774
FXUS65 KREV 311940
AFDREV
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
1240 PM PDT SUN AUG 31 2025
KEY MESSAGES
* 15-20% CHANCE FOR AFTERNOON SHOWERS AND THUNDERSTORMS IN MONO,
MINERAL, AND FAR SOUTHERN LYON COUNTIES TODAY WITH EVEN LESSER
CHANCES (<10%) MONDAY.
* AREAS OF SMOKE AND HAZE MAY LOCALLY IMPACT VISIBILITY AND AIR
QUALITY THE NEXT SEVERAL DAYS DUE TO FIRES IN CALIFORNIA AND
NORTHERN WASHOE COUNTY.
* THUNDERSTORM CHANCES RETURN TUESDAY THROUGH THE END OF THE WEEK.
DISCUSSION
HAZY CONDITIONS WILL PREVAIL FOR THE NEXT COUPLE OF DAYS AS FIRES
CONTINUE TO BLAZE IN CALIFORNIA. THE MAIN CULPRIT IS THE GARNET
FIRE IN THE SOUTHERN SIERRA. CURRENT AIR QUALITY ACROSS THE AREA
IS IN "MODERATE." FOR THOSE WHO ARE SENSITIVE TO CHANGING AIR
QUALITY CONDITIONS, PLEASE VISIT AIRNOW.GOV FOR MORE DETAILS.
HEAT WILL ACCOMPANY THE HAZE, AT LEAST THROUGH MONDAY. AFTERNOON
HIGHS WILL BE ROUGHLY 5 DEGREES ABOVE AVERAGE ACROSS THE AREA;
VALLEY LOCATIONS WILL SEE HIGHS IN THE MID 90S WHILE SIERRA
COMMUNITIES WILL BE IN THE MID 80S. WARM CONDITIONS WILL CONTINUE
THROUGH THE WEEK WITH A COOLING TREND STARTING THIS WEEKEND.
SHOWERS AND THUNDERSTORMS WILL BE THE MAIN NAME OF THE GAME THIS
WEEK. CHANCES TODAY WILL BE 15-20% AND PRIMARILY LOCATED ALONG THE
EASTERN SIERRA OF MONO COUNTY, MINERAL COUNTY, AND SOUTHERN LYON
AND ALPINE COUNTIES. SHOWER CHANCES DROP SIGNIFICANTLY MONDAY FOR
THE AFOREMENTIONED AREAS (<10%). MONDAY WILL BE BOTH THE HOTTEST
AND DRIEST DAY OF THE WEEK. CHANCES INCREASE TUESDAY, WITH A
25-50% CHANCE AREAWIDE. STORM CHANCES (15-20%) CONTINUE EACH DAY
THROUGH FRIDAY BUT WILL BE LESSER IN AREAL COVERAGE.
LET'S DISCUSS TUESDAY, SHALL WE? AS HIGH PRESSURE SETTLES OVER
THE FOUR CORNERS REGION AND A NEGATIVELY TILTED SHORTWAVE TROUGH
PUSHES INLAND INTO CENTRAL CALIFORNIA, SHOWER AND STORM CHANCES
GREATLY INCREASE. WITH NEGATIVELY TILTED SHORTWAVES DURING THIS
TIME OF THE YEAR, THE MAIN CONCERN WE ASSOCIATE WITH THESE SYSTEMS
ARE THOSE RELATED TO FIRE WEATHER. THAT TYPICALLY INCLUDES
DIFFLUENCE ALOFT, DRY LIGHTNING, GUSTY WINDS, AND FAST STORM
MOTIONS. HOWEVER, DUE TO THE PLACEMENT OF THE HIGH PRESSURE,
MOISTURE FROM THE GULF OF CALIFORNIA GETS SHUTTLED INTO THE AREA;
ALBEIT IT WILL BE LESS MOISTURE THAN WE EXPERIENCED LAST WEEK.
TAKING THESE TWO PIECES INTO CONSIDERATION, WE CAN EXPECT MORE
HYBRID-TYPE STORMS. IMPACTS WOULD INCLUDE BRIEF, HEAVY RAINFALL,
GUSTY OUTFLOW WINDS (MODEL SOUNDINGS ARE PUTTING 1200-1400 J/KG OF
DCAPE ALONG THE SIERRA FRONT TUESDAY), FREQUENT LIGHTNING, AND
SMALL HAIL.
-GIRALTE
AVIATION
* SMOKE FILTERING IN FROM THE GARNET FIRE MAY BRING PERIODS OF
VISIBILITY REDUCTION AT KMMH. THE BUFFALO FIRE IN NORTHERN
WASHOE COUNTY AND FIRES IN NORTHERN CA MAY ALSO BRING VISIBILITY
REDUCTIONS TO PORTIONS OF WESTERN NV AND NORTHEAST CA. ANY
OTHER RESTRICTIONS TO VISIBILITY WILL BE PRIMARILY SLANTWISE DUE
TO HAZE ALOFT. OTHERWISE, VFR CONDITIONS WILL PREVAIL.
* MOSTLY DRY CONDITIONS TODAY, WITH A 15-20% CHANCE FOR A STRAY
STORM TO IMPACT KMMH. STORM CHANCES INCREASE TUESDAY THROUGH
THE REMAINDER OF THE WEEK.
* HIGH DENSITY ALTITUDES MAY BECOME A PROBLEM IN WESTERN NV TODAY
AND MONDAY.
-GIRALTE/MCKELLAR
FIRE WEATHER
* 15-20% CHANCE OF ISOLATED SHOWERS AND STORMS THIS AFTERNOON
ACROSS PORTIONS OF MONO, MINERAL, AND S.LYON COUNTIES. THESE
WILL BE MORE TYPICAL RUN-OF-THE-MILL PULSE STORMS CAPABLE OF
GUSTY OUTFLOW WINDS AND FEW CLOUD-TO-GROUND LIGHTNING STRIKES.
* AFTER A LULL MONDAY, A CRITICAL FIRE WEATHER PATTERN DEVELOPS
WHICH COULD PRODUCE HIGH BASED AND FAST MOVING THUNDERSTORMS ON
TUESDAY. THIS SET-UP IS FORCED BY A NEGATIVELY TILTED SHORTWAVE
TROUGH THAT ALIGNS INSTABILITY AND JET FORCING TO PRODUCE AN
ENVIRONMENT FAVORABLE FOR T-STORMS ACROSS THE E.SIERRA/W.NV.
* NORMALLY THIS WOULD FAVOR A SET-UP FOR DRY THUNDERSTORMS, BUT
THIS WAVE DOES DRAW IN ADDITIONAL MONSOON MOISTURE (PWATS > 90TH
PERCENTILE) SO WE COULD LIKELY BE SEEING A MIX OF WET AND DRY,
FAST MOVING STORMS. NEW LIGHTNING IGNITIONS WILL BE POSSIBLE IN ANY
AREAS OF RECEPTIVE FUELS.
* ANY THUNDERSTORM WILL HAVE THE POTENTIAL FOR STRONG AND GUSTY
OUTFLOW WINDS IN EXCESS OF 45 MPH, WHICH COULD EXACERBATE ANY
NEW IGNITIONS OR ONGOING FIRES. FUENTES
REV WATCHES/WARNINGS/ADVISORIES
NV...NONE.
CA...NONE.
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