High Wind in Nevada, December 10, 2015

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE ELKO NV
906 AM PST THU DEC 10 2015

.SYNOPSIS...A VERY STRONG COLD FRONT WILL MOVE SOUTHEAST ACROSS
THE GREAT BASIN TODAY INTO THIS EVENING. STRONG SOUTHWEST WINDS IN
ADVANCE OF THE FRONT WILL BE REPLACED BY NORTHWEST WINDS USHERING
MUCH COLDER AIR ACROSS THE GREAT BASIN. A RAPID TRANSITION OF RAIN
SHOWERS TO SNOW SHOWERS WILL OCCUR WITH THE HIGHEST ACCUMULATIONS
OVER NORTHERN ELKO AND WHITE PINE COUNTIES THROUGH EARLY FRIDAY
MORNING. SNOW SHOWERS POSSIBLE FRIDAY AND SATURDAY THEN ANOTHER
SNOW EVENT MAY IMPACT THE REGION SUNDAY.

&&

.UPDATE...THE FRONT IS STRONG ENOUGH AND FGEN FORCING ADEQUATE FOR
A FEW LIGHTNING STRIKES IN FAR NORTHERN HUMBOLDT COUNTY. AS THE
FRONT SLIDES EAST, EXPECT THAT MORE LIGHTNING STRIKES WILL OCCUR
NEAR THE IDAHO BORDER. HAVE UPDATED GRIDS AND ZONES TO SHOW SLIGHT
CHANCE T IN A NARROW BAND ALONG THE BORDER. EVEN "ISOLATED" SEEMS
TO MUCH...BUT FELT SOMETHING NEEDED TO BE DONE.

&&

.PREV DISCUSSION... /ISSUED AT 320 AM /

SHORT TERM...TODAY THROUGH SATURDAY.

WATER VAPOR IMAGERY IS INDICATING A POWERFUL CYCLONE APPROACHING
THE PACIFIC NORTHWEST COAST WHICH WILL DRIVE A VERY STRONG COLD
FRONT ACROSS THE GREAT BASIN TODAY INTO EARLY TONIGHT.

SHORT RANGE DETERMINISTIC GUIDANCE SHOWS A VERY WEAK WARM FRONT
LIFTING NORTH AND BECOMING ABSORBED WITH THE SOUTHWEST FLOW ALOFT
THIS MORNING. RADAR IS PICKING UP SOME WEAK ECHOES ASSOCIATE WITH
WEAK ISENTROPIC LIFT MOVING ACROSS HUMBOLDT COUNTY ATTM. BOTH THE
HRRR/NAM12 MODELS SUPPORT THIS ACTIVITY EARLY THIS MORNING.

THE PRIMARY CONCERN FOR WILL BE THE SOUTH TO SOUTHWEST WINDS
WHICH ENSEMBLE GUIDANCE SHOWS H7 WINDS OF 3 TO 4 STANDARD
DEVIATIONS ABOVE NORMAL FOR NORTHERN AND CENTRAL NEVADA LATER THIS
MORNING INTO EARLY THIS EVENING. HIGH WIND WARNINGS REMAIN IN
PLACE FOR SOUTHERN LANDER/EUREKA...NORTHERN NYE AND WHITE PINE
COUNTIES UNTIL 7 PM THIS EVENING. IN ADDITION...A WIND ADVISORY
ALSO REMAINS IN EFFECT FOR EXTREME EASTERN ELKO COUNTY UNTIL 7
PM.

IT IS INTERESTING TO NOTE THAT MOS GUIDANCE HAS BEEN DECREASING
THE 3 HOURLY WIND SPEEDS DURING THE PAST FEW RUNS. AT THIS POINT
MOS GUIDANCE APPEARS TO LOW AND WILL NOT BE FOLLOWED. 90 AGL WINDS
ARE VERY IMPRESSIVE IN ADVANCE OF THE COLD FRONT WITH 80 KTS
MOVING THROUGH HOMBOLDT COUNTY WHILE WIDESPREAD 50 TO 60 KTS TAKES
PLACE ELSEWHERE THEN DIMINISH IN WAKE OF THE COLD FRONT. MIXING
OF THE LOW/MID LEVEL WIND FIELD WILL SUPPORT THE ABOVE MENTIONED
HEADLINES IN PLACE.

