Lake effect snow will continue through Friday bringing significant snowfall to areas east to southeast of the Great Lakes. Snow squalls may impact New Year's Eve travel this evening and overnight across parts of the Great Lakes, Ohio Valley, Mid-Atlantic, and Upstate New York. Heavy rain will bring another flash flooding threat for southern California New Year's Eve into New Year's Day. Read More >
| ZOA CWSU Discussion | KSFO TAF TDA | |
| AWAITING CWSU INPUT | TAF TDA KSFO/KSQL METAR METARArea PIREPs PIREP |
|
| Satellite | Webcams, Ceiling≤030 Prob | |
|
Webcams
|
||
| SIERRA 03 Hour Forecast | SIERRA 12 Hour Forecast | SIGMETs |
| TANGO 03 Hour Forecast | TANGO 12 Hour Forecast | |
| ZULU 03 Hour Forecast | ZULU 12 Hour Forecast | |
| Area Forecast Discussion | Forecast Maps |
|
455 FXUS66 KMTR 311802 AFDMTR Area Forecast Discussion National Weather Service San Francisco CA 1002 AM PST Wed Dec 31 2025 ...New AVIATION... .KEY MESSAGES... Updated at 859 AM PST Wed Dec 31 2025 - High astronomical tides combined with storm surge will bring minor to moderate coastal flooding around high tide through Sunday. - A prolonged rainy period starts today. - Strong southerly winds are likely Friday and into Saturday morning. && .UPDATE... Issued at 859 AM PST Wed Dec 31 2025 Light rain is occurring across the coastal ranges, especially across the Santa Lucia Range and Santa Cruz Mountains with generally less than 0.05" of rainfall in the past 6 hours. Rain will increase in coverage throughout the day, yet amount are forecast to generally remain light. The ongoing forecast remains on track at this time with no updates anticipated this morning. The San Francisco tidal gauge reached 1.47 ft above normal (7.31 ft MLLW) at around 7:51 AM PST and is gradually lowering. RGass && .SHORT TERM... Issued at 1229 AM PST Wed Dec 31 2025 (Today and tonight) We switched KMUX to precip mode as rain and/or virga moving in from the south is coming in range. Most of this activity is over the coastal waters, and the lowest radar scan can only see 7,000 feet at this range. Unfortunately there aren`t any buoys or ships capable or willing to report if anything is reaching the surface. Based on the 00Z sounding, most of these rain drops will evaporate in the well defined dry layer below 800 mb where the average relative humidity is less than 15%. Of course the evaporation itself raises the humidity and makes it easier for subsequent drops to make it further down. The moistening process will continue through the morning, priming the lower atmosphere for more efficient rain as the day progresses. The overall pattern is driven by a vertically stacked cut-off low roughly 500 miles west of the Channel Islands. The eastern periphery of this feature is pumping a large area of southerly winds and associated moisture from the deep tropics. This low will catch the next ride NE on an the upstream portion of an approaching long wave trough moving across the Eastern Pacific. This upper level pattern will also provide divergence aloft, removing weight from above the surface low, thus decreasing the surface pressure and providing some moderate cyclogenesis as the feature moves towards the Bay Area. We should pick up between 0.5-1.0" of rain over the next 24 hours as a warm up for the rest of the week. Will it rain for NYE celebrations? Probably, yes. In the Bay Area a rain jacket or umbrella should do just fine in the steady light rain and gentle wind expected up till midnight. If you`re celebrating on the Central Coast, it may be a little heavier in the last hour or two of the year. && .LONG TERM... Issued at 1229 AM PST Wed Dec 31 2025 (Thursday through Tuesday) The warm, moist southerly winds with an approaching, deepening low pressure system to our west means we should get a somewhat uncommon warm frontal passage Thursday. Antecedent warm moist air with increasing kinematics support as the front approaches should support some stronger convection and possibly trigger some thunderstorms as the front passes. This threat will be greatest if the triple point (where the occlusion, cold front, and warm front meet) moves over land. The Central Coast has the best chance for thunderstorms. The thermodynamics don`t look great until midday on Thursday, but if the timing lines up with frontal passage, it could get interesting. A NAM point sounding at Salinas shows the FROPA timing will be very close to the instability window opening around noon. Otherwise the afternoon of New Years Day should just bring scattered showers as opposed to the more widespread rain on NYE. After the low makes landfall Thursday, a more typical atmospheric river set-up will takes shape for Friday. A deep trough over the Eastern Pacific will bring strong SW flow to the California, with a ribbon of moisture pointed somewhere between the North Bay and Southern California. The high moisture anomaly near Baja never really clears out, and will push north again, reinforcing this round of rain. This should be the wettest and windiest day of the week, with bigger impacts bleeding into Saturday morning. Southerly winds will likely gust into the 50 mph range along the coast and in higher terrain just ahead of the cold frontal passage. Conditions will improve behind the front, but scattered showers will continue through the weekend, with 0.5-1.0" expected each day from Saturday through Monday. A new low pressure system