221
FXUS65 KBOI 030358
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
858 PM MST TUE DEC 2 2025
DISCUSSION
LIGHT SHOWERS ASSOCIATED WITH A CONVERGENCE ZONE
IN THE MAGIC VALLEY WILL PERSIST THROUGH THIS EVENING. WHILE ITD
WEB CAMERAS SHOWED LIGHT SNOW NEAR HAZELTON, ID, NOTHING HAS
BEEN REPORTED FURTHER WEST AT JEROME OR TWIN FALLS AS OF 8 PM
MST. ELSEWHERE, SKIES ARE CLEARING AS THE SYSTEM EXITS THE
REGION. WEST TO NORTHWEST WINDS CONTINUE, THOUGH SPEEDS HAVE
DECREASED COMPARED TO EARLIER THIS AFTERNOON.
FOR WEDNESDAY MORNING, SOME HIGH-RESOLUTION GUIDANCE CONTINUES
TO SUGGEST STRATUS AND FOG DEVELOPMENT IN THE SNAKE RIVER PLAIN,
EXTENDING FROM THE WESTERN MAGIC VALLEY THROUGH THE UPPER
TREASURE VALLEY. HOWEVER, THERE IS CONSIDERABLE SKEPTICISM
REGARDING THIS EXTENT, ESPECIALLY FOR FOG, GIVEN THE PERSISTENT
WESTERLY WINDS AND LACK OF ADDITIONAL SURFACE MOISTURE TODAY.
THE LAST THREE RUNS OF THE HRRR AND THE RRFS HAVE BACKED OFF ON
FOG AND STRATUS IN THE TREASURE VALLEY, LIMITING THE EXTENT TO
THE NORTHERN PARTS OF THE WESTERN MAGIC VALLEY (INCLUDING
JEROME) AND ALONG THE FOOTHILLS OF THE CENTRAL IDAHO MOUNTAINS
NORTH OF MOUNTAIN HOME.
THIS SCENARIO APPEARS FAR MORE LIKELY GIVEN THE CURRENT
PRECIPITATION FOOTPRINT AND LOW CEILINGS. CONSEQUENTLY, THERE IS
HIGH CONFIDENCE (80% CHANCE) IN STRATUS AND FOG ACROSS THE
WESTERN MAGIC VALLEY, WHICH COULD IMPACT THE WEDNESDAY MORNING
COMMUTE. CONVERSELY, THERE IS LOW CONFIDENCE (30% CHANCE) IN
DEVELOPMENT FURTHER WEST ACROSS THE TREASURE VALLEY. THE CURRENT
FORECAST REFLECTS THIS REASONING WELL, SO NO UPDATES ARE NEEDED
AT THIS TIME.
AVIATION
SNOW SHOWERS AND LOW CEILINGS NEAR THE MAGIC VALLEY
RESULTING IN MVFR/IFR CONDITIONS. SHOWERS ENDING AROUND WED/06Z.
PATCHY FOG/LOW STRATUS DEVELOPING AFTER WED/06Z RESULTING IN
IFR/LIFR CONDITIONS, HIGHEST CONFIDENCE IN THE MAGIC VALLEY NEAR
KJER. SURFACE WINDS: W-NW 5-15, BECOMING VARIABLE UP TO 13 KT
OVERNIGHT. WINDS ALOFT AT 10KFT MSL: N-NW 15-30 KT.
KBOI...MAINLY VFR. FOG/LOW STRATUS POSSIBLE RESULTING IN IFR/LIFR
CONDITIONS (30% CHANCE) EARLY WEDNESDAY MORNING. CONFIDENCE ON
FOG/LOW STRATUS DEVELOPMENT IS LOW. SURFACE WINDS: NW 8-12 KT,
BECOMING LIGHT AND VARIABLE AFTER WED/12Z.
PREV DISCUSSION
SHORT TERM...TONIGHT THROUGH THURSDAY NIGHT...A COLD FRONT AND
UPPER LEVEL TROUGH CONTINUES TO MOVE SOUTHEAST TODAY, WITH
LINGERING RAIN AND SNOW SHOWERS OVER THE AREA. SHOWERS WILL
TAPER OFF AFTER SUNSET. THE SYSTEM WILL BRING AREAS OF LOW
CLOUDS AND FOG TO THE AREA TONIGHT AND ON WEDNESDAY AS UPPER
LEVEL RIDGING BUILDS IN BEHIND THE COLD FRONT. THE RIDGE WILL
REMAIN OVER THE AREA THROUGH THURSDAY BEFORE THE NEXT SYSTEM
ARRIVES FROM THE NORTHWEST. SNOW IS EXPECTED OVER THE WEST
CENTRAL ID MOUNTAINS AND BLUE MOUNTAINS THURSDAY AFