FXUS66 KMTR 200645 AFDMTR Area Forecast Discussion National Weather Service San Francisco CA 1145 PM PDT Sun May 19 2024 ...New AVIATION, MARINE... .SYNOPSIS... Issued at 1237 PM PDT Sun May 19 2024 Typical summer-like pattern to persist throughout the first half of the week. Temperatures are forecast to dip below seasonal averages by late week and into the upcoming weekend as an upper level trough impacts the region. && .UPDATE... Issued at 927 PM PDT Sun May 19 2024 It's clear except for patchy low clouds forming along coastal San Mateo County and Santa Cruz County, including around the rest of the Monterey Bay and northern Salinas Valley in northern Monterey County. Satellite also shows a couple patches of low clouds over southern Santa Clara County. The marine layer slopes from a depth of a few hundred feet at Bodega Bay to 2,000 feet at Fort Ord. A high pressure system is located 1,000 miles west of the Bay Area and a 500 mb low pressure trough is over the western states. With weak (and dry) surface low pressure over interior California, a strong pressure gradient exists mainly over the coastal waters, generating gales over the coastal waters. Point Arena buoy and Bodega Bay buoy wind gusts have been near 40 knots, recently cold water upwelling has lowered the sea surface temperature to 49F at Point Arena buoy. && .SHORT TERM... (This evening through Monday) Issued at 1237 PM PDT Sun May 19 2024 Clouds continue to rapidly erode as of early this afternoon and will continue to do so into the evening. Low clouds are more than likely to return to the Monterey Bay region and the San Francisco Peninsula overnight but will clear by early-to-mid morning. Also, cannot rule out patchy drizzle in and around the Monterey Bay early Monday morning. Afternoon temperatures for Monday will be similar to today, yet coastal areas will warm by a few degrees thanks to northerly flow across the region. Thus, expecting highs to range from the lower 60's to near 70 degrees at the coast with mid 70's to lower 80's across the interior. && .LONG TERM... (Monday through Saturday) Issued at 301 AM PDT Sun May 19 2024 A slight warming trend is expected through mid-week with temperatures building into the upper 70s to mid 80s by Tuesday/Wednesday. Inland stratus coverage is expected to be less impressive this week as a deeper marine layer and gusty offshore winds keep the atmosphere well mixed and low clouds confined to the coast. Ensemble guidance agrees that Tuesday is looking to be the warmest day this week with the highest probability of widespread temperatures greater than 80 degrees. Minor heat risk begins to spread through most of the Bay Area and portions of the Salinas Valley Monday through Thursday. People who are incredibly sensitive to heat should take precautions while outdoors and remember to drink plenty of water. By late week, upper level troughing strengthens and moves farther south into California with an associated surface low passing through the state. This will bring about a pattern change with widespread below average temperatures expected. By the weekend, inland highs will be in the upper 60s to mid 70s with coastal highs in the upper 50s to low 60s. CPC temperature outlooks have temperatures leaning below average through the end of May and into the beginning of June. Ensemble guidance suggests this system will be fairly dry for our region with any precipitation associated with it directed northwards of us into far northern California/southern Oregon. && .AVIATION... (06Z TAFS) Issued at 1145 PM PDT Sun May 19 2024 VFR through the TAF Period for all but the Monterey Bay, which will see MVFR CIGs through the mid morning. Expect light to moderate winds overnight for most areas overnight. Moderate winds build into Monday afternoon, with gusty winds expected along the immediate coast and around the SF Bay. Vicinity of SFO...VFR through the TAF period. Expect moderate west winds overnight. Gusty westerly winds arrive Monday afternoon with peak gusts around 25 kts. These winds reduce into the early night. SFO Bridge Approach...Similar to SFO Monterey Bay Terminals...MVFR CIGs linger into the mid morning. Expect light winds overnight with more moderate westerly winds arriving Monday afternoon and lasting into the night. && .MARINE... (Tonight through next Saturday) Issued at 1145 PM PDT Sun May 19 2024 Strong and gusty northwesterly winds will continue over much of the coastal waters tonight and Monday, with only slight reductions in wind speed over the inner coastal waters during the overnight hours. Expect hazardous conditions and steeper wind waves during the week. Winds may ease late in the week. && .MTR WATCHES/WARNINGS/ADVISORIES... CA...None. PZ...Gale Warning until 3 AM PDT Monday for Pt Arena to Pt Reyes 0-10 nm. Small Craft Advisory until 3 AM PDT Tuesday for Pt Reyes to Pigeon Pt 0-10 nm. Small Craft Advisory until 3 AM PDT Monday for Pt Pinos to Pt Piedras Blancas 0-10 nm. Gale Warning until 9 AM PDT Tuesday for Pt Arena to Pt Reyes 10- 60 NM. Gale Warning until 3 AM PDT Tuesday for Pigeon Pt to Pt Pinos 10- 60 NM. && $$ SHORT TERM...RGass LONG TERM....Kennedy AVIATION...Murdock MARINE...Canepa 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