797
FXUS65 KBOI 171041
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
341 AM MST SUN NOV 17 2024
SHORT TERM...TODAY THROUGH TUESDAY NIGHT
WARM FRONT
CURRENTLY IN EASTERN OREGON WILL PASS THROUGH WESTERN IDAHO
THIS MORNING THROUGH EARLY AFTERNOON WITH A RAPID RISE IN SNOW
LEVEL. SNOW WILL CHANGE TO RAIN AS HIGH AS 6000 FEET MSL NORTH
TO 7000 FEET MSL SOUTH. COLDER WIND-PROTECTED VALLEYS IN HARNEY
AND MALHEUR COUNTIES, AND IN THE OWYHEE MOUNTAINS, WILL HAVE
A SLIGHT CHANCE OF FREEZING RAIN DURING THE CHANGEOVER. THE
STORM'S COLD FRONT WILL PASS THROUGH EASTERN OREGON EARLY
THIS EVENING, WESTERN IDAHO SHORTLY BEFORE MIDNIGHT, AND SOUTH-
CENTRAL IDAHO AFTER MIDNIGHT. WINDS WILL SHIFT TO GUSTY
NORTHWEST BUT NOT STRONG ENOUGH FOR A WIND ADVISORY. SNOW LEVEL
WILL LOWER RAPIDLY BEHIND THE FRONT, DOWN TO VALLEY FLOORS BY
SUNRISE, BUT LITTLE IF ANY ACCUMULATION IS EXPECTED IN THE
SNAKE BASIN. NORTHERN MOUNTAINS WILL RECEIVE 6 TO 12 INCHES NEW
SNOW TODAY THROUGH MONDAY NIGHT, BUT ONLY 4 TO 7 INCHES AT THE
5000 FOOT LEVEL. TOTAL LIQUID EQUIVALENT THROUGH MONDAY NIGHT
WILL BE .75 TO 1.30 INCH IN THE IDAHO MOUNTAINS NORTH OF THE
SNAKE BASIN, .25 TO .75 INCH IN BAKER COUNTY, AND GENERALLY .15
TO .30 INCH IN SOUTHERN AREAS, EXCEPT UP TO .50 INCH IN THE
SOUTHERN MOUNTAINS. AFTER DRYING TUESDAY THE NEXT NORTH PACIFIC
WARM FRONT WILL SPREAD MORE PCPN ACROSS EASTERN OREGON TUESDAY
NIGHT.
LONG TERM...WEDNESDAY THROUGH SUNDAY
AN ATMOSPHERIC RIVER
WILL ARRIVE WEDNESDAY, SPREADING A SIGNIFICANT PLUME OF
MOISTURE INTO MUCH OF EAST OREGON AND WEST-CENTRAL IDAHO THROUGH
FRIDAY. PRECIPITABLE WATER VALUES ARE FORECAST TO REACH ABOVE
THE 90TH PERCENTILE (HIGH). TEMPERATURES WILL TREND WARMER EACH
DAY, PEAKING AROUND 10 DEGREES ABOVE NORMAL FRIDAY. THE LOWER
SNOW LEVELS ON WEDNESDAY WILL RAPIDLY INCREASE TO ABOVE 7000 FT
MSL THU/FRI. AS A RESULT, MOUNTAINS ARE EXPECTED TO SEE SEVERAL
INCHES OF SNOW ACCUMULATION WEDNESDAY, THEN NOTABLY LOWER
AMOUNTS AS THE MID ELEVATIONS TRANSITION TO RAIN, AND SNOW
RATIOS DECREASE FOR THE REMAINING HIGH ELEVATIONS. SOUTHEAST
TO SOUTHWEST WINDS WILL ALSO INCREASE AND CREATE BREEZY TO
WINDY CONDITIONS WED THROUGH FRI, ESPECIALLY FOR MOUNTAIN
RIDGES AND THE WESTERN SNAKE PLAIN. SOME MODEL GUIDANCE
CONTINUES A MOIST, WEST-SOUTHWEST FLOW FOR THE WEEKEND,
EXPANDING THE PRECIPITATION CHANCES ACROSS THE REST OF
SOUTHEAST OREGON AND SOUTHWEST IDAHO BOTH SAT/SUN. SNOW LEVELS
WILL LOWER SLIGHTLY TO 4500-5500 FT MSL BY SUNDAY AS A COLD
FRONT ARRIVES SOMETIME SATURDAY NIGHT. THIS COLD FRONT WILL
STRENGTHEN THE SURFACE PRESSURE GRADIENT, RESULTING IN WINDY
CONDITIONS AHEAD AND BEHIND THE FRONT.
AVIATION
WIDESPREAD RAIN/SNOW MOVING NW TO SE THROUGH EARLY
MONDAY. POCKETS OF FREEZING RAIN IN E OREGON THIS MORN. MVFR TO
LIFR IN PRECIP/LOW CEILINGS. RISING SNOW LEVELS TODAY, THEN
LOWERING TO VALLEY FLOORS BY EARLY MON. MOUNTAINS OBSCURED.
AREAS OF LOW LEVEL WIND SHEAR. SURFACE WINDS: SE-SW 5-15 KT,
INCREASING TO 10-20 KT WITH GUSTS 25-35 KT THIS AFTERNOON.
TRANSITIONING TO W-NW 10-20 KT GUSTS 25-35 KT THIS EVENING WITH
COLD FRONT. WINDS ALOFT AT 10KFT MSL: W TO SW 25-45 KT.
KBOI...CEILINGS LOWERING TO LOW VFR/MVFR LATE THIS MORNING
THRU EVENING. A 20% CHANCE OF LIGHT RAIN/SNOW THIS MORNING,
THEN RAIN EXPECTED THIS AFTERNOON. TRANSITION TO LIGHT SNOW OR
MIX MON/06Z-09Z WITH BRIEF IFR POSSIBLE, THEN PRECIPITATION
ENDING AND BECOMING VFR. SURFACE WINDS: SE 5-15 KT. INCREASING
TO 10-20 KT WITH GUSTS 25-35 KT IN AFTN/EVE. SHIFT TO NW 10-15
KT GUSTS 25-30 KT AROUND MON/06Z.
BOI WATCHES/WARNINGS/ADVISORIES
ID...NONE.
OR...NONE.
WWW.WEATHER.GOV/BOISE
INTERACT WITH US VIA SOCIAL MEDIA:
WWW.FACEBOOK.COM/NWSBOISE
WWW.TWITTER.COM/NWSBOISE
SHORT TERM...LC
LONG TERM....SH
AVIATION.....SH
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