AS FOR PRECIPITATION...RAIN WILL CHANGEOVER TO SNOW AS H7 TEMPS
OF PLUS 1 TO PLUS 3 DEGS C IN ADVANCE OF THE FRONT LOWER TO MINUS
9 DEG C ACROSS NORTHERN NEVADA LATE THIS AFTERNOON AND TO MINUS 9
DEG C ELSEWHERE BE EARLY TONIGHT. AT THIS POINT...THE TIMING FOR
THE COLD FRONT IS: WMC 16Z...ELKO 19Z...AUSTIN 20Z...EUREKA 22Z
AND ELY...03Z FRIDAY.

WITH REGARD TO QPF AMOUNTS THE HRRR/GFS WERE QUIET SIMILAR AND
FOLLOWED FOR THIS FORECAST PACKAGE WITH AMOUNTS UP TO A QUARTER
INCH WHILE THE NAM MODEL ONLY INDICATING A FEW HUNDRETHS OF AN
INCH.

LATE THURSDAY NIGHT THROUGH SATURDAY...BROAD AND UNSTABLE TROUGH
WILL RESIDE OVER THE GREAT BASIN DURING THIS TIME-FRAME WITH SNOW
SHOWERS AND TEMPERATURES AVERAGING BELOW NORMAL. LATE IN THE DAY
SATURDAY...OVERRUNNING SNOW WITH SPREAD INTO NORTHERN AND CENTRAL
NEVADA AND CONTINUE INTO SATURDAY NIGHT.

LONG TERM...SATURDAY NIGHT THROUGH NEXT THURSDAY.

5-WAVE PATTERN INDICATES THAT THE LONG WAVE TROF WILL OVERHEAD
THROUGH TUESDAY BEFORE SHIFTING EAST OF THE AREA ON WEDNESDAY
PERIOD; HOWEVER NO INDICATIONS THAT A LONG WAVE RIDGE WILL BUILD
OVERHEAD  THIS MEANS ABOVE AVERAGE PRECIP AND AVERAGE TO BELOW
AVERAGE TEMPS.

SATURDAY NIGHT...A WARM FRONT ASSOCIATED WITH FRONTAL SYSTEM OFF THE
WEST COAST SLIDES EAST ACROSS NORTHERN HALF OF THE AREA SATURDAY
NIGHT.  STRONG ISENTROPIC LIFT WILL PRODUCE ACCUMULATING SNOW ACROSS
THIS AREA BEFORE THE WARM FRONT LIFTS JUST NORTH OF THE STATE SUNDAY
MORNING. QPF AMOUNTS ARE QUITE IMPRESSIVE IN NORTHERN ELKO COUNTY
FROM 00-12Z SUNDAY...SO AT LEAST A WINTER WEATHER ADV IS LIKELY FOR
AT LEAST THIS AREA...POSSIBLY FOR OTHER NORTHEASTERN LOCATIONS AS
WELL.  DUE TO THE WARM FRONT...SNOW LEVELS RISE ABOVE 6000FT LATE
SATURDAY NIGHT OR SUNDAY MORNING SO THIS COULD LIMIT THE SNOW
AMOUNTS IN THE VALLEYS BELOW 6500FT.  WITH CLOUD COVER AND WARM
FRONT PASSING THROUGH...OVERNIGHT LOWS SHOULD REMAIN IN THE 20S OR
30S.

SUNDAY THROUGH MONDAY NIGHT...THE FRONTAL SYSTEM MENTIONED ABOVE
SLAMS INTO THE PACNW BEFORE DIVING TO THE SOUTHEAST.  THERE ARE
STILL SOME TIMING DIFFERENCES BUT ALL DRIVE THE COLD FRONT THROUGH
THE AREA LATE SUNDAY AFTERNOON TO SUNDAY NIGHT...AND FINALLY EXITING
THE CWA MONDAY MORNING.  HEADLINES ARE LIKELY FOR THIS EVENT AS MOST
OF THE PRECIP SHOULD BE IN THE FORM OF SNOW WITH WIDESPREAD
ACCUMULATION.  ADDITIONALLY...STRONG AND GUSTY WINDS ARE ALSO
EXPECTED PRE AND POST-FRONTAL SO WIND ADVISORIES ARE ALSO LIKELY ON
SUNDAY THROUGH MONDAY.  POST FRONTAL SHOWERS SHOULD CONTINUE THROUGH
MONDAY NIGHT WITH AS MODELS HAVE BEEN DISPLAYING A MORE BROAD 500MB
TROF/LOW THAN JUST A NARROW TROF AXIS. WILL NEED TO WATCH THE
TYPICAL LOCATIONS FOR UPSLOPE SNOW POTENTIAL AS THE SFC TO 700MB
WINDS TURN TO THE NORTHWEST FOR A BRIEF PERIOD MONDAY MORNING. TEMPS
ARE EXPECTED TO REMAIN IN THE 30S AND POSSIBLE 40S SUNDAY (PRIOR TO
FRONTAL PASSAGE) WITH 20S AND 30S MONDAY AS 500MB HEIGHTS DROP NEAR
540DM RANGE.  OVERNIGHT LOWS SHOULD BE IN THE TEENS AND 20S MONDAY
MORNING.

