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000
FXUS65 KBOI 081000
AFDBOI

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
300 AM MST SAT MAR 8 2014

.SHORT TERM...TODAY THROUGH SUNDAY...UPPER RIDGE WILL BE IN PLACE
TODAY PROVIDING THE REGION WITH MOSTLY CLEAR SKIES AND MILD
TEMPERATURES. FURTHER WEST...A VERY MOIST SOUTHWEST FLOW OFF THE
COAST WILL SHIFT INLAND TODAY AND GRADUALLY WORKS ITS WAY
EASTWARD INTO OUR AREA TONIGHT AND SUNDAY. WIDESPREAD RAIN AND
HIGH ELEVATION SNOW WILL DEVELOP OVER SOUTHEAST OREGON LATE
TONIGHT AND OVERSPREAD SOUTHWEST IDAHO ON SUNDAY. MAIN CONCERN
WILL BE WITH THE COMBINATION OF THE RAIN AND SNOWMELT IN THE
HIGHER TERRAIN...PARTICULARLY IN THE UPPER WEISER BASIN AND IN
THE BOISE/WEST CENTRAL MOUNTAINS OF SOUTHWEST IDAHO. SEE THE
HYDROLOGY SECTION BELOW FOR DETAILS.

.LONG TERM...SUNDAY NIGHT THROUGH FRIDAY...WIDESPREAD
PRECIPITATION WILL CONTINUE OVER THE REGION SUNDAY NIGHT AND
MONDAY AS AN UPPER LEVEL TROUGH MOVES INTO THE PACIFIC NORTHWEST.
AXIS OF THIS UPPER LEVEL TROUGH WILL MOVE EAST OF THE FORECAST
AREA MONDAY NIGHT WITH DECREASING PRECIPITATION FROM WEST TO EAST
ALONG WITH LOWERING SNOW LEVELS. SUNDAY NIGHT SNOW LEVELS WILL BE
BETWEEN 7000 TO 8500 FEET FALLING TO 4000 TO 5000 FEET MONDAY
NIGHT. AN UPPER LEVEL RIDGE WILL BEGIN TO BUILD ALONG THE WEST
COAST TUESDAY BUT PRECIPITATION WILL LINGER OVER THE WEST CENTRAL
AND BOISE MOUNTAINS WITH PRECIPITATION ENDING OVER ALL AREAS BY
TUESDAY EVENING. DRY CONDITIONS AND WARMING TEMPERATURES WEDNESDAY
AS THE AXIS OF THE UPPER LEVEL RIDGE MOVES OVER THE AREA. THURSDAY
NIGHT LATEST MODEL RUNS ARE NOW IN BETTER AGREEMENT WITH THE NEXT
SHORTWAVE TROUGH TO MOVE OVER THE AREA AND HAVE ALSO TRENDED
TOWARDS A WEAKER SOLUTION. PREVIOUS RUNS HAD MORE ENERGY AND
PRECIPITATION WITH THE SHORTWAVE TROUGH BUT WITH THE WEAKENING OF
THIS TROUGH AS IT MOVES OVER THE AREA LATEST MODEL TREND IS FOR
SLIGHT CHANCE POPS OVER NORTHERN ZONES AND DRY OVER SOUTHERN
ZONES. IF LATER MODELS CONTINUE THE TREND OF WEAKENING THIS
SHORTWAVE TROUGH FURTHER AS IT MOVES OVER THE AREA COULD SEE DRY
CONDITIONS CONTINUE OVER ALL AREAS INTO THURSDAY. FLAT RIDGE
BEGINS TO BUILD OVER THE AREA FRIDAY BUT SOME UNCERTAINTY AS TO
HOW MUCH MOISTURE WILL BE RIDING OVER THE TOP OF THE RIDGE. LATEST
MODEL TRENDS SHOWING MOSTLY DRY CONDITIONS FOR FRIDAY WITH SLIGHT
CHANCE POPS OVER NORTHERN ZONES...BUT CURRENT FORECAST HAS POPS
NEAR CLIMATOLOGY. WITH LOW CONFIDENCE IN THE MODELS FOR FRIDAY
WILL NOT MAKE ANY CHANGES TO POPS AT THIS TIME BUT WILL CONTINUE
TO SEE HOW THIS DEVELOPS WITH LATER MODEL RUNS. TEMPERATURES
MONDAY AND TUESDAY WILL BE NEAR NORMAL WARMING TO AROUND 5 TO 7
DEGREES ABOVE NORMAL WEDNESDAY THROUGH FRIDAY.

&&

.AVIATION...VFR. MOSTLY CLEAR SKIES THIS MORNING WITH INCREASING
HIGH LEVEL CLOUDS THIS AFTERNOON. SURFACE WINDS WILL BE LIGHT THIS
MORNING...BECOMING EAST TO SOUTH THIS AFTERNOON 5-15 KNOTS. WINDS
ALOFT UP THROUGH 10K FEET WILL BE WESTERLY AROUND 10 KNOTS THIS
MORNING...SHIFTING TO SOUTHWEST AND INCREASING TO AROUND 25 KNOTS
THIS AFTERNOON.

NEXT PACIFIC STORM SYSTEM WILL BRING WIDESPREAD PRECIPITATION TO
SOUTHEAST OREGON TONIGHT AFTER 06Z AND SPREAD INTO SOUTHWEST IDAHO
BY 12Z SUNDAY. WITH THE PRECIPITATION WILL SEE AREAS OF MOUNTAIN
OBSCURATION AND LOCAL MVFR CONDITIONS. SNOW LEVEL WILL BE HIGH
ENOUGH THAT TAF SITES WILL SEE ALL RAIN.

&&

.HYDROLOGY...A VERY MOIST SOUTHWEST FLOW WILL DEVELOP OVER THE
AREA ON SUNDAY AND CONTINUE INTO MONDAY RESULTING IN WIDESPREAD
RAIN AND HIGH ELEVATION SNOW. PRECIPITATION TOTALS OF 1-2 INCHES
ARE EXPECTED IN THE UPPER WEISER BASIN AND THE BOISE/WEST CENTRAL
MOUNTAINS. THE COMBINATION OF THE RAIN AND SNOWMELT WILL CAUSE
RUNOFF AND INCREASE THE POTENTIAL FOR ROCK/MUDSLIDES AND LOW-
LAND FLOODING. MAINSTEM RIVERS ARE EXPECTED TO REMAIN BELOW FLOOD
STAGE...ALTHOUGH THE WEISER RIVER AT WEISER IS FORECAST TO CREST
TO WITHIN A HALF A FOOT OF FLOOD STAGE MONDAY NIGHT. A FLOOD WATCH
MAY BE ISSUED FOR PORTIONS OF SOUTHWEST IDAHO LATER TODAY. FOR
MONITORING RIVER STAGES AND FORECASTS ON THE WEB...VISIT
WATER.WEATHER.GOV/AHPS.

&&

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

&&

$$

WEATHER.GOV/BOISE

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