349
FXUS65 KREV 090925
AFDREV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
225 AM PDT FRI OCT 9 2026
KEY MESSAGES
* ONE LAST DAY OF WELL ABOVE AVERAGE TEMPERATURES.
* A POTENT COLD FRONT IS EXPECTED TO PRODUCE GUSTY WINDS WITH
ENHANCED FIRE WEATHER CONCERNS FRIDAY AND SATURDAY.
* SIGNIFICANT COOLING IS EXPECTED BEHIND THE FRONT WITH BELOW
AVERAGE TEMPERATURES RETURNING, ALONG WITH 50-70% CHANCES FOR
RAIN AND MOUNTAIN SNOW SHOWERS BY SUNDAY INTO EARLY NEXT WEEK.
DISCUSSION
WE'LL GET ONE MORE DAY OF WELL ABOVE AVERAGE TEMPERATURES BEFORE
A STRONG PACIFIC TROUGH AND COLD FRONT BRINGS A DRASTIC CHANGE TO
OUR PATTERN. HIGH TEMPERATURES WILL RANGE FROM THE MID TO UPPER
80S IN WESTERN NV, NORTHEAST CA, AND THE LOWER ELEVATIONS OF MONO
COUNTY. MEANWHILE, TEMPERATURES FOR A MAJORITY OF OUR EASTERN
SIERRA COMMUNITIES WILL RANGE FROM THE MID 70S TO NEAR 80S, WITH
MID 50S TO MID 60S IN THE HIGHER ELEVATIONS.
AS THIS SYSTEM APPROACHES THE REGION TODAY, SOUTHWEST WINDS WILL
INCREASE BY THE EARLY AFTERNOON. GUSTS BETWEEN 25-35 MPH ARE
LIKELY ALONG THE SIERRA FRONT, NORTHWEST NV, AND NORTHEAST CA.
THESE INCREASED WINDS ALONG WITH THE DRY ANTECEDENT CONDITIONS
WILL BRING CRITICAL FIRE WEATHER CONDITIONS TO NORTHEAST CA AND
NORTHWEST NV THIS AFTERNOON AND EVENING. THE FIRE WEATHER WATCH
WAS UPGRADED TO A RED FLAG WARNING.
AS THE COLD FRONT MOVES THROUGH THE AREA ON SATURDAY, WIDESPREAD
SOUTHWEST WIND GUSTS BETWEEN 35-45 MPH ARE LIKELY THROUGHOUT THE
REGION. ADDITIONALLY, RIDGETOPS IN THE EASTERN SIERRA AND WESTERN
NV WILL HAVE GUSTS BETWEEN 70-80 MPH. ONCE AGAIN, THESE WINDS
COMBINED WITH THE DRY CONDITIONS IN PLACE WILL LEAD TO CRITICAL
FIRE WEATHER CONDITIONS IN THE INNER BASIN AND RANGE, THE SIERRA
FRONT, AND MONO COUNTY. FIRE WEATHER WATCHES ARE IN PLACE FOR
THOSE AREAS SATURDAY AFTERNOON AND EVENING. SEE THE FIRE WEATHER
DISCUSSION FOR DETAILS. IN ADDITION TO THE FIRE WEATHER CONCERNS,
THESE STRONG WINDS WILL LEAD TO DANGEROUS BOATING CONDITIONS ON
ALL AREA LAKES, INCLUDING LAKE TAHOE AND PYRAMID LAKE. WE COULD
ALSO SEE TRAVEL IMPACTS ALONG WIND-PRONE AREAS OF US-395 IN
WESTERN NV, EASTERN LASSEN, AND MONO COUNTY.
TEMPERATURES WILL DROP UPWARDS OF 25 DEGREES FROM TODAY TO SUNDAY.
