Heavy Snow and Strong Wind in Nevada, February 8 to 9, 2014

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE RENO NV
1211 PM PST SAT FEB 8 2014

.UPDATE...
UPDATING TO EXPIRE WINTER STORM WARNING FOR TAHOE AND CANCEL WIND
ADVISORIES. SNOW LEVELS ARE STUBBORN AROUND TAHOE AT 6500 TO 7000
FEET BUT IN THE LAST HOUR ARE SHOWING SIGNS OF RISING. TEMPS AT
NEAR 7000 FEET ARE NOW 34 DEGREES SO THE CHANGEOVER AT DONNER PASS
SHOULD OCCUR IN THE NEXT TWO HOURS. WEBCAM FROM ECHO SUMMIT LOOKS
TO BE RAIN AS THE ROAD SURFACE JUST LOOKS WET NOW. SNOW LEVELS ON
UPSTREAM PROFILERS AT CHICO AND COLFAX ARE BOTH ABOVE 8500 FEET SO
EXPECT THIS SNOW LEVELS TO RISE. GRANTED, THE HEAVY PRECIP AND
DRAG IS LOCALLY LOWERING SNOW LEVELS SO EXPECT SNOW LEVELS TO PEAK
AT 7500 FEET TO 8000 FEET.

FURTHER EAST, OCCASIONAL LIGHT SPILLOVER IS OCCURRING AS EXPECTED.
THE WINDS ARE RESPONDING TO THIS AS PEAK GUSTS ARE GENERALLY
AROUND 30 MPH. CANCELED THE ADVISORY AS THE CURRENT AND FORECAST
THERMODYNAMIC PROFILES DO NOT SUPPORT THE STRONGER WINDS.

WITH THE LOWER SNOW LEVELS, THE HYDRO CONCERNS FROM EARLIER MAY BE
SOMEWHAT MITIGATED. IF THE SNOW LEVELS REMAIN LOWER THAN FORECAST,
WE WILL STILL SEE RISES BUT NO FLOODING CONCERNS. HOWEVER, IF THEY
DO PEAK AROUND 8000 FEET AND REMAIN THERE FOR A SOLID 12 HOURS,
THE FLOODING POTENTIAL WOULD BE THERE. THEREFORE, CONTINUING WITH
THE AREAL FLOOD WATCH ISSUED EARLIER AND CONTINUE TO MONITOR THIS
SITUATION.

&&

.PREVIOUS DISCUSSION... /ISSUED 919 AM PST SAT FEB 8 2014/

HYDROLOGY...
MAIN UPDATE TO ISSUE SMALL STREAM FLOOD WATCH TO TONIGHT INTO
SUNDAY. HEAVY RAIN AND SNOW IS NOW AFFECTING THE EASTERN SIERRA
FROM HIGHWAY 44 SOUTH TO EASTERN ALPINE COUNTY. SOME SPILLOVER IS
OCCURING INTO THE FOOTHILLS OF RENO/CARSON CITY AS WELL. SNOW
LEVELS ARE CURRENTLY RUNNING NEAR 7000 FEET BUT ARE EXPECTED TO
RISE TO 8000 TO 8500 FEET THIS AFTERNOON.

THE ATMOSPHERIC RIVER WILL REMAIN DIRECTED AT THE SIERRA TODAY
WILL LEAD TO A STEADY UPSLOPE PRECIPITATION EVENT ALONG AND WEST
OF HIGHWAY 89. LIFTING IS WEAK TODAY SO ONLY LIGHT PRECIPITATION
WILL CROSS THE SIERRA AND INTO WESTERN NEVADA ALTHOUGH MODERATE
RAIN IS POSSIBLE IN THE RENO/CARSON FOOTHILLS. THE HEAVIEST
PRECIPITATION EVENT WILL OCCUR SUNDAY AS THE JET SAGS SOUTH, BUT
THIS WILL OCCUR WHILE SNOW LEVELS ARE LOWERING.

