Area Forecast Discussion
Issued by NWS San Francisco Bay Area, CA
Issued by NWS San Francisco Bay Area, CA
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646 FXUS66 KMTR 251558 AFDMTR Area Forecast Discussion National Weather Service San Francisco CA 858 AM PDT Sat May 25 2024 ...New UPDATE... .SYNOPSIS... Issued at 1259 AM PDT Sat May 25 2024 Cool with abundant overnight stratus through the weekend. Warming and drying trend set for next week with temperatures around seasonal normal. && .UPDATE... Issued at 857 AM PDT Sat May 25 2024 May gray in full effect this morning across the Bay Area and Central Coast with widespread clouds, drizzle, and patchy fog. Enough onshore flow is present that may gray filtered through the Delta and up the Sacramento Valley. Morning balloon sounding out of Oakland Airport puts the moist marine layer depth at 3k ft, which is definitely on the upper end of marine layer depths. Patchy fog: a few automated sensors have visibilities bouncing between 3-5 miles. Patchy fog is also being seen on Bay Area webcams. Drizzle: as noted below enough lift overhead led to precipitation last night through early this morning. It was more than just few wet roads as rain gages tipped a few hundredths to as much at two tenths. Impressive to say the least with weak forcing and moist low levels. For the rest of the day - a gradual thinning of inland clouds will continue through mid-late morning. Coastal areas will be the last to clear out. In fact, hi-res guidance suggests that locations around Monterey Bay and SF Peninsula Coast will struggle to clear with patchy clouds lingering through much of the day. No update needed this morning. MM && .SHORT TERM... (Today and tonight) Issued at 1259 AM PDT Sat May 25 2024 Deep, moist marine layer this morning allowing for stratus to push well inland. Additionally, a weak passing trough has provided just enough lift to bring drizzle to areas along the coast and in the hills. Several locations along the SF Peninsula, East Bay hills, and Central Coast have actually measured a few hundredths of an inch here and there as a result. Skies will gradually clear inland today with some coastal locations remaining in the clouds. Another cool day with afternoon highs similar to yesterday. && .LONG TERM... (Sunday through Friday) Issued at 1259 AM PDT Sat May 25 2024 Warming and drying trend starts Sunday into the middle of next week as a broad ridge builds across the West Coast. Afternoon highs expected to be near seasonal normals by mid-to-late week. Typical onshore flow pattern persists with overnight and morning clouds clearing back to the shoreline each afternoon. && .AVIATION... (12Z TAFS) Issued at 410 AM PDT Sat May 25 2024 Low stratus clouds are expanding across the region is morning with a troughing pattern supporting a deep marine layer and onshore winds. As with yesterday expect a slower erosion of ceilings towards the coast during the afternoon. Low confidence in exact clearing times around the Monterey Bay and at KSFO/KOAK as a result, and there is a ~20% chance that clouds may stick around longer than advertised in the current TAF. Breezy onshore winds return this afternoon and evening. Vicinity of SFO...Sub-VFR ceilings in low stratus will persist through the morning (high confidence). There is a low potential (~20%) for stratus lingering into the afternoon hours at or around the terminal. Winds will remain breezy and onshore with gusts up to 25 kt this afternoon. Low stratus returns/expands once again tonight. SFO Bridge Approach... Similar to SFO. Monterey Bay Terminals...Sub-VFR conditions this morning in low stratus with periods of minor visibility restrictions in -DZ. Somewhat lower confidence in clearing times today, with most indications suggesting clouds scatter out during the late morning to early afternoon hours. However an alternate scenario would keep low stratus around through the entire day. For now opted to show some period of scattering out this afternoon but adjustments could be necessary based on trends. Breezy onshore winds return this afternoon and early this evening with low stratus expanding across the area yet again. && .MARINE... (Today through Thursday) Issued at 410 AM PDT Sat May 25 2024 Fresh northwest breeze over the outer waters persists through the weekend creating hazardous conditions for small crafts. Fresh to strong northwest and onshore winds across the coastal waters and bays during the afternoons by early to mid next week. Otherwise mostly quiet marine conditions through the forecast period. && .MTR WATCHES/WARNINGS/ADVISORIES... CA...None. PZ...Small Craft Advisory from 3 PM this afternoon to 9 PM PDT this evening for Mry Bay. Small Craft Advisory until 3 AM PDT Sunday for Pt Arena to Pt Reyes 0-10 nm. Small Craft Advisory until 9 AM PDT this morning for Pt Reyes to Pigeon Pt 0-10 nm. Small Craft Advisory from 3 PM this afternoon to 3 AM PDT Sunday for Pigeon Pt to Pt Pinos 0-10 nm-Pt Pinos to Pt Piedras Blancas 0-10 nm. Small Craft Advisory until 3 AM PDT Monday for Pt Arena to Pt Reyes 10-60 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...Behringer LONG TERM....Behringer AVIATION...SPM MARINE...Behringer 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