Area Forecast Discussion
Issued by NWS Sacramento, CA
Issued by NWS Sacramento, CA
965 FXUS66 KSTO 062122 AFDSTO Area Forecast Discussion National Weather Service Sacramento CA 122 PM PST Thu Mar 6 2025 .SYNOPSIS... Lingering showers through the early afternoon then dry weather returns for Friday through Sunday with northerly flow. Active weather then returns next week bringing periods of major travel impacts from rain, wind and mountain snow impacts across Northern CA. && .DISCUSSION... Isolated showers continued this morning with lingering chain controls over the Sierra. As we progress through the day, conditions will continue to dry and see the inevitable end to our Winter Weather Advisory later today. Looking past this event, we can expect dry weather through the weekend with temperatures getting into the mid 60s to low 70s by Sunday. Friday will see breezy winds with gusts up to 15-25 MPH in the Valley but no significant impacts expected. We continue to look next week for more active weather bringing periods of moderate to very heavy snowfall, rain, gusty winds, and possible isolated thunderstorms. Be sure to check the latest update at weather.gov/sto as we get closer to the event. && .EXTENDED DISCUSSION (Monday THROUGH Thursday)... Ensemble guidance and cluster analysis continue to exhibit high confidence in an active weather pattern returning to the forecast over the extended forecast period with multiple weather systems moving through Monday and again Tuesday through Thursday bringing along rain, wind and mountain snow impacts to interior northern California. Here is a look at some 72 hour probabilities from the National Blend of Models (NBM) ending 5 AM Thursday: Probability of Rain > 1 inch: 55-95% Probability of Rain > 2 inches: 15-30% (Valley), 45-80% (foothills) Probability of Mountain Snow > 48 inches: 40-85% Probability of Mountain Snow > 60 inches (N of I-80): 40-70% Probability of Mountain Snow > 60 inches (S of I-80): 15-45% Probability of Wind Gusts > 40 mph: 50-85% (Valley/Foothills) Probability of Wind Gusts > 55 mph: 45-75% (Foothills/Mountains) In addition to the higher probabilities from the NBM, the Extreme Forecast Index (EFI) is also highlighting the potential for these impacts, especially in the middle of next week. Although there is still some uncertainty in exact details such as snow levels, precipitation amounts and wind speeds, confidence is high in the active weather over the extended forecast period for Interior NorCal. Stay tuned for more information as we get closer and plan ahead for wet, cool and windy weather! (Listed Snow Probs are for above 5000 feet but still fair amount of uncertainty regarding exact snow levels!) && .AVIATION... MVFR/IFR conditions along the Sierra through 00z. Otherwise, widespread VFR conditions evolve through the afternoon elsewhere, then persist into Friday. Generally light winds less than 12 kts expected next 24 hours, becoming gradually breezier from a north to east direction after 15z Friday. && .STO WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until 4 PM PST this afternoon for Burney Basin / Eastern Shasta County-West Slope Northern Sierra Nevada- Western Plumas County/Lassen Park. && $$