644 FXUS66 KMTR 161749 AFDMTR Area Forecast Discussion National Weather Service San Francisco CA 1049 AM PDT Thu May 16 2024 ...New AVIATION, MARINE... .SYNOPSIS... Issued at 1232 PM PDT Wed May 15 2024 Quiet weather will continue with a persistent marine layer through the forecast period. Morning clouds and mist will clear in the afternoon. Despite the clearing, coastal areas will remain in the cool marine air, keeping highs in the 60s. Inland and high elevation areas will reach the 70s and 80s each afternoon. && .SHORT TERM... (Today and tonight) Issued at 1217 AM PDT Thu May 16 2024 High pressure aloft remains the predominant weather feature over the northeast Pacific as weak troughing prevails across the Desert Southwest. We remain on the eastern periphery of the ridge, with minimal influence so far. In fact, the marine layer remains relatively stable from where it was 24 hours ago with a depth of 1.5- 2 kft. Some patchy drizzle was observed around the Monterey Bay area within the past few hours as well. Expect the upper ridge location to remain fairly similar for the remainder of the short term forecast period with little overall change. It's possible that the marine layer may compress a little given the nearby ridge, but so far it's remained fairly consistent in depth. Otherwise it's another day of low clouds clearing to the coast during the afternoon before returning this evening and overnight. Highs today will remain seasonally cool and range from the upper 50s along the coast to the lower-mid 80s inland. && .LONG TERM... (Friday through Wednesday) Issued at 1217 AM PDT Thu May 16 2024 Expect a transition towards west coast troughing by early next week. This pattern is supportive of weak cold frontal passages, cooler temperatures, and breezy northwest winds. Coastal drizzle may become a bit more prominent at times as well. High temperatures will be mostly in the 60s and 70s, with the warmest inland areas perhaps breaking 80 degrees. But by and large readings will remain a touch below seasonal averages. && .AVIATION... (18Z TAFS) Issued at 1034 AM PDT Thu May 16 2024 A 2,000 ft deep marine layer is proving persistent. The clouds are mixing out this morning, and the terminals should enjoy a VFR window this afternoon. NW winds will be moderate to strong before decreasing overnight. The stratus return will be similar to last night with a mix of IFR and MVFR ceilings expected. Vicinity of SFO...Due to southerly flow, SFO managed to dodge a ceiling this morning, and the window has now closed as the cloud bank retreats for the day. Winds will soon shift to westerly as the sea breeze kicks in. Low clouds are expected to return overnight and there is a 50% chance of developing an IFR ceiling in the morning at both SFO and OAK. The visibility should reamin VFR with moderate winds persisting overnight. Monterey Bay Terminals...While the clouds are getting thinner, they skies are only expected to open up for a few hours this afternoon before an early return of stratus this evening at both MRY and SNS. Otherwise W-NW winds will be moderate this afternoon before decreasing overnight. With the deep marine layer, there is also a chance for coastal drizzle in the early morning. && .MARINE... (Today through Tuesday) Issued at 1034 AM PDT Thu May 16 2024 Surface high pressure over the Eastern Pacific Ocean shift eastward towards California. As a result, the pressure gradient will tighten and northwesterly winds will increase, particularly over the northernmost zones and outer waters. Significant wave heights will build to very rough over the outer waters through early next week. && .MTR WATCHES/WARNINGS/ADVISORIES... CA...None. PZ...Small Craft Advisory until 3 AM PDT Saturday for Pt Arena to Pt Reyes 10-60 NM. && $$ SHORT TERM...SPM LONG TERM....SPM 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