000 
FXUS65 KBOI 290913
AFDBOI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
313 AM MDT TUE SEP 29 2009

.SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT...SIGNIFICANT PATTERN
CHANGE TODAY WITH A COLD FRONT EXPECTED THROUGH SE OREGON THIS
MORNING AND SW IDAHO THIS AFTERNOON. GUSTY W-NW POST-FRONTAL WINDS
CAN BE EXPECTED TODAY THROUGH WEDNESDAY NIGHT WITH PLENTY OF COLD
AIR ADVECTION. HIGH TEMPERATURES TODAY WILL BE 15 TO 25 DEGREES
COOLER THAN YESTERDAY WITH AN ADDITIONAL 5 TO 10 DEGREES OF
COOLING ACROSS SE OREGON AND 15 TO 20 DEGREES OF COOLING ACROSS SW
IDAHO WEDNESDAY. BEST CHANCES FOR PRECIPITATION COME WHEN THE
ASSOCIATED TROUGH SWINGS OVER THE CWA TONIGHT. DEEPEST MOISTURE
BAND FORMS ALONG THE LEADING EDGE OF THE TROUGH OVER SW
IDAHO...WHERE SHOWERS ARE LIKELY TONIGHT THROUGH WEDNESDAY. SNOW
LEVELS WILL FALL SIGNIFICANTLY...DOWN TO 5500 FT MSL WITH A COUPLE
INCHES OF ACCUMULATION POSSIBLE BY WEDNESDAY MORNING. AS THE
TROUGH EXITS WEDNESDAY NIGHT AND SURFACE HIGH PRESSURE BUILDS
IN...SKIES WILL CLEAR AND WINDS WILL BECOME LIGHT...ALLOWING
RADIATIONAL COOLING TO BE MAXIMIZED. LOW TEMPERATURES WILL DIP
INTO THE UPPER 20S TO MID 30S IN THE VALLEYS AND TEENS AND 20S IN
THE MOUNTAINS. FROST IS LIKELY THROUGHOUT ALL AGRICULTURAL VALLEY
LOCATIONS THURSDAY MORNING.

.LONG TERM...THURSDAY THROUGH TUESDAY...THURSDAY AND FRIDAY WILL BE 
THE CALM BETWEEN THE STORMS...SO TO SPEAK...AS THIS CURRENT SYSTEM 
MOVES OFF AND THE NEXT SYSTEM GETS READY TO MOVE IN ON SATURDAY. 
THIS NEXT SYSTEM LOOKS JUST AS COLD WITH EVEN MORE PRECIPITATION. 
NOW THAT THE EC AND GFS ARE IN EXCELLENT AGREEMENT ON THE 
TIMING...WE HAVE OPTED TO GO AHEAD AND LOWER TEMPERATURES TO MATCH 
THE EXPECTED CLOUDY...SHOWERY...AND WINDY DAYS OF SAT THROUGH MON. 
THE SNOW LEVEL WILL BE NEAR 6000 FEET. THIS SYSTEM WILL BE SLOW TO 
PULL AWAY...BUT BY TUESDAY RIDGING SHOULD TAKE OVER AND CONDITIONS 
WILL BECOME DRIER AND WARMER.


&&

.AVIATION...VFR TROUGH TODAY...BUT WITH LOWERING CEILINGS THIS 
AFTERNOON IN SE OREGON AND AREAS OF LOW-VFR CEILINGS AND RAIN/SNOW 
SHOWERS DEVELOPING TONIGHT. AREAS OF MVFR CEILINGS WILL DEVELOP OVER 
THE MTNS OF SW IDAHO EARLY WED MORNING...WITH LOCAL IFR CONDITIONS 
IN SNOW AS LOW AS 5500 FEET. VFR IN THE LOWER VALLEYS THROUGH WED. 
STRONG SW WINDS ALOFT AHEAD OF THE FRONT TODAY...WITH WINDS OF 50+ 
KTS ABOVE 8K FEET MSL. ALSO...MODERATE TO STRONG SFC WINDS.


&&

.BOI WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
OR...NONE.
&&

$$

WEATHER.GOV/BOISE

SHORT TERM...DF
LONG TERM....SP
AVIATION.....SP