FXUS65 KREV 102340
AFDREV

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE RENO NV
340 PM PST THU DEC 10 2009

.SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT...
FIRST SYSTEM MOVING INTO THE CENTRAL CALIFORNIA COAST WILL PUSH A
BAND OF SNOW THROUGH THE AREA TONIGHT AND EARLY FRIDAY MORNING.
MODELS ARE A BIT WETTER WITH THIS SYSTEM...WITH AS MUCH AS 0.50 TO
0.75 INCHES OF LIQUID IN THE SIERRA. THIS WOULD YIELD ABOUT 5-10
INCHES OF SNOW...WITH HIGHER AMOUNTS POSSIBLE ABOVE 7000 FEET.
DYNAMICS ARE FAVORABLE FOR THIS BAND TO EASILY CROSS THE SIERRA
AND PRODUCE A FEW INCHES OF SNOW ACROSS WESTERN NEVADA LATE TONIGHT
AND EARLY FRIDAY MORNING. GOOD CONFIDENCE IN 1-3 INCHES OF SNOW IN
THE RENO-CARSON CITY AREA FOR THE FRIDAY MORNING COMMUTE. MOST
SNOW WITH THIS SYSTEM WILL END BY FRIDAY AFTERNOON...BUT IT IS
POSSIBLE LIGHT SNOW WILL CONTINUE IN THE SIERRA FROM US-50 NORTH
THROUGH FRIDAY EVENING AS THE NEXT SYSTEM APPROACHES.

SECOND AND STRONGER STORM WILL MOVE INTO THE SIERRA AND WESTERN
NEVADA SATURDAY MORNING...WITH THE HEAVIEST SNOW SATURDAY
AFTERNOON AND EVENING. MODELS STILL TRY TO RAISE SNOW LEVELS OFF
THE NEVADA VALLEY FLOORS...BUT WITH A LACK OF MIXING THAT IS NOT
LIKELY TO HAPPEN. THUS THINKING PRECIP ACROSS WESTERN NEVADA WILL
BE ALL SNOW AND HAVE ISSUED A WINTER STORM WATCH FOR THE RENO-
CARSON CITY AREA FOR SATURDAY AND SATURDAY NIGHT. WATCH MAY NEED
TO BE EXPANDED TO OTHER PORTIONS OF WESTERN NEVADA...AS 18Z RUNS
LOOK WETTER. FOR NOW FORECAST IS ON TRACK FOR 1-3 FEET OF SNOW IN
THE SIERRA...WITH HIGHEST AMOUNTS SOUTH OF US-50 AND INTO MONO
COUNTY. AMOUNTS IN RENO-CARSON COULD REACH 6 INCHES...WITH UP TO
10 INCHES IN THE FOOTHILLS. BRONG

.LONG TERM...SUNDAY THROUGH WEDNESDAY...
UPPER LEVEL TROUGH WILL BE PASSING ACROSS THE GREAT BASIN ON 
SUNDAY...WITH FLOW ALOFT BEGINNING TO CHANGE TO NORTHWESTERLY. SNOW 
SHOWERS ARE EXPECTED TO CONTINUE IN THIS POST-FRONTAL AIR MASS...WITH 
SOME LIGHT ADDITIONAL ACCUMULATIONS POSSIBLE IN THE MORNING. AS THE 
TROUGH MOVES OFF THE THE EAST...SKIES WILL BEGIN TO CLEAR OUT AND 
SHOWERS DISSIPATE. 

WEAK RIDGE OF HIGH PRESSURE WILL BUILD INTO THE SOUTHWESTERN CONUS 
FOR MONDAY...WITH COLDER AIR SETTLING DOWN INTO THE VALLEYS AND 
TEMPERATURE INVERSIONS SETTING UP. THERE REMAINS SOME DIFFERENCES IN 
THE FORECAST OF TEMPERATURES FOR THE MON-WED TIME FRAME. EC MODEL 
CONTINUES TO SUGGEST A STORM TRACK JUST TO THE NORTH...OVER WA/OR. 
THIS WOULD KEEP WINDS ALOFT STRONGER AND MIX OUT THE COLD DENSE AIR 
FROM THE LOWER VALLEYS. IF WE END UP GETTING SIGNIFICANT SNOWFALL 
THIS WEEKEND ACROSS THE REGION...AND THE RIDGE AMPLIFIES OVER THE 
WESTERN STATES...WE COULD SEE SOME STRONG TEMPERATURE INVERSIONS 
MUCH LIKE WE HAVE SEEN THIS WEEK. TO INCLUDING FREEZING FOG...HAZE 
AND WELL BELOW NORMAL TEMPERATURES IN THE LOWER VALLEYS THROUGH NEXT 
WEEK. EC MODEL STILL HAS BETTER SUPPORT OF TELECONNECTIONS... AND 
LATEST GFS SEEMS TO BE TRENDING THIS WAY AS WELL...SO DIDN'T MAKE ANY 
BIG CHANGES TO THE LONG TERM. HOON

&&

.AVIATION...
LIGHT HAZE AND MIST TO AFFECT KRNO THROUGH THIS EVENING...BUT MAINLY 
VFR THROUGH 12Z FRI. A PAIR OF STORM SYSTEMS ARE EXPECTED TO MOVE 
INTO THE REGION FRI-SAT. THE FIRST WILL ARRIVE LATE TONIGHT INTO 
FRIDAY MORNING...WITH SOME SNOW EXPECTED FOR KRNO...KTRK...KTVL. 

MVFR-IFR CONDS BEGINNING TONIGHT AFTER 12Z...ESPECIALLY FOR KTRK AND 
KTVL...THROUGH ABOUT 18-21Z OR SO. 

KRNO...UP TO A COUPLE INCHES POSSIBLE ON KRNO RUNWAYS BY FRI 
MORNING...COULD HAMPER OPERATIONS. MVFR-IFR CONDS FOR A FEW HOURS 
AFTER 12Z. STRONGER STORM EXPECTED FOR SATURDAY. HOON

&&

.REV WATCHES/WARNINGS/ADVISORIES...
NV...WINTER WEATHER ADVISORY FROM 10 PM THIS EVENING TO 10 AM PST 
     FRIDAY FOR NVZ002. 

     WINTER STORM WATCH FROM FRIDAY EVENING THROUGH LATE SATURDAY 
     NIGHT FOR NVZ002. 

     WINTER WEATHER ADVISORY FROM 10 PM THIS EVENING TO 10 AM PST 
     FRIDAY FOR NVZ001-003. 

     WINTER STORM WATCH FROM FRIDAY EVENING THROUGH LATE SATURDAY 
     NIGHT FOR NVZ003. 

CA...WINTER WEATHER ADVISORY FROM 10 PM THIS EVENING TO 10 AM PST 
     FRIDAY FOR CAZ071. 

     WINTER STORM WATCH FROM FRIDAY EVENING THROUGH LATE SATURDAY 
     NIGHT FOR CAZ071. 

     WINTER WEATHER ADVISORY FROM 10 PM THIS EVENING TO 10 AM PST 
     FRIDAY FOR CAZ072-073. 

     WINTER STORM WATCH FROM FRIDAY EVENING THROUGH LATE SATURDAY 
     NIGHT FOR CAZ072-073. 

&&

$$

HTTP://WEATHER.GOV/RENO