Lake Wind Advisory 7, NWS Reno, NV

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
232 AM PST WED JAN 27 2016

.SYNOPSIS...
WARM AND DRY CONDITIONS WITH HIGH PRESSURE OVER THE REGION TODAY
AND THURSDAY. THE NEXT SYSTEM WILL IMPACT THE REGION EARLY FRIDAY
AND THIS WEEKEND. RAIN, HIGH ELEVATION SNOW AND GUSTY WINDS ON
FRIDAY WITH SNOW LEVELS LOWERING AND SIGNIFICANT SNOW LIKELY IN
THE HIGHER ELEVATIONS OF THE SIERRA FOR THE WEEKEND.

&&

.SHORT TERM...

FORECAST REMAINS ON TRACK FOR THE END OF THE WEEK, WITH HIGH
CONFIDENCE IN A WINTER STORM IMPACTING THE AREA. BIGGEST AREAS OF
UNCERTAINTY ARE THE TIMING OF A COLD FRONT FORECAST TO MOVE
THROUGH THE REGION FRIDAY NIGHT AND SATURDAY, AND THE POTENTIAL
FOR A SECOND BURST OF HEAVY PRECIPITATION ON SUNDAY. SNOW LEVELS
WILL START ABOVE 8000 FEET, THEN FALL TO 5000 FEET OR LESS AFTER
THE FRONT PASSES FRIDAY NIGHT OR SATURDAY. SIGNIFICANT SNOW
ACCUMULATIONS ARE LIKELY IN THE SIERRA ABOVE 8000 FEET. LIQUID
TOTALS FOR FRIDAY-FRIDAY NIGHT WILL RANGE FROM 1-2 INCHES ALONG
THE SIERRA CREST TO 0.50 INCH OR LESS FOR WESTERN NEVADA.

HIGHS CLOUDS HAVE KEPT TEMPERATURES UP A BIT EARLY THIS MORNING
AND THUS VALLEY INVERSIONS ARE NOT AS STRONG AS YESTERDAY MORNING.
AREAS OF FOG HAVE ALSO DEVELOPED IN THE NORTHERN SIERRA VALLEYS
AND SHOULD BURN OFF BY 10 AM THIS MORNING.

MODELS DEVELOP THE INITIAL WARM ADVECTION PRECIPITATION OVER
NORTHEAST CALIFORNIA AND THE NORTHERN SIERRA ON THURSDAY. THE MAIN
MOISTURE PLUME SHOULD ARRIVE LATE THURSDAY NIGHT OR EARLY FRIDAY
MORNING AS A DEEPER LAYER OF WARM AIR ADVECTION MOVES ACROSS
NORTHERN CALIFORNIA AND NORTHWEST NEVADA. THIS SHOULD PRODUCE
SHORT PERIOD OF LIGHT RAIN ACROSS MOST AREAS NORTH OF US-50.

ONCE THE WAVE OF WARM AIR ADVECTION PASSES FRIDAY MORNING, THE JET
NOSES INTO NORTHERN CALIFORNIA AND OROGRAPHIC FORCING WILL BE THE
MAIN DRIVER OF PRECIPITATION ALONG THE NORTHERN SIERRA CREST.
MODELS ARE IN GOOD AGREEMENT IN DEVELOPING THE RAIN SHADOW OVER
WESTERN NEVADA AND THE EASTERN SIERRA BY FRIDAY AFTERNOON. MAIN
POINT HERE IS MODERATE TO HEAVY PRECIPITATION WILL CONTINUE ALONG
AND WEST OF HIGHWAY 89 AND NORTH OF A SUSANVILLE-GERLACH LINE.
SOUTH OF THIS LINE A MODERATE TO STRONG WIND EVENT IS LIKELY FROM
FRIDAY AFTERNOON UNTIL THE COLD FRONT PASSES SOMETIME FRIDAY NIGHT
OR SATURDAY MORNING. PEAK GUSTS OF 40-55 MPH WILL OCCUR ACROSS
MOST OF THE AREA SOUTH OF SUSANVILLE-GERLACH. GUSTS IN WIND PRONE
AND FOOTHILL LOCATIONS ALONG US-395 COULD REACH 60-70 MPH. WITH
THE WINDS AND WARM AIR ALOFT, FRIDAY AFTERNOON HIGHS COULD CLIMB
INTO THE LOWER 60S AND APPROACH RECORD LEVELS ACROSS WESTERN
NEVADA.