IT APPEARS MINOR SMALL STREAM FLOODING IS POSSIBLE AND THE LATEST
UNOFFICIAL FORECAST FOR THE TRUCKEE RIVER NEAR TRUCKEE IS RIGHT
NEAR FLOOD STAGE. HOISTED A SMALL STREAM FLOOD WATCH FOR SMALL
STREAMS AROUND THE SIERRA VALLEY, TAHOE BASIN, SIERRA FRONT WEST
OF 395 AND EASTERN ALPINE COUNTY. THIS WILL INCLUDE THE TRUCKEE
RIVER NEAR TRUCKEE. SMALL STREAMS THAT MAY BE AFFECTED INCLUDE
BEAR CREEK, SQUAW CREEK AND WARD CREEK IN THE TAHOE BASIN AS WELL
STEAMBOAT CREEK IN WESTERN NEVADA.

IN ADDITION, IF HEAVY RAIN DOES OCCUR OVER THE BISON FIRE A FEW
DEBRIS FLOWS MAY RESULT, BUT APPEARS THIS WOULD NOT OCCUR UNTIL
SUNDAY AFTERNOON AT THE EARLIEST. WALLMANN

PREVIOUS DISCUSSION... /ISSUED 551 AM PST SAT FEB 8 2014/

UPDATE...
SNOW LEVELS CONTINUE TO CLIMB SLOWLY THIS MORNING AS AN AREA OF
WARM AIR ADVECTION PRECIPITATION MOVES INTO THE NORTHERN SIERRA
AND TAHOE BASIN. PROFILER AT COLFAX CA RECENTLY REPORTED A SNOW
LEVEL OF 7800 FEET. THIS COINCIDES WELL WITH DUAL POL RADAR
ESTIMATES OF SNOW LEVELS NEAR 7500 FEET, AND TEMPERATURES IN THE
LOW 30S BETWEEN 7500 AND 8500 FEET. THE MORNING SOUNDING FROM
OAKLAND INDICATED A SNOW LEVEL NEAR 9500 FEET. THERE IS POTENTIAL
THE SNOW LEVEL WILL CONTINUE TO RISE THIS MORNING, BUT HEAVY
PRECIPITATION ALONG THE SIERRA CREST SHOULD DRAG ENOUGH COLD AIR
DOWNWARD TO PREVENT SNOW LEVELS FROM CLIMBING ABOVE 8000-8500 FEET.

THE WARM AIR ADVECTION IS STARTING TO COUNTERACT THE MOUNTAIN WAVE
WITH THE RADAR SHOWING PRECIPITATION CROSSING THE SIERRA CREST AND
INTO WESTERN NEVADA. HOWEVER THE RAIN MOVING EAST OF THE CARSON
RANGE MAY BE SHORT LIVED AS THE WARM AIR ADVECTION WEAKENS LATE
THIS MORNING. RAPID REFRESH, NAM AND GFS MODELS ALL SHOW A RETURN
OF THE RAIN SHADOW ALONG THE SIERRA FRONT BY EARLY AFTERNOON.

WINDS HAVE ALSO DIMINISHED A BIT THIS MORNING FOR RENO-TAHOE WITH
THE WARM AIR ADVECTION. BRONG

SYNOPSIS...
A DEEP MOISTURE PLUME WILL CONTINUE TO IMPACT THE SIERRA AND
WESTERN NEVADA THROUGH THE WEEKEND. SNOW LEVELS WILL REMAIN HIGH,
ABOVE MAJOR PASS LEVEL THROUGH TONIGHT BEFORE FALLING SUNDAY.
HEAVY RAINS ARE LIKELY IN THE SIERRA WITH BRIEF HEAVY RAINS IN
WESTERN NEVADA SUNDAY. GUSTY WINDS WILL CONTINUE FOR AREAS LACKING
HEAVY RAIN THROUGH THIS EVENING. DRY WEATHER RETURNS EARLY IN THE
WEEK BEFORE ANOTHER STORM IMPACTS AREAS NORTH OF INTERSTATE 80
WEDNESDAY.

