FXUS66 KMTR 192323 AFDMTR Area Forecast Discussion National Weather Service San Francisco CA 423 PM PDT Fri Jul 19 2024 ...New AVIATION, MARINE, FIRE WEATHER... .SYNOPSIS... Issued at 302 AM PDT Fri Jul 19 2024 Warm again going into the weekend. Short cool down Sunday with another warm up on the way through next week. && .SHORT TERM... (This evening through Saturday) Issued at 301 PM PDT Fri Jul 19 2024 Hot weather continues through today before closer to seasonal temperatures return Saturday. A heat advisory is currently in effect for interior portions of the Bay Area and the Central Coast through 11PM tonight when it will be allowed to expire. Highs are generally running 5 to 12 degrees above average inland while coastal temperatures continue to be closer to seasonal averages. Widespread moderate heat risk continues through Friday. Those who are sensitive to heat should take precautions to avoid being outdoors during peak heating (afternoon/evening hours) and drink plenty of water while participating in any outdoors activities. Not a fan of today's heat? You're in luck because temperatures will drop 5 to 6 degrees on Saturday as a weak shortwave trough moves inland over the Western United States. For the past few days building high pressure has helped to keep the marine layer compressed below 1000 ft which has kept stratus more patchy and confined closer to the coastline. The passage of this shortwave trough will allow the marine layer to deepen slightly and for stratus to spread slightly farther inland by Saturday night. Warmer and drier conditions in combination with locally gustier winds across mountain gaps/passes will lead to elevated fire weather concerns in the North/East/South Bay and in interior Monterey/San Benito Counties Friday and Saturday. However, fair to good overnight relative humidity recoveries and decent daytime minimum relative humidity values will reduce the overall fire weather risk. && .LONG TERM... (Saturday night through next Thursday) Issued at 301 PM PDT Fri Jul 19 2024 Seasonal temperatures continue Sunday before our next warm up begins Monday. By Monday, the shortwave trough which brought us cooler weather will have moved out of our region and upper level ridging will build again. Forecast high temperatures, thankfully, continue to look cooler than those observed during our previous early July heatwave. Across the interior, temperatures will peak in the 90s to low 100s. Temperatures cool down the closer to the coast you go with highs close to the coast peaking in the upper 70s to 80s but only peaking in the mid 60s to low 70s directly along the coastline. The most recent guidance suggests Monday and Tuesday to be the peak of the heatwave for our region with temperatures trending a few degrees (1-3 degrees) cooler Wednesday and Thursday. Moderate heat risk will become more widespread Monday through Thursday with pockets of major heat risk expected in elevated terrain across the East/South Bay and interior Central Coast. Take advantage of the more seasonal weather Saturday and Sunday and take care of any activities that require you to be outdoors for long periods of time. Looking past this forecast period, high temperatures are expected to drop off more significantly beginning Friday. CPC guidance indicates that cooler, more seasonal temperatures are likely to return by the end of the July and potentially bring some relief from the hot weather through early August. && .AVIATION... (00Z TAFS) Issued at 417 PM PDT Fri Jul 19 2024 VFR across the region with breezy onshore winds setting up through the evening. Stratus development tonight is limited to the Central Coast and Monterey Bay regions, with very low confidence of stratus near OAK. Beyond the 24-hour TAF period, winds look to be much gustier on Saturday afternoon and evening. Vicinity of SFO... VFR through the TAF period with low confidence for stratus on Saturday evening. Winds will build through the evening gusting up to 30 knots, with gusts abating overnight before gusts in the 30-35 knot range resume Saturday afternoon and evening. Low confidence in gusts above 35 knots on Saturday. SFO Bridge Approach... Similar to SFO. Monterey Bay Terminals... With the marine layer not as compressed as yesterday, IFR stratus is set to return to the terminals late tonight around 08-10Z. Low to moderate confidence in the timing of any clearing on Saturday morning with model output suggesting some chance of ceilings continuing beyond the end of the TAF period, especially over MRY. Breezy onshore winds expected during the afternoon and evening hours both today and Saturday. && .MARINE... (Tonight through next Wednesday) Issued at 417 PM PDT Fri Jul 19 2024 Gusty northwest winds will increase tonight with strongest mainly across the northern waters which will see gale force gusts. In the unprotected waters, short period seas will build with wave heights between 10-12 feet Friday and further deteriorate to very rough by Sunday. && .FIRE WEATHER... Issued at 417 PM PDT Fri Jul 19 2024 ...Near critical fire weather conditions continue through Saturday due to hot and dry conditions inland... Dry and warm conditions continue inland with very dry fine fuels contributing to an increased risk of fire starts. This results in near critical fire weather conditions through Saturday across the interior regions of the North Bay, East Bay, South Bay, and Monterey and San Benito counties. Onshore winds will develop each afternoon and evening, with peak gusts in the gaps and passes up to 30 to 40 miles per hour. The strongest gusts appear to develop for the evening hours on Saturday, but as relative humidities are expected to be recovering from daytime minimums during the period of peak wind gusts, the alignment between dry air and high winds is not there for acute fire weather concerns. && .MTR WATCHES/WARNINGS/ADVISORIES... CA...Coastal Flood Advisory from 9 PM this evening to 2 AM PDT Tuesday for CAZ006-506-508. Heat Advisory until 11 PM PDT this evening for CAZ503-504-506- 510-513>515-517-518. PZ...Gale Warning until 9 PM PDT Saturday for Pigeon Pt to Pt Pinos 10-60 NM-Pt Arena to Pt Reyes 0-10 nm-Pt Arena to Pt Reyes 10-60 NM. Small Craft Advisory until 9 PM PDT Saturday for Pigeon Pt to Pt Pinos 0-10 nm-Pt Pinos to Pt Piedras Blancas 0-10 nm-Pt Reyes to Pigeon Pt 0-10 nm. && $$ SHORT TERM...Kennedy LONG TERM....Kennedy AVIATION...DialH MARINE...Murdock 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