Strong Wind in California, January 2, 2009

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
330 AM PST FRI JAN 2 2009

.SHORT TERM...

A COLD FRONT OVER WRN OREGON EARLY THIS MORNING WILL MOVE SOUTHEAST
ACROSS NRN ZONES THIS MORNING AND THROUGH CENTRAL AND SRN ZONES THIS
AFTERNOON AND EVENING. AHEAD OF THIS FRONT WINDS HAVE BEEN PICKING
UP WITH GUSTS REACHING 30-40 MPH NORTH OF HIGHWAY 50. 700 MB WINDS
INCREASE TO 50-70 KTS NORTH OF INTERSTATE 80 THIS MORNING WITH A
TIGHT GRADIENT ALONG AND AHEAD OF THE FRONT. RIDGE GUSTS HAVE
ALREADY INCREASED TO 80-90 MPH THIS MORNING...AND WILL PEAK ABOVE
100 MPH IN THE TAHOE BASIN TODAY. MODEL SOUNDINGS ARE NOT OVERLY
IMPRESSIVE WITH A CRITICAL LAYER...BUT DO HINT AT A WEAK ONE ALONG
THE SIERRA FRONT. WINDS WILL PICK UP FURTHER AS THE FRONT NEARS AND
WIND ADVISORIES ARE IN EFFECT FOR NWRN NV AND IN THE SIERRA AND WRN
NV ESPECIALLY ALONG THE HIGHWAY 395 CORRIDOR. WIND GUSTS 45-50 MPH
ARE EXPECTED BEFORE THE FRONT MOVES THROUGH WITH LOCAL GUSTS UP TO
60 MPH POSSIBLE IN THE FOOTHILLS AND WIND PRONE AREAS ALONG HIGHWAY
395. IN MONO COUNTY THE STRONGEST WINDS ARE EXPECTED NORTH OF MONO
LAKE...WITH GUSTS UP TO 35-40 MPH EXPECTED OVER SRN AREAS. FURTHER
EAST OF THE SIERRA FRONT WINDS WILL NOT BE AS STRONG...AND THE LAKE
WIND ADVISORY FOR CHURCHILL/PERSHING COUNTY SHOULD BE SUFFICIENT.
WINDS WILL DECREASE UP NORTH BEFORE NOON...AND GRADUALLY DIMINISH
FURTHER SOUTH THROUGH THE AFTERNOON/EARLY EVENING.

AS FOR PRECIPITATION...THE MAIN BAND OF PRECIPITATION ALONG THE
FRONT IS PUSHING ACROSS CENTRAL OREGON AND EXTENDS INTO NORTH
CENTRAL CA. THIS BAND WILL WEAKEN AS IT MOVES EAST THIS MORNING..BUT
STILL PRODUCE DECENT PRECIP AMOUNTS IN THE SIERRA AND FAR NRN AREAS.
PRIOR TO THE ARRIVAL OF MORE STRATIFORM PRECIP UP NORTH AND IN THE
SIERRA INTERMITTENT SHOWERS ARE LIKELY EARLY THIS MORNING. QPF
AMOUNTS OVER NRN WASHOE COUNTY INTO THE SURPRISE VALLEY ARE AROUND A
QUARTER INCH...HOWEVER NOT ALL OF THAT WILL FALL AS SNOW. THEREFORE
ONLY AN INCH OR TWO OF SNOW IS EXPECTED THIS MORNING BEFORE
PRECIPITATION SHIFTS FURTHER SOUTH WITH THE FRONT. QPF AMOUNTS ALONG
THE SIERRA CREST GENERALLY BELOW 0.75 INCH OF LIQUID TRANSLATE TO
SNOW AMOUNTS OF 6-10 INCHES POSSIBLE IN THE HIGH SIERRA. SNOW LEVELS
IN THE TAHOE BASIN THIS MORNING HAVE REMAINED 7500-8000 FEET BASED
ON MTN TOP TEMPERATURES AND WILL LIKELY DROP TO AROUND 7000 FEET
THIS MORNING BEFORE DROPPING TO LAKE LEVEL THIS AFTERNOON. WARM
SURFACE TEMPERATURES AND SLOWLY LOWERING SNOW LEVELS WILL NOT ALLOW
TOO MUCH SNOW TO ACCUMULATE DOWN TO LAKE LEVEL...WITH ONLY 2-4
INCHES POSSIBLE QUICKLY LATE THIS AFTERNOON. SNOW AMOUNTS UP TO 6-10
INCHES CAN BE EXPECTED ABOVE 8000 FEET STARTING LATER THIS MORNING
THROUGH EARLY EVENING. SNOW AMOUNTS ARE EXPECTED TO REMAIN BELOW
ADVISORY LEVELS BELOW 7500-8000 FEET...THEREFORE SNOW ACCUMULATION
WILL JUST BE MENTIONED IN THE WIND ADVISORIES.