PREVIOUS DISCUSSION... /ISSUED 221 AM PST SAT FEB 8 2014/

SHORT TERM...
AFTER A BRIEF LULL IN THE WINDS FRIDAY EVENING, SOUTHWEST WINDS HAVE
INCREASED HIS MORNING WITH WIND REPORTS BETWEEN 40 TO 50 MPH ACROSS
THE SIERRA FRONT. SIERRA RIDGE GUSTS HAVE BEEN IMPRESSIVE OVER THE
PAST 24 HOURS WITH REPORTS OF 129 MPH IN THE WHITE MOUNTAINS AND 80
MPH AT VIRGINIA PEAK. STRONG 700MB FLOW WILL SURGE INTO THE SIERRA
AND WESTERN NEVADA JUST BEFORE SUNRISE, ALLOWING PEAK WIND GUSTS TO
MATERIALIZE ALONG THE HIGHWAY 395/INTERSTATE 580 CORRIDOR SOUTH INTO
MONO COUNTY. WIND ADVISORIES HAVE ALSO BEEN ADDED TO NORTHERN WASHOE
COUNTY, EASTERN LASSEN AND PLUMAS COUNTIES, AND THE SURPRISE VALLEY.
PRECIPITATION COVERAGE LOOKING SPARSE FOR THESE AREAS THROUGH TODAY.
WITHOUT HEAVY PRECIPITATION TO DAMPEN THE WINDS, IT APPEARS THESE
LOCATIONS WILL BE FAIRLY GUSTY THROUGH THE AFTERNOON AS THE STRONG
UPPER LEVEL FLOW PUSHES INTO NORTHEASTERN CALIFORNIA AND WESTERN
NEVADA.

SNOW CHANGED OVER TO RAIN BEFORE MIDNIGHT FOR SIERRA LOCATIONS, SUCH
AS THE TRUCKEE AND SOUTH LAKE TAHOE AIRPORTS. PROFILER OBSERVATIONS
FROM COLFAX WERE SHOWING AN HOURLY INCREASE IN SNOW LEVELS, WITH THE
LAST AVAILABLE OBSERVATION AT 330Z AT 5000 FEET MSL. KDAX DUAL POL
RADAR ALSO SUPPORTS THE HIGHER SNOW LEVELS EARLY THIS MORNING WITH
THE RAIN/SNOW MIX LAYER NEAR 7000 FEET MSL. LIGHT RAIN WILL CONTINUE
FOR LOCATIONS BELOW 7000 FEET IN THE SIERRA, WHILE VERY WET SNOW
ACCUMULATES IN ELEVATIONS ABOVE THAT MARK.

PRECIPITATION IS EXPECTED TO INCREASE THIS MORNING (12Z-18Z) AS THE
NEXT WAVE OF MOISTURE PUSHES INTO THE SIERRA AND NORTHEASTERN
CALIFORNIA. CURRENT REFLECTIVITY BULK OF PRECIPITATION PUSHING IN
ACROSS SFO EARLY THIS MORNING, WHICH IS FURTHER SOUTH THAN LATEST
FORECAST MODELS. THE 6Z NAM LIFTS THE MAIN JET ASSOCIATED WITH THE
SYSTEM A BIT FURTHER NORTH BY THIS AFTERNOON. THE GOOD NEWS IS THAT
THE MOISTURE TAP WOULD REFOCUS NORTHWARD ACROSS THE TAHOE BASIN, THE
BAD NEWS IS THAT THE FORCING FROM THE JET, WHICH WOULD PROMOTE
SPILLOVER INTO WESTERN NEVADA, WOULD BE DISPLACED NORTH TOWARDS THE
OREGON BORDER. LACK OF UPPER LEVEL LIFT AND DIVERGENCE FROM THE JET
WOULD ALSO RESULT IN LESS INTENSE PRECIPITATION FOR THE SIERRA, AS
IT WOULD ONLY BE LIMITED TO OROGRAPHIC AND ISENTROPIC LIFT.
UNFORTUNATELY, THIS IS TRENDING TOWARDS A VERY WET WEST SIDE UP TO
THE CREST EVENT. EKL

SUNDAY THROUGH MONDAY...
THE SIERRA AND NORTHWEST NEVADA REMAINS UNDER A DEEP MOISTURE PLUME
SUNDAY WITH INCREASED CHANCES FOR HEAVY PRECIPITATION ON SUNDAY
TAPERING OFF BY MONDAY. SATURDAY NIGHT INTO SUNDAY AFTERNOON STILL
LOOKS LIKE THE PERIOD OF HEAVIEST PRECIPITATION FOR WESTERN NEVADA.
A WEST TO EAST JET ORIENTATION ALONG WITH EXCELLENT LIFT AND
DYNAMICS WILL ALLOW A PUSH OF PRECIPITATION INTO THE SIERRA TO
SPILLOVER INTO WESTERN NEVADA AND THE BASIN AND RANGE.

