078
FXUS65 KREV 220928
AFDREV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
228 AM PDT THU OCT 22 2026
KEY MESSAGES
* A SLOW MOVING STORM WILL BRING PERIODS OF WETTING RAIN WITH
THUNDERSTORMS AND HIGH ELEVATION SNOW TO THE REGION THROUGH
TONIGHT.
* BREEZY WEST TO NORTHWEST WINDS TONIGHT INTO FRIDAY AS SHOWERS
LINGER ACROSS WEST CENTRAL NV AND MONO COUNTY.
* COOL AND DRY CONDITIONS PREVAIL THIS WEEKEND THROUGH THE MIDDLE
OF NEXT WEEK. A MORE ACTIVE STORM PATTERN MAY RETURN BY THE END
OF OCTOBER OR EARLY NOVEMBER.
DISCUSSION
THE FIRST ROUND OF RAIN AND THUNDERSTORMS MOVED ACROSS THE REGION
WEDNESDAY AFTERNOON AND EVENING, WITH THE HEAVIEST RAIN TOTALS
FROM 0.50" TO LOCALLY OVER 1" ACROSS THE CARSON VALLEY AND
NORTHERN AREAS OF THE TAHOE BASIN. SOME STORMS PRODUCED
ACCUMULATING SMALL HAIL, INCLUDING I-580 IN WASHOE VALLEY DURING
THE PM COMMUTE. ANOTHER WET DAY IS ON THE WAY, WITH THE LATEST
WPC OUTLOOK KEEPING MOST OF WESTERN NV AND EASTERN CA IN A
MARGINAL (5-15%) RISK OF EXCESSIVE/FLOOD-PRODUCING RAINFALL
THROUGH EARLY FRIDAY MORNING.
* AS THE UPPER LOW CENTER OFF THE SOUTHERN CA COAST MOVES INLAND
TODAY AND TRACKS NORTHEASTWARD TO CENTRAL-EASTERN NV TONIGHT,
ADDITIONAL SHOWER BANDS WITH EMBEDDED LIGHTNING WILL FORM
THROUGH THIS MORNING. THE MOST FAVORED AREAS INCLUDE MONO COUNTY
NORTHWARD ACROSS WEST CENTRAL NV, ALTHOUGH LIGHTER SHOWERS
REMAIN IN PLAY ACROSS THE REMAINDER OF EASTERN CA-WESTERN NV.
FOR HIGHER ELEVATIONS ABOVE 8000-8500 FEET IN MONO COUNTY, 1-3"
OF NEW SNOW IS EXPECTED THROUGH LATE MORNING, WITH UP TO 6" FOR
HIGHER PEAKS SUCH AS MAMMOTH MOUNTAIN AND THE WHITE MOUNTAINS.
* FOR THIS AFTERNOON, INSTABILITY INCREASES AS COLDER AIR ALOFT
MOVES ACROSS THE SIERRA AND WESTERN NV, LEADING TO ANOTHER
AROUND OF SHOWERS AND THUNDERSTORMS. HIGHER RESOLUTION GUIDANCE
APPEARS TO BE FOCUSING ON TWO AREAS WHERE STORM CHANCES/COVERAGE
ARE HIGHER. THE FIRST IS AROUND THE TAHOE BASIN NORTHWARD TO
SOUTHERN LASSEN COUNTY AND ALSO INTO FAR WESTERN NV MAINLY FROM
I-80 NORTHWARD, AND THE SECOND IS ACROSS WEST CENTRAL NV NEAR
AND EAST OF US-95. WHILE BOTH AREAS CAN EXPECT STORMS WITH
LOCALLY HEAVY RAINFALL, LIGHTNING AND SMALL HAIL/GRAUPEL, SOME
OF THE CELLS IN THE US-95 VICINITY COULD BECOME STRONGER AND
MORE ORGANIZED AS MORE INSTABILITY (CAPE UP TO 500-700 J/KG) IS
EXPECTED IN THIS AREA. ADDITIONAL RAINFALL AMOUNTS THROUGH
SUNSET TODAY WILL BE IN A WIDER RANGE FROM 0.10-0.50", WITH
LOCALLY HIGHER AMOUNTS UP TO 1" WHERE HEAVIER SHOWERS/STORMS
OCCUR. FOR THE SIERRA ABOVE 8000 FEET, ISOLATED LOCATIONS WHERE
HEAVIER SHOWERS/STORMS OCCUR COULD RECEIVE A FEW MORE INCHES OF
SNOW, WHILE SPOTTY AMOUNTS OF 1" OR LESS BETWEEN 7000-8000 FEET.
