Winter Storm Warning 4, NWS Reno, NV

000 
WWUS45 KREV 180634
WSWREV

URGENT - WINTER WEATHER MESSAGE
NATIONAL WEATHER SERVICE RENO NV
1034 PM PST SAT DEC 17 2005

...SIGNIFICANT SNOW ACCUMULATIONS IN THE SIERRA...

.A WET PACIFIC STORM SYSTEM WILL MOVE INTO THE REGION AND BRING
HEAVY SNOW TO THE SIERRA AS WELL AS PARTS OF NORTHEAST CALIFORNIA
AND NORTHWEST NEVADA SUNDAY. LIGHT SNOW OVERNIGHT WILL BECOME
HEAVY AT TIMES SUNDAY MORNING AND CONTINUE INTO THE AFTERNOON.
SNOW LEVELS ARE EXPECTED TO RISE DURING THE DAY SUNDAY AND INTO
SUNDAY NIGHT. MOST VALLEY LOCATIONS SOUTH OF A SUSANVILLE TO
GERLACH LINE INCLUDING THE TAHOE BASIN WILL LIKELY SEE SOME MIX
OF RAIN AND SNOW BY SUNDAY AFTERNOON AFTER A VERY WET SNOWFALL TO
START THE DAY. HIGHER ELEVATIONS INCLUDING AREA PASSES WILL
RECEIVE THE HEAVIEST AMOUNTS.

IF YOU PLAN TO TRAVEL THROUGH THE SIERRA SUNDAY AND SUNDAY
NIGHT...BE PREPARED FOR DIFFICULT WINTER DRIVING CONDITIONS AND
TRAVEL DELAYS. STAY TUNED TO LOCAL MEDIA OUTLETS FOR ADDITIONAL
STATEMENTS FROM THE NATIONAL WEATHER SERVICE.

CAZ070-NVZ005-181315-
/O.UPG.KREV.WS.A.0003.051218T1700Z-051219T0500Z/
/O.NEW.KREV.HS.W.0003.051218T1400Z-051219T0200Z/
SURPRISE VALLEY CALIFORNIA-NORTHERN WASHOE COUNTY-
INCLUDING THE CITIES OF...CEDARVILLE...EAGLEVILLE...
FORT BIDWELL...EMPIRE...GERLACH
1034 PM PST SAT DEC 17 2005

...HEAVY SNOW WARNING IN EFFECT FROM 6 AM TO 6 PM PST SUNDAY...

THE NATIONAL WEATHER SERVICE IN RENO HAS ISSUED A HEAVY SNOW
WARNING...WHICH IS IN EFFECT FROM 6 AM TO 6 PM PST SUNDAY. THE
WINTER STORM WATCH IS NO LONGER IN EFFECT. 

LIGHT SNOW WILL MOVE INTO FAR NORTHEASTERN CALIFORNIA AND
NORTHWESTERN NEVADA OVERNIGHT AND BECOME HEAVY AT TIMES SUNDAY.
SNOW LEVELS WILL START OUT AT THE VALLEY FLOORS AND RISE UP TO
AROUND 5000 FEET BY SUNDAY EVENING. THE PRECIPITATION WILL TAPER
SUNDAY NIGHT. TOTAL SNOW ACCUMULATIONS UP TO A FOOT ARE POSSIBLE
AT THE HIGHEST ELEVATIONS...WITH 4 TO 6 INCHES IN THE VALLEYS.

A HEAVY SNOW WARNING MEANS SIGNIFICANT AMOUNTS OF SNOW ARE
FORECAST THAT WILL MAKE TRAVEL DANGEROUS. ONLY TRAVEL IN AN
EMERGENCY. IF YOU MUST...KEEP AN EXTRA FLASHLIGHT...FOOD...AND
WATER IN YOUR VEHICLE IN CASE OF AN EMERGENCY.

$$

CAZ073-181315-
/O.UPG.KREV.SN.Y.0004.051218T1400Z-051219T0700Z/
/O.EXA.KREV.WS.W.0004.051218T1400Z-051219T0700Z/
MONO-
INCLUDING THE CITIES OF...BRIDGEPORT...COLEVILLE...LEE VINING...
MAMMOTH LAKES
1034 PM PST SAT DEC 17 2005

...WINTER STORM WARNING IN EFFECT FROM 6 AM TO 11 PM PST SUNDAY...

