974
FXUS65 KREV 280832
AFDREV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
132 AM PDT WED OCT 28 2026
KEY MESSAGES
* DRY AND MILD CONDITIONS CONTINUE THROUGH THURSDAY, WITH A
GRADUAL COOLING TREND THIS WEEKEND.
* ISOLATED AND LIGHT RAIN AND SNOW SHOWERS THURSDAY EVENING ACROSS
THE SIERRA, LINGERING THROUGH FRIDAY.
* UPPER LEVEL TROUGH ON SATURDAY AND SUNDAY BRINGS WETTER
CONDITIONS WITH VALLEY RAIN, AND MOUNTAIN SNOW ABOVE 7000 FEET.
DISCUSSION
MILD AND DRY CONDITIONS ALONG WITH LIGHTER WINDS CONTINUE TODAY
AND TOMORROW AS WEAK RIDGING SLOWLY DEVELOPS OVER THE AREA.
AFTERNOON HIGHS WILL BE IN THE UPPER 50S AND LOW 60S FOR WESTERN
NV, NORTHEAST CA AND SOUTHERN MONO VALLEYS; WITH LOW TO MID 50S IN
SIERRA COMMUNITIES. HOWEVER, WEATHER CONDITIONS DETERIORATE AS WE
GET CLOSER TO THE WEEKEND.
ON THURSDAY EVENING THROUGH FRIDAY AFTERNOON, A CLOSED-LOW OFF
THE PACNW WILL SEND A WEAK SHORTWAVE TROUGH TOWARDS NORTHERN
CA/NV. THIS WILL LEAD TO THE START OF OUR COOLING TREND, AN
INCREASE IN CLOUD COVER, AND LOW (10-30%) CHANCES OF RAIN AND SNOW
IN THE SIERRA. TEMPERATURES WILL DROP A FEW DEGREES COMPARED TO
THURSDAY. HREF AND REFS MEMBERS SHOW THESE SHOWERS, ALTHOUGH IT
APPEARS THAT MOST OF THE ACTIVITY WILL BE BLOCKED BY THE SIERRA
CREST, SO SPILLOVER WILL BE MINIMAL. THEREFORE, EXPECT LIGHT
AMOUNTS OF RAIN IN SIERRA VALLEYS AND LIGHT SNOW ABOVE 6500-7000
FT. RAIN AMOUNTS WILL BE BELOW 0.05" AND SNOW AMOUNTS UP TO 0.5"
(10-20% CHANCE OF EXCEEDING 0.5"). A FEW STRAY SHOWERS MAY MAKE IT
TO WESTERN NV VALLEYS WITH CHANCES BELOW 5%.
AS WE GET INTO THE WEEKEND, A DEVELOPING TROUGH FROM THE EASTERN
PACIFIC MERGES WITH THE AFOREMENTIONED TROUGH OVER THE PACNW AS
THEY MOVE INLAND TOWARDS THE GREAT BASIN AND CENTRAL ROCKIES. SO,
OUR PRECIPITATION CHANCES INCREASE FROM SATURDAY THROUGH SUNDAY
MORNING. POPS ARE AROUND 20-35% FOR THE SIERRA FRONT, NE CA AND
EASTERN MONO, AND 30-70% FOR THE SIERRA INCLUDING THE TAHOE
BASIN, AND FOR EASTERN MINERAL/CHURCHILL/PERSHING COUNTIES.
THERE IS PLENTY OF UNCERTAINTY ABOUT THE DETAILS WITH THIS SYSTEM
AS THE FORECAST HAS CHANGED EVERY SINGLE DAY THIS WEEK WITH ITS
EVOLUTION. AS OF THIS WRITING, THE TROUGH TO OUR NORTH IS PULLING
INTO THE LOW PRESSURE SYSTEM IN THE EASTERN PACIFIC POTENTIALLY
LEADING TO SNOW LEVELS SOMEWHERE BETWEEN 6500-8500 FT, TRENDING
HIGHER EARLY ON SATURDAY AND THEN LOWERING BY SUNDAY MORNING AS
THE MOISTURE STARTS TO EXIT THE REGION. THIS, OF COURSE, AFFECTS
HOW MUCH SNOW WE ARE GOING TO GET. THERE IS A 10-40% CHANCE OF
SNOW AMOUNTS GREATER THAN ONE INCH BETWEEN 6500-8500 FEET, AND
30-50% CHANCE OF SNOW GREATER THAN 2 INCHES ABOVE 8000 FEET.
LIQUID EQUIVALENTS APPEAR TO BE BELOW 0.1 INCHES FOR MOST OF THE
AREA, AND 0.1-0.2 INCHES FOR THE HIGHER ELEVATIONS OF THE SIERRA
AND EASTERN CHURCHILL/PERSHING.
ANOTHER RIDGE APPEARS TO DEVELOP SUNDAY THROUGH MID-WEEK NEXT WEEK
UNTIL THE NEXT LOW PRESSURE SYSTEM ARRIVES SOMETIME LATE NEXT
WEEK. THUS, DRIER AND WARMER CONDITIONS SHOULD RETURN BRIEFLY.
HOWEVER, THE GUIDANCE HAS BEEN UNRELIABLE IN THE EXTENDED PERIOD.
SO, KEEP AN EYE OUT FOR CHANGES OVER THE NEXT FEW DAYS.
-HC
AVIATION
VFR CONDITIONS PREVAIL THROUGH THE NEXT 36 HOURS. WINDS REMAIN
THE MAIN CONCERN WITH PERIODS OF LLWS AND MINOR TURBULENCE OVER
THE SIERRA THROUGH 15Z WED, AND AGAIN AFTER 09Z THURS WITH FL100
WINDS AROUND 25-30 KTS. SURFACE WINDS WILL BE GENERALLY LIGHT AND
VRB WITH A FEW AFTERNOON GUSTS TO AROUND 15 KTS FROM THE EAST FOR
KCXP AND FROM THE WEST FOR KTRK/KTVL.
-HC
REV WATCHES/WARNINGS/ADVISORIES
NV...NONE.
CA...NONE.
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page