601
FXUS65 KREV 210858
AFDREV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
158 AM PDT TUE OCT 21 2025
KEY MESSAGES
* MILD AND MOSTLY DRY WEATHER WILL PREVAIL MUCH OF THIS WEEK WITH
A CHANCE OF SHOWERS AND THUNDERSTORMS SOUTH OF US-50 WEDNESDAY.
* A MODEST ATMOSPHERIC RIVER SYSTEM BRING PERIODS OF STRONG WINDS,
VALLEY RAIN, AND HIGH ELEVATION SIERRA SNOW LATE FRIDAY THROUGH
SUNDAY, BUT CONFIDENCE REMAINS LOW.
DISCUSSION
AN UPPER-LEVEL RIDGE WILL MAINTAIN SEASONABLE TEMPERATURES, LIGHT
WINDS, AND MOSTLY DRY CONDITIONS THROUGH THURSDAY, BEFORE A MORE
ACTIVE WEATHER PATTERN SETS IN FOR THE WEEKEND. FOR TODAY, EXPECT
MOSTLY SUNNY SKIES THIS AFTERNOON, WITH HIGH TEMPERATURES RUNNING
ABOUT 5 DEGREES ABOVE AVERAGE—REACHING THE MID TO UPPER 60S IN
SIERRA VALLEYS AND LOW 70S IN WESTERN NEVADA VALLEYS.
OVERNIGHT, A CUTOFF LOW OFF THE S.CALIFORNIA COAST WILL BEGIN TO
MOVE INLAND, BRINGING A 10–20% CHANCE OF ISOLATED SHOWERS,
PRIMARILY FOR AREAS SOUTH OF US-50. INSTABILITY AND UPPER FORCING
WITH THE LOW WILL INCREASE CHANCES OF AFTERNOON THUNDERSTORMS ON
WEDNESDAY AFTERNOON TO 15–25%, AGAIN MAINLY SOUTH OF US-50. THE
HIGHEST CHANCES WILL BE ALONG THE E.SIERRA, PARTICULARLY IN MONO
COUNTY WHERE SMALL HAIL AND PELLET SHOWERS WILL BE POSSIBLE.
SHOWERS AND THUNDERSTORMS WILL DIMINISH THROUGH THE EVENING WITH
DRY AND SEASONABLE CONDITIONS RETURNING FOR THURSDAY.
FOR THIS WEEKEND, ATTENTION TURNS TO A MODEST ATMOSPHERIC RIVER
SYSTEM. RECENT MODEL TRENDS HAVE SHIFTED THE MAIN MOISTURE AXIS
NORTHWARD INTO THE PACIFIC NORTHWEST, DECREASING THE EXPECTED
PRECIPITATION ACROSS THE SIERRA AND W.NEVADA. WHILE CONFIDENCE IS
LOW ON PRECIPITATION TOTALS, CONFIDENCE IS GROWING IN A TRANSITION
TO AN OVERALL COLDER, WETTER, AND WINDIER PATTERN THIS WEEKEND.
CURRENTLY, THERE’S A 40–50% CHANCE OF AT LEAST 1 INCH OF LIQUID
EQUIVALENT PRECIPITATION IN THE NORTHERN SIERRA, AND ABOUT A 25%
CHANCE IN MONO COUNTY. SNOW LEVELS ARE EXPECTED TO REMAIN HIGH
SATURDAY, MOSTLY ABOVE 7,500 TO 8,000 FEET, BUT COULD LOWER TO
BELOW 7,000 FEET BY SUNDAY. HOWEVER, PRECIPITATION APPEARS LESS
WIDESPREAD BY THEN. TRAVELERS SHOULD MONITOR FORECASTS CLOSELY IF
CROSSING THE SIERRA FROM LATE FRIDAY THROUGH SUNDAY.
DESPITE REDUCED PRECIPITATION PROJECTIONS, WIND REMAINS A CONCERN.
STRONG SOUTHWESTERLY GUSTS OF 35–45 MPH ARE POSSIBLE AREAWIDE ON
SATURDAY AFTERNOON, WITH LOCALIZED HIGHER GUST IN WIND PRONE
AREAS. MOUNTAIN RIDGETOPS COULD EXCEED 90–100 MPH. THESE WINDS
COULD IMPACT OUTDOOR PLANS, AVIATION, AND ROAD TRAVEL PARTICULARLY
FOR HIGH-PROFILE VEHICLES DUE TO CROSSWIND HAZARDS. FUENTES
AVIATION
FZFG MAY DEVELOP AT KTRK THROUGH 16Z THIS MORNING, LOWERING
CIGS/VIS TO IFR/LIFR CONDITIONS. OTHERWISE, VFR CONDITIONS AND
LIGHT BREEZES PREVAIL TODAY AS HIGH PRESSURE OVERSPREADS THE
REGION. MCKELLAR/FUENTES
REV WATCHES/WARNINGS/ADVISORIES
NV...NONE.
CA...NONE.
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