Area Forecast Discussion
Issued by NWS Sacramento, CA
Issued by NWS Sacramento, CA
077 FXUS66 KSTO 152110 AFDSTO Area Forecast Discussion National Weather Service Sacramento CA 110 PM PST Sat Nov 15 2025 For additional details on weather and expected impacts over the next 7 days, please visit weather.gov/sto/briefing. .KEY MESSAGES... - Widespread light to moderate precipitation spreads from the south late this afternoon through Sunday morning. Less widespread precipitation expected Sunday afternoon. - A colder system will bring more widespread rain and moderate mountain snow Sunday PM into Monday. Breezy southerly winds will accompany the system, along with isolated thunderstorms on Monday. - Drier conditions return Tuesday into Wednesday morning, followed by another weather system late Wednesday into Friday. .DISCUSSION... ...Saturday through Sunday Morning... Light to moderate widespread precipitation is expected late this afternoon through Sunday morning as an upper low pushes northward. Highest precipitation amounts are expected over the eastern Valley and Sierra foothills/mountains. Forecast precipitation totals are 0.75-1.00 in the Valley and Delta. Amounts over the mountains and foothills are generally between 1.00 to 1.75 inches. Snow levels will start out above 8000 feet before dropping down to 6500-7500 feet Sunday morning. Breezy southerly winds will also increase over the weekend with the strongest gusts in the Delta and northern Sacramento Valley. ...Late Sunday through Early Next Week... Less widespread precipitation is expected Sunday afternoon as system exits the area. Then, renewed chances for widespread precipitation are forecast late Sunday into Monday as colder weather system drops down from the north. WPC Guidance shows the latest precipitation totals to be around 0.50-1.00" in the Valley and Delta, with 1.00-1.50" in the foothills and mountains. This system will be colder, with snow levels around 6500-7000 feet Sunday, lowering to around 5500-6000 feet by Monday morning. A Winter Weather Advisory has been issued for the Sierra and southern Cascades above 6000 feet from 10 PM tonight through 4 PM Monday. Total snow accumulations of 4 to 10 inches are anticipated above 6000 feet with 1 to 2 feet at the highest peaks. Additionally there is a 10 to 20% chance of isolated thunderstorms Monday afternoon. Breezy southerly winds are also expected with this system, with forecast gusts between 25 to 35 mph. The strongest winds are expected across portions of the northern Sacramento Valley, Delta, and the Sierra. ...Mid to Late Next Week... Drier conditions are expected Tuesday through Wednesday morning. Another system may approach the region Wednesday evening into Friday, potentially bringing widespread precipitation and mountain snow. However, high uncertainty remains regarding potential storm track and precipitation totals. .AVIATION... VFR conditions until around 05z in the northern San Joaquin Valley as a weather system moves in from the south. Conditions gradually deteriorate northward in the evening/night hours as rain overtakes most of the area. MVFR/IFR conditions with southerly wind gusts up to 25 knots in the Valley; 35 knots in the Delta. Snow levels around 6500 feet in the mountains Sunday morning with 20-30 knot southerly wind gusts. && .STO WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory from 10 PM this evening to 4 PM PST Monday for West Slope Northern Sierra Nevada-Western Plumas County/Lassen Park. && $$