Winter Storm Watch 21, NWS Reno, NV

000 
WWUS45 KREV 142340
WSWREV

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE RENO NV
340 PM PST THU DEC 14 2006

CAZ071-072-NVZ002-150800-
/O.CON.KREV.WS.A.0021.061216T0000Z-061216T1800Z/
LASSEN-EASTERN PLUMAS-EASTERN SIERRA COUNTIES-
GREATER LAKE TAHOE AREA-
INCLUDING THE CITIES OF...PORTOLA...SUSANVILLE...WESTWOOD...
SIERRAVILLE...SOUTH LAKE TAHOE...TAHOE CITY...TRUCKEE...
MARKLEEVILLE...GLENBROOK...INCLINE VILLAGE
340 PM PST THU DEC 14 2006

...WINTER STORM WATCH REMAINS IN EFFECT FROM FRIDAY AFTERNOON
THROUGH SATURDAY MORNING...

A WINTER STORM WATCH REMAINS IN EFFECT FROM FRIDAY AFTERNOON
THROUGH SATURDAY MORNING. 

A LOW PRESSURE SYSTEM WILL DROP SOUTHWARD INTO THE REGION TONIGHT
THROUGH SATURDAY WITH A MUCH COLDER AIRMASS AND STRONG JET STREAM
OFF THE PACIFIC CREATING CONDITIONS FAVORABLE FOR RAIN AND SNOW.
LIGHT RAIN AND SNOW WILL DEVELOP IN THE TAHOE BASIN AND PARTS OF
NORTHEAST CALIFORNIA LATE TONIGHT AND FRIDAY WITH SNOW LEVELS
LOWERING TO ALL LOCATIONS BY FRIDAY AFTERNOON.

DETAILS ARE STILL UNCERTAIN BUT THERE IS POTENTIAL FOR A BRIEF PERIOD
OF MODERATE TO HEAVY SNOW OVER THE CENTRAL AND NORTHERN SIERRA
FRIDAY NIGHT. UP TO A FOOT OF VERY LIGHT SNOW COULD FALL IN THE
WATCH AREA BY SATURDAY MORNING.

A WINTER STORM WATCH MEANS THERE IS A POTENTIAL FOR SIGNIFICANT
SNOW ACCUMULATIONS THAT MAY CREATE HAZARDOUS WINTER DRIVING
CONDITIONS. CONTINUE TO MONITOR THE LATEST FORECASTS.

$$


HTTP://WEATHER.GOV/RENO

000 
WWUS45 KREV 150442
WSWREV

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE RENO NV
842 PM PST THU DEC 14 2006


CAZ071-072-NVZ002-150545-
/O.CAN.KREV.WS.A.0021.061216T0000Z-061216T1800Z/
LASSEN-EASTERN PLUMAS-EASTERN SIERRA COUNTIES-
GREATER LAKE TAHOE AREA-
INCLUDING THE CITIES OF...PORTOLA...SUSANVILLE...WESTWOOD...
SIERRAVILLE...SOUTH LAKE TAHOE...TAHOE CITY...TRUCKEE...
MARKLEEVILLE...GLENBROOK...INCLINE VILLAGE
842 PM PST THU DEC 14 2006

...WINTER STORM WATCH IS CANCELLED...

THE NATIONAL WEATHER SERVICE IN RENO HAS CANCELLED THE WINTER
STORM WATCH. 

LATEST COMPUTER MODEL AND SATELITE IMAGERY SHOWING FRONTAL SYSTEM
IN EASTERN PACIFIC MOVING SOUTHEAST TOWARD SOUTHERN CALIFORNIA
LEAVING MUCH OF THE SIERRA AND WESTERN NEVADA WITH ONLY LIGHT
ACCUMULATIONS OVER THE NEXT 48 HOURS. MOTORIST PLANNING TRAVEL
ACROSS THE SIERRA SHOULD MONITOR CHECK ROAD CONDITIONS BEFORE
DEPARTING.

$$
TC

HTTP://WEATHER.GOV/RENO

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE RENO NV
430 AM PST THU DEC 14 2006

CORRECTED LAST SENTENCE IN THE SHORT TERM DISCUSSION

.SHORT TERM...
VERY BRIEF AND FLAT RIDGING WILL BE OVER THE REGION TODAY...WITH
RESIDUAL LIGHT SHOWERS OR SPRINKLES ALONG THE SIERRA RIDGELINE AND
OVER FAR NORTHERN WASHOE COUNTY. HIGHS WILL BE QUITE MILD WITH
AROUND 60 COMMON IN THE LOWER VALLEYS OF WESTERN NEVADA. ENJOY
IT...BECAUSE THE BOTTOM FALLS OUT FRIDAY AND INTO THE WEEKEND.

TONIGHT...A STRONG COLD FRONT WILL ENTER FAR NORTHERN LASSEN AND
WASHOE COUNTIES WELL AFTER MIDNIGHT. AHEAD OF THE FRONT...ALL THE
INGREDIENTS SEEM TO BE THERE FOR A VERY WINDY NIGHT. BY LATE
TONIGHT...I WOULD NOT BE SURPRISED TO SEE WIND GUSTS CLOSE TO 70 MPH
IN THE FOOTHILLS OF THE NORTHERN SIERRA...WITH GUSTS OVER 50 MPH
WIDESPREAD. SEE OUR NPWREV PRODUCTS FOR MORE DETAILS.

FRIDAY...THE COLD FRONT WILL JAM ITS WAY THROUGH THE ENTIRE CWFA IN
THE AFTERNOON. WITH THE STRONG WINDS OVER THE REGION...AND THE BEST
UPPER SUPPORT REMAINING OVER FAR NORTHERN CALIFORNIA AND NEVADA
DURING THE DAY FRIDAY...PRECIPITATION LOOKS RATHER LIGHT WITH THE
FROPA. OTHER THAN A FEW INCHES OF SNOW IN THE SIERRA...THE FRONT
LOOKS TO BRING MAINLY AN ABRUPT COOL DOWN FROM THURSDAY.

