Area Forecast Discussion
Issued by NWS San Francisco Bay Area, CA
Issued by NWS San Francisco Bay Area, CA
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922 FXUS66 KMTR 131130 AFDMTR Area Forecast Discussion National Weather Service San Francisco CA 430 AM PDT Mon May 13 2024 ...New AVIATION, MARINE... .SYNOPSIS... Issued at 1208 AM PDT Mon May 13 2024 A relatively quiet pattern will persist featuring overnight and morning coastal clouds with clear skies elsewhere. Inland temperatures will warm into the 70s and 80s each afternoon with cool onshore breezes keeping coastal temperatures in the 60s. && .SHORT TERM... (Today and tonight) Issued at 1208 AM PDT Mon May 13 2024 A weak upper low will drift towards the central CA coast while upstream ridging dominates the northeast Pacific. This pattern will promote the subsequent deepening of the marine layer today as low stratus clouds penetrate deeper inland. The top of the marine inversion has continued to increase, and is now up to around 2,000 feet per the Fort Ord profiler. Given this depth wouldn`t be surprised to see a little coastal drizzle early this morning in the favorable spots so added this to the forecast. Any accumulations should be quite minor. Otherwise look for low clouds to clear back towards the coast this afternoon with the marine influence keeping coastal/bayside temperatures in the 60s. Elsewhere look for 70s and 80s in the warmest inland valleys, with a few locations in southern Monterey County perhaps nearing 90 degrees. Clouds will push back inland by this evening with mostly cloudy conditions again prevailing for many areas tonight. Lows will dip into the upper 40s && .LONG TERM... (Tuesday through Sunday) Issued at 1208 AM PDT Mon May 13 2024 Temperatures will cool slightly with onshore flow and weak troughing aloft persisting. An upper ridge does build/strengthen over the northeast Pacific by mid week, but it appears our area will remain along its periphery with no strong signal for a warming trend. In general high temperatures will range from the 60s along the coast to the lower-mid 80s for the warmest inland areas. This will only produce a minor HeatRisk for the warmest locations. Lows will generally be in the lower to mid 50s. Coastal clouds are likely during the overnight and AM hours with a gradual clearing towards the coast each afternoon. && .AVIATION... (12Z TAFS) Issued at 430 AM PDT Mon May 13 2024 Currently seeing a mix of VFR-LIFR at the terminals. The marine layer is overall on a deepening trend with the depth currently at about 1,800 feet according to the Fort Ord Profiler; however, it did experience a few hours of compression between the 06Z TAF issuance and this one. LIFR-MVFR conditions are slated to return to all terminals except LVK tonight. Ceiling heights will be highly dependent on the evolution of the marine layer between now and then. Widespread VFR and breezy onshore flow will prevail by this afternoon. Vicinity of SFO...Currently IFR with breezy westerly flow. High-end IFR-low-end MVFR stratus will continue to impact the terminal through the late morning. Winds will remain onshore and breezy through the TAF period. Confidence is low on what exactly the terminal will see overnight in terms of ceiling height due to the lack of model/guidance consensus and a finicky marine layer. The outcome is highly dependent on the evolution of the marine layer between now and then, but current thinking is that the terminal will see a ceiling and it will likely be low-end MVFR-high-end IFR again. SFO Bridge Approach...Similar to SFO. Monterey Bay Terminals...Currently LIFR with westerly flow at both terminals. Conditions will briefly improve to VFR by the afternoon with a quick return to LIFR this evening for MRY and IFR tonight for SNS. Westerly/northwesterly winds will prevail through the TAF period. && .MARINE... (Today through Saturday) Issued at 430 AM PDT Mon May 13 2024 Fair weather will prevail through the week as surface high pressure over the Eastern Pacific Ocean builds and moves east. Fresh northwesterly breezes will prevail Monday and Tuesday before winds begin to diminish mid-week. Significant wave heights will continue to build to 12-15 feet by Tuesday before gradually abating through the rest of the week. && .MTR WATCHES/WARNINGS/ADVISORIES... CA...None. PZ...Small Craft Advisory from 3 PM this afternoon to 9 PM PDT this evening for Mry Bay-Pt Pinos to Pt Piedras Blancas 0-10 nm. Small Craft Advisory until 9 AM PDT Tuesday for Pt Arena to Pt Reyes 10-60 NM. Small Craft Advisory from 9 PM this evening to 9 AM PDT Tuesday for Pigeon Pt to Pt Pinos 10-60 NM. && $$ SHORT TERM...SPM LONG TERM....SPM AVIATION...Sarment MARINE...Sarment 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