FXUS65 KBOI 152148
AFDBOI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
245 PM MST TUE DEC 15 2009

.SHORT TERM...HEAVY SNOW TO CONTINUE IN THE MOUNTAINS TONIGHT AND
ONLY GRADUALLY DECREASE FROM WEST TO EAST OVERNIGHT.  SNOW WILL ALSO 
CONTINUE IN THE COLDER WIND-PROTECTED VALLEYS BELOW 3000 FEET NORTH 
TO 4000 FEET SOUTH.  OTHER AREAS BELOW 3000 FEET NORTH TO 4000 FEET 
SOUTH WILL HAVE EITHER RAIN OR MIXED RAIN AND SNOW WITH LITTLE SNOW 
ACCUMULATION.  AFTER A SHORT BREAK IN PCPN WEDNESDAY MORNING ANOTHER 
WAVE WILL BRING MORE LIGHT RAIN AND SNOW TO THE VALLEYS AND SNOW TO 
THE MOUNTAINS WEDNESDAY AFTERNOON AND EVENING. ANOTHER BREAK LATER 
WEDNESDAY NIGHT THEN A CHANCE OF WARM-FRONTAL RAIN AND SNOW THURSDAY 
...MAINLY IN NORTHERN ZONES.  LOW TEMPS 25 TO 35 TONIGHT WITH HIGHS 
32 TO 42 BOTH WEDNESDAY AND THURSDAY.  WEDNESDAY NIGHT WILL BE ABOUT
5 DEGS COLDER THAN TONIGHT. MODERATE SOUTHEAST WINDS TONIGHTB AND
WEDNESDAY MORNING...LIGHTER WEDNESDAY LATER WEDNESDAY...LIGHT AND
VARIABLE WEDNESDAY NIGHT AND THURSDAY.

.LONG TERM...THURSDAY NIGHT THROUGH TUESDAY...FORECAST AREA WILL BE 
LEFT IN ZONAL FLOW THURSDAY NIGHT AS A SHORTWAVE EXITS TO THE EAST. 
AMPLE MOISTURE IN WESTERLY FLOW WARRANTS SLIGHT CHANCES FOR 
PRECIPITATION OVER SE OREGON - WITH LESS LIKELIHOOD OF RAIN/SNOW 
OVER ID ZONES. UPPER RIDGE WILL ATTEMPT TO REBUILD ON FRIDAY...BUT 
ANOTHER MOIST TROUGH /NEAR THE BC COAST/ WILL MOVE INLAND. THIS 
SYSTEM IS PROGGED TO DIG SOUTHEASTWARD OVER THE WEEKEND - 
SUPPRESSING RIDGE HEIGHTS AND BRINGING ANOTHER ROUND OF RAIN/SNOW TO 
THE AREA. MODELS DIVERGE MONDAY AND BEYOND...AS MORE PROMINENT 
SYSTEM IS PROGGED TO MOVE INTO THE AREA EARLY NEXT WEEK. HAVE 
INCREASED POPS /ABOVE CLIMO/ AND LOWERED TEMPERATURES TO REFLECT 
THIS BUT HAVE REMAINED CONSERVATIVE DUE TO MODEL TIMING DIFFERENCES.

&&

.AVIATION...WIDESPREAD IFR AND LOCAL LIFR IN SNOW...RAIN...MIXED 
PRECIPITATION...AND FOG WILL PERSIST THIS AFTERNOON AND TONIGHT. 
MOUNTAINS WILL BE OBSCURED. KBOI TO EXPERIENCE MOSTLY RAIN AS P-TYPE 
- FOR LOW-END MVFR CIGS THROUGH 06Z. GUSTY SE-SW SURFACE WINDS WITH 
STRONG WESTERLY WINDS ALOFT.

&&
.BOI WATCHES/WARNINGS/ADVISORIES...
ID...WINTER STORM WARNING UNTIL 11 PM MST TONIGHT FOR IDZ011-IDZ012-
      IDZ013-IDZ033.
     WINTER WEATHER ADVISORY UNTIL 11 PM MST TONIGHT FOR             
      IDZ016-IDZ028-IDZ029.
OR...WINTER STORM WARNING UNTIL 11 PM MST TONIGHT FOR ORZ064.
     WINTER WEATHER ADVISORY UNTIL 10 PM PST TONIGHTN FOR ORZ062.

&&

$$

WEATHER.GOV/BOISE

SHORT TERM...LC
LONG TERM....MT/LH
AVIATION.....MT