FOR AREAS FURTHER EAST INTO NEVADA...PRECIPITATION WILL BE SHADOWED
OUT THIS MORNING AS GOOD SUBSIDENCE IS EVIDENT ON SATELLITE
IMAGERY...AND STABILITY REMAINS HIGH AND WINDS REMAIN STRONG. AS THE
FRONT DROPS SOUTH THIS AFTERNOON A BAND OF SNOW MAY DEVELOP FURTHER
EAST STRETCHING FROM SUSANVILLE/PORTOLA EAST ALONG OR NORTH OF
INTERSTATE 80. SNOW LEVELS WILL REMAIN ABOVE 5000 FEET IN THE RENO
AREA UNTIL LATE THIS AFTERNOON AND WILL DROP TO VALLEY FLOORS
TONIGHT...AS PRECIPITATION IS ENDING. THEREFORE LIGHT SNOW
ACCUMULATIONS OF AN INCH OR SO ARE POSSIBLE MAINLY ABOVE 5000 FEET
LATER TODAY...AND MAINLY ALONG/NORTH OF INTERSTATE 80.

TEMPERATURES HAVE JUMPED UP THIS MORNING AS GUSTY WINDS MIXED DOWN
TO THE SURFACE AND THIS HAS RAISED ALL TEMPERATURES ABOVE FREEZING
IN ALL AREAS...WHICH REMOVES ANY CHANCE OF FREEZING RAIN THIS
MORNING. THEREFORE PRECIP TYPE SHOULD BEGIN AS RAIN IN THE LOWER
ELEVATIONS AND CHANGE TO SNOW AS SNOW LEVELS DROP ALONG THE FRONT.
THERE WILL LIKELY BE A MIX OF RAIN AND SNOW AROUND TRANSITION
TIME...BUT THIS WILL BE SHORT LIVED.

TRAVEL OVER THE SIERRA PASSES WILL LIKELY BECOME SLOW LATER THIS
MORNING WITH EXPECTED SNOW ACCUMULATIONS. THIS WILL AFFECT PEOPLE
HEADING TO SKI AREAS FOR THE WEEKEND AND THOSE RETURNING HOME FROM
HOLIDAY TRAVELS.

TEMPERATURES IN THE UPPER 40S TO LOW 50S TODAY AHEAD OF THE FRONT
WILL DROP DRAMATICALLY TOMORROW WITH HIGHS ONLY IN THE MID 30S
ACROSS MOST AREAS. TEMPERATURES WILL REMAIN COOL INTO SUNDAY AS
INVERSIONS REMAIN IN PLACE. MILD LOW TEMPERATURES THIS MORNING DUE
TO WINDY CONDITIONS WILL DROP CLOSER TO SEASONAL NORMALS BY SATURDAY
MORNING...INTO THE TEENS AND AROUND 20 IN WRN NV...AND INTO THE
SINGLE DIGITS AND TEENS IN THE SIERRA AND WILL BE EVEN COLDER BY
SUNDAY MORNING. GMCGUIRE

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

LONGWAVE PATTERN WILL UNDERGO SOME ADJUSTMENT NEXT WEEK AS THERE ARE
SIGNALS SUGGESTING TROUGH WILL UNDERGO AMPLIFICATION ACROSS EASTERN
NORTH AMERICA. THIS WOULD POINT TO INCREASING HEIGHTS ACROSS WESTERN
NORTH AMERICA ALTHOUGH THERE ARE TWO OPINIONS REGARDING HOW FAR EAST
TO BRING RIDGE AXIS. THE GFS/GEFS MEAN AND ECMWF ARE MOST AGGRESSIVE
AT BRINGING RIDGE INTO THE WESTERN U.S. WHILE NAEFS AND MEAN ECMWF
ENSEMBLES ARE MORE IN FAVOR OF A BROADER RIDGE RESIDING OVER THE
EAST PACIFIC. THE LATTER WOULD KEEP A BRISK NORTHWEST FLOW ALOFT AND
ALLOW SYSTEMS TO BRUSH AREA.

