Area Forecast Discussion
Issued by NWS Sacramento, CA
Issued by NWS Sacramento, CA
751 FXUS66 KSTO 212015 AFDSTO Area Forecast Discussion National Weather Service Sacramento CA 1215 PM PST Fri Nov 21 2025 .KEY MESSAGES... - Dry conditions prevail this weekend through next week, with periods of breezy offshore flow and morning Valley fog - Seasonable temperatures and dry weather favored for Thanksgiving Day - Potential for unsettled weather to return late next week into next weekend, but confidence is very low on details, impacts and timing && .DISCUSSION... ...Today-Thursday... Current GOES-West visible satellite imagery shows lingering low stratus in the southern Sacramento Valley and northern San Joaquin Valley starting to lift and slowly dissipate early on this Friday afternoon. Dry weather is expected across interior northern California this weekend through most of next week, including Thanksgiving Day, as high pressure acts as the primary synoptic influence. Temperatures will be seasonable for late November climatology, generally in the 60s in the Valley, 50s to 60s in the foothills, and 30s to low 60s in the mountains each day. Locally gusty offshore/downcanyon flow will return this evening into Saturday morning, strongest in the Sierra Nevada where gusts of 20 to 50 mph are possible. Winds will decrease over the weekend. Another round of offshore flow is expected early next week behind the passage of a weather system to the north, but little to no impacts are expected. Areas of dense fog will be possible each morning, mainly in the Valley and Delta. High resolution guidance suggests a 50 to 80 percent probability of visiblities less than 1/2 mile late tonight into Saturday morning across these areas. Be sure to slow down and use low-beam headlights if fog is encountered! ...Next Weekend... Cluster analysis and ensemble guidance continue to suggest the potential for the upper level ridge to break down and for low pressure to develop and approach the West Coast. Confidence is very low on details, impacts and timing, but there is a chance for unsettled weather to return to the region next weekend (or as early as Friday). There is quite a spread in possible outcomes but we will be keeping a close eye on how this trends. Be sure to check back for updates and for local forecast information at weather.gov/sto. && .AVIATION... VFR to MVFR conditions expected from lingering stratus across portions of the Sacramento Valley, mainly over the northern San Joaquin areas and adjacent foothills until around 06z Saturday before conditions will worsen to possible IFR to MVFR conditions. Chances for IFR to LIFR conditions are 60-80% for visibility lower than a half mile from 11z into 18z Saturday, highest over the southern Sac. Valley. North winds with gusts up to 15-20 kts will become light winds into the afternoon with lingering north winds over the northern Sac. Valley through 18z Saturday. Breezy east winds over the Sierra expected after 03z Saturday into 18z Saturday with gusts up to 15 to 25 kts. && .STO WATCHES/WARNINGS/ADVISORIES... None. && $$