Area Forecast Discussion
Issued by NWS San Francisco Bay Area, CA
Issued by NWS San Francisco Bay Area, CA
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772 FXUS66 KMTR 211955 AFDMTR Area Forecast Discussion National Weather Service San Francisco CA 1255 PM PDT Fri Jun 21 2024 ...New SYNOPSIS, SHORT TERM... .SYNOPSIS... Issued at 1253 PM PDT Fri Jun 21 2024 A Heat Advisory comes into effect on Saturday for the interior regions with a moderate risk of heat-related illnesses. Temperatures moderate through the early part of next week, but remain warm across the interior. && .SHORT TERM... (This evening through Saturday) Issued at 1253 PM PDT Fri Jun 21 2024 Tonight, temperatures will generally cool into the mid 50`s for most locations away from the immediate coast with some upper 40`s in those locations. However, warm temperatures will persist across the higher elevations where temperatures will only dip into the upper 60`s to upper 70`s. Stratus will also return to the region this evening, yet will penetrate less inland overnight as high pressure compresses the marine layer. Temperatures on Saturday will be the warmest of the week with maximum temperatures reaching 105 degrees across the warmest inland areas to mid 90`s in the interior valleys. This is where we have a Heat Advisory in effect where HeatRisk reach moderate levels, across the interior and higher elevations in the Santa Lucia Range. Near the coast and areas just inland, mid 70`s to mid 80`s for the Bayshore, and the 60`s and low 70`s along the Pacific coast as a shallow marine layer remains in place. Much of the interior is expected to see Moderate HeatRisk tomorrow, most notably the interior East Bay, South Bay, and southern Salinas Valley. This means that there is a risk of heat-related illnesses for most people sensitive to heat, including children, the elderly, pregnant women, those working or living outside, and those with certain medical conditions. Here are heat safety tips: * Stay hydrated and drink plenty of fluids. * Wear lightweight, light-colored clothing. * Reduce time spent outdoors or stay in the shade. * Never leave people, the elderly, or pets unattended in vehicles. * Use sunscreen if going to the coast or the pool. && .LONG TERM... (Saturday night through Thursday) Issued at 1231 AM PDT Fri Jun 21 2024 Sunday should be noticeably cooler with an upper level trough to our west beginning to promote stronger onshore flow. High temperatures will drop into the mid 80s to the low 90s in the interior valleys (perhaps close to 100 in the warmest spots), the 70s into the lower 80s along the Bayshore, and the upper 50s to the 60s along the coast. Expect these temperatures to continue into the next work week. Beyond that, CPC outlooks continue to suggest chances for temperatures above seasonal averages (around 33-50% probability) and precipitation near or below seasonal averages into the first few days of July. && .AVIATION... (18Z TAFS) Issued at 1057 AM PDT Fri Jun 21 2024 Deep marine layer this morning allowing ample stratus coverage. Expecting all terminals to clear to VFR through the remainder of the day today, with stratus returning in the evening hours for coastal sites. Winds today follow the typical diurnal onshore pattern. Marine layer compresses tonight and Saturday under a high pressure ridge, leading to LIFR/IFR cigs and FG impacts at coastal terminals early Saturday morning. All sites clear to VFR by mid Saturday morning with high confidence of VFR through the day. Vicinity of SFO...Clear and remaining VFR through the day. Gusty NW winds 20-25 kts this afternoon, diminishing by about 05-06Z. Some marine stratus will make its way into the Bay overnight. However, not currently expecting enough coverage for a cig at the terminal (low-medium confidence). SFO Bridge Approach...Similar to SFO. Monterey Bay Terminals...Clouds pulling back to the coastline and VFR through the afternoon. Expecting IFR cigs to return between 01-03Z (medium-high confidence), lowering to LIFR during the overnight period. Some FG impacts as well for terminals more near the coast with vis as low as 1/4SM. Conditions are expected to improve rapidly mid Saturday morning. && .MARINE... (Today through Wednesday) Issued at 845 AM PDT Fri Jun 21 2024 Moderate to fresh northwesterly winds prevail into the weekend with strong near gale forced winds over the northern outer waters. These stronger gusts may pose hazardous for small craft. Significant wave heights of 6-8 feet will persist until the end of the week, then build back up to 10-12 feet over the outer waters for the weekend, when northwest winds increase once again over much of the waters. Light southerly swell continues to move through the waters today, accompanied by moderate NW swell. && .MTR WATCHES/WARNINGS/ADVISORIES... CA...Heat Advisory from 11 AM to 10 PM PDT Saturday for CAZ504-510- 513>518. PZ...Small Craft Advisory until 9 AM PDT Sunday for Pt Arena to Pt Reyes 10-60 NM. Small Craft Advisory until 9 PM PDT Saturday for Pigeon Pt to Pt Pinos 10-60 NM. && $$ SHORT TERM...RGass LONG TERM....DialH AVIATION...Behringer 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