


Area Forecast Discussion
Issued by NWS Sacramento, CA
Issued by NWS Sacramento, CA
156 FXUS66 KSTO 171921 AFDSTO Area Forecast Discussion National Weather Service Sacramento CA 1221 PM PDT Fri Oct 17 2025 .KEY MESSAGES... - Dry weather with near normal temperatures across the region this weekend through much of next week - Locally breezy north to east winds on Monday behind a weather system passing to the north - Potential for a potent atmospheric river event late next week into next weekend (October 24-27) .DISCUSSION... Today through Sunday...Current GOES-West visible satellite imagery illustrates mostly sunny skies across interior northern California this afternoon with just a few high clouds passing overhead. Dry weather and near normal temperatures prevail today and over the weekend. Upper level ridging will continue through Saturday before an upper trough crosses the Pacific Northwest on Sunday. Chances for fog development are lower on Saturday morning than they were today (generally 15-35% chance of 1/2 mile visibility or less in portions of the Valley and Delta), however some patchy fog in the Valley cannot be ruled out. Forecast highs in the Valley are in the 70s to low 80s. Ensembles and clusters have trended a little farther north with the upper trough for Sunday and there is no precipitation or impacts expected from this system. Monday through Thursday...Behind the passage of the Pacific Northwest trough, there will be some locally breezy north to east winds. The strongest winds will be mainly along and west of Interstate 5 in the Delta, the Sacramento Valley, the adjacent Coast Range foothills and the Sierra, with gusts of 15 to 20 mph on Monday. Little to no impacts are expected at this time, with fire weather concerns minimal due to recent rain and mountain snow. Much lighter northerly flow may linger into Tuesday morning. Near normal temperatures are favored at the start of the week and then temperatures gradually cool to slightly below normal later in the week as ridging flattens. Next Weekend...We are monitoring the potential for a potent atmospheric river event late next week into next weekend (October 24-27) as an upper level trough deepens off the Gulf of Alaska and approaches the West Coast. The Climate Prediction Center (CPC) is indicating a risk for heavy precipitation, heavy mountain snow and strong winds over this timeframe for much of northern California. Stay tuned for more information as details on timing and intensity of this storm become more clear. The dry weather this weekend into next week would be a good time to clean up leaves, gutters and drains ahead of the incoming storm to help minimize potential flood impacts. /KH .AVIATION... Expect general VFR conditions are expected to prevail, with clear skies and light variable winds for TAF sites. Confidence is low for the return of fog tonight, with a slight chance (20%) of visibility 0.5 miles or less 11z-16z for the Sacramento metro area and into the Delta. && .STO WATCHES/WARNINGS/ADVISORIES... None. && $$