FXUS66 KSTO 241903

AFDSTO



Area Forecast Discussion

National Weather Service Sacramento CA

1203 PM PDT Fri Oct 24 2025



For additional details on weather and expected impacts over the

next 7 days, please visit weather.gov/sto/briefing.





.KEY MESSAGES...



 - AN ATMOSPHERIC RIVER BRINGS BENEFICIAL SHOWERS, ISOLATED 

   THUNDERSTORM CHANCES, HIGH ELEVATION MOUNTAIN SNOW SHOWERS 

   GUSTY SOUTHERLY WINDS, AND COOLER TEMPERATURES THIS EVENING 

   THROUGH THE WEEKEND.

 

 - ISOLATED SHOWER CHANCES MAY LINGER ACROSS THE NORTHERN/CENTRAL

   SACRAMENTO VALLEY AND SURROUNDING TERRAIN MONDAY MORNING, BUT 

   GENERALLY DRY AND SEASONABLE WEATHER ANTICIPATED ELSEWHERE.



.DISCUSSION...

TODAY - SUNDAY...LATEST GOES-WEST VISIBLE SATELLITE IMAGERY

ILLUSTRATES A BAND OF MID TO HIGH LEVEL CLOUDS DRAPED ACROSS

NORTHERN CALIFORNIA EARLY ON THIS FRIDAY AFTERNOON. THESE CLOUDS

ARE ASSOCIATED WITH THE UPPER LEVEL TROUGH THAT WILL BE DIGGING

DOWN FROM THE GULF OF ALASKA TODAY AND TAPPING INTO ATMOSPHERIC 

RIVER MOISTURE TO BRING PERIODS OF SHOWERS, HIGH ELEVATION 

MOUNTAIN SNOW SHOWERS, GUSTY SOUTHERLY WINDS, COOLER TEMPERATURES 

AND ISOLATED THUNDERSTORM CHANCES LATER TODAY AND THROUGH THE 

WEEKEND AS THE SYSTEM MOVES ACROSS THE PACIFIC NORTHWEST.

STRONGEST WINDS AND THE BEST CHANCES FOR THUNDERSTORMS ARE IN THE

NORTHERN SACRAMENTO VALLEY AND SURROUNDING TERRAIN ON SATURDAY 

AFTERNOON AND EVENING. SLICK ROADS AND MINOR TRAVEL DELAYS WILL BE

POSSIBLE AT TIMES FROM PERIODS OF LIGHT TO MODERATE PRECIPITATION.

FOR MOST AREAS, THERE WILL BE BREAKS IN PRECIPITATION AT TIMES 

OVER THE NEXT 72 HOURS AS PERIODS OF SHOWERS MOVE THROUGH. 

GENERALLY LESS THAN AN INCH OF SNOW ARE FORECAST FOR THE MOUNTAIN 

PASSES, WITH SEVERAL INCHES AT LASSEN PEAK OVER THE WEEKEND. SNOW 

LEVELS WILL INITIALLY BE VERY HIGH TODAY, OVER 8,000 FEET, BEFORE 

LOWERING TO THE PASSES SATURDAY NIGHT INTO EARLY SUNDAY MORNING.



MONDAY - FRIDAY...SOME SHOWERS MAY LINGER OVER THE NORTH/CENTRAL 

SACRAMENTO VALLEY AND SURROUNDING TERRAIN ON MONDAY MORNING AS THE

SYSTEM EXITS THE REGION, HOWEVER LITTLE TO NO IMPACTS ARE 

EXPECTED AND FORECAST AMOUNTS ARE FAIRLY LIGHT. UPPER LEVEL 

RIDGING WILL THEN BUILD BACK IN OVER THE REGION BEHIND IT, 

ALLOWING FOR DRY WEATHER AND SEASONABLE TEMPERATURES TO RETURN TO 

THE FORECAST. PERIODS OF WEAK OFFSHORE FLOW ARE FORECAST, ALONG 

WITH A SLIGHT DRYING TREND IN THE DAYTIME RELATIVE HUMIDITY. SOME 

ENSEMBLES ARE INDICATING THE POTENTIAL FOR THE RETURN OF SHOWERS 

TO THE PACIFIC NORTHWEST NEXT FRIDAY INTO THE FOLLOWING WEEKEND, 

HOWEVER DETAILS REMAIN UNCERTAIN AT THIS TIME. /KH



.AVIATION...

General VFR conditions are expected through this afternoon. A 

weather system will bring scattered showers after 00z-06z Sat, 

with MVFR/local IFR conditions. Isolated thunderstorms possible 

across the northern Sacramento Valley and adjacent terrain 18z Sat

- 00z Sun. Surface winds generally less than 12 kts through 

tonight. Increasing southerly winds after 12z Saturday, with gusts

up to 15-30 kts in the Sacramento Valley and up to 20-35 kts over

the mountains. Patchy fog and mist possible across portions of 

the southern Sacramento Valley and northern San Joaquin Valley 

10z-15z Saturday, with local MVFR conditions.



&&



.STO WATCHES/WARNINGS/ADVISORIES...

None.



&&



$$