CONFIDENCE REMAINS HIGH IN HEAVY RAIN AND SNOW, BUT LOW TO MEDIUM
WITH REGARDS TO SNOW LEVELS DUE TO UNCERTAINTY ON HOW QUICKLY THEY
WILL DROP. SNOW LEVELS SUNDAY MORNING WILL STILL BE HIGH, AROUND
7000-8000 FEET NORTH OF INTERSTATE 80 AND 8000-8500 FEET SOUTH OF
THERE. AS THE JET SAGS SOUTH, COLDER AIR WILL BEGIN TO WORK INTO THE
REGION, WITH SNOW LEVELS FALLING THROUGH THE DAY, POSSIBLY DROPPING
TO AROUND 6500-7000 FEET MSL BY LATE SUNDAY AFTERNOON. THIS WILL
TRANSLATE TO ACCUMULATING SNOW OVER SIERRA PASSES AND SIGNIFICANT
TRAVEL IMPACTS LIKELY SUNDAY AFTERNOON AND EVENING. PRECIPITATION
WILL TAPER TO SHOWERS LATE SUNDAY NIGHT, WITH ONLY LIGHT SHOWERS
LINGERING IN THE AREA MONDAY. DJ/EKL

LONG TERM...TUESDAY THROUGH SATURDAY...

LITTLE HAS CHANGED IN THE MODELS OVER THE LAST 24 HOURS WITH DEEP
LOW OVER THE GULF OF ALASKA FOR MOST OF NEXT WEEK. TELECONNECTIONS
SUPPORT SOME RIDGING ALONG THE WEST COAST WITH THE JET DIRECTED
TOWARD THE OREGON COAST. THIS WILL LEAVE THE SIERRA AND WESTERN
NEVADA ON THE WARM SIDE OF THE MOIST ONSHORE FLOW INTO THE WEST
COAST.

LATEST MODEL SOLUTIONS SUPPORT A COUPLE PERIODS OF LIGHT WARM AIR
ADVECTION PRECIPITATION NORTH OF HIGHWAY 50 WEDNESDAY-FRIDAY WITH
UPSLOPE SHOWERS ALONG THE SIERRA CREST. CONFIDENCE IN A
SIGNIFICANT PRECIPITATION EVENT IS LOW DUE TO THE LACK OF STRONG
LIFT INTO THE NORTHERN SIERRA DESPITE THE MOIST ONSHORE FLOW.
BRONG

AVIATION...

PERIODS OF LIGHT RAIN AT KTRK AND KTVL TODAY WITH MVFR CONDITIONS
IN THE SIERRA. VERY LITTLE TO NO RAINFALL WILL BE ABLE TO CROSS
INTO WESTERN NEVADA DUE TO LACK OF LIFT. WINDS TO REMAIN GUSTY
TODAY WITH PEAK SURFACE WINDS OF 35-45KTS, A FEW WIND PRONE
LOCATIONS MAY APPROACH 50 KTS. MOUNTAIN WAVES DOWNWIND OF THE
SIERRA WILL CONTINUE TO PRODUCE TURBULENT APPROACHES AND NEAR
SURFACE ROTORS.

HEAVIER PRECIPITATION SHOULD IMPACT THE REGION SUNDAY AS THE JET
BRINGS A STRONGER SOURCE OF LIFT TO ACT ON THE ABUNDANT MOISTURE IN
PLACE. THE JET WILL ALSO LOWER THE FREEZING LEVELS CLOSER TO
6000-7000 FEET SUNDAY AND SUNDAY NIGHT. RAIN SHOULD TURN BACK TO
SNOW AT THE SIERRA TERMINALS LATE SUNDAY, WITH AN ALL RAIN EVENT
FOR WESTERN NEVADA. BRONG

&&

.REV WATCHES/WARNINGS/ADVISORIES...
NV...FLOOD WATCH FROM 4 PM PST THIS AFTERNOON THROUGH SUNDAY
     AFTERNOON NVZ002-003.