TUESDAY AND TUESDAY NIGHT...ANOTHER POSITIVE TILTED SHORTWAVE WILL
DIG SOUTH OVER WESTERN NV INTO THE BASE OF THE BROAD 500MB TROF
(MAIN LOW IS IN SOUTH DAKOTA) UNDER THE NORTHERN FLOW ALOFT. THIS
SYSTEM MAY DEVELOP A NARROW DEFORMATION ZONE OVER CENTRAL NV BEFORE
IT PUSHES SOUTH OF THE STATE.  SHOWERS ARE STILL POSSIBLE ELSEWHERE
BUT SHOULD REMAIN SCATTERED OR ISOLATED IN COVERAGE. TEMPS ARE IN
THE 20S AND A FEW 30S AS 500MB HEIGHTS REMAIN NEARLY UNCHANGED.
TUESDAY MORNING LOWS DROP INTO THE SINGLE DIGITS ABOVE AND BELOW
ZERO...ESPECIALLY WHERE SKIES CLEAR OUT.

WEDNESDAY AND THURSDAY...MODELS DIFFERENCE REMAIN ON THE EVOLUTION
OF THE BROAD TROF...BUT THAT'S TYPICALLY THIS FAR OUT.  WHILE THE
GFS TRIES TO BUILD A WEAK 500MB SHORT WAVE RIDGE...THE EC AS WELL AS
THE DGEX DIGS ANOTHER WEAK 500MB TROF FROM THE PACIFIC NW INTO THE
CWA..SHIFTING SOUTH OF THE AREA BY THURSDAY. SINCE THE RIDGE AXIS
UNDER THE GFS AND GFS ENSEMBLE SOLUTION KEEPS TO THE NORTH OF THE
AREA ON WED...WENT WITH A BLENDED APPROACH FOR WEDNESDAY...WHICH
PLACED MINOR POPS OVER MOST OF THE AREA.  OVERALL THURSDAY LOOKS DRY
WITH WEAK RIDGING ALOFT.  ONCE AGAIN COLD MORNING LOWS ARE EXPECTED
OVERNIGHT WEDNESDAY AND THURSDAY WITH AT OR BELOW ZERO READINGS AT
MANY LOCATIONS. HIGH TEMPS ARE EXPECTED IN THE 20S AND 30S AS 500MB
HEIGHTS CHANGE VERY LITTLE...AND WE MAYBE DEALING WITH VALLEY
INVERSIONS.

AVIATION...HORRIBLE FLYING DAY WITH VERY STRONG AND GUSTY
WINDS...MVFR OR LOWER CIGS/VIS...AND SNOW OR RAIN AS STRONG COLD
FRONT MOVES THROUGH.  ALSO WILL HAVE TO DEAL WITH TURBULENCE AND
ICING ALOFT. CONFIDENCE IS ONLY MEDIUM ON TIMING OF CHANGE OVER OF
PRECIP BUT IT SHOULD OCCUR QUICKLY AS FRONT PASSES THROUGH.  WINDS
DECREASE BY THIS EVENING.

&&

.LKN WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 4 AM PST FRIDAY FOR HUMBOLDT
COUNTY-NORTHERN ELKO COUNTY-NORTHERN LANDER COUNTY AND NORTHERN
EUREKA COUNTY-RUBY MOUNTAINS AND EAST HUMBOLDT RANGE-SOUTH
CENTRAL ELKO COUNTY-SOUTHWEST ELKO COUNTY.

WIND ADVISORY UNTIL 7 PM PST THIS EVENING FOR SOUTHEASTERN ELKO
COUNTY.

HIGH WIND WARNING UNTIL 7 PM PST THIS EVENING FOR NORTHEASTERN
NYE COUNTY-NORTHWESTERN NYE COUNTY-SOUTHERN LANDER COUNTY AND
SOUTHERN EUREKA COUNTY-WHITE PINE COUNTY.

WINTER WEATHER ADVISORY FROM 1 PM THIS AFTERNOON TO 4 AM PST
FRIDAY FOR NORTHEASTERN NYE COUNTY-NORTHWESTERN NYE COUNTY-
SOUTHERN LANDER COUNTY AND SOUTHERN EUREKA COUNTY-WHITE PINE
COUNTY.

&&

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