Area Forecast Discussion
Issued by NWS San Francisco Bay Area, CA
Issued by NWS San Francisco Bay Area, CA
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368 FXUS66 KMTR 230938 AFDMTR Area Forecast Discussion National Weather Service San Francisco CA 238 AM PDT Sun Jun 23 2024 ...New SYNOPSIS, SHORT TERM, LONG TERM, MARINE... .SYNOPSIS... Issued at 237 AM PDT Sun Jun 23 2024 Somewhat cooler temperatures in the interior today, continuing into the beginning of the work week with a slight cooldown midweek. Very low chance of elevated convection and associated dry lightning in the southern Central Coast. && .SHORT TERM... (Today and tonight) Issued at 237 AM PDT Sun Jun 23 2024 Skies remain generally clear throughout the region, save for stratus that has developed around the Monterey Bay region, and stratus development for the rest of the morning is limited to the coast and potentially the North Bay valleys and northern SF Bay region. Low temperatures tonight range from the low to mid 50s in the lower elevations to the 60s to low 70s in the higher elevations. With the upper level ridge moving off to the east, highs will be somewhat cooler today, with highs in the upper 80s to mid 90s in the interior valleys, perhaps close to 100 in the warmest spots, with highs in the 70s expected across the Bayshore and the mid 50s to mid 60s across the Pacific coast. The main forecast issue continues to be the potential for elevated convection over the southern sections of Monterey and San Benito counties this afternoon and evening. A shot of mid-level moisture will come into the region from the south, ahead of a weak upper level trough. The latest 3km NAM forecast soundings for Paso Robles continue to show a moistening low to mid layer and respectable lapse rates. Below the moist layer, conditions remain dry, which will hamper any precipitation from any cells that pop up, but will also raise the risk of dry lightning, especially with MUCAPE levels above 1000 J/kg. All that said, the potential for any storms to develop continues to be low, hovering around 10-15%. One factor that limits storm potential is that the synoptic forcing remains to our north and west, requiring any storms that do develop to be topographically- driven. Confidence in any fire weather concerns remains too low to message as a fire weather headline. The day shift will take another look at the forecast as updated model output comes in. && .LONG TERM... (Monday through Saturday) Issued at 237 AM PDT Sun Jun 23 2024 The mid-layer moisture continues to push through the region and will push across the Bay Area on Tuesday. In addition to the mid- to upper level clouds that will typically accompany the moisture, the chance for elevated convection mainly across the Central Coast remains through Tuesday, although as with Sunday, the chances are very low. Interior temperatures will cool off on Wednesday and Thursday, with highs in the 80s to the mid 90s, as an upper level trough comes into the West Coast and promotes improved onshore flow. CPC outlooks continue to suggest that temperatures above seasonal averages will continue into the first week of July. && .AVIATION... (06Z TAFS) Issued at 1031 PM PDT Sat Jun 22 2024 Satellite imagery shows stratus across the Monterey Bay region, with the rest of the region generally clear. Stratus will build across the coastal regions through the night, with moderate confidence of ceilings at the North Bay and northern SF Bay terminals. Stratus will retreat to the immediate coast Sunday morning with breezy onshore winds developing in the afternoon and evening. Stratus expected to build back in Sunday evening, mostly after the end of the 24-hour TAF period. Vicinity of SFO...Currently VFR. Moderate confidence of an IFR ceiling at the terminal early morning on Sunday, with some high- resolution models still showing VFR through the night. If ceilings do form, expect clearing by 16Z. Breezy west-northwest winds with gusts up to 20 knots will develop on Sunday afternoon, diminishing in the evening. Some model output is showing a chance for ceilings on Sunday night, mostly after the end of the TAF period. SFO Bridge Approach...Lower confidence of stratus impacts to the south of the terminal. Otherwise similar to SFO. Monterey Bay Terminals...LIFR stratus through the night with the chance for fog at MRY. Clearing is expected later on Sunday morning, with breezy onshore winds developing in the afternoon. Stratus will return to the terminals Sunday evening near the end of the TAF period. && .MARINE... (Today through Friday) Issued at 237 AM PDT Sun Jun 23 2024 Strong, northwest winds persist over the northern outer waters through Monday, creating hazardous conditions for small craft. Fresh gusts remain possible over the southern outer waters and portions of the northern interior coastal waters. Wave heights up to 10 feet are expected throughout the northern outer waters with significant wave heights diminishing below 10 feet by the middle of the work week. Light southerly swell and moderate NW swell continue over the coastal waters through the beginning of next week. && .MTR WATCHES/WARNINGS/ADVISORIES... PZ...Small Craft Advisory from 9 AM this morning to 9 PM PDT this evening for Pt Arena to Pt Reyes 0-10 nm. Small Craft Advisory until 9 AM PDT Tuesday for Pt Arena to Pt Reyes 10-60 NM. && $$ SHORT TERM...DialH LONG TERM....DialH AVIATION...DialH MARINE...DialH 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