Strong Wind in Nevada, May 31, 2011

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
902 AM PDT TUE MAY 31 2011

.UPDATE...
WIND HAS INCREASED A BIT FASTER TODAY THAN ORIGINALLY FORECAST AND
THUS MIXING HAS INCREASED AND CAUSED TEMPS TO RISE A LITTLE
QUICKER THAN FORECAST. THINK TEMPS MAY INCREASE A FEW DEGREES
ABOVE THE CURRENT FORECAST FOR PARTS OF WRN NV AND THE LOWER
ELEVATIONS OF MONO COUNTY. BUT ONCE MIXING IS COMPLETE LATE THIS
MORNING/EARLY THIS AFTN THIS INCREASE WILL SLOW. FOR AREAS ACROSS
ERN CA THE CLOUDS WILL INCREASE AND LIMIT THE AMOUNT OF HEATING.
SO BUMPED UP TEMPS JUST A BIT OVER PARTS OF WRN NV AND MONO
COUNTY. OTHERWISE NO SIGNIFICANT CHANGES THIS MORNING. MLF

&&

.PREVIOUS DISCUSSION... /ISSUED 557 AM PDT TUE MAY 31 2011/

UPDATE...

QUICK UPDATE THIS MORNING TO BUMP UP TIMING FOR THE TAHOE LAKE
WIND ADVISORY TO NOW. WINDS HAVE ALREADY PICKED UP ACROSS THE LAKE
SURFACE...WITH GUSTS ALREADY HITTING 40 MPH. REST OF THE FORECAST
LOOKS ON TRACK. PRETTY STRONG WINDS OVERHEAD RIGHT NOW...AS
MORNING SOUNDING SHOWS +50KT WIND AROUND 600MB. WINDS STILL
EXPECTED TO BE JUST BELOW WIND ADVISORY CRITERIA IN RENO-
SPARKS...WITH GUSTS UP TO 45 MPH THIS AFTERNOON. HOON

PREVIOUS DISCUSSION... /ISSUED 337 AM PDT TUE MAY 31 2011/

SHORT TERM...
THE NEXT IN A SEEMINGLY ENDLESS PARADE OF UNSEASONABLY COLD UPPER
LOWS IS BECOMING WELL ORGANIZED THIS MORNING OFF THE NW CA COAST.
THIS WILL BRING GUSTY SOUTH TO SOUTHWEST WINDS TO MUCH OF THE
FORECAST AREA THIS AFTERNOON AND EVENING. THE STRONGEST WINDS ARE
EXPECTED OVER MONO AND MINERAL COUNTIES WHERE THE FLOW IS BETTER
ORIENTED TO THE TERRAIN ALLOWING WINDS TO DUCT TO THE SURFACE WITH
GUSTS OF 40 TO 50 MPH. ALTHOUGH THE FLOW ALOFT IS FAIRLY
STRONG...THE PRESSURE GRADIENT WILL BE THE MAIN DRIVER IN PRODUCING
THE GUSTY WINDS EVEN WITH A 120+ KT JET BECOMING ENTRENCHED OVER NRN
CA AND NV. SOUNDINGS ARE WELL MIXED WITH LIMITED CRITICAL LAYER
DEVELOPMENT. GUSTS OF UP TO 35-45 MPH ARE EXPECTED FROM DOYLE SOUTH
THROUGH RENO/CC/MINDEN AND WOULD LIKELY BE STRONGER IF THE FLOW
WASNT AS SOUTHERLY AS WHAT IS ANTICIPATED.

MOISTURE FOR THIS SYSTEM TO WORK OFF IS QUITE MEAGER AND THEREFORE
MODERATE-HEAVY WIDESPREAD PRECIPITATION IS NOT EXPECTED WITH THIS
SYSTEM. SOME LIGHT SHOWERS ARE POSSIBLE TODAY IN WESTERN LASSEN
COUNTY UP TO THE OREGON BORDER BUT NOTHING OVERLY IMPRESSIVE. AS THE
LOW GRADUALLY TRACKS INTO THE SIERRA AND WESTERN NV TONIGHT AND
WEDNESDAY...SHOWERS WILL GRADUALLY INCREASE...ESPECIALLY WEDNESDAY
AFTERNOON WHEN THE CORE OF THE UPPER LOW WILL BE OVERHEAD. ISOLATED
THUNDERSTORMS ARE POSSIBLE NORTH OF AROUND INTERSTATE 80 WITH
SUFFICIENT INSTABILITY DUE TO STEEP LAPSE RATES ALOFT COMBINED WITH
DAYTIME HEATING. SNOW LEVELS WILL GRADUALLY LOWER TO AROUND
5000-5500 FEET BY WEDNESDAY EVENING BUT ONLY MINOR ACCUMULATIONS
ABOVE 7000 FEET ARE EXPECTED.

AS THE LOW SLOWLY TRACKS INTO NORTHEASTERN NV WED NIGHT AND
THURSDAY...SHOWERS WILL GRADUALLY WIND DOWN WHILE AFTERNOON AND
EVENING WINDS WILL REMAIN GUSTY. JUST AS THIS LOW DEPARTS AN EVEN
BETTER ORGANIZED UPPER LEVEL LOW WILL BE ON ITS HEELS.  MILNE

LONG TERM...FRIDAY THROUGH MONDAY...

YET ANOTHER DEEP CUTOFF LOW SET TO MOVE DOWN THE WEST COAST NEXT
WEEKEND...BRINGING COOLER TEMPERATURES AND CHANCES FOR RAIN/SNOW TO
THE SIERRA AND WESTERN NV. MODELS ARE COMING INTO BETTER
AGREEMENT...WITH ECMWF BEING THE MOST CONSISTENT OVER THE LAST FEW
DAYS. THERE STILL REMAINS A LOT OF UNCERTAINTY IN THE TIMING...AS
OUR MODELS DO POORLY WITH THESE BAROTROPIC CUTOFF LOWS.

CONTINUED TO INCREASE POPS FOR THE SIERRA ON SATURDAY AS THE LOW
BEGINS TO PUSH SOME MOISTURE INTO NORTHERN CA. EVEN THE GFS
ENSEMBLES ARE SHOWING AN 80% POP FOR THE TAHOE BASIN ON SATURDAY.
AFTER SATURDAY...THE MODELS BEGIN TO DIVERGE SHARPLY. THE EURO
EJECTS THE LOW INTO THE GREAT BASIN...THE GFS LEAVING IT OVER
CA...AND THE GEM SHUNTING THE LOW INTO BAJA CA.

DIDN'T REALLY MAKE ANY CHANGES PAST SATURDAY...KEEPING SOME CHANCES
OF SHOWERS IN WESTERN NV. MOST LIKELY OUTCOME IS THAT WE WILL SEE
SHOWERS/THUNDERSTORMS AT SOME POINT SUN-MON WHEN THE LOW DECIDES TO
PUSH INLAND...WITH TIMING BEING THE BIG QUESTION. AS FOR
TEMPERATURES...KEPT WITH THE MIDDLE OF THE PACK AS IT COULD GO
WARMER OR COLDER DEPENDING ON THE TRACK OF THE LOW.  HOON

AVIATION...

GUSTY SOUTH TO SOUTHWEST WINDS EXPECTED TODAY. GUSTS 25 TO 35 KTS BY
22Z. OVER RIDGES...WINDS WILL GUST UP TO 65-75 KTS BRINGING CONTINUED
LIGHT TO MODERATE TURBULENCE DOWNWIND OF THE SIERRA.

PRECIPITATION WISE...ISOLATED TO SCATTERED SHOWERS ARE EXPECTED FOR
THE NORTHERN SIERRA AND NORTHEAST CALIFORNIA EAST OF THE CREST
TODAY. MVFR/IFR CIG/VIS WILL BE POSSIBLE OVER NORTHERN LASSEN COUNTY
THIS AFTERNOON AS SNOW LEVELS FALL TO ARND 5500 FT MSL. HOON

&&

.REV WATCHES/WARNINGS/ADVISORIES...
NV...LAKE WIND ADVISORY FROM 1 PM THIS AFTERNOON TO 8 PM PDT THIS
     EVENING NVZ004.

     WIND ADVISORY FROM 1 PM THIS AFTERNOON TO 8 PM PDT THIS EVENING
     NVZ001.

     LAKE WIND ADVISORY UNTIL 8 PM PDT THIS EVENING NVZ002.

CA...WIND ADVISORY FROM 1 PM THIS AFTERNOON TO 8 PM PDT THIS EVENING
     CAZ073.

     LAKE WIND ADVISORY UNTIL 8 PM PDT THIS EVENING CAZ072.

&&

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