THE NATIONAL WEATHER SERVICE IN RENO HAS ISSUED A WINTER STORM
WARNING...WHICH IS IN EFFECT FROM 6 AM TO 11 PM PST SUNDAY. THE
SNOW ADVISORY IS NO LONGER IN EFFECT. 

SNOW OVER MONO COUNTY WILL BECOME HEAVY DURING THE DAY SUNDAY.
RISING SNOW LEVELS ARE EXPECTED WITH THIS STORM AND BY MONDAY
MORNING THEY WILL BE NEAR 7000 FEET. TOTAL SNOW ACCUMULATIONS OF 1
TO 2 FEET ARE POSSIBLE IN THE HIGH SIERRA JUST TO THE EAST OF THE
CREST WHILE 6 TO 12 INCHES CAN BE EXPECTED ABOVE 7000 FEET
INCLUDING HIGHWAY 395. GUSTY WINDS WILL RESULT IN BLOWING AND
DRIFTING SNOW AT THE HIGHER ELEVATIONS AND PASSES.

CONDITIONS CAN DETERIORATE RAPIDLY IN WINTER WEATHER SITUATIONS...
SLOW DOWN AND ALLOW EXTRA TIME WHEN TRAVELING.  PRACTICE YOUR
WINTER SAFETY RULES...CARRY TIRE CHAINS...FOOD...WATER...BLANKETS
AND A FLASHLIGHT IN YOUR CAR IN CASE OF AN EMERGENCY.

$$

CAZ071-072-NVZ002-181315-
/O.CON.KREV.WS.W.0004.051218T1400Z-051219T0700Z/
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
1034 PM PST SAT DEC 17 2005

...WINTER STORM WARNING REMAINS IN EFFECT FROM 6 AM TO 11 PM PST
SUNDAY...

LIGHT TO MODERATE SNOW WILL CONTINUE TO MOVE INTO THE LAKE TAHOE
AREA AND LASSEN COUNTY OVERNIGHT AND BECOME HEAVY BY SUNDAY
MORNING. THE SNOW WILL TAPER SUNDAY NIGHT. SNOW LEVELS WILL START
OUT ON THE VALLEY FLOORS AND RISE UP TO 6000 FEET BY SUNDAY
EVENING. TOTAL SNOW ACCUMULATIONS OF 18 TO 30 INCHES ARE POSSIBLE
ABOVE 7000 FEET AND 8 TO 16 INCHES AT LAKE LEVEL.

IN WESTERN LASSEN COUNTY 8 TO 16 INCHES ARE POSSIBLE ABOVE
5000 FEET WITH 4 TO 8 INCHES POSSIBLE OVER EASTERN LASSEN COUNTY.

GUSTY WINDS WILL ACCOMPANY THE HEAVY SNOW...CAUSING AREAS OF
BLOWING AND DRIFTING SNOW AND LOCAL WHITE OUT CONDITIONS IN THE
HIGHER ELEVATIONS. WIND GUSTS UP TO 75 MPH ARE POSSIBLE OVER THE
RIDGES.

$$

NVZ004-181315-
/O.NEW.KREV.SN.Y.0005.051218T1400Z-051219T0200Z/
WESTERN NEVADA BASIN AND RANGE INCLUDING PYRAMID LAKE-
INCLUDING THE CITIES OF...FERNLEY...FALLON...LOVELOCK...
SILVER SPRINGS...NIXON...IMLAY
1034 PM PST SAT DEC 17 2005

...SNOW ADVISORY IN EFFECT FROM 6 AM TO 6 PM PST SUNDAY...

THE NATIONAL WEATHER SERVICE IN RENO HAS ISSUED A SNOW ADVISORY...
WHICH IS IN EFFECT FROM 6 AM TO 6 PM PST SUNDAY. 

