741
FXUS65 KREV 160926
AFDREV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
226 AM PDT WED APR 16 2025
KEY MESSAGES
* ONE MORE DAY OF WARM WEATHER WITH SNOWMELT RESULTING IN STREAMS
RUNNING FAST AND COLD.
* AFTERNOON SHOWERS AND THUNDERSTORMS ARE POSSIBLE THROUGH
THURSDAY WITH ISOLATED AREAS OF HEAVY RAINFALL POSSIBLE TODAY.
* A COLD FRONT BRINGS LIGHT MOUNTAIN SNOW AND VALLEY RAIN, GUSTY
WINDS, AND COOLER WEATHER TOMORROW AND FRIDAY, BEFORE A WARMING
AND DRYING TREND RETURNS EASTER WEEKEND.
DISCUSSION
ONE MORE DAY OF WARMTH AS THE UPPER RIDGE IS SLOWLY PUSHED EAST BY
THE INTRUSION AN UPPER LEVEL CLOSED LOW INTO CA. HIGH TEMPERATURES
ARE EXPECTED TO BE SLIGHTLY COOLER TODAY AS THE RIDGE MOVES AWAY.
HOWEVER, AFTERNOON HIGHS WILL STILL BE 10-15 DEGREES ABOVE NORMAL.
TEMPERATURES WILL CONTINUE TO COOL DOWN OVER THE NEXT FEW DAYS
WITH THE APPROACH OF AN UPPER LEVEL TROUGH ON THURSDAY. WARMER
CONDITIONS RETURN THIS WEEKEND AS ANOTHER UPPER RIDGE TAKES OVER,
SO THE COOLER WEATHER IS NOT EXPECTED TO LAST LONG.
IN THE MEANTIME, THE DEFORMATION ZONE DEVELOPING RIGHT OVER
NORTHERN CA/NV ALONG WITH SOME MARGINAL INSTABILITY WILL AID IN
THE DEVELOPMENT OF STORMS OVER THE SIERRA TODAY. THERE IS A 20-40%
CHANCE FOR STORMS TO DEVELOP OVER THE MOUNTAINS, AND 10-30% FOR
WESTERN NV. THE HREF MEMBERS AGREE WITH THE DEVELOPMENTS OF CELLS
THIS AFTERNOON OVER THE SIERRA AND VICINITY. THE DIFFLUENCE ALOFT
COMBINED WITH SLOW MOTIONS BETWEEN 500-700 MB IS STILL THERE, BUT
IT LOOKS LIKE WE MAY NOT HAVE AS MUCH MOISTURE AROUND TO WORK
WITH. SO, THE RISK FOR BRIEF HEAVY DOWNPOURS HAS DECREASED BELOW
5%. HOWEVER, THE AVERAGE MOTION OF STORMS IS EXPECTED TO BE SLOW
SO THERE IS STILL THE POSSIBILITY FOR A STORM TO BRING SOME MINOR
FLASH FLOODING, ESPECIALLY IF THE HEAVY RAINFALL HAPPENS NEAR ANY
RECENT BURN SCARS.
BY THURSDAY, WE HAVE AN UPPER LEVEL TROUGH THAT MERGES WITH THE
CLOSED LOW AS IT WEAKENS AND TRACKS TO THE EAST. THE ASSOCIATED
COLD FRONT WITH THIS SYSTEM WILL MOVE FROM NORTH TO SOUTH. THE
MAIN HAZARD WILL BE GUSTY NORTHERLY WINDS WITH SPEEDS IN THE 20-30
MPH RANGE AND GUSTS UP TO 45 MPH. HOWEVER, IT LOOKS LIKE MINERAL
COUNTY MAY HAVE GUSTS UP TO 45-50 MPH WITH A 60-80% CHANCE OF
EXCEEDING 45 MPH. ISOLATED THUNDERSTORMS WILL BE MOSTLY CONFINED
TO THE SIERRA SOUTH OF US-50 WHERE HIGHER INSTABILITY WILL BE
PRESENT. OTHERWISE, THE CHANCES FOR STORMS IN WESTERN NV WILL BE
LESS THAN 10%. SNOW LEVELS WILL DROP AS THIS SYSTEM MOVES THROUGH,
HOWEVER THE LATEST RUNS HAVE BEEN TRENDING HIGHER. CURRENTLY,
EXPECTING SNOW LEVELS BETWEEN 7-8 KFT THURSDAY. ALTHOUGH, STILL
EXPECTING THOSE SNOW LEVELS TO DROP TO 4-5 KFT BY FRIDAY MORNING.
BY THEN MOST OF THE MOISTURE WILL HAVE LEFT THE AREA, AND ONLY
SOME FLURRIES MAY BE POSSIBLE, MAINLY IN MONO/MINERAL COUNTIES.
SNOW IS STILL POSSIBLE ALONG AND NEAR THE EASTERN SIERRA CREST
WITH A 10-30% CHANCE OF EXCEEDING 1 INCH OF SNOW.
THIS WEEKEND THE PATTERN APPEARS TO REVERT BACK TO ANOTHER RIDGE
LEADING TO A WARMER AND DRIER TREND. A FEW WEAK DISTURBANCES MAY
AFFECT THE REGION, BUT WITH NO SIGNIFICANT IMPACTS THROUGH EARLY
NEXT WEEK.
-HC
AVIATION
MOSTLY VFR CONDITIONS CONTINUE THROUGH 17/12Z. THERE MAY BE BRIEF
PERIODS OF MVFR CONDITIONS IN THE SIERRA DUE TO -TSRA BETWEEN
21Z-03Z. THE CHANCES FOR SHOWERS AND STORMS IS 15-40% IN THE
AFOREMENTIONED AREA. SOME SHOWERS MAY EXTEND INTO ADJACENT AREAS
IN WESTERN NV (10-20%), IMPACTING SIERRA FRONT TERMINALS FOR THE
SAME TIME FRAME. WINDS START LIGHT AND VRB, THEN BECOME GENERALLY
FROM THE W WITH OCCASIONAL GUSTS UP TO 30 KTS FROM GUSTY AND
ERRATIC OUTFLOWS. WINDS BECOME NORTHERLY AFTER 06Z THURSDAY.
CHANCES FOR WIDESPREAD SHOWERS AND THUNDERSTORMS DECREASES BY AT
LEAST 10% COMPARED TO TODAY ON THURSDAY.
-HC/GIRALTE
REV WATCHES/WARNINGS/ADVISORIES
NV...NONE.
CA...NONE.
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