FXUS65 KBOI 071028
AFDBOI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
328 AM MST MON DEC 7 2009

.SHORT TERM...TODAY THROUGH TUESDAY...BANDS OF LIGHT SNOW CONTINUE 
ACROSS PORTIONS OF THE TREASURE VALLEY...MAINLY SOUTH OF INTERSTATE 
84 BETWEEN CALDWELL AND MOUNTAIN HOME...INCLUDING THE BOISE METRO. 
THERE HAVE BEEN NO SIGNS OF LETTING UP AND IN FACT...THE RADAR 
COVERAGE HAS INCREASED IN THE PAST COUPLE HOURS. NOT SURE EXACTLY 
WHEN THE SNOW WILL QUIT...BUT THE LATEST NAM12 INDICATES THAT IT 
WILL CONTINUE THROUGH MID-MORNING. QPF AMOUNTS WILL BE LIGHT...BUT 
BECAUSE TEMPS ARE COLD EVEN A COUPLE HUNDREDTHS OF AN INCH WOULD 
RESULT IN A HALF INCH OF POWDERY SNOWFALL. SINCE THE ROADS ARE 
ALREADY SNOW-COVERED AND EXPECTING MORE LIGHT SNOW THROUGH THE 
MORNING COMMUTE...WILL HOIST A WINTER WEATHER ADVISORY FOR THE 
TREASURE VALLEY UNTIL 9 AM MST. SNOW SHOWERS EXTEND EAST INTO THE 
WESTERN MAGIC VALLEY AND SOUTH TO THE NEVADA BORDER...AND WILL 
LIKELY CONTINUE IN THOSE AREAS AS WELL THIS MORNING. BITTER COLD 
WIND CHILLS HAVE NOT MATERIALIZED IN THE CAMAS PRAIRIE...SO WILL 
CANCEL THE WIND CHILL WARNING...ALTHOUGH WIND CHILLS DOWN TO 10 
BELOW ZERO WILL CONTINUE FOR THE NEXT SEVERAL HOURS. UPPER TROUGH 
RESPONSIBLE FOR THE SNOW WILL SLOWLY WORK EAST TONIGHT WITH DRIER 
AIR MOVING IN FROM THE NORTH AND WEST. SKIES ARE EXPECTED TO CLEAR 
IN MOST AREAS BY TUESDAY MORNING RESULTING IN SOME OF THE COLDEST 
TEMPS IN A LONG TIME. TEMPS COULD BE EVEN COLDER IN THE TREASURE 
VALLEY TONIGHT IF THE SNOW STICKS AROUND THROUGH TONIGHT. 

.LONG TERM...TUESDAY NIGHT THROUGH SUNDAY...MODELS REMAIN IN GOOD 
AGREEMENT WITH EACH OTHER FOR THE EARLY PORTION OF THE EXTENDED.  
MAIN UPPER LEVEL TROUGH WILL SLOWLY EXIT THE REGION BEGINNING 
WEDNESDAY AS THE UPPER LEVEL RIDGE OFF THE WEST COAST PUSHES FURTHER 
TO THE EAST.  THIS WILL GRADUALLY SHIFT THE FLOW ALOFT FROM A COLD 
NORTHERLY FLOW TO A MODERATING NORTHWESTERLY FLOW.  MODELS STILL 
KEEP THE MOIST SUBTROPICAL FLOW SOUTH OF THE FORECAST AREA BUT COULD 
SEE A SMALL CHANCE OF PRECIPITATION ALONG THE NEVADA BORDER.  POPS 
FOR WEDNESDAY THROUGH FRIDAY WILL REMAIN LOW WITH SLOWLY WARMING 
TEMPERATURES.  FOR THE WEEKEND MODELS ARE IN BETTER AGREEMENT BUT 
ENOUGH DIFFERENCE IN TIMING OF THE WEATHER SYSTEM FOR UNCERTAINTY IN 
THE FORECAST.  MODELS AGREE ON A MOIST SOUTHWEST FLOW ALOFT 
DEVELOPING OVER THE REGION FOR THE WEEKEND BUT DIFFER ON THE TIMING 
OF WHEN THE PRECIPITATION WILL MOVE INTO THE FORECAST AREA AND HOW 
MUCH PRECIPITATION WILL FALL.  FOR NOW WILL HAVE POP ABOVE 
CLIMATOLOGY AND WITH THE WARMER SOUTHWEST FLOW WILL WARM 
TEMPERATURES TO NEAR NORMAL.

&&

.AVIATION...WIDESPREAD IFR/MVFR CONDITIONS IN LOW CLOUDS AND LIGHT 
SNOW IN THE SNAKE RIVER PLAIN FROM KEUL EAST TO KJER/KTWF THIS 
MORNING BECOMING LOCAL BY THIS AFTERNOON.  REST OF THE FORECAST AREA 
WILL HAVE VFR CONDITIONS BUT COULD SEE ISOLATED MVFR CONDITIONS IN 
LOW CLOUDS AND LIGHT SNOW TODAY.  EAST TO NORTHEAST WINDS WILL BE 
LIGHT OVER MOST OF THE REGION BUT WILL BE MODERATE AND GUSTY OVER 
THE MAGIC VALLEY.

&&

.BOI WATCHES/WARNINGS/ADVISORIES...
ID...WINTER WEATHER ADVISORY UNTIL 9 AM MST THIS MORNING FOR IDZ012-
     IDZ014.
OR...NONE.
&&

$$

WEATHER.GOV/BOISE

SHORT TERM...BW
LONG TERM....JA
AVIATION.....JA