Lake Wind Advisory 52, NWS Reno, NV

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
345 AM PDT MON JUN 27 2011

.SHORT TERM...
UPPER LEVEL LOW PRESSURE WILL DROP DOWN THE WEST COAST TODAY...THEN
SWING INLAND THROUGH CA/NV TUESDAY EVENING THROUGH WEDNESDAY. THIS
WILL BRING A SIGNIFICANT CHANGE TO OUR WEATHER IN THE FORM OF GUSTY
WINDS...SHOWERS AND THUNDERSTORMS...HIGH ELEVATION SNOW...AND WELL
BELOW AVERAGE TEMPERATURES.

FOR TODAY...THE FLOW ALOFT WILL INCREASE FROM THE SOUTHWEST AS THE
UPPER LOW APPROACHES...WITH BUILDING HEIGHTS FOR NV. THIS WILL BRING
MINOR WARMING AND A LITTLE STRONGER WINDS THIS AFTERNOON AS COMPARED
TO YESTERDAY.

FOR TUESDAY...THE MAIN CONCERN WILL BE GUSTY WINDS. SOUTHWEST WINDS
ALOFT WILL CONTINUE TO INCREASE AS THE UPPER LOW APPROACHES THE WEST
COAST. 700 MB WINDS IN EXCESS OF 45 KTS IN COMBINATION WITH A VERY
IMPRESSIVE EAST-WEST THERMAL/PRESSURE GRADIENT WILL RESULT IN GUSTY
WINDS  TO 45 MPH ACROSS WESTERN NV TUESDAY AFTERNOON...POSSIBLY UP
TO 60 MPH IN WIND PRONE AREAS ALONG THE 395 CORRIDOR. SIERRA RIDGES
WILL LIKELY SEE GUSTS IN EXCESS OF 80 MPH. WIND ADVISORIES MAY BE
NEEDED.

IN ADDITION TO GUSTY WINDS...00Z MODELS CONTINUE TO INDICATE THE
POTENTIAL FOR FAST MOVING DRY THUNDERSTORMS ACROSS THE BASIN AND
RANGE TUESDAY AFTERNOON AS THE JET NOSES INTO THE REGION AND THE
FLOW ALOFT BECOMES INCREASINGLY DIFFLUENT. INSTABILITY IS NOT THAT
GREAT...BUT ITS THERE. LEFT THUNDER OUT OF THE FORECAST FOR ZONE
4...BUT DAY SHIFT MAY WANT TO REEVALUATE CONVECTIVE POSSIBILITY IN
OUR EASTERN ZONES FOR TUESDAY AFTERNOON.

00Z MODEL RUNS TONIGHT ARE SIGNIFICANTLY FASTER WITH THIS SYSTEM
THAN LAST NIGHT...WITH SHOWERS MOVING INTO LASSEN/PLUMAS COUNTIES AS
EARLY AS LATE TUESDAY MORNING...AND THE TAHOE BASIN TUESDAY EVENING.
BULK OF THE PRECIP SHOULD FALL OVERNIGHT. MODEL QPF HAS INCREASED AS
IT NOW LOOKS LIKE A 1.25+ INCH PWAT PLUME WILL MOVE INTO THE REGION.
WOULD NOT BE SURPRISED TO SEE 0.5-1.0 INCH IN WRN LASSEN AND PLUMAS
COUNTIES...0.20-0.50 INCH IN THE TAHOE BASIN...AND 0.10-0.30 ACROSS
WRN NV NORTH OF HWY 50. WITH 700 MB TEMPS FALLING TO -1 TO -2C...SNOW
LEVELS SHOULD FALL TO BETWEEN 8000-8500 FT LATE TUESDAY NIGHT INTO
WEDNESDAY MORNING. COULD SEE 1-3 INCHES OF SNOW ON THE HIGHEST PEAKS
BY WEDNESDAY MORNING.