SNOW WILL DEVELOP OVERNIGHT AND BECOME WIDESPREAD SUNDAY MORNING.
SNOW ACCUMULATIONS OF 2 TO 4 INCHES CAN BE EXPECTED WITH SNOW
MIXING WITH OR CHANGING TO RAIN AT THE VALLEY FLOORS DURING THE
AFTERNOON. 

THIS SNOW ADVISORY MEANS THAT PERIODS OF SNOW WILL CAUSE TRAVEL
DIFFICULTIES. BE PREPARED FOR SNOW COVERED OR SLUSHY ROADS AND
LIMITED VISIBILITIES. USE CAUTION WHILE DRIVING.

$$

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
845 AM PST SAT DEC 17 2005

.UPDATE...
PER INITIAL CALL FROM WFO SACRAMENTO...WILL MATCH THEM WITH A WINTER
STORM WATCH FOR LASSEN-TAHOE FOR SUNDAY INTO SUNDAY EVENING. AS
MENTIONED YESTERDAY...MODELS SEEM TO BE A BIT SLOW AND TOO DRY AT
TIMES WITH THE INITIAL UNDERCUTTING SYSTEMS. THIS WEEKEND
APPEARSBEEN NO WITH BOTH THE NAM/GFS QUITE A BIT WETTER THAN
YESTERDAY FOR SUNDAY. AT THIS POINT...IT LOOKS TO BE HIGH END
ADVISORY/LOW END WARNING POTENTIAL FOR THOSE AREAS. SNOW LEVELS WILL
ALSO START OUT LOW...NEAR 4000 FEET BEFORE RISING TO 6000 FEET LATE
ON SUNDAY. EVEN VALLEY LOCATIONS OF LASSEN COULD SEE LOW END WARNING
SNOW AMOUNTS BEFORE THE CHANGEOVER. TO MATCH THE IDEAS AND THE
POTENTIAL COLD AIR DAMMING THAT CAN OCCUR IN THE SURPRISE
VALLEY...WILL ALSO ISSUE A WATCH FOR NORTHERN WASHOE AND THE SV.
EXPECT ANY HEAVY SNOWS IN WASHOE TO REMAIN NORTH OF GERLACH. IN THE
UPDATE WILL ALSO LOWER SNOW LEVELS MOST ZONES TONIGHT TO ACCOUNT FOR
THE LOWER SNOW LEVELS EXPECTED. WALLMANN

&&

.PREV DISCUSSION...ISSUED AT 304 AM
ACTIVE WEATHER DURING THE SHORT TERM.  NARROW RIDGE NOW OVER THE
WEST COAST IS BEING SQUEEZED BY AN APPROACHING DEEP TROUGH OVER
135W.  A VORT MAX SHOWING UP ON SATELLITE IMAGERY THIS MORNING IS
MOVING TOWARD THE CENTRAL CALIFORNIA COAST AND WILL UNDERCUT THE
NORTHERN PART OF THE RIDGE TODAY.  MODELS ARE SIMILAR IN THEIR
EVOLUTION OF THIS SCENARIO WITH THE ETA...GFS...ECMWF...CANADIAN AND
NOGAPS ALL SHOWING THE SYSTEM OFF THE COAST AT 12Z THIS MORNING.
THE FIRST VORT MAX IS PROGGED TO MOVE THROUGH NORTHERN CALIFORNIA
THIS EVENING.  A SECOND STRONGER SHORTWAVE IS THEN PROGGED TO MOVE
THROUGH THE SAME REGION LATE SUNDAY.

WITH THE APPROACHING SYSTEM WILL CONTINUE WILL A CHANCE OF RAIN AND
MOUNTAIN SNOW FOR THIS AFTERNOON AND EVENING.  SOUTHERLY FLOW WILL
ALLOW FOR GOOD MOISTURE ADVECTION TONIGHT INTO SUNDAY.  THE GFS
ADVECTS PRECIPITABLE WATER VALUES OF BETWEEN 0.25 AND 0.50 INCH INTO
WESTERN NEVADA BY 06Z SUNDAY.  SNOW LEVELS WILL START OUT AROUND
6000 FT TODAY BEFORE LOWERING TO BETWEEN 5000 AND 5500 FT TONIGHT AS
COLD AIR MOVES IN WITH THE FIRST SHORTWAVE.  PRECIP SHOULD TAPER OFF
MONDAY AFTERNOON AS THE SECOND SHORTWAVE MOVES EAST OF THE REGION.