* FOR THIS EVENING AND OVERNIGHT, A SURFACE COLD FRONT ACROSS
NORTHEAST CA-NORTHWEST NV COMBINES WITH OUTFLOWS AND MOISTURE
FROM THE AFTERNOON STORM ACTIVITY TO SUSTAIN A LARGER AREA OF
LIGHT TO MODERATE RAIN. THIS RAIN AREA IS THEN PROJECTED TO WRAP
AROUND THE MAIN LOW AND TRACK ACROSS WESTERN NV MAINLY FROM
US-50 NORTHWARD OVERNIGHT INTO EARLY FRIDAY MORNING. AREAS NORTH
OF SUSANVILLE-PYRAMID LAKE-FALLON HAVE THE HIGHEST PROBABILITY
(60-80%) OF RECEIVING AT LEAST 0.25" OF ADDITIONAL RAINFALL
TONIGHT INTO FRIDAY MORNING. AN INCREASE IN WEST TO NORTHWEST
WINDS WILL ALSO ACCOMPANY/FOLLOW THIS RAIN AREA AS THE COLD
FRONT MOVES THROUGH, WITH GUSTS 25-35 MPH AND RIDGE TOP GUSTS OF
40-50 MPH.
* FOR THE REMAINDER OF FRIDAY, LIGHT SHOWERS SOUTH OF US-50 AND
EAST OF US-95 ALONG THE BACK EDGE OF THE COLD FRONT MAY LINGER
INTO THE EARLY AFTERNOON FOR MONO COUNTY, OTHERWISE A DRIER AIR
MASS SPREADS OVER THE REGION. TEMPERATURES DROP TO BELOW AVERAGE
THROUGH FRIDAY WITH HIGHS MAINLY IN THE 50S TO NEAR 60. AS SKIES
CLEAR OUT FRIDAY NIGHT, LOWS PLUNGE INTO THE 20S FOR MOST LOWER
ELEVATIONS, WITH TEENS AND SINGLE DIGITS FOR SIERRA AND
TYPICALLY COLDER VALLEY SITES. A SHORT PERIOD OF INCREASED NE-E
RIDGE WINDS (GUSTS 40-60 MPH) FOR THE SIERRA CREST IS ALSO
PROJECTED FOR FRIDAY NIGHT, WHICH MAY ALSO BRING BRIEF CHOPPY
CONDITIONS ON LAKE TAHOE.
* A DRY FALL WEEKEND IS THEN EXPECTED WITH A SLOW WARMUP INTO THE
60S FOR MOST AREAS BY SUNDAY. SIMILAR TEMPERATURES AND DRY
CONDITIONS ARE ANTICIPATED THROUGH EARLY-MID NEXT WEEK,
ALTHOUGH A SHORTWAVE TROUGH PASSAGE ACROSS THE PACIFIC NW COULD
BRING INCREASED PM BREEZES MONDAY OR TUESDAY MAINLY FROM I-80
NORTHWARD, AND LOW END (10-15%) LIGHT SHOWER CHANCES NEAR THE OR
BORDER. LONGER RANGE GUIDANCE SIGNALS A POTENTIAL RETURN TO AN
ACTIVE STORM PATTERN TOWARD THE END OF OCTOBER, ALTHOUGH MORE OF
THE ENSEMBLE MEMBERS DELAYS THIS CHANGE UNTIL EARLY NOVEMBER.
MJD
AVIATION
* RECENT AND UPCOMING RAIN AT KTRK PROVIDES THE SETUP FOR AREAS
OF FOG/LOW STRATUS THIS MORNING AND AGAIN EARLY FRIDAY MORNING,
PRODUCING LIFR CONDITIONS MAINLY BETWEEN 08-16Z.
* WIDESPREAD RAIN AND EMBEDDED THUNDERSTORMS (15-20% CHANCE)
BRING PERIODS OF MVFR/IFR CONDITIONS AND MOUNTAIN OBSCURATIONS
THROUGH MUCH OF TODAY, WITH ADDITIONAL RAIN TONIGHT MAINLY FOR
KTRK/KRNO/KCXP.
* WINDS WILL BE LIGHT OVERALL THROUGH THIS AFTERNOON, THOUGH
HEAVIER SHOWERS/STORMS MAY TRIGGER BRIEF GUSTS TO 30+ KTS. A
COLD FRONTAL PASSAGE WILL BRING W-NW GUSTS OF 20-25 KT TONIGHT
FOR KRNO.
* CLEARING SKIES BRING PREVAILING VFR CONDITIONS TO THE MAIN
TERMINALS FRIDAY THROUGH THE WEEKEND, ALTHOUGH FZFG POTENTIAL
CONTINUES EACH MORNING AT KTRK. MJD
REV WATCHES/WARNINGS/ADVISORIES
NV...NONE.
CA...WINTER WEATHER ADVISORY UNTIL 5 PM PDT THURSDAY CAZ073.
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