cigs this evening and for the rest of the night. Less than 15% chc of a brief period of SCT cigs at MRY/SNS this evening. Cigs have a better chance of clearing late Saturday AM. && .MARINE... (Tonight through next Thursday) Issued at 914 PM PDT Fri May 17 2024 Strong high pressure off the Pacific Northwest coast and low pressure over southern Nevada will maintain moderate to locally strong northerly winds. Winds will gradually increase over the weekend. The strongest winds will be strong north of Point Reyes, especially the outer waters with gale force gusts. Stronger winds will lead to hazardous conditions and steeper wind waves. && .MTR WATCHES/WARNINGS/ADVISORIES... CA...None. PZ...Small Craft Advisory from 3 PM Saturday to 9 AM PDT Sunday for Pt Arena to Pt Reyes 0-10 nm. Small Craft Advisory until 3 PM PDT Saturday for Pt Arena to Pt Reyes 10-60 NM. Gale Warning from 3 PM Saturday to 9 AM PDT Sunday for Pt Arena to Pt Reyes 10-60 NM. Small Craft Advisory from 9 PM Saturday to 9 AM PDT Sunday for Pigeon Pt to Pt Pinos 10-60 NM. && $$ SHORT TERM...RGass LONG TERM....DialH AVIATION...MM MARINE...MM 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