FRIDAY NIGHT AND SATURDAY...THINGS GET A LITTLE MORE INTERESTING
ALBEIT MUDDLED. A 150 KNOT JET CORE REMAINING OVER OR JUST NORTH OF
LAKE TAHOE DURING THE DAY FRIDAY WILL SAG SOUTH TO NORTHERN MONO
COUNTY BY 12Z SATURDAY. AS THE JET SAGS SOUTH...DEEPER MOISTURE WILL
MOVE INTO AREAS GENERALLY NORTH OF HIGHWAY 50. WITH FAVORABLE UPPER
DYNAMICS IN THE LEFT FRONT QUADRANT OF THE VERY POWERFUL JET STREAK
AND THE DEEPENING MOISTURE...WE EXPECT STEADY SNOW TO DEVELOP IN THE
NORTHERN SIERRA AND PERHAPS EVEN WESTERN NEVADA LATE FRIDAY NIGHT
AND EARLY SATURDAY. SURPRISINGLY...THE GFS DOES NOT SHOW ANY
PRECIPITATION RELATED TO THE JET DYNAMICS AND COLD AIR ALOFT. THIS
SEEMS VERY SUSPECT GIVEN THE OVER WATER TRAJECTORY OF THE JET WITH A
COLD POOL ALOFT OFF THE CENTRAL CALIFORNIA COAST. WE BELIEVE THE GFS
IS WAY UNDERDONE WITH POPS AND QPF FRIDAY NIGHT AND SATURDAY. THIS
FACT...AS WELL AS THE CONSIDERATION OF HIGH SNOW RATIOS IN THE COLD
AIR...LEAD US TO ISSUE A WINTER STORM WATCH FOR THE TAHOE AND LASSEN
ZONES. THERE COULD BE A 6 TO 12 HOUR PERIOD OF MODERATE TO HEAVY
SNOWFALL IN THE SIERRA...WITH THE POSSIBILITY OF A BAND OF SPILLOVER
SNOW INTO WESTERN NEVADA (ALTHOUGH THE IMPACT OF THIS IS VERY
UNCERTAIN AT THIS POINT).

SATURDAY AFTERNOON...THE MAIN JET STREAK MOVES WELL SOUTH OF THE
REGION AS A VORT MAX APPROACHES SOUTHERN CALIFORNIA...LIKELY
DIMINISHING SNOW TO SCATTERED SHOWER ACTIVITY. ONE FINAL VORT MAX
LOOKS TO DROP INTO THE MAIN TROUGH OVER SOUTHERN NEVADA SATURDAY
NIGHT INTO SUNDAY...CONTINUING THE CHANCE FOR SNOW SHOWERS. SNYDER

.LONG TERM...SUNDAY THROUGH WEDNESDAY...
UPPER TROUGH TO BEING PULLING OUT SLOWLY WITH INSIDE SLIDER WAVE
POSSIBLE SUNDAY ALONG THE EASTERN SIERRA AS UPPER JET WILL STILL BE
JUST TO THE WEST OF AREA AND COLD CYCLONIC FLOW WILL BE AVAILABLE TO
LEND SUPPORT. THIS WILL HAVE TO BE WATCHED AS IT COULD PRODUCE A
QUICK SHOT OF SNOWFALL. POPS WERE BUMPED UP TO CHANCE MOST AREAS AND
MAY NEED TO BE RAISED FURTHER IF THE TREND CONTINUES TOWARD THIS
SOLUTION. OTHERWISE A DRIER NORTH TO NORTHEAST FLOW WILL ENSUE AS
UPPER LOW EXITS MONDAY AND RIDGE BEGINS TO BUILD INTO THE PACIFIC
NORTHWEST. SO DRY CONDITIONS ARE EXPECTED BEYOND SUNDAY WITH A
GRADUAL WARMUP MOST NOTICEABLE IN THE UPPER ELEVATIONS AS VALLEYS
WILL LIKELY STAY INVERTED UNDER LIGHT WIND REGIME. HOHMANN
&&

AVIATION...
VFR. WINDS ARE EXPECTED TO INCREASE AFTER 00Z WITH GUSTS TO 50KT
LIKELY OVERNIGHT...ESPECIALLY TO IMMEDIATE SIERRA LEE INCLUDING KRNO.
HOHMANN
&&

.REV WATCHES/WARNINGS/ADVISORIES...
NV...HIGH WIND WARNING FROM 4 PM THIS AFTERNOON TO 7 AM PST
     FRIDAY FOR NVZ005.

     WINTER STORM WATCH FROM FRIDAY AFTERNOON THROUGH SATURDAY
     MORNING FOR NVZ002.

     HIGH WIND WARNING FROM 10 PM THIS EVENING TO 10 AM PST FRIDAY
     FOR NVZ002-003.

     WIND ADVISORY FROM 4 AM TO 4 PM PST FRIDAY FOR NVZ001-004.

CA...HIGH WIND WARNING FROM 4 PM THIS AFTERNOON TO 7 AM PST FRIDAY
     FOR CAZ070-071.

     WINTER STORM WATCH FROM FRIDAY AFTERNOON THROUGH SATURDAY
     MORNING FOR CAZ071-072.

     HIGH WIND WARNING FROM 4 AM TO 4 PM PST FRIDAY FOR CAZ073.

     HIGH WIND WARNING FROM 10 PM THIS EVENING TO 10 AM PST FRIDAY
     FOR CAZ072.
&&

HTTP://WEATHER.GOV/RENO