UPPER LOW RAPIDLY FILLS WHILE IT MOVES EAST THROUGH NV ON WEDNESDAY.
HIGHS WILL BE WELL BELOW AVERAGE FOR THIS TIME OF YEAR...AROUND 60
IN THE TAHOE BASIN AND AROUND 70 FOR RENO/CC/MINDEN. WITH THE COLD
POOL ALOFT OVERHEAD...WILL LIKELY SEE SCATTERED SHOWERS AND POSSIBLE
THUNDERSTORMS DURING THE DAY. BEST INSTABILITY FOR T-STORMS LOOKS TO
BE EAST OF HWY 95. SCV

.LONG TERM...THURSDAY THROUGH SUNDAY...
MEDIUM RANGE MODELS IN GOOD AGREEMENT THROUGH MUCH OF THE EXTENDED
PERIOD THIS FORECAST CYCLE. NOT UNUSUAL FOR A BUILDING RIDGE. THE
GEM IS LESS DEVELOPED WITH THE RIDGE BY THE END OF THE PERIOD THAN
THE OPERATIONAL GFS OR ECMWF AND MOST OF THE GEFS ENSEMBLE MEMBERS.
FORECAST PERIOD STARTS UNDER FLAT FLOW THEN RIDGE BEGINS TO GET
BETTER ORGANIZED. A LITTLE SHARPER ON ECMWF THAN GFS BUT BOTH...
ALONG WITH MOST ENSEMBLE MEMBERS...DEVELOP THE RIDGE AND SLIDE THE
AXIS EAST BY THE END OF THE PERIOD.

WARMING TEMPS THROUGH THE FORECAST PERIOD. STARTING NEAR AVERAGE
THURSDAY THEN WARMING TO ABOUT 10 DEGREES ABOVE AVERAGE BY SUNDAY.
HOLIDAY WEEKEND SHOULD SEE THE WARMEST TEMPS SO FAR THIS SUMMER.
GENERALLY DRY FORECAST AS WELL THROUGH THE EXTENDED WITH FAIRLY
LIGHT WINDS THURSDAY AND FRIDAY. BY SATURDAY AFTN/EVNG WINDS SHOULD
BEGIN TO INCREASE AS THERMAL GRADIENT STRENGTHENS BETWEEN THE SIERRA
AND THE WRN NV BASINS. SUNDAY WINDS SHOULD ALSO BE A BIT STRONGER
WITH UP TO 20 DEGREE TEMP DIFFERENCE BETWEEN LOVELOCK AND TRUCKEE.
AS RIDGE AXIS SHIFTS EAST SUNDAY THERE WILL ALSO BE THE POSSIBILITY
OF LOW/MID LVL MSTR STARTING TO EASE BACK NORTH. GFS PWAT PROGS SHOW
UP TO 0.75 INCHES IN FAR SRN MONO COUNTY SUNDAY AFTN. WHILE THIS IS
LIKELY OVER DONE...THERE SHOULD BE ENOUGH MSTR AND DEFINITELY ENOUGH
INSTABILITY FOR A SLIGHT CHANCE OF THUNDERSTORMS BY SUNDAY OVER
MONO/MINERAL COUNTIES. SO THESE WERE ADDED TO THE FORECAST. LIKELY
TO BE A REPEAT AS WELL FOR THE FOURTH OF JULY. MLF
&&

.AVIATION...
ONE MORE DAY OF VFR CONDITIONS OVER THE ENTIRE REGION AHEAD OF
APPROACHING STRONG SYSTEM. FAIRLY LIGHT WINDS AS WELL TODAY. BIG
CHANGES FOR TUESDAY AS WINDS BEGIN TO INCREASE SIGNIFICANTLY AND
MSTR BEGINS TO MOVE INTO THE RGN. SHOWERS AND THUNDERSTORMS SHOULD
DEVELOP OVER THE SIERRA AND NORTH OF TAHOE TUESDAY AFTN...LOWERING
CIGS AND VSBYS AT TIMES. WINDS TO THE EAST OF THE SIERRA COULD GUST
AS HIGH AS 40 KT BY LATE TUESDAY AFTN/TUES EVENING. SHOWERS AND
THUNDERSTORMS MOVE EAST TUESDAY NIGHT...WITH SOME POSSIBLY QUITE
STRONG...THEN LINGER INTO WEDNESDAY AS WELL. MLF

