FXUS65 KBOI 042129
AFDBOI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
229 PM MST THU DEC 4 2008

.SHORT TERM...TONIGHT THROUGH SATURDAY...LOW STRATUS STILL HANGING
ON IN THE WESTERN MAGIC VALLEY AND EXTREME UPPER TREASURE
VALLEY...BUT IS SHOWING SIGNS OF FINALLY THINNING AT THIS TIME.
WILL NOT INCLUDE THIS IN THE EVENING FORECAST BECAUSE EXPECTATION
IS STILL THAT DRY AIR WILL ERODE THIS THIN MOIST LAYER BEFORE
SUNSET. OTHERWISE WITH DRY AIR OVER THE REGION...WILL SEE MOSTLY
CLEAR SKIES TONIGHT AND FRIDAY WITH TEMPS A FEW DEGREES ABOVE
NORMAL IN MOST AREAS. AN UPPER LEVEL RIDGE BUILDS IN FROM THE WEST
THROUGH LATE FRIDAY BEFORE FLATTENING OUT SATURDAY. THIS WILL GIVE
US A SLIGHT WARMING TREND INTO SATURDAY WITH CONTINUED MOSTLY
CLEAR SKIES. THERE IS A SLIGHT CHANCE THAT ENOUGH MOISTURE WILL
WORK ITS WAY SOUTH INTO THE WEST CENTRAL MTNS SATURDAY FOR
SHOWERS...BUT ANY PRECIP THAT DOES OCCUR WILL BE VERY LIGHT. THE
INVERSION WILL BEGIN TO REFORM IN THE LOWER TREASURE VALLEY FRIDAY
AND BY SATURDAY THERE WILL BE A NOTICEABLE LAYER OF TRAPPED AIR.
PATCHY FOG IS POSSIBLE BY LATE FRIDAY NIGHT INTO SATURDAY MORNING
IN THE LOWER TREASURE VALLEY...THE BURNS OREGON AREA...AND MOST OF
THE HIGH ELEVATION MOUNTAIN-VALLEYS OF BAKER COUNTY AND THE WEST
CENTRAL AND BOISE MTNS.

.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...UPPER RIDGE
CONTINUES TO WEAKEN THROUGH SUNDAY. DESPITE THE WEAKENING
RIDGE...INVERSION REMAINS IN PLACE. MODELS CONTINUE TO TREND TOWARDS
A WEAKER AND DRIER SYSTEM FOR EARLY MONDAY. THE BEST CHANCES FOR
PRECIPITATION WILL BE IN THE MOUNTAINS OF SOUTHWEST IDAHO AS THE
SYSTEM TRACKS SOUTHEAST ACROSS CENTRAL IDAHO INTO WESTERN WY.
INVERSION REBUILDS ON TUESDAY AND DEPENDING ON HOW MUCH MOISTURE GETS
TRAPPED IN THE VALLEYS WE MAY GET FOG AND/OR STRATUS TUESDAY
MORNING. UPPER RIDGE LOOKS TO BE MUCH WEAKER ON TUESDAY WITH MOIST
ZONAL FLOW SETTING UP JUST TO THE NORTH OF THE AREA. THIS WILL
ALLOW CLOUDS AND WEAK SHORTWAVES TO BRING A CHANCE OF
PRECIPITATION ACROSS THE NORTHERN ZONES. TEMPERATURES LOOK TO
REMAIN SLIGHTLY ABOVE NORMAL THROUGH THE MIDDLE OF NEXT WEEK.

&&

.AVIATION...MVFR/IFR CONDITIONS IN VALLEY STRATUS CONTINUES IN THE
WESTERN MAGIC AND UPPER TREASURE VALLEYS. STRATUS DECK APPEARS TO BE
THINNING AS DRIER MOVES INTO THE REGION BUT MAY NOT COMPLETELY
DISSIPATE UNTIL LATER THIS AFTERNOON. NORTHWESTERLY WINDS SHOULD
KEEP STRATUS DECK SOUTHEAST OF KBOI AIRPORT. VFR CONDITIONS
ELSEWHERE UNDER MOSTLY CLEAR SKIES. LIGHT NW WINDS SURFACE AND ALOFT
THROUGH FRIDAY. LOOKS TO BE TOO DRY FRIDAY MORNING FOR FOG FORMATION
EVEN IN FAVORED MOUNTAIN VALLEYS.

&&

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

$$

WEATHER.GOV/BOISE

SHORT TERM...SP
LONG TERM....JS/MT
AVIATION.....JS




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