000
FXUS65 KBOI 032138
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
238 PM MST WED DEC 3 2008
.SHORT TERM...TONIGHT THROUGH FRIDAY...UPPER LEVEL WAVE COMING
THROUGH IN NORTHERLY FLOW LATE TONIGHT AND EARLY THURSDAY...
BRINGING COOLER AIR AND...BY LATE IN THE DAY...DECREASING CLOUDS.
SLIGHT CHANCE TO CHANCE POPS IN THE WEST CENTRAL AND BOISE MTNS
TONIGHT AND MAINLY THE FIRST HALF OF TOMORROW...WITH DRY
CONDITIONS IN THE VALLEYS. THERE IS NOT ENOUGH MOISTURE TO GET THE
SHOWERS ALL THE WAY TO THE GROUND IN THE VALLEYS. TEMPS WILL
CONTINUE TO COOL BACK TOWARD NORMAL WITH THIS REINFORCING SHOT OF
COOLER AIR. ALSO...THIS WILL BRING MORE FRESH AIR INTO THE REGION
TO HELP COMPLETE THE DEPARTURE OF THE INVERSION FROM THIS PAST
WEEKEND. NO SIGNIFICANT DIFFERENCES IN THE MODELS IN THE SHORT
TERM. MAIN WEATHER IMPACTS WILL BE SNOW SHOWERS IN THE MOUNTAINS.
.LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY...HIGH CONFIDENCE IN
FORECAST THROUGH SUNDAY WITH LONGWAVE UPPER RIDGE FLATTENING AHEAD
OF A SHORTWAVE FOR LATE SUNDAY/EARLY MONDAY. TEMPERATURES WILL
REMAIN ABOVE NORMAL THOUGH THE VALLEYS WILL BE SLIGHTLY COOLER THAN
HIGHER ELEVATIONS. DRY CONDITIONS CONTINUE THROUGH SUNDAY WITH WEAK
INVERSION IN PLACE. CLOUDS WILL INCREASE ACROSS THE NORTHERN ZONES
AHEAD OF THE LATE SUNDAY/MONDAY SYSTEM. OPERATIONAL ECMWF AND GFS
MODELS CONTINUE TO KEEP BEST LIFT AND MOISTURE NORTH OF THE FORECAST
AREA OVER THE PANHANDLE. 12Z GFS DOES BRING THE SHORTWAVE INTO
SOUTHERN IDAHO MONDAY NIGHT FOR PRECIPITATION ACROSS MUCH OF
SOUTHWESTERN IDAHO. HAVE CONTINUED ABOVE CLIMO POPS FOR THIS PERIOD.
OVERALL MODEL AGREEMENT IN REDEVELOPMENT OF HIGHLY AMPLIFIED RIDGE
IS GOOD...THOUGH THE GFS AND ECMWF DIFFER ON ANOTHER RIDGE
BREAKDOWN/SHORTWAVE TROUGH FOR EARLY NEXT WEEK. BASED ON THIS WILL
KEEP CLIMO POPS IN THE FORECAST THROUGH THROUGH TUESDAY.
&&
.AVIATION...MOSTLY VFR CONDITIONS THIS AFTERNOON THROUGH THURSDAY.
MID-LEVEL CEILINGS NORTH AND EAST OF THE MAGIC...TREASURE AND BAKER
VALLEYS WITH CLOUD BASES BETWEEN 8K AND 10K FEET MSL...OBSCURING
MTNS AND MAKING FOR LOW-VFR CEILINGS OVER MTN VALLEYS. WIDELY
SCATTERED SNOW SHOWERS OVER THE WEST CENTRAL MTNS STARTING LATER
TONIGHT WILL PRODUCE BRIEF PERIODS OF IFR CONDITIONS. EXPECT
SCATTERED LOW-VFR TO MVFR CEILINGS IN THE MAGIC AND BAKER
VALLEYS BY THURSDAY MORNING WITH ISOLATED SHOWERS. LIGHT WINDS
SURFACE AND ALOFT TONIGHT. SKIES CLEAR BY THURSDAY AFTERNOON.
&&
.BOI WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
OR...NONE.
&&
$$
WEATHER.GOV/BOISE
SHORT TERM...SP
LONG TERM....JS/SL
AVIATION.....JS
