925
FXUS65 KREV 010712
AFDREV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
1212 AM PDT TUE SEP 1 2026
KEY MESSAGES
* THE PASSAGE OF A DRY COLD FRONT WILL PRODUCE GUSTY WINDS AND LOW
HUMIDITIES TODAY, BRINGING CRITICAL FIRE WEATHER CONCERNS FOR
NORTHEAST CA AND PARTS OF WESTERN NV.
* COOLER AND BREEZY CONDITIONS FOR THE REMAINDER OF THE WEEK WITH
RAIN SHOWER CHANCES FOR NORTHEAST CA AND NORTHWEST NV THURSDAY
AND FRIDAY.
* REMNANT MOISTURE FROM A TROPICAL SYSTEM MAY INCREASE CHANCES FOR
SHOWERS AND THUNDERSTORMS EARLY NEXT WEEK, THOUGH CONFIDENCE
REMAINS LOW.
DISCUSSION
TODAY WILL BE THE DRIEST AND WINDIEST DAY OF THE WEEK, WITH
AFTERNOON WIND GUSTS REACHING 30-40 MPH FROM ROUGHLY TOPAZ LAKE
NORTH TO THE OR BORDER, INCLUDING PARTS OF NE CA NEAR SUSANVILLE.
RIDGETOP GUSTS WILL INCREASE TO 70-80 MPH TODAY, WITH GUSTS IN THE
REMAINDER OF THE AREA BETWEEN 20-30 MPH. COMBINED WITH HUMIDITY
VALUES RANGING FROM 12-20%, RED FLAG WARNINGS HAVE BEEN ISSUED.
PLEASE SEE THE FIRE DISCUSSION BELOW FOR MORE DETAILS.
ADDITIONALLY, A LAKE WIND ADVISORY HAS BEEN ISSUED FOR AREA LAKES
IN AND AROUND THE TAHOE BASIN, NE CA, AND W NV. THIS INCLUDES LAKE
TAHOE, PYRAMID LAKE, DONNER LAKE, AND MANY OTHERS. PLEASE SEE THE
PRODUCT FOR MORE DETAILS. IN ADDITION TO BRINGING IMPACTS TO
BOATERS ON AREA LAKES, EXPECT BLOWING DUST ON DESERT PLAYAS AND
SINKS BRINGING REDUCED VISIBILITIES, CHOPPY AIR
TRAVEL/TURBULENCE, AND LOCALIZED DIFFICULT TRAVEL FOR HIGH PROFILE
VEHICLES.
BREEZY CONDITIONS CONTINUE THROUGH THE REMAINDER OF THE WEEK, WITH
AFTERNOON HIGH TEMPERATURES 10-15 DEGREES BELOW NORMAL. THIS
EQUATES TO HIGHS IN THE MID 70S FOR VALLEYS AND LOW TO MID 60S FOR
SIERRA COMMUNITIES. OVERNIGHT LOWS WILL ALSO DROP NEAR TO BELOW
FREEZING FOR SIERRA COMMUNITIES LIKE TRUCKEE AND MAMMOTH LAKES.
RECREATORS ARE ENCOURAGED TO MONITOR THE FORECAST AND BRING LAYERS
WHEN ENJOYING THE OUTDOORS, ESPECIALLY IF STAYING OUT PAST SUNSET.
PRECIPITATION CHANCES (15-40%) CREEP INTO THE AREA WEDNESDAY
NIGHT FOR LASSEN COUNTY IN NE CA AS A LOW PRESSURE SYSTEM TRACKS
INLAND. RAIN WILL BE MORE SHOWERY IN NATURE, WITH 5-10% CHANCES
FOR EMBEDDED THUNDERSTORMS. SHOWERS WILL EXPAND BOTH IN
PROBABILITY (30-55%) AND AREAL COVERAGE AS THURSDAY PROGRESSES,
DIPPING SOUTH INTO THE TAHOE BASIN AND THE FOOTHILLS OF THE SIERRA
FRONT THURSDAY INTO THURSDAY NIGHT.
FRIDAY AND SATURDAY LOOK TO BE RELATIVELY DRY, WITH SUNDAY
INTRODUCING A WILDCARD INTO THE FORECAST; PRECIP CHANCES INCREASE
TO 15-25% ACROSS ALL OF WEST-CENTRAL NV AND NE CA AS MODELS HINT
AT MOISTURE FROM A TROPICAL SYSTEM MOVING INTO THE AREA. THERE IS
STILL PLENTY OF UNCERTAINTY ON THE TRACK OF THIS TROPICAL SYSTEM
SO STAY TUNED FOR MORE CONCRETE DETAILS AS WE GET CLOSER.
-GIRALTE
AVIATION
VFR CONDITIONS PERSIST AREAWIDE TODAY WITH AFTERNOON GUSTS OF
25-30 KTS. FL100 WINDS INCREASE TO 60-70 KTS THIS AFTERNOON,
BRINGING LLWS AND MOUNTAIN WAVE TURBULENCE TO ALL SIERRA AND
SIERRA FRONT SITES.
AREAS OF REDUCED VISIBILITY FROM BLOWING DUST MAY IMPACT KLOL,
KNFL, KHTH AS WELL AS AVIATION OPERATIONS ON THE BLACK ROCK
DESERT TODAY.
-GIRALTE/FUENTES
FIRE WEATHER
TODAY WILL POSE THE HIGHEST CONCERN FOR CRITICAL FIRE WEATHER
CONDITIONS AS HUMIDITY VALUES DROP TO 12-20% AND AFTERNOON WIND
GUSTS INCREASE UP TO 40 MPH. THIS IS DUE TO A DRY COLD FRONTAL
PASSAGE TODAY. AS SUCH, A RED FLAG WARNING HAS BEEN ISSUED FOR THE
NORTHERN SIERRA FRONT AND EXTENDING NORTHWARD INTO NE CA EAST OF
CA-139, NORTHERN WASHOE COUNTY, AND THE SURPRISE VALLEY IN MODOC
COUNTY. WINDS WILL BE PRIMARILY OUT OF THE SOUTHWEST, SHIFTING
WESTERLY/NORTHWESTERLY AFTER SUNSET.
WINDS WILL REMAIN GUSTY WEDNESDAY (20 TO 30 MPH) BUT HIGHER
HUMIDITY VALUES WILL LIMIT FIRE CONCERNS FOR MOST AREAS. BREEZY
AFTERNOONS CONTINUE THROUGH FRIDAY, WITH PRECIP CHANCES AND COOLER
TEMPERATURES MITIGATING THE FIRE THREAT FOR THE REMAINDER OF THE
WEEK.
-GIRALTE
REV WATCHES/WARNINGS/ADVISORIES
NV...RED FLAG WARNING FROM 11 AM TO 11 PM PDT TUESDAY NVZ458.
RED FLAG WARNING FROM 11 AM TO 11 PM PDT TUESDAY NVZ420.
LAKE WIND ADVISORY FROM 11 AM TO 8 PM PDT TUESDAY NVZ002>004.
CA...RED FLAG WARNING FROM 11 AM TO 11 PM PDT TUESDAY CAZ270-278.
LAKE WIND ADVISORY FROM 11 AM TO 8 PM PDT TUESDAY CAZ071-072.
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