000
FXUS65 KBOI 130426
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
926 PM MST FRI MAR 12 2010
.DISCUSSION...FRONT IS PASSED BURNS AND BAKER CITY...MOVING EAST
AT A RAPID PACE. SHOULD PASS ONTARIO NEAR 11 PM MST...MCCALL
AROUND MIDNIGHT...THE BOISE METRO AREA BY 1 AM...MOUNTAIN HOME
ABOUT 2 AM...AND TWIN FALLS AND JEROME AROUND 4 AM. THERE WILL BE
HEAVY RAIN FOR A TIME NEAR AND AFTER FRONTAL PASSAGE. THIS COULD
LAST UP TO 2 HOURS. AFTER THAT...EXPECT SCATTERED SHOWERS FOR 6
ADDITIONAL HOURS. WINTER WEATHER ADVISORY FOR LATE TONIGHT INTO
EARLY SATURDAY STILL ON TARGET...AND WIND ADVISORY FOR SATURDAY
LOOKS GOOD AS WELL. WILL ISSUE UPDATED PRODUCTS FOR THOSE EVENTS.
OTHERWISE...NO CHANGES AT THIS TIME.
&&
.AVIATION...THE COLD FRONT WAS FROM KBKE TO NEAR KREO OREGON AT
04Z...WILL REACH KMYL-KBOI BY ABOUT 07-08Z AND NEAR KTWF BY 11Z.
RAIN AND SNOW...HEAVY AT TIMES WITHIN 100NM EITHER SIDE OF THE
FRONT WITH WIDESPREAD MVFR AND AREAS OF IFR CEILINGS. FREEZING
LEVEL NEAR 7000 MSL AHEAD OF THE FRONT DROPPING TO 4500 FT MSL
BEHIND IT. CONDITIONS BECOMING VFR SE OREGON SATURDAY MORNING AND
SW IDAHO SATURDAY AFTERNOON. MODERATE SE WINDS AHEAD OF THE FRONT
AND MODERATE NW WINDS BEHIND THE FRONT BECOMING STRONG DURING THE
DAY SATURDAY.
&&
.PREV DISCUSSION...
SHORT TERM...SOUTHEAST WINDS CURRENTLY STRONGEST NEAR MUO...
SUSTAINED 30 MPH WITH GUSTS TO 40 MPH. NOT QUITE AS WINDY ELSEWHERE
IN THE TREASURE VALLEY...AND MAGIC VALLEY HAS YET TO DEVELOP GUSTY
WINDS. THE SOUTHEAST WINDS...EXCEPT NORTHEAST NEAR JEROME...WILL
CONTINUE INTO THE EVENING AS SURFACE COLD FRONT APPROACHES FROM
OREGON. FRONT SHOULD REACH BOI AROUND MIDNIGHT TONIGHT...MAGIC
VALLEY 12Z SATURDAY. TIGHT THICKNESS PACKING AND SHARP WIND SHIFT
WILL MAKE THIS A STRONG FRONT. TEMPERATURES AND SNOW LEVEL WILL
DROP RAPIDLY BEHIND THE FRONT AND THERE WILL BE ENOUGH PCPN FOR A
WINTER WX ADVISORY FOR SNOW ABOVE THE 4500 FOOT MARK IN IDAHO ZONES
NORTH OF THE SNAKE BASIN OVERNIGHT AND SATURDAY MORNING. RAIN MAY
MIX WITH OR CHANGE TO SNOW EARLY SATURDAY MORNING IN THE TREASURE
VALLEY AND MAGIC VALLEY WITH SLUSHY ACCUMULATION LESS THAN ONE INCH
ON GRASSY AREAS. POST-FRONTAL SURFACE PRESSURE GRADIENT WILL
DEVELOP GUSTY WEST-NORTHWEST WINDS IN THE SNAKE BASIN AND SOUTH TO
THE NEVADA BORDER SATURDAY AFTERNOON...WIND ADVISORY HAS BEEN ISSUED
FOR ZONES LISTED BELOW. PCPN AND WINDS WILL DECREASE SATURDAY
EVENING AS THE COLD FRONT CONTINUES EAST. MAX TEMPS SATURDAY WILL
BE ABOUT 15F COLDER THAN TODAY...AND SATURDAY NIGHT MINS WILL BE
6-12F COLDER THAN TONIGHT/S MINS. SUNNY AND WARMING SUNDAY AS NEXT
UPPER RIDGE COMES IN FROM THE COAST.
LONG TERM...SUNDAY NIGHT THROUGH FRIDAY...A STRONG UPPER LEVEL
RIDGE WILL REMAIN OVER THE INTERMOUNTAIN WEST THROUGH TUESDAY FOR
WARMER AND DRIER CONDITIONS. RIDGE AXIS SETS UP OVER IDAHO EARLY
MONDAY THEN SHIFTS EAST TO WYOMING TUESDAY SETTING UP SOUTHEAST
FLOW IN THE VALLEY. THIS WILL MAKE TUESDAY THE WARMEST DAY WITH
HIGHS RANGING FROM LOWER 50S IN THE MOUNTAINS TO MID 60S ACROSS THE
TREASURE VALLEY. WEDNESDAY...RIDGE WEAKENS AS A BROAD UPPER LEVEL
TROUGH SLOWLY MOVES INTO THE PACIFIC NORTHWEST. THE TROUGH WEAKENS
AS IT MOVES EAST FOR CHANCES OF PRECIPITATION ACROSS NORTHERN
TERRAIN /INCLUDING BOISE MOUNTAINS/ WEDNESDAY. CANADIAN AND GFS
SHOWING UPPER RIDGE BUILDING OFF THE WEST COAST THURSDAY TROUGH
FRIDAY WITH UPPER FLOW BECOMING NORTHWESTERLY. ECMWF REMAINS THE
OUTLIER SHOWING A LOW DROPPING SOUTH AHEAD OF THE RIDGE INTO THE
REGION THURSDAY NIGHT. CONTINUED POPS ACROSS NORTHERN ZONES AS
NORTHERLY FLOW COULD BRING ENERGY INTO THE REGION LATE NEXT WEEK.
TEMPERATURES TREND BACK TOWARD CLIMO.
&&
.BOI WATCHES/WARNINGS/ADVISORIES...
ID...WIND ADVISORY FROM 11 AM TO 6 PM MST SATURDAY IDZ014>016-030.
WINTER WEATHER ADVISORY UNTIL 9 AM MST SATURDAY IDZ011-013-028.
WIND ADVISORY FROM 2 PM TO 6 PM MST SATURDAY IDZ012.
OR...WIND ADVISORY FROM 2 PM TO 6 PM MST SATURDAY ORZ064.
&&
$$
WEATHER.GOV/BOISE
DISCUSSION...SP
AVIATION.....JJ
PREV SHORT TERM...LC
PREV LONG TERM....JDS/DD
