427
FXUS65 KREV 012145
AFDREV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
145 PM PST THU JAN 1 2026
KEY MESSAGES
* RAIN AND SNOW SHOWERS WILL DIMINISH THIS AFTERNOON WITH MAINLY
DRY CONDITIONS FRIDAY.
* A STRONGER STORM WILL BRING PERIODS OF HEAVIER SIERRA SNOW AND
VALLEY RAIN LATE FRIDAY NIGHT THROUGH EARLY MONDAY, WITH
POSSIBLE FLOODING CONCERNS IN NORTHEAST CA.
* ADDITIONAL STORMS COULD BRING MORE SNOW CHANCES TO THE SIERRA,
WITH RAIN AND SNOW IN LOWER ELEVATIONS BY MID-LATE NEXT WEEK.
DISCUSSION
FINAL BAND OF SNOW CONTINUES TO DIMINISH AS IT MOVES ACROSS MONO
COUNTY, WITH AN AREA OF LIGHT RAIN PUSHING ACROSS WEST CENTRAL NV.
THE SESAME SNOW STUDY PLOT (~9000 FT AT MAMMOTH MOUNTAIN) HAS
RECEIVED ABOUT 11 INCHES OF NEW SNOW AS OF 1230 PM, AND PATCHY
SLICK TRAVEL COULD LINGER THROUGH THIS AFTERNOON FOR SOUTHERN
MONO COUNTY, BUT OVERALL CONDITIONS WILL IMPROVE AS THIS SNOW
WINDS DOWN. FOR THE TAHOE BASIN, MOST OF THE PRECIP TODAY FELL AS
RAIN UP TO 8000 FEET WITH HIGHWAY WEB CAMERAS SHOWING WET ROADS ON
THE MAIN PASSES INCLUDING MT. ROSE SUMMIT.
FOR TONIGHT AND FRIDAY WE'LL SEE A BREAK IN THE ACTION, WITH
PATCHY FOG/LOW CLOUDS OVERNIGHT IN SOME VALLEY LOCATIONS THAT
RECEIVED RAIN SINCE EARLY THIS MORNING. TEMPERATURES ON FRIDAY
WILL CLIMB UPWARD TO A BIT ABOVE AVERAGE TO THE MID 40S FOR SIERRA
COMMUNITIES TO LOWER 50S FOR WESTERN NV VALLEYS.
THE NEXT STORM IS PROJECTED TO REACH NORTHEAST CA-EASTERN SIERRA
BY LATE FRIDAY NIGHT/EARLY SATURDAY MORNING, WITH PERIODS OF
VALLEY RAIN AND MOUNTAIN SNOW CONTINUING THROUGH THE REMAINDER OF
THE WEEKEND, AND EVEN INTO MONDAY. SIERRA SNOWFALL WILL PILE UP
THROUGH THIS TIME FRAME, WITH WINTER STORM WARNINGS NOW ISSUED
FROM TAHOE SOUTHWARD TO MONO COUNTY. FOR NORTHEAST CA AND WESTERN
NV, MAINLY RAIN IS EXPECTED SATURDAY, BUT SNOW LEVELS WILL
GRADUALLY TREND DOWNWARD TO NEAR 5500-6000 FEET SATURDAY NIGHT-
SUNDAY, THEN SETTLE TO 4500-5000 FEET BY EARLY MONDAY AS PRECIP
WINDS DOWN. DURING PERIODS OF HEAVIER PRECIP, THESE SNOW LEVELS
OVER THE WEEKEND CAN TEMPORARILY DIP BY 500 OR MORE FEET. WHILE
THE VALLEY FLOORS IN THE MAIN URBAN AREAS OF WESTERN NV HAVE A
LESS THAN 10% CHANCE FOR 1" OR MORE OF SNOW, FOOTHILL LOCATIONS
SUCH AS VIRGINIA CITY COULD END UP WITH MINOR ACCUMULATIONS UP TO
A FEW INCHES BY EARLY MONDAY.
WE'RE STILL WATCHING THE POTENTIAL FOR FLOODING CONCERNS IN
NORTHEAST CA DUE TO RAIN FALLING ON EXISTING SNOWPACK AND WILL
KEEP THE AREAL FLOOD WATCH IN PLACE. HOWEVER, RECENT TRENDS OF
MORE INTERMITTENT PRECIP DURING THE MILDER DAY ON SATURDAY
FOLLOWED BY LOWERING SNOW LEVELS SUNDAY MAY REDUCE THE EXTENT OF
FLOODING RISK. THIS STORM HAS SHOWN MORE VARIANCE OVER NORTHEAST
CA WITH PRECIP AMOUNTS AND SNOW LEVELS, SO IT REMAINS A GOOD IDEA
TO HAVE FLOOD PREPARATIONS READY IF NEAR RIVERS OR CREEKS.
