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000 FXUS66 KSTO 182031 AFDSTO Area Forecast Discussion National Weather Service Sacramento CA 131 PM PDT Sat Apr 18 2026For additional details on weather and expected impacts over the next 7 days, please visit weather.gov/sto/briefing.KEY MESSAGES
- Dry weather with near to slightly above normal temperatures over the weekend
- Storm system brings renewed precipitation chances in rain, mountain snow and thunderstorms Monday through Wednesday, along with cooler temperatures and breezy winds
DISCUSSION
..Today through Sunday
Current GOES-West satellite imagery illustrates some high clouds starting to move into California on this Saturday afternoon. Temperatures are currently trending approximately 5 to 10 degrees warmer than this time yesterday, valid at 115 PM PDT. The upper level pattern features ridging, bringing warm and dry conditions today the forecast area. Forecast highs this weekend will be in the 70s to low 80s in the Valley and foothills, and in the 50s to 60s in the mountains. These temperatures will be trending near to slightly above normal for this time of year. Generally light winds are prevailing across the area and will gradually increase out of the south on Sunday ahead of an approaching storm system.
..Next Week
An upper low will approach California and move inland early to mid next week, bringing along cooler temperatures, breezy southerly winds, rain, thunderstorms and mountain snow Monday through Wednesday. The latest forecast precipitation amounts have not changed much, with 1 to 2 inches of rain in the Valley and 1.5 to 3 inches of rain in the foothills, with 1 to 2 feet of snow in the mountains. Snow levels will initially be high on Monday, around 6000 to 7000+ feet, and will lower down to the passes Tuesday, and down to 5000 to 6000 feet late Tuesday into Wednesday. Moderate impacts from mountain snow are forecast, with chain controls, travel delays and reduced visibilities at times. The threat for thunderstorms will have the highest chances on Tuesday, which will bring the potential for strong to severe thunderstorms on this day. There are also be some lingering thunderstorm chances into Wednesday as well. Check back frequently for updates on this storm and always check the forecast and road conditions before traveling!
AVIATION
General VFR conditions at TAF sites over the next 24 hours. Increasing cloud cover around 00z Monday as a weather system moves into the area, but no changes in flight categories in the next 24 hours. Winds generally less than 12 kts everywhere until 18z Sunday. Then, southerly winds gradually increase with gusts up to 25 kts in the northern Sacramento Valley and foothills, and up to 30 kts in the mountains through 06z Monday.
STO WATCHES / WARNINGS / ADVISORIES
None.