Area Forecast Discussion
Issued by NWS Reno, NV

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000
FXUS65 KREV 040934
AFDREV

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
234 AM PDT FRI SEP 4 2015

.SYNOPSIS...

STRONG AND GUSTY WINDS TODAY WILL RESULT IN HAZARDOUS BOATING
CONDITIONS, AREAS OF BLOWING DUST, DANGEROUS CROSSWINDS FOR HIGH
PROFILE VEHICLES, AND CRITICAL FIRE WEATHER CONDITIONS. THERE ARE
CHANCES FOR LIGHT SHOWERS NORTH OF INTERSTATE 80 TODAY AND
SATURDAY, WITH THE REMAINDER OF THE WEEKEND AND INTO NEXT WEEK
DRY. WELL BELOW NORMAL TEMPERATURES WILL START THE HOLIDAY
WEEKEND, WITH A WARMING TREND BEGINNING SUNDAY INTO NEXT WEEK.

&&

.SHORT TERM...

THE GREATEST CONCERN TODAY INTO SATURDAY REMAINS AN AREA OF LOW
PRESSURE AND ASSOCIATED COLD FRONT MOVING ACROSS NORTHEAST
CALIFORNIA AND NORTHWEST NEVADA. THIS SYSTEM WILL BRING GUSTY
WINDS TO THE EASTERN SIERRA AND WESTER NEVADA TODAY, RESULTING IN
HAZARDOUS BOATING CONDITIONS, TURBULENCE FOR AVIATION, AREAS OF
BLOWING DUST DOWNWIND OF DESERTS AND SINKS, AND DANGEROUS
CROSSWINDS FOR HIGH PROFILE VEHICLES. LAKE WIND ADVISORIES REMAIN
IN EFFECT FOR ALL AREA LAKES TODAY ALONG WITH BLOWING DUST
ADVISORIES FOR AREAS DOWNWIND OF THE BLACK ROCK AND SMOKE CREEK
DESERTS AS WELL AS THE CARSON/HUMBOLDT SINKS. FOR THOSE AT THE
BURNING MAN FESTIVAL IN BLACK ROCK CITY - VISIBILITY MAY DROP
BELOW A MILE IN BLOWING DUST ON THE PLAYA TODAY AND LOOSE OBJECTS
COULD BECOME AIRBORNE, BECOMING A DANGER FOR FESTIVAL GOERS.

A VERY DRY AIR MASS IN THE 700-650 MB RANGE WORKS INTO THE EASTERN
SIERRA AND WESTERN NEVADA TODAY, WITH A SHARP GRADIENT BETWEEN THE
MOISTURE TO THE NORTH AND THIS DRIER AIR TO THE SOUTH. THE
COMBINATION OF THE DRY AIR ALONG WITH GUSTY WINDS WILL MAKE FOR
CRITICAL FIRE WEATHER CONDITIONS TODAY AND A RED FLAG WARNING
REMAINS IN EFFECT. SEE THE FIRE WEATHER SECTION BELOW FOR
ADDITIONAL DETAILS.

AS THE CORE OF THE LOW DIGS SOUTH, THERE WILL BE CHANCES FOR
SHOWERS NORTH OF I-80 TODAY INTO SATURDAY. WILL MAINTAIN THE
SLIGHT CHANCES FOR THUNDERSTORMS TODAY WITH DECENT VORTICITY
ADVECTION AND JET DYNAMICS, BUT THE UPPER LEVEL LAPSE RATES ARE
RATHER STABLE, SO CONFIDENCE IS LOW. PRECIPITATION AMOUNTS WILL
GENERALLY BE LIGHT, UNDER A TENTH OF AN INCH, WITH THE BEST
CHANCES NORTH OF A PORTOLA-PYRAMID LAKE-LOVELOCK LINE, WHICH DOES
INCLUDE BLACK ROCK CITY.

THE OTHER MAJOR IMPACT FROM THIS LOW WILL BE SIGNIFICANTLY COLDER
TEMPERATURES. HIGHS ARE ONLY EXPECTED TO BE IN THE MID 60S TO MID
70S IN WESTERN NEVADA VALLEYS TO START THE WEEKEND WITH UPPER 50S
TO LOW 60S IN SIERRA VALLEYS. OVERNIGHT LOWS WILL BE QUITE COOL AS
WELL, WITH THE COLDEST MORNING ON SUNDAY AS SKIES CLEAR AND WINDS
BECOME LIGHT. THOSE IN COLDER WESTERN NEVADA VALLEYS SHOULD
PREPARE FOR TEMPERATURES DIPPING TO NEAR FREEZING, WHILE SIERRA
VALLEYS WILL LIKELY BE IN THE MID 20S. COVER SENSITIVE VEGETATION
AND BE PREPARED FOR MUCH COLDER TEMPERATURES IF YOU HAVE OUTDOOR
PLANS TODAY THROUGH SUNDAY MORNING. DJ


.LONG TERM...MONDAY THROUGH THURSDAY...