and associated cold front is possible Monday or Tuesday. The ensemble clusters have differing opinions on the strength and timing of this feature, but they all show a trough off the coast, which is enough to keep rain chances around through the entire 7-day forecast period. KMUX will stay in precip mode for the foreseeable future. && .AVIATION... (18Z TAFS) Issued at 1002 AM PST Wed Dec 31 2025 Light rain has returned to much of the Bay Area and the Central Coast. Current ceilings are VFR but guidance shows them dropping to MVFR by late this afternoon/early this evening. Confidence on timing of ceilings dropping is low to moderate with moderate confidence and models in agreement that CIGs will drop to around 2000-2500 ft for much of this TAF period. Models do show CIGs dropping to IFR overnight but confidence is currently low for that scenario. Winds stay out of the south to southeast and remain breezy through the forecast period. Gusts to around 20 to 25 knots are expected at breezier sites (SFO, OAK, and SNS with some potential for gusts at HAF and MRY) Thursday morning. Maintained visibilities dropping slightly as rain moves in. However, I followed a similar trend as the previous forecaster and kept drops in visibility limited to around 4SM to 5SM given light rainfall expected. Models show visibilities dropping down to 2-3SM but confidence is low that will occur unless locally moderate to heavy rain is able to develop. Vicinity of SFO...Light showers are located offshore of SFO with scattered showers to move in throughout the remainder of the morning. Moderate confidence in MVFR CIGs developing by late this afternoon/early this evening with low confidence that CIGs will become IFR overnight. Winds generally remain southerly and are expected to strengthen by tomorrow morning. Currently kept gusts to around 18 knots at SFO tomorrow but this may need to be adjusted upwards to between 20-25 knots. SFO Bridge Approach...Similar to SFO. Monterey Bay Terminals...Light rain is moving over the Monterey Peninsula with VFR conditions to continue. Ceilings lower to MVFR by late this afternoon/early this evening as showers become more scattered in nature. Winds remain southerly through the TAF period with winds strengthening after 06Z. Gusts will strengthen at SNS overnight with highest confidence in gusts to 26 knots developing but there may be occasional gusts up to 30 knots tomorrow morning. && .MARINE... (Today through Monday) Issued at 859 AM PST Wed Dec 31 2025 Moderate to fresh winds and moderate seas continue into Thursday. Widespread light rain and a low potential for thunderstorms across the southern waters continues into Thursday. Winds rapidly strengthen from strong to gale force by early Friday as a second, stronger, system arrives. Periods of moderate to heavy rain and a slight potential for thunderstorms are expected Friday into Saturday. Winds diminish early Sunday but breezy conditions and rain showers continue into next week. && .BEACHES... Issued at 859 AM PST Wed Dec 31 2025 Perigean spring tides (King Tides) will impact the region through Sunday. This is due to the combination of the full moon on 1/3, lunar perigee on 1/1, and perihelion on 1/3. In other words all three planetary bodies are lined up and close to each other. In addition to the high astronomical tide, the incoming low pressure system will bring strong southerly winds, generating some storm surge. The combination of these factors will bring minor to moderate coastal flooding to the low-lying areas near shorelines and tidal waterways during high tide through Sunday. At the San Francisco tidal gauge, high tide is expected to be 2.0 ft above normal at 8:41 AM Thursday, 2.2 ft above normal at 9:34 AM Friday, 2.2 ft above normal at 10:26 AM Saturday, and 1.8 ft above normal at 11:18 AM Sunday. These predictions include up to 1 foot of storm surge that will enhance the astronomical tide and flooding threat. High tide varies up to 90 minutes earlier or later along the Pacific Coast and through the San Francisco Bay, respectively. && .MTR WATCHES/WARNINGS/ADVISORIES... CA...Coastal Flood Advisory until 2 PM PST Sunday for CAZ006-505-506- 508-509-529-530. PZ...Small Craft Advisory from 9 PM Thursday to 3 AM PST Friday for Pt Arena to Pt Reyes 0-10 nm-Pt Arena to Pt Reyes 10-60 NM. Gale Warning from 3 AM to 9 AM PST Friday for Pt Arena to Pt Reyes 0-10 nm-Pt Arena to Pt Reyes 10-60 NM-Pt Pinos to Pt Piedras Blancas 0-10 nm. Small Craft Advisory from 3 AM to 3 PM PST Thursday for Pigeon Pt to Pt Pinos 0-10 nm. Gale Warning from 9 PM this evening to 3 PM PST Thursday for Pt Pinos to Pt Piedras Blancas 0-10 nm. Small Craft Advisory from 9 PM this evening to 3 PM PST Thursday for Pigeon Pt to Pt Pinos 10-60 NM. Small Craft Advisory from 3 AM to 9 AM PST Friday for Pigeon Pt to Pt Pinos 10-60 NM. && $$ SHORT TERM...Flynn LONG TERM....Flynn AVIATION...Kennedy MARINE...Kennedy Visit us at www.weather.gov/sanfrancisco Follow us on Facebook, X, and YouTube at: www.facebook.com/nwsbayarea x.com/nwsbayarea www.youtube.com/nwsbayarea |
|
| Yesterday | ⇛Visible ⇛Nighttime ⇛GeoColor+GLM | Today | |
| 24-Hour Temp Change | 24-Hour RH Change | ||
⇛Visible ⇛Nighttime ⇛GeoColor+GLM
 |
|
Additional Links
National Airspace System Status
Other Webcams:
Alert California San Bruno Mountain
Alert California Sutro Tower 2
Alert California Coll of San Mateo Bldg36
Follow us on X
ZOA RSS Feed