WINDS WILL START TO SUBSIDE AND SNOW LEVELS WILL DROP BELOW 8000
FEET AS THE COLD FRONT MOVES INTO THE REGION FRIDAY NIGHT. THERE
IS QUITE A BIT OF UNCERTAINTY ON HOW FAST THE FRONT WILL TRACK
SOUTH. WITH THE JET AND FRONT ORIENTED WEST TO EAST, THE FRONT IS
LIKELY TO STALL ALONG AND NORTH OF US-50 UNTIL A SECONDARY WAVE
KICKS IT SOUTH EARLY SATURDAY MORNING. MAIN CONCERN HERE IS
POTENTIAL FOR ACCUMULATING SNOW AS LOW AS 4000-5000 FEET NORTH OF
FRONTAL BOUNDARY. HEAVY SNOW MAY ALSO BEGIN ALONG THE WEST SHORE
OF TAHOE FRIDAY EVENING AS A DEEP ISOTHERMAL LAYER DEVELOPS. THIS
COULD CAUSE SNOW LEVELS TO DROP AS LOW AS 6000-6500 FEET ALONG
HIGHWAY 89. BRONG

.LONG TERM...SATURDAY THROUGH TUESDAY...
PLENTY OF UNCERTAINTY REMAINS DURING THIS TIME FRAME AS THE GFS/EC
CONTINUE TO BE IN TWO DIFFERENT CAMPS. THEIR ENSEMBLES GENERALLY
SUPPORT EACH OTHER AS WELL SO IT DOES NOT ADD MUCH CLARITY. PER THE
EC, THE COLD FRONT SAGS SOUTH WITH SNOW IN THE SIERRA AND RAIN/SNOW
DOWN TO THE WRN NEVADA VALLEY FLOORS WITH LIGHT TO MODERATE AMOUNTS.
THEN IT BECOMES DRIER AND SHOWERY BEHIND THE FRONT INTO SUNDAY AS
THE NEXT WAVE IS WELL SOUTH AND INTO SOUTHERN CALIFORNIA.

THE GFS HAS MORE OF A BREAK SATURDAY AFTER THE FIRST WAVE WITH THE
FRONT STALLING SOUTH OF HIGHWAY 50, THEN IT VERY SLOWLY WORKS NORTH
AS A POTENT WAVE RIDES ALONG THE FRONT FOR SUNDAY WITH HEAVY SNOW IN
THE SIERRA AND WESTERN NEVADA. IT WOULDN'T HAVE THE SNOW END UNTIL
LATE SUNDAY NIGHT. WITH THESE DIFFERENCES, ALSO LOOKED INTO THE
UK/GEM AND THEY ARE SOMEWHAT IN BETWEEN THE TWO SOLUTIONS. HAVE
GENERALLY GONE WITH THEIR MIDDLE GROUND. ALSO, AS OF THIS WRITING,
THE NEW 06Z GFS HAS TRENDED TOWARD THE EC AND LOOKS MORE LIKE THE UK.

THE FORECAST REMAINS A BLEND OF ALL THE MODELS, BUT LEANS HEAVIEST
TO THE EC/UK/GEM IDEAS. KEPT MODERATE TO HIGH POPS IN THROUGH SUNDAY
AND QPF AMOUNTS LIGHT TO MODERATE. A COUPLE INCHES OF SNOW REMAINS
POSSIBLE INTO WESTERN NEVADA AND SEVERAL IN THE SIERRA EVEN WITH THE
DRIER EC, MORE IN SATURDAY.

AFTER THE SYSTEM PASSES, COLD AIR WILL FUNNEL IN WITH 700 MB TEMPS -
10 C OR LOWER. TEMPS WILL BE A LITTLE BELOW AVERAGE MONDAY AND
TUESDAY. THE GFS AND EC THEN DIFFER ON A POTENTIAL SYSTEM FOR LATE
TUESDAY. THE EC IS MORE AGGRESSIVE THAN THE GFS SHOWING A FEW INCHES
OF SNOW POSSIBLE WHILE THE GFS WASHES IT OUT MORE. WENT WITH CHANCE
POPS FOR THE SIERRA AS EVEN THE GFS WOULD INDICATE A FEW SNOW
SHOWERS THERE. UNLIKE THIS NEXT SYSTEM, THAT ONE WOULD NOT HAVE MUCH
CONCERN WITH SNOW LEVELS NOR WINDS. WALLMANN

&&

.AVIATION...
VFR WITH MID AND HIGH CLOUDS INTO THURSDAY. SOME FZFG AT KTRK THRU
17Z THIS MORNING. WINDS ARE EXPECTED TO REMAIN LIGHT THRU 12Z
THURSDAY BEFORE RIDGE WINDS BEGIN TO INCREASE AHEAD OF THE NEXT
STORM. WALLMANN

&&

.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&

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