NO CHANGES WERE MADE AS NORTHWEST FLOW ALOFT AT BEGINNING OF PERIOD
RETREATS/WEAKENS BY THE END OF THE WEEK AND HEIGHTS RISE. THIS WILL
RESULT IN A WARMUP WITH HIGHS RETURNING TO ABOVE NORMAL LEVELS.
HIGHS WILL APPROACH 80 IN THE SIERRA VALLEYS AND LOWER 90S IN
WESTERN NV VALLEYS BY WED-THU. WINDS WILL GENERALLY BE LIGHT AS
THERMAL TROUGH OVER CALIFORNIA DOMINATES THE SURFACE PATTERN,
RESULTING IN WEAK OR NON-EXISTENT ZEPHYR FLOW TO THE LEE OF THE
SIERRA LATE EACH DAY. HOHMANN

&&

.AVIATION...

UPPER LEVEL TROUGH WILL SWING THROUGH THE PACNW TODAY THROUGH
SATURDAY, PUSHING A STRONG COLD FRONT THROUGH THE SIERRA AND
NORTHERN NV TONIGHT. MOST OF THE MOISTURE AND INSTABILITY WILL
REMAIN ACROSS NORTHEAST CA AND NORTHERN NV WITH SCATTERED SHOWERS
AND AN ISOLATED THUNDERSTORM GENERALLY NORTH OF A PORTOLA TO
LOVELOCK LINE. THE AIRMASS FARTHER SOUTH WILL REMAIN TOO STABLE
FOR ANY SHOWERS.

INCREASING UPPER LEVEL WINDS AND STRENGTHENING GRADIENTS AHEAD OF
FRONT WILL BRING STRONG SOUTHWEST TO WEST WINDS TODAY WITH LEE
SIDE TURBULENCE AND AREAS OF BLOWING DUST AND REDUCED VISIBILITY
ACROSS THE BASIN AND RANGE. SURFACE GUSTS WILL GENERALLY BE IN THE
30-35KT RANGE BUT COULD REACH 40KT IN WINDPRONE AREAS (RIDGE GUSTS
50-60KT). STRONGEST SFC WINDS WILL GENERALLY BE 18Z-03Z AND THEN
DECREASE BEHIND THE FRONT TONIGHT. RIDGE LEVEL WINDS WILL LIKELY
STAY UP UNTIL SATURDAY MORNING. HOHMANN

&&

.FIRE WEATHER...

MODELS CONTINUE TO INDICATE A PRONOUNCED DRY SLOT PUSHING INTO AREAS
SOUTH OF I-80 ABOVE ABOUT 650-700MB (10,000-11,000 FT MSL) WITH THE
NAM 700 RH FIELDS REFLECTING THIS DRYING MORE DRAMATICALLY THIS
MORNING. BASED ON EXPECTED TEMPERATURES BY EARLY-MID AFTERNOON, THE
DRIER AIR ALOFT SHOULD BEGIN TO BE TAPPED AND LATEST MOS GUIDANCE
INDICATES FALLING DEWPOINTS DURING THE AFTERNOON AND EARLY EVENING.
MOS RH FIELDS ARE ALSO DOWN QUITE A BIT COMPARED TO YESTERDAY. THIS
INCREASES OUR CONFIDENCE THAT MIXING WILL BE VIGOROUS, PUSHING
SURFACE RH VALUES AS LOW AS SINGLE DIGITS ACROSS THE BASIN AND RANGE
AND LOWER TEENS FOR THE SIERRA FRONT DOWN INTO MONO COUNTY. SO ALL
RED FLAG WARNINGS WILL REMAIN IN PLACE.

FOR TONIGHT AND SATURDAY, THE COLD FRONT MOVES THROUGH AND BRINGS
WELL BELOW AVERAGE TEMPERATURES TO THE REGION WITH A SUBSTANTIAL
REDUCTION IN WINDS. TEMPERATURES WILL RETURN TO NEAR OR SLIGHTLY
ABOVE AVERAGE NEXT WEEK WITH DRY/STABLE CONDITIONS AND LIGHT
WINDS. HOHMANN

&&


.REV WATCHES/WARNINGS/ADVISORIES...
NV...LAKE WIND ADVISORY FROM 11 AM THIS MORNING TO 9 PM PDT THIS
     EVENING NVZ002.

     BLOWING DUST ADVISORY FROM 2 PM THIS AFTERNOON TO 9 PM PDT THIS
     EVENING NVZ004-005.

     RED FLAG WARNING FROM 2 PM THIS AFTERNOON TO 9 PM PDT THIS
     EVENING NVZ453-459.

     RED FLAG WARNING FROM 2 PM THIS AFTERNOON TO 9 PM PDT THIS
     EVENING NVZ450.

     LAKE WIND ADVISORY FROM 2 PM THIS AFTERNOON TO 9 PM PDT THIS
     EVENING FOR PYRAMID LAKE IN NVZ001-004.

CA...LAKE WIND ADVISORY FROM 11 AM THIS MORNING TO 9 PM PDT THIS
     EVENING CAZ071>073.

     RED FLAG WARNING FROM 2 PM THIS AFTERNOON TO 9 PM PDT THIS
     EVENING CAZ273.

&&

$$

FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)



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