FXUS65 KBOI 052210 CCA
AFDBOI

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE BOISE ID
308 PM MST SAT DEC 5 2009

.SHORT TERM...TONIGHT THROUGH MONDAY...LIGHT SNOW BRIEFLY COVERED
ROADWAYS FOR UP TO AN HOUR IN THE PERIOD FROM 9-11 AM IN SOUTH
CENTRAL IDAHO THIS MORNING. THIS INCLUDED PINE TURNOFF...GLENNS
FERRY...PERRINE BRIDGE...RIDGEWAY AND GWYNN RANCH. WATER VAPOR
SATELLITE IMAGERY ENHANCEMENT SHOWS NEXT UPPER LOW FORMING OVER SE
OREGON WHILE ANOTHER EXITS INTO SE IDAHO. LOW LEVEL NW WINDS 15-25
THIS AFTERNOON DIMINISH THIS EVENING. WINDS WILL SWITCH OVER TO N
AND NE TONIGHT THEN SHIFT AROUND NE/E/SE SUNDAY THROUGH MONDAY.
LIGHT SNOW SHOWERS AND LOW CLOUDS HAVE BEEN MOVING WESTWARD ACROSS
SOUTHWESTERN IDAHO TODAY TO NEAR MOUNTAIN HOME AND SOUTHERN OWYHEE
COUNTY AS OF 230 PM. LOOK FOR SOUTHERN IDAHO SHOWERS TO MIGRATE
WWD TONIGHT AND SE OREGON SHOWERS TO INCREASE TONIGHT AS THE
OREGON LOW BECOMES DOMINANT. ON SUNDAY AND SUNDAY NIGHT THIS
FEATURE ELONGATES OVER THE REGION THEN DRIFTS THROUGH IDAHO
MONDAY. THIS BRINGS A CONTINUED PERIOD OF LOW QPF SNOW SHOWERS
FAVORING THE OREGON SOUTHERN ZONES SUNDAY...THE AREA FROM BURNS
THROUGH THE FAR SOUTHERN IDAHO MOUNTAINS SUNDAY NIGHT...AND AREAS
NEAR THE NV BORDER SUNDAY. WHILE THE COLDEST AIR REMAINS EAST OF
THE DIVIDE A COOLING TREND IS ON TAP FOR THE SHORT TERM.

.LONG TERM...MONDAY NIGHT THROUGH SATURDAY...MODELS FINALLY IN GOOD 
AGREEMENT FOR THE MID TERM OF TUESDAY THROUGH THURSDAY CONTINUING TO 
SHOW A LONG WAVE TROUGH OVER THE WESTERN SECTION OF THE COUNTRY.   
THIS KEEPS THE FORECAST AREA UNDER A COLD AND MAINLY DRY NORTHERLY 
FLOW. CONTINUED THE TREND OF WHAT THE MID SHIFT HAD FOR POPS FOR 
THIS TIME PERIOD BELOW CLIMATOLOGY DUE TO THE LACK OF MOISTURE AND 
DYNAMICS. TEMPERATURES TUESDAY AND WEDNESDAY WILL BE 10 TO 15 
DEGREES BELOW NORMAL WITH MODERATING TEMPERATURES BY THURSDAY AS 
FLOW BACKS TO THE SOUTH AND SOUTHEAST AS A SYSTEM UNDERCUTS THE WEST 
COAST RIDGE AND MOVES INTO CALIFORNIA. THIS BEGINS TO BRING CLOSER TO 
NORMAL TEMPERATURES TO THE OREGON SIDE AND SLIGHTLY BELOW NORMAL FOR 
THE IDAHO ZONES. AS MENTIONED...EXTENDED MODELS ARE IN GOOD 
AGREEMENT BY THE FIRST OF THE WEEKEND KEEPING THE BRUNT OF THE 
MOISTURE ALONG AND SOUTH OF THE IDAHO/NEVADA BORDER AS PACIFIC RIDGE 
REMAINS JUST ALONG THE WEST COAST AND ENOUGH ENERGY CONTINUES TO 
DROP DOWN THE PERIPHERY OF THE RIDGE TO KEEP THE MOIST SUBTROPICAL 
FLOW OUT OF THE AREA.  TIMING DIFFERENCES REMAIN FOR THE WEEKEND 
WITH THE NEXT PACIFIC STORM SYSTEM MOVING INTO THE WEST COAST AS 
RIDGE OVER THE GULF OF ALASKA WEAKENS AND LIFTS NORTHWARD.   

&&

.AVIATION...WITH THE UPPER TROUGH OVER THE REGION...GENERALLY VFR 
CONDITIONS ARE EXPECTED. PERIODS OF MVFR IN LOW CLOUDS AND -SHSN CAN 
ALSO BE EXPECTED AT TIMES AS WEAK DISTURBANCES MOVES INTO THE UPPER 
TROUGH POSITION THROUGH SUNRISE SUNDAY MORNING. STRONG AND GUSTY 
WINDS WILL DECREASE AND SHIFT MORE TO THE NORTHEAST ACROSS THE AREA 
AS THE NEXT COLD LOW PRESSURE AREA DROPS INTO OREGON OVERNIGHT. 

&&

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

$$

WEATHER.GOV/BOISE

SHORT TERM...VM
LONG TERM....CR/BB
AVIATION.....CR