FXUS65 KREV 221659
AFDREV

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
859 AM PST TUE DEC 22 2009

.UPDATE...ALLOWED WINTER WEATHER ADVISORY FOR THE NORTHERN AND
CENTRAL SIERRA TO EXPIRE AS WINTER WEATHER IS DIMINISHING RAPIDLY
AND ONLY MINOR SNOW SHOWERS ARE EXPECTED FOR THE REMAINDER OF
TODAY. 

RCM/NWS ELKO

&&

.PREVIOUS DISCUSSION... /ISSUED 415 AM PST TUE DEC 22 2009/ 

SHORT TERM...TODAY THROUGH WEDNESDAY. WINTER STORM IS MOVING RAPIDLY EAST
INTO CENTRAL NEVADA THIS MORNING. SURFACE COLD FRONT IS ALREADY
WELL EAST...AND CAA SHOULD BEGIN THIS MORNING...WITH 700MB TEMPS
FALLING TO -15C ACROSS THE AREA BY 00Z THIS EVENING.

AT 500MB A DEEP LOW OVER CENTRAL OREGON WILL DIVE SHARPLY SSE OVER
THE EASTERN EDGE OF THE FCST AREA TODAY...WITH STRONG VORT MAX 
TRIGGERING SCATTERED SNOW SHOWERS. ISOLATED ADDITION SNOWFALL
AMOUNTS OF UP TO AN INCH WILL BE POSSIBLE THROUGH THE DAY. SKIES
WILL CLEAR THIS EVENING. 

A STRONG NW FLOW WILL DEVELOP WEDNESDAY AHEAD OF A SHARP RIDGE
MOVING ONSHORE. AFTERNOON SURFACE TEMPS WILL CONTINUE THEIR
DOWNWARD TREND WEDNESDAY WITH VALLEY HIGHS MAINLY 30 TO 35...BUT
700MB TEMPS WILL BEGIN A QUICK RECOVERY WITH -3C TO -4C WEDNESDAY
AFTERNOON. REA

LONG TERM...THURSDAY THROUGH MONDAY. THE NW FLOW AT 500MB WILL
WEAKEN THURSDAY AS THE RIDGE MOVES ONSHORE. THE RIDGE WILL MOVE
OVERHEAD FRIDAY AND SATURDAY. AFTERNOON SURFACE TEMPS THRU THIS
PERIOD WILL CONTINUE ON THE COOL SIDE...WITH OVERNIGHT VALLEY LOWS
FROM ZERO TO 10 ABOVE.

CLOUDS WILL BEGIN TO INCREASE SATURDAY AHEAD OF A SHORT WAVE
MOVING ONSHORE. THE GFS AND EC ARE COMING INTO CLOSER AGREEMENT IN
TIMING THIS WAVE...WITH PRECIP POSSIBLE STARTING SATURDAY NIGHT
AND CONTINUING THRU SUNDAY. THE MAIN DIFFERENCE BETWEEN THE MODELS
IS THAT THE EC HAS HIGHER QPF SATURDAY NIGHT AS THE WAVE MOVES
INTO THE MOUNTAINS. EC HAS 700MB TEMPS OF -5 SATURDAY EVENING
FALLING TO -10C ON SUNDAY...WITH THE GFS MAYBE 2C WARMER. EITHER WAY...BY
THE TIME SNOW LEVELS FALL TO VALLEY FLOORS SUNDAY...THE MAIN QPF
WILL ALREADY HAVE FALLEN IN THE MOUNTAINS. CURRENT INDICATIONS ARE
THAT SNOWFALL AMOUNTS WILL BE ON THE LIGHT SIDE. REA

AVIATION...MVFR CIGS WILL BE THE RULE TODAY WITH SCATTERED SNOW
SHOWERS. VSYBS WILL FALL TO 2 TO 3 MILES LOCALLY IN SNOW SHOWERS.
CONDITIONS WILL IMPROVE LATE THIS AFTERNOON...WITH SKIES CLEARING THIS
EVENING. VFR CONDITIONS ARE EXPECTED ON WEDNESDAY. REA 

&&

.REV WATCHES/WARNINGS/ADVISORIES...
NONE.

&&

$$

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