699
FXUS65 KREV 120820
AFDREV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
120 AM PDT FRI SEP 12 2025
KEY MESSAGES
* MORE ISOLATED SHOWER ACTIVITY MAINLY NEAR THE SIERRA TODAY, WITH
DRIER CONDITIONS SATURDAY.
* NEXT CHANCE OF SHOWERS ON SUNDAY FAVORS NORTHEAST CA AND FAR
NORTHWEST NV, WITH INCREASING BREEZES ELSEWHERE.
* BELOW NORMAL TEMPERATURES AGAIN TODAY WITH POSSIBLE MORNING FOG
IN SIERRA VALLEYS THROUGH SATURDAY. WARMER TEMPERATURES EXPECTED
THIS WEEKEND THROUGH NEXT WEEK, WITH MAINLY DRY CONDITIONS.
DISCUSSION
THE UPPER LOW WHICH HAS BROUGHT THE RECENT COOL AND SHOWERY
CONDITIONS IS CURRENTLY CENTERED OVER NORTHWEST NV AND PROJECTED
TO MOVE SLOWLY EAST TO EASTERN NV BY THIS EVENING. LINGERING
MOISTURE AND INSTABILITY WILL BRING ANOTHER CHANCE FOR SHOWERS
AND EMBEDDED THUNDER THIS AFTERNOON, ALTHOUGH COVERAGE IS
EXPECTED TO BE MORE ISOLATED AND MAINLY LIMITED TO THE EASTERN
SIERRA (20-40%) AND WEST CENTRAL NV EAST OF US-95 (15-30%). A FEW
BRIEF SHOWERS/SPRINKLES COULD ALSO POP UP IN OTHER PARTS OF
WESTERN NV THIS AFTERNOON, BUT WITH ONLY ABOUT 10% PROBABILITY.
COOL NORTHERLY FLOW BEHIND THIS LOW WILL KEEP TEMPERATURES BELOW
AVERAGE AGAIN TODAY WITH HIGHS MAINLY IN THE MID-UPPER 70S FOR
MOST LOWER ELEVATIONS AND 60S NEAR THE SIERRA. DRIER CONDITIONS
RETURN FOR SATURDAY WITH HIGHS WARMING UP TO THE LOWER 80S FOR
LOWER ELEVATIONS AND LOWER-MID 70S NEAR THE SIERRA.
THE NEXT WEATHER SYSTEM THEN MOVES QUICKLY ACROSS THE PACIFIC
NORTHWEST ON SUNDAY, WITH ANOTHER CHANCE (15-30%) FOR SHOWERS AND
ISOLATED THUNDER MAINLY FOR AREAS NEAR THE OR BORDER. SOME OF THE
ENSEMBLE GUIDANCE ALSO LEAVES OPEN THE CHANCES FOR SHOWERS AND A
FEW STORMS NEAR AND EAST OF US-95 IN WEST CENTRAL NV, ALTHOUGH
CONFIDENCE IS LOWER FOR THE ACTIVITY SPREADING THIS FAR SOUTH.
APART FROM THE SHOWERS, WE ARE ANTICIPATING AN INCREASE IN WEST
BREEZES SUNDAY AFTERNOON WITH GUSTS 25-30 MPH, POSSIBLY UP TO 35
MPH FOR SOME AREAS NEAR AND NORTH OF I-80.
FOR NEXT WEEK, A HIGH PRESSURE RIDGE IS PROJECTED TO BUILD OVER
CA-NV, LEADING TO OVERALL DRY CONDITIONS, LIGHTER WINDS AND
WARMER TEMPERATURES. HIGHS LOOK TO REBOUND INTO THE MID-UPPER 80S
FOR LOWER ELEVATIONS AND NEAR 80 NEAR THE SIERRA FROM TUESDAY-
THURSDAY. LONGER RANGE GUIDANCE BRINGS THE POTENTIAL FOR ANOTHER
UPPER LOW DROPPING SOUTHWARD TO NEAR (OR OFFSHORE FROM) THE CA
COAST LATE NEXT WEEK AND INTO THE SEPTEMBER 20-21 WEEKEND, WHICH
WOULD BRING RENEWED CHANCES FOR SHOWERS AND THUNDERSTORMS AND A
COOLING TREND IN ADVANCE OF THE FALL EQUINOX. MJD
AVIATION
* FOR KTRK, LATEST WEB CAMERA IS SHOWING SOME FOG RETURNING, EVEN
WITH THE PRESENCE OF LOWER-MID LEVEL CLOUD COVER. THE LIGHT
RAIN THAT FELL THURSDAY EVENING IS PROVIDING MORE FAVORABLE FOG
CONDITIONS WITH LIFR CIGS/VIS WHICH COULD CONTINUE THRU AROUND
17Z THIS MORNING. WITH CLEARING SKIES AND LIGHT WINDS EXPECTED
TONIGHT, FOG HAS A SOLID 60+% CHANCE TO RETURN AT KTRK OVERNIGHT
INTO SATURDAY AM. MEANWHILE AT KTVL, MVFR CIGS ARE CURRENTLY
BEING REPORTED BUT THESE LOWER CLOUDS SHOULD DIMINISH BY
DAYBREAK.
* FOR THE EASTERN SIERRA, SHOWER AND THUNDERSTORM CHANCES RETURN
BETWEEN 20-01Z THIS AFTERNOON AT KMMH (25-35%) WITH LESSER
CHANCES FROM 21-00Z AT KTVL (10-20%). BRIEF MVFR CONDITIONS WITH
MODERATE RAIN, ISOLATED LIGHTNING STRIKES AND OUTFLOW WIND GUSTS
TO 30 KT COULD OCCUR WITH THESE SHOWERS/STORMS ESPECIALLY
AROUND KMMH.
* FOR WESTERN NV TERMINALS, VFR CONDITIONS WILL PREVAIL TODAY
ALTHOUGH OBSCURATION OF HIGHER TERRAIN MAY RETURN WITH CLOUD
FORMATION THIS AFTERNOON-EARLY EVENING BETWEEN 20-03Z. LESS
CLOUD COVER WITH BASES ABOVE MOST PEAKS IS EXPECTED FOR SATURDAY
AFTERNOON. MJD
REV WATCHES/WARNINGS/ADVISORIES
NV...NONE.
CA...NONE.
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