823
FXUS65 KREV 110951
AFDREV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
151 AM PST THU DEC 11 2025
KEY MESSAGES
* DRY WEATHER WITH LIGHT WINDS AND UNSEASONABLY WARM TEMPERATURES
CONTINUE THROUGH THE WEEKEND.
* HAZY SKIES AND MINOR REDUCTIONS IN AIR QUALITY POSSIBLE EACH
MORNING ACROSS LOWER URBAN VALLEYS.
* A CHANGE TO A MORE ACTIVE WEATHER PATTERN WITH PERIODS OF
INCREASED WINDS AND PRECIPITATION APPEARS MORE LIKELY FOR NEXT
WEEK.
DISCUSSION
THE WEATHER PATTERN REMAINS DOMINATED BY A PERSISTENT UPPER LEVEL
RIDGE EXTENDING FROM OFF THE CA COAST TO THE SOUTHWEST US,
LEADING TO CONTINUED DRY AND MILD CONDITIONS. TODAY WILL BRING
ONE MORE CHANCE TO COME NEAR RECORD HIGHS (64 FOR RENO AND 59 FOR
SOUTH LAKE TAHOE), THEN AS THE RIDGE WEAKENS AND DRIFTS SLIGHTLY
WESTWARD FRIDAY THROUGH THIS WEEKEND, HIGHS EDGE DOWNWARD A BIT
BUT STILL REMAIN ABOUT 10-15 DEGREES ABOVE AVERAGE AS WE APPROACH
MID-DECEMBER. LIGHT WINDS AND VALLEY INVERSIONS WILL CONTINUE
CONTRIBUTING TO AREAS OF HAZE AROUND URBAN AREAS FOR THE NEXT FEW
MORNINGS, WITH MINOR REDUCTIONS IN AIR QUALITY.
AFTER A LONG PERIOD OF INCONSISTENCY WITH LONGER RANGE GUIDANCE,
THE MOST RECENT DATA BRINGS INCREASING CONFIDENCE FOR A MORE
ACTIVE WEATHER PATTERN RETURNING BY NEXT WEEK. THE FIRST SHORTWAVE
TO MAKE A DENT IN THE CURRENT UPPER LEVEL RIDGE IS PROJECTED TO
REACH THE WEST COAST MONDAY NIGHT-TUESDAY, BRINGING AN INCREASE IN
WINDS FOR HIGHER ELEVATIONS, BUT ONLY LOW-END (15-25%) LIGHT
SHOWER CHANCES MAINLY FROM THE SIERRA CREST NEAR I-80 NORTHWARD TO
THE OR BORDER.
A SECOND WAVE THEN APPEARS POISED TO QUICKLY FOLLOW LATE TUESDAY
THROUGH WEDNESDAY, BRINGING A FURTHER INCREASE IN WINDS FOR THE
SIERRA, WITH INCREASING CHANCES FOR GUSTY WINDS INTO LOWER
ELEVATIONS. MORE PACIFIC MOISTURE IS LIKELY TO BE DIRECTED INTO
THE SIERRA WITH THIS SYSTEM, ALTHOUGH AMOUNTS STILL LOOK
RELATIVELY MODEST BY SIERRA STANDARDS. LATEST BLENDED GUIDANCE
SHOWS A 30-50% CHANCE OF AT LEAST 0.25" OF LIQUID FROM THE
EASTERN SIERRA/TAHOE BASIN NORTHWARD TO THE OR BORDER, DROPPING
OFF TO 15-30% CHANCE ACROSS FAR WESTERN NV AND 10% OR LESS FOR
WEST CENTRAL NV AND EASTERN MONO COUNTY. SNOW LEVELS REMAIN QUITE
HIGH IN THE 8000-9000 FOOT RANGE, SO UNFORTUNATELY THIS FIRST
CHANCE FOR PRECIP IN A FEW WEEKS DOESN'T LOOK TO BRING MUCH BOOST
TO THE BELOW AVERAGE SIERRA SNOWPACK.
LOOKING FURTHER DOWN THE ROAD FROM LATE NEXT WEEK TO NEAR THE
CHRISTMAS HOLIDAY, LONGER RANGE GUIDANCE IS PROJECTING CONTINUED
CHANCES FOR GUSTY WINDS AND PRECIP, WITH ATMOSPHERIC RIVER-TYPE
PACIFIC MOISTURE PUSHING FARTHER SOUTH ACROSS THE SIERRA AND
SPILLING INTO WESTERN NV. COOLER TEMPERATURES ARE ALSO SHOWING UP
IN THIS LONGER RANGE GUIDANCE, WHICH WOULD HELP BRING SNOW LEVELS
DOWN TO INCLUDE MORE OF THE SIERRA COMMUNITIES. CONSIDERING THE
CONSISTENCY ISSUES AFFECTING THE LONGER RANGE GUIDANCE SO FAR THIS
MONTH, IT'S A LITTLE EARLY TO DREAM OF A WHITE CHRISTMAS
ESPECIALLY IN LOWER ELEVATIONS. BUT IF THIS SCENARIO HOLDS
TOGETHER, IT WOULD HELP RAISE SIERRA SNOWPACK LEVELS NEARER TO
AVERAGE FOR THIS POINT IN THE WATER YEAR, BUT ALSO LEAD TO
DIFFICULT WINTER DRIVING CONDITIONS AS WE ENTER THE BUSY HOLIDAY
TRAVEL PERIOD. MJD
AVIATION
VFR CONDITIONS WITH LIGHT WINDS PERSIST THROUGH THIS WEEKEND, WITH
ONLY A COUPLE OF EXCEPTIONS. THE BEST CHANCE FOR FZFG WITH LIFR
CONDITIONS AT KTRK CONTINUES THROUGH 16-17Z THIS MORNING. FOG CHANCES
REDUCE TO 20-40% FOR THE NEXT COUPLE OF MORNINGS AS WINDS UP TO
FL100 SHIFT TO A MORE NORTH TO NORTHEAST DIRECTION (LESS FAVORABLE
FOR FOG) BUT MAY BE LIGHT ENOUGH TO NOT FULLY PREVENT PATCHY FOG
FORMATION AROUND KTRK. ALSO, VALLEY INVERSIONS WITH URBAN HAZE
COULD PRODUCE MINOR SLANTWISE VISIBILITY REDUCTIONS FOR THE NEXT
FEW DAYS IN THE MORNING TO MIDDAY HOURS NEAR WESTERN NV TERMINALS.
MJD
REV WATCHES/WARNINGS/ADVISORIES
NV...NONE.
CA...NONE.
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