AS FOR WINDS, SATURDAY LOOKS TO HAVE THE BEST POTENTIAL IN LOWER
ELEVATIONS WITH GUSTS OF 30-40 MPH AND SOME GUSTS UP TO 50 MPH IN
WIND PRONE SITES. THE SPILLING OVER OF PRECIP AND MORE LIMITED 700
MB FLOW (MAINLY 30-40 KT) APPEARS SUFFICIENT TO PREVENT A
SIGNIFICANT WIND EVENT THIS WEEKEND FOR LOWER ELEVATIONS. HOWEVER,
SIERRA RIDGE TOP GUSTS WILL BE TYPICALLY STRONG FOR A PACIFIC
WINTER STORM, WITH GUSTS IN THE 80-100 MPH RANGE.
FOR NEXT WEEK, UNSETTLED WEATHER IS LIKELY TO CONTINUE WITH
ADDITIONAL STORM SYSTEMS APPROACHING THE REGION. THE TIMING
CONTINUES TO VARY, ALTHOUGH THERE IS NOW AN INCREASED POTENTIAL
FOR A COLDER STORM WHICH COULD BRING SNOW INTO LOWER ELEVATIONS
BY NEXT WEDNESDAY OR THURSDAY. MJD
AVIATION
MAINLY VFR WITH LIGHT WINDS THROUGH FRIDAY, EXCEPT LINGERING
SHOWERS WILL PRODUCE LOWER CIGS TO MVFR AT TIMES FOR THE
SIERRA/TAHOE TERMINALS AND TERRAIN OBSCURATIONS FOR WESTERN NV
TERMINALS, MAINLY THROUGH 03Z. PATCHY FZFG COULD RETURN TO KTRK
OVERNIGHT, ALTHOUGH ADVANCING AREAS OF MID-HIGH LEVEL CLOUD COVER
REDUCES THE PROBABILITY OF PREVAILING IFR/LIFR CONDITIONS TO
ABOUT 40%.
THE NEXT STORM SATURDAY-SUNDAY WILL BRING MORE WIDESPREAD WEATHER
IMPACTS TO AVIATION ESPECIALLY FOR THE SIERRA/TAHOE TERMINALS
WHERE PERIODS OF RAIN AND SNOW TRANSITION TO MAINLY SNOW BY
SUNDAY. FOR WESTERN NV TERMINALS, RAIN WILL BE THE PREVAILING
PRECIP TYPE. INCREASING RIDGE TOP WINDS WILL BRING PERIODS OF
TURBULENCE/SHEAR TO ALL TERMINALS BOTH DAYS THIS WEEKEND. MJD
AVALANCHE
A MORE POTENT WINTER STORM WILL BRING PERIODS OF MORE SIGNIFICANT
SNOW AND WINDY CONDITIONS TO ALL AVALANCHE CENTER TERRAIN FROM
EARLY SATURDAY MORNING THROUGH MONDAY MORNING.
* SNOW LEVELS: STARTING AROUND 7500-8000 FT AT STORM'S ONSET
BEFORE DROPPING SLOWLY TO BELOW 7000 FT FROM SATURDAY NIGHT
ONWARD.
* SNOW/SWE AMOUNTS: 1-3 FEET WITH LOCALLY UP TO 4 FEET FOR MONO
COUNTY. SWE TOTALS BETWEEN 1.5" AND 3", WITH A FEW SITES
RECEIVING UP TO 4".
* SNOW-LIQUID RATIOS (SLR): HIGHER DENSITY 8-11:1 SATURDAY, THEN
BECOMING LESS DENSE WITH SLR'S INCREASING TO 10-14:1 FROM EARLY
SUNDAY MORNING THROUGH MONDAY.
* SNOWFALL RATES: STEADY AT 0.5-1"/HOUR WITH PERIODIC BURSTS OF UP
TO 2"/HOUR THROUGH THE WEEKEND.
* RIDGE TOP WINDS: GUSTS 70-90 MPH, WITH STRONGER GUSTS UP TO 100
MPH FOR SUNDAY. MJD
REV WATCHES/WARNINGS/ADVISORIES
NV...WINTER STORM WARNING FROM MIDNIGHT FRIDAY NIGHT TO 10 AM PST
MONDAY NVZ002.
CA...FLOOD WATCH FROM SATURDAY MORNING THROUGH MONDAY AFTERNOON
CAZ071.
WINTER STORM WARNING FROM MIDNIGHT FRIDAY NIGHT TO 10 AM PST
MONDAY CAZ072-073.
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