DID NOT MAKE ANY MAJOR CHANGES TO TEMPERATURES FOR TODAY AND
SUNDAY.  TEMPS BOTH DAYS SHOULD BE NEAR BOTH CLIMO AND GUIDANCE WITH
AFTERNOON HIGHS IN THE 40S.  EXPECT A SLIGHT WARM UP ON MONDAY AS
RIDGING BUILDS INTO THE WEST COAST.  OHARA

LONG TERM...TUESDAY THROUGH FRIDAY...
MEDIUM RANGE GUIDANCE IS IN REASONABLY GOOD AGREEMENT FOR AN ACTIVE
WEATHER PATTERN IN THE MEDIUM RANGE. RIDGE AXIS OVER CA-NV TUES IS
EXPECTED TO MOVE EAST TO NEAR THE NV-UTAH BORDER BY WED AS TROF
APPROACHES THE WEST COAST. DESPITE HIGH 500 MB HEIGHTS...PACIFIC
MOISTURE WILL BE TAPPED WITH WIDESPREAD HIGH CLOUDS BOTH DAYS AND A
POSSIBILITY OF LIGHT PRECIP OVER NERN CA AND ALONG THE SIERRA WITH
HIGH SNOW LEVELS ABOVE 7500 FEET. MAX TEMPS ARE EXPECTED TO REACH OR
EXCEED 50 DEGREES

BY WED NIGHT AND THURS THE TROF MOVES INLAND AND WILL BRING PRECIP
AND LOWER SNOW LEVELS TO THE FORECAST AREA. MODEL DATA HAVE SOME
DIFFERENCES IN WHETHER THE SYSTEM MOVES IN AS A NEGATIVE TILT
SHORTWAVE OR A CLOSED LOW BREAKING OFF FROM THE MEAN FLOW WHICH
WOULD MAKE A DIFFERENCE AMOUNT OF COOLING ASSOCIATED WITH THE
PRECIP. THE CURRENT FORECAST WAS FAVORING THE 00Z GFS WHICH WOULD
BRING SNOW DOWN TO AROUND 6000 FEET...BUT THE 06Z GFS WAS WEAKER AND
FARTHER NORTH AND WOULD RESULT IN HIGHER SNOW LEVELS AROUND 7000
FEET AND LOWER QPF.

THIS SYSTEM EXITS THE REGION THURS NIGHT WITH REBUILDING RIDGE ON
FRIDAY BRINGING DRIER AIR MASS TO THE REGION. LIGHT E-NE FLOW WILL
RETURN WHICH WOULD LIMIT WARMING...BUT THE INVERSION IS NOT EXPECTED
TO BE AS STRONG AS IT WAS THIS PAST WEEK. MJD

&&

.AVIATION...
THE FOG AND LOW CLOUD EVENT IS ESSENTIALLY OVER ACROSS THE TAF
POINTS AND TWEB ROUTES. SOME SLIGHTLY REDUCED VISIBILITY TO AROUND 5
MILES IS POSSIBLE BETWEEN 15Z AND 17Z IN PARTS OF WRN NV WITH LOCAL
FOG IN CHURCHILL...MINERAL AND MONO COUNTIES OTHERWISE VFR CONDS ARE
EXPECTED TODAY WITH LOWERING CIGS TONIGHT AND AREAS OF MVFR AND
LOCAL IFR CIGS/VSBY AS LIGHT SNOW SPREADS ACROSS THE REGION. MJD

&&

.REV WATCHES/WARNINGS/ADVISORIES...
.NV...WINTER STORM WATCH NVZ002 6 AM TO 11 PM SUNDAY.
      WINTER STORM WATCH NVZ005 9 AM TO 9 PM SUNDAY.
.CA...WINTER STORM WATCH CAZ070 9 AM TO 9 PM SUNDAY.
      WINTER STORM WATCH CAZ071-072 6 AM TO 11 PM SUNDAY.
&&