&&

.FIRE WEATHER...
STRONG WINDS WILL BEGIN TO AFFECT WESTERN NEVADA AND THE SIERRA ON
TUESDAY AFTERNOON WITH GUSTS BETWEEN 35 MPH TO 45 MPH. ALONG THE
SIERRA FRONT AND EASTERN AREAS OF MONO COUNTY WINDS COULD GUST AS
HIGH AS 60 MPH IN WIND PRONE LOCATIONS. WINDS WILL INCREASE ALONG
THE RIDGES EARLY TUESDAY MORNING AHEAD OF AN AREA OF STRONG LOW
PRESSURE...WITH PEAK WINDS OCCURRING IN THE LATE AFTERNOON ALONG THE
SIERRA FRONT AND INTO THE BASIN AND RANGE.

STRONG WINDS WITH DRY FINE FUELS WILL COMBINE FOR THE POTENTIAL OF
CRITICAL FIRE CONDITIONS SO A FIRE WEATHER WATCH HAS BEEN ISSUED FOR
ZONES 450...453...459...AND 273 BELOW 7000 FEET. RELATIVE HUMIDITY
THROUGHOUT THE DAY WILL FLUCTUATE AND MAY REMAIN JUST SHY OF
CRITERIA...BUT THE STRONG WINDS WILL BE ENOUGH TO CREATE FIRE
WEATHER CONCERNS. MINIMUM VALUES BETWEEN 15% TO 20% ALONG THE SIERRA
FRONT...WITH VALUES IN 453 AND 459 AROUND 15%. WINDS WILL CONTINUE
INTO THE EARLY EVENING...BUT RELATIVE HUMIDITIES SHOULD BEGIN TO
RECOVER OVERNIGHT INTO WEDNESDAY.

IN ADDITION...MODELS ARE HINTING AT THE POSSIBILITY OF A FEW FAST
MOVING THUNDERSTORMS ACROSS THE BASIN AND RANGE TUESDAY AFTERNOON
AND EVENING. WHILE POSSIBLE...HAVE NOT INCLUDED T-STORMS IN THE
FORECAST AT THIS TIME AS CONFIDENCE IS LOW. IF T-STORMS WERE TO
DEVELOP...MAIN THREAT WOULD BE DRY LIGHTNING DUE TO FAST STORM
MOTIONS. MAY NEED TO ADD ISOLATED DRY T-STORMS TO THE FORECAST FOR
ZONE 453 IF MODELS CONTINUE TO SHOW SIGNS OF CONVECTIVE ACTIVITY
TUESDAY AFTERNOON. LINDAMAN/SCV

&&

.HYDROLOGY...

* MODERATE TO MAJOR FLOODING CONTINUES IN MASON VALLEY...YERINGTON
  AND WABUSKA AREAS. SEE THE LATEST FLOOD STATEMENT FOR THE WALKER
  RIVER FOR ADDITIONAL DETAILS.

COOLER TEMPERATURES AND A DIMINISHING SNOWPACK FOR MOST BASINS HAVE
ALLOWED FLOWS ON CREEKS AND RIVERS TO DECREASE. ONLY EXCEPTION
IS THE HIGHER ELEVATIONS OF MONO COUNTY WHERE THE HIGH ELEVATION
SNOWPACK REMAINS AND WILL CONTINUE TO PRODUCE HIGH FLOWS AND
FLOODING IN MONO COUNTY AND INTO THE WALKER RIVER SYSTEM.

TEMPERATURES WILL WARM TODAY AND TUESDAY AHEAD OF AN APPROACHING LOW
AND LEAD TO INCREASING SNOWMELT RUN OFF AND HIGHER FLOWS. THIS WILL
BE ESPECIALLY EVIDENT IN THE WALKER BASIN.