BY SUNDAY, HIGH TEMPERATURES WILL ONLY REACH THE LOW 60S IN
WESTERN NV AND LOW 50S FOR EASTERN SIERRA COMMUNITIES. THESE
READINGS ARE BETWEEN 10-15 DEGREES BELOW AVERAGE. LOW
TEMPERATURES ON SUNDAY THROUGH WEDNESDAY WILL BE WELL BELOW
FREEZING IN SIERRA VALLEYS. WESTERN NV VALLEYS ARE STILL LOOKING
AT A 20-30% CHANCE OF REACHING FREEZING, WITH A 50-60% CHANCE OF
SUBFREEZING TEMPERATURES IN MORE RURAL AREAS.
AS HAS BEEN THE CASE FOR SEVERAL DAYS, ENSEMBLES AND MODELS ARE
STILL SHOWING DIFFERENCES IN THE TIMING, LOCATION, AND INTENSITY
OF THE UPPER LOW. THERE IS ALSO HIGH UNCERTAINTY ON HOW THE UPPER
LOW INTERACTS WITH THE REMNANTS OF TROPICAL STORM RACHEL. HOWEVER,
GIVEN THE BROAD AREA OF UPPER LEVEL DIVERGENCE SHOWN BY EACH MODEL
AND ENSEMBLE, WIDESPREAD PRECIPITATION IS LIKELY (50-80%) ON
SUNDAY AND MONDAY. CURRENT GUIDANCE STILL FAVORS THE SIERRA FROM
TAHOE BASIN INTO MONO COUNTY AND WESTERN NV SOUTH OF I-80, WITH A
20-50% CHANCE OF AT LEAST 0.50 INCHES OF LIQUID. SNOW LEVELS ARE
VARIABLE, RIGHT NOW RANGING FROM 7,500-8,500 FEET. CURRENT
GUIDANCE IS SHOWING A 50-90% LIKELIHOOD FOR AT LEAST 2 INCHES OF
SNOWFALL FROM THE TAHOE BASIN SOUTH INTO MONO COUNTY ON SUNDAY
INTO MONDAY. AFTER TUESDAY INTO THE END THE WEEK, WE RETURN TO A
RIDGE PATTERN WITH TEMPERATURES WARMING BACK TO AVERAGE. -MCKELLAR
AVIATION
THROUGH SATURDAY MORNING:
* VFR PREVAILS THROUGH TONIGHT. SW-W WINDS INCREASE THIS AFTERNOON
WITH GUSTS OF 20-30 KT, PRODUCING MECHANICAL TURBULENCE NEAR
TERRAIN. MOUNTAIN WAVE TURBULENCE IS EXPECTED ALONG AND EAST OF
THE SIERRA. SURFACE WINDS EASE FRIDAY EVENING, BUT SW WINDS OF 35-
45 KT AT FL100 FAVOR LLWS OVERNIGHT INTO SATURDAY MORNING.
OUTLOOK FOR SATURDAY AFTERNOON THROUGH SUNDAY NIGHT:
* STRONGER WINDS SATURDAY BRING GUSTS OF 25-35 KT, LOCALLY NEAR 40
KT, WITH THE STRONGEST WINDS AT KRNO-KCXP-KMEV EXPECTED FROM 18Z
SATURDAY TO 00Z SUNDAY. GUSTY WINDS AT SIERRA TERMINALS AND
MOUNTAIN WAVE TURBULENCE CONTINUE INTO SATURDAY NIGHT, WITH LLWS
POSSIBLE AS VALLEY WINDS EASE. VFR CONTINUES THROUGH SATURDAY,
THEN SHOWERS INCREASE SUNDAY AFTER 12Z AND EXPAND THROUGH SUNDAY
NIGHT. MOUNTAIN OBSCURATION AND LOCALIZED MVFR CONDITIONS ARE
POSSIBLE ACROSS THE SIERRA AND WESTERN NV, MAINLY SUNDAY AFTERNOON
AND NIGHT; CONFIDENCE IS LOWER IN TIMING AND DURATION AT
INDIVIDUAL TERMINALS. WINDS GENERALLY DECREASE SUNDAY, ALTHOUGH
KMMH MAY GUST 25-35 KT DURING THE AFTERNOON.