     LAKE WIND ADVISORY UNTIL 4 AM PST SUNDAY FOR LAKE TAHOE IN
     NVZ002.

     WINTER STORM WARNING UNTIL NOON PST TODAY NVZ002.

     WINTER STORM WARNING FROM 4 AM SUNDAY TO 4 AM PST MONDAY ABOVE
     7000 FEET FOR NVZ002.

     LAKE WIND ADVISORY UNTIL 7 PM PST THIS EVENING FOR PYRAMID LAKE
     IN NVZ004.

CA...FLOOD WATCH FROM 4 PM PST THIS AFTERNOON THROUGH SUNDAY
     AFTERNOON CAZ071-072.

     LAKE WIND ADVISORY UNTIL 4 AM PST SUNDAY FOR LAKE TAHOE IN
     CAZ072.

     WINTER STORM WARNING UNTIL NOON PST TODAY CAZ072.

     WINTER STORM WARNING FROM 4 AM SUNDAY TO 4 AM PST MONDAY ABOVE
     7000 FEET FOR CAZ072.

&&

FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE RENO NV
1101 AM PST SAT FEB 08 2014

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0600 AM     HEAVY SNOW       SQUAW VALLEY SKI AREA   39.21N 120.25W
02/08/2014  M16.0 INCH       PLACER             CA   TRAINED SPOTTER

            SQUAW VALLEY SKI RESORT. 24 HOUR SNOWFALL 16 INCHES AT
            8200 FEET. 5 INCHES AT 6200 FEET.

0638 AM     HEAVY SNOW       HOMEWOOD                39.08N 120.17W
02/08/2014  E17.0 INCH       PLACER             CA   TRAINED SPOTTER

            HOMEWOOD SKI AREA. 24 HOUR TOTAL 17 INCHES AT 7880 FEET.
            11 INCHES AT 6230 FEET.

0721 AM     SNOW             3 E INCLINE VILLAGE     39.25N 119.92W
02/08/2014  M4.0 INCH        WASHOE             NV   TRAINED SPOTTER

            DIAMOND PEAK SKI AREA REPORTED 4 INCHES OF SNOWFALL
            OVERNIGHT.

0721 AM     SNOW             5 WNW KINGS BEACH       39.26N 120.13W
02/08/2014  M5.0 INCH        PLACER             CA   TRAINED SPOTTER

            NORTHSTAR SKI RESORT REPORTED 5 INCHES OF SNOWFALL
            OVERNIGHT.

0912 AM     SNOW             HOMEWOOD                39.08N 120.16W
02/08/2014  M5.0 INCH        PLACER             CA   TRAINED SPOTTER

            TRAINED WEATHER SPOTTER REPORTED 5 INCHES OF NEW SNOWFALL
            AT 6330 FEET.

0933 AM     HEAVY SNOW       1 SW ALPINE MEADOWS     39.16N 120.24W
02/08/2014  M15.0 INCH       PLACER             CA   PUBLIC

            ALPINE MEADOWS SKI RESORT. 24 HOUR TOTAL 15 INCHES AT
            8637 FEET. 11 INCHES AT 6385 FEET.

0952 AM     HEAVY SNOW       5 W DONNER SUMMIT       39.33N 120.49W
02/08/2014  M21.0 INCH       NEVADA             CA   TRAINED SPOTTER

            SOUTH SIDE OF DONNER LAKE. 21 INCHES FOR A 3-DAY TOTAL.
            SNOWING HEAVILY AT TIME OF OBSERVATION WITH ABOUT 1 INCH
            PER HOUR RATES. CURRENTLY 31.7 DEGREES AT 7000 FEET.

1025 AM     SNOW             S MOUNT ROSE SKI AREA   39.32N 119.89W
02/08/2014  M10.0 INCH       WASHOE             NV   TRAINED SPOTTER

            6-10 INCHES SINCE FRIDAY EVENING. STILL SNOWING HEAVILY.

1054 AM     SNOW             MAMMOTH MOUNTAIN        37.65N 119.03W
02/08/2014  M9.0 INCH        MONO               CA   TRAINED SPOTTER

            24 HOUR SNOWFALL TOTAL REPORTED AT MAMMOTH MOUNTAIN SKI
            RESORT.

&&

MCGUIRE