AS THE LOW MOVES INTO THE SIERRA AND WESTERN NEVADA TUESDAY NIGHT
AND WEDNESDAY...TEMPERATURES WILL COOL BUT THERE IS POTENTIAL FOR
MODERATE TO HEAVY SHOWERS. MAXIMUM RAINFALL AMOUNTS NEAR 0.75 INCHES
IN THE NORTHERN SIERRA...0.25-0.50 FOR THE CARSON/WALKER HEADWATERS
IN ALPINE AND MONO COUNTIES...AND POTENTIAL FOR 0.25 INCHES OR MORE
ACROSS WESTERN NEVADA.  MAIN CONCERN WITH THIS SYSTEM IS THE STRONG
LIFT AND A PRECIPITABLE WATER PLUME OVER 1.25 INCHES PUSHING INTO
THE SIERRA TUESDAY EVENING AND OVERNIGHT. IF EVERYTHING COMES INTO
LINE WITH THE SYSTEM PRECIPITATION AMOUNTS COULD BE HIGHER...AND MAY
EXACERBATE FLOOD IMPACTS IN SMALL CREEKS AND STREAMS FROM TAHOE
SOUTH DUE THE CURRENT HIGH FLOWS AND MOIST SOIL CONDITIONS. SNOW
LEVELS WITH THIS SYSTEM START ABOVE 9500 FEET THEN BEGIN TO LOWER BY
LATE TUESDAY NIGHT TO AROUND 8000-8500 FEET. HEAVIEST PRECIPITATION
STILL APPEARS TO BE NORTH OF TAHOE...WHERE THERE IS LESS SNOW PACK.

BEHIND THE LOW HIGH PRESSURE WILL BUILD ACROSS THE WEST WITH
AFTERNOON HIGHS RISING TO NEAR 10 DEGREES ABOVE NORMAL FOR THE JULY
4TH HOLIDAY WEEKEND AND AGAIN INCREASE RUN OFF AND FLOWS INTO MANY
AREA STREAMS AND RIVERS.

FOR THE WALKER RIVER SYSTEM...FLOWS INTO TOPAZ AND BRIDGEPORT HAVE
LOWERED AND CURRENTLY THERE ARE LITTLE TO NO FLOOD CONCERNS ON THE
WEST AND EAST FORKS OF THE WALKER...ALTHOUGH FLOWS WILL REMAIN
ABNORMALLY HIGH...UNTIL WARMER TEMPERATURES RETURN LATER TODAY AND
TUESDAY. ADDITIONAL RELEASES FROM TOPAZ AND BRIDGEPORT MAY NOT BE
NEEDED...BUT THE CURRENT STEADY RELEASES WILL MAINTAIN A SLOW
INCREASE IN FLOWS AND EXPANDING FLOOD IMPACTS FOR THE MAINSTEM
WALKER FROM YERINGTON/MASON VALLEY NORTHWARD INTO WABUSKA. SPOTTERS
HAVE REPORTED WATER IS WITHIN A FEW INCHES OF BRIDGE BOTTOMS
CROSSING THE WALKER RIVER IN THE MASON VALLEY...WITH SIGNIFICANT
FLOODING OF AGRICULTURAL AREAS AND FLOOD WATERS NEARING THE LOWEST
STRUCTURES ALONG THE RIVER.

FOR SMALLER CREEKS AND STREAMS IN MONO COUNTY...THE SMALL CREEK AND
STREAM FLOOD WARNING WAS EXTENDED THROUGH TUESDAY. FLOODING WILL
CONTINUE DUE TO THE MELTING SNOWPACK...WITH SEVERAL REPORTS OF
FLOODED CAMPGROUNDS AND BACK COUNTY ROADS. STREAM FLOWS ARE LIKELY
TO INCREASE TODAY THROUGH TUESDAY WITH ADDITIONAL WARMING. ANY
ADDITIONAL RAINFALL TUESDAY NIGHT WILL ALSO INCREASE STREAM FLOWS.
THIS WEEK SHOULD SEE PEAK FLOWS OF THE SEASON AS WELL ABOVE AVERAGE
TEMPS RETURN BY FRIDAY. BRONG/MLF
&&

.REV WATCHES/WARNINGS/ADVISORIES...
NV...FIRE WEATHER WATCH FROM TUESDAY MORNING THROUGH TUESDAY EVENING
     NVZ450-453-459.

CA...FIRE WEATHER WATCH FROM TUESDAY MORNING THROUGH TUESDAY EVENING
     BELOW 7000 FEET FOR CAZ273.

&&

HTTP://WEATHER.GOV/RENO