Area Forecast Discussion
Issued by NWS Sacramento, CA
Issued by NWS Sacramento, CA
423 FXUS66 KSTO 292055 AFDSTO Area Forecast Discussion National Weather Service Sacramento CA 1255 PM PST Mon Dec 29 2025 For additional details on weather and expected impacts over the next 7 days, please visit weather.gov/sto/briefing. .KEY MESSAGES... - Dry weather through mid-week with cold overnight lows and areas of frost and fog/mist/low clouds in the Valley - Next weather system moves in New Year`s Day bringing the potential for showers and mountain snow showers into the weekend, although confidence is low on details at the moment && .DISCUSSION... ...Today through Wednesday... Fog and low clouds returned this morning across portions of the central Valley. Lower visibilities are currently being observed from Marysville AP through Stockton AP with visibilities at or below 0.25 miles. With the current upper level ridging support and the recent rain, we will keep low clouds/fog/misty conditions in the Valley the next few days. Resultant high temperatures will likely be cooler than forecast, so some adjustments to Valley high temperatures have been made for the afternoon forecast package. Some morning frost will again be possible, mainly in areas that are not seeing low cloud decks or fog. Currently, Redding, Red Bluff, and areas west of I-5 will stand the best chances, as clear skies are dominating at the time of this writing. ...New Years Day through Sunday... Ensembles are continue to depict another round of active weather entering the region by New Years Day and continuing through the weekend and into next week. Latest forecast runs have shown a slight increase in rain totals, with minor fluctuations in snow totals. Initial onset of precipitation looks to be Wednesday afternoon/evening, with mostly if not all rain as snow levels look to be above 8500 feet. Snow levels look to crash late Friday night into Saturday, with levels dropping to around 6000-7000 feet. Uncertainty remains in exact precipitation totals, how fast snow levels fall, and if the Valley gets shadowed as heights are again suggesting a west to east orientation. Regardless, holiday travel looks to be impacted once again for New Years Day and into early next week. We are considering a Winter Storm Watch possibly beginning Friday evening, and will likely make a decision sometime tomorrow on issuance. Stay tuned to the forecast and check our impacts briefing (link at the top of this discussion) for latest thinking and potential impacts for the New Years weather system. && .AVIATION... IFR/LIFR ceilings and/or visibilities are likely to impact the Sacramento area terminals, as well as Stockton and Modesto through much of the 24 hour TAF period as a result of fog/stratus. Limited opportunity for improved visibilities may occur in the afternoon/evening hours, but are then expected to deteriorate again overnight. The BKN/OVC cloud deck will be difficult to mix out today as satellite trends depict an overall expansion over the course of Monday morning. Winds are forecast to be less than 12 kts at terminals today. && .STO WATCHES/WARNINGS/ADVISORIES... None. && $$