-JOHNSTON
FIRE WEATHER
THE SEASON’S FIRST POTENT COLD FRONT WILL BRING INCREASING SOUTHWEST
WINDS TODAY, PEAKING SATURDAY AS IT MOVES THROUGH NE CALIFORNIA
AND W.NEVADA. WINDS COMBINED WITH LOW HUMIDITY AND DRY ANTECEDENT
CONDITIONS MAY PRODUCE PERIODS OF CRITICAL FIRE WEATHER CONDITIONS
BOTH DAYS.
FRIDAY:
AFTERNOON GUSTS WILL REACH 25-35 MPH AS MINIMUM RH FALLS TO
10-17%. THE STRONGEST WINDS WILL FAVOR AREAS NEAR THE OREGON
BORDER, THOUGH ELEVATED FIRE WEATHER CONCERNS MAY EXTEND ALONG THE
SIERRA FRONT. RED FLAG WARNINGS ARE IN EFFECT THIS AFTERNOON AND
EVENING FOR PORTIONS OF NE CA AND NW NV, INCLUDING FIRE WEATHER
ZONES 270, 278, AND 458.
SATURDAY:
WINDS PEAK SATURDAY AFTERNOON AND EVENING, WITH WIDESPREAD GUSTS
OF 35-45 MPH MAINLY SOUTH OF I-80. HUMIDITY WILL INCREASE ACROSS
NE CALIFORNIA AND FAR NW NEVADA, WHILE AREAS SOUTH OF I-80 MAY SEE
CONTINUED ELEVATED CONCERNS WITH A MORE MARGINAL MINIMUM RH OF
15-20% ON SATURDAY AFTERNOON. DUE TO RECENT RECORD WARMTH COMBINED
WITH PROLONGED DRY CONDITIONS, ADDITIONAL FIRE WEATHER WATCHES
HAVE BEEN ISSUED FOR PORTIONS OF W.NEVADA INCLUDING THE SIERRA
FRONT AND THE E.SIERRA FROM E.ALPINE COUNTY INTO MONO COUNTY.
SUNDAY ONWARD:
BEHIND THE FRONT, HIGHS WILL DROP 20-25 DEGREES FROM FRIDAY TO
SUNDAY, REACHING THE LOW 60S ACROSS W.NEVADA AND LOW 50S IN
E.SIERRA COMMUNITIES. WETTING RAIN POTENTIAL INCREASES SUNDAY-
MONDAY, MAINLY SOUTH OF I-80, AS REMNANT MOISTURE FROM TROPICAL
STORM RACHEL MOVES NORTHWARD. THE MOISTURE’S TRACK AND
PRECIPITATION TOTALS STILL SHOW HIGHER UNCERTAINTY, BUT THE
OVERALL TREND HAS BEEN WETTER. AREAS SOUTH OF I-80 HAVE A 20-50%
CHANCE OF RECEIVING AT LEAST 0.50 INCHES OF RAINFALL THROUGH EARLY
NEXT WEEK, WITH THE HIGHEST CHANCES FARTHER SOUTH.
FUENTES/MCKELLAR
REV WATCHES/WARNINGS/ADVISORIES
NV...RED FLAG WARNING FROM 1 PM TO 9 PM PDT FRIDAY NVZ458.
FIRE WEATHER WATCH FROM SATURDAY MORNING THROUGH SATURDAY
EVENING NVZ420-421-423-429.
LAKE WIND ADVISORY FROM 5 AM TO 11 PM PDT SATURDAY NVZ002>004.
LAKE WIND ADVISORY FROM 11 AM TO 11 PM PDT SATURDAY NVZ001.
CA...RED FLAG WARNING FROM 1 PM TO 9 PM PDT FRIDAY CAZ270-278.
FIRE WEATHER WATCH FROM SATURDAY MORNING THROUGH SATURDAY
EVENING CAZ274.
LAKE WIND ADVISORY FROM 5 AM TO 11 PM PDT SATURDAY CAZ072.
LAKE WIND ADVISORY FROM 11 AM TO 11 PM PDT SATURDAY CAZ073.
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