DUE TO MODEL SPREAD IN DETAILS...ESPECIALLY TOWARDS DAY 7...THE
FORECAST WILL FOLLOW A COMPROMISE OF THE TWO LONGWAVE PATTERNS. WEAK
LIFT ASSOCIATED WITH WARM ADVECTION WILL BRUSH AREA MONDAY FOR A
SMALL CHANCE OF RAIN AND MOSTLY HIGH ELEVATION SNOW. A BREAK TUESDAY
AND WEDNESDAY WILL THEN BE FOLLOWED BY ANOTHER PIECE OF SHORTWAVE
ENERGY THAT WILL BE DROPPING SOUTHEAST TOWARD AREA FROM ATOP EAST
PACIFIC/WEST COAST RIDGE. THIS COULD BRING ANOTHER ROUND OF LIGHT
PRECIPITATION AND WIND DEPENDING ON FINAL SETUP OF LARGER SCALE
FEATURES. A SLIGHT CHANCE WAS INTRODUCED MAINLY NORTH THU-THU NGT.
TEMPERATURES SHOULD REMAIN UNSEASONABLY MILD FOR JANUARY WITH
READINGS PUSHING 50S IN WESTERN NEVADA VALLEYS UNDER WEAK INVERSIONS
AND SUFFICIENT WEST-NORTHWEST FLOW ALOFT (20-25KT). HOHMANN
&&

.AVIATION...

FOR THE NORTHERN SIERRA INCLUDING KTRK AND KTVL...

SNOW LEVELS WILL REMAIN 7000-8000 FT FROM TAHOE NORTH BEFORE FALLING
TO 5000-6000 FEET AROUND 18Z. THIS SHOULD KEEP KTRK AND KTVL -RA
WITH VISIBILITIES AOA 5SM UNTIL AFT 18Z. AFT 18Z...-RA/RA WILL
CHANGE TO -SN/SN WITH A PD OF +SN PSBL 20Z-00Z BRINGING VSBYS/CIGS I
BELOW MINIMUMS. CIGS/VSBYS SHOULD IMPROVE AROUND 03Z AS SNOW SHWRS
TAPER OFF.

WIND WISE FOR THE NORTHERN AND CENTRAL SIERRA...EXPECT WINDS OF
40-50 KTS WITH GUSTS 70-90 KTS OVER RIDGES TODAY WITH GUSTS IN
EXCESS OF 30KT AT KTVL/KTRK.

FOR THE WESTERN GREAT BASIN INCLUDING KRNO AND KLOL...

WIND GUSTS 30-40 KTS EXPECTED ALONG AND AHEAD OF COLD FRONT TODAY
...MAINLY WEST OF KLOL. WINDS TO DECREASE AFT 00Z BEHIND COLD FRONT.

WITH REGARD TO PRECIPITATION...PERIODS OF -RA WITH VSBYS/CIGS ABV
P6SM/BKN030. A BRIEF PD OF -SN IS PSBL BEHIND FRONT 00Z-06Z ALTHOUGH
SNOWFALL IS NOT EXPECTED TO POSE ANY IMPACTS FOR TERMINALS. HOHMANN
&&

.REV WATCHES/WARNINGS/ADVISORIES...
NV...WIND ADVISORY UNTIL 10 AM PST THIS MORNING FOR NVZ005.

     WIND ADVISORY UNTIL 4 PM PST THIS AFTERNOON FOR NVZ002-003.

     LAKE WIND ADVISORY UNTIL 4 PM PST THIS AFTERNOON FOR NVZ004.

CA...WIND ADVISORY UNTIL 10 AM PST THIS MORNING FOR CAZ070-071.

     WIND ADVISORY FROM 9 AM THIS MORNING TO 6 PM PST THIS AFTERNOON
     FOR CAZ073.

     WIND ADVISORY UNTIL 4 PM PST THIS AFTERNOON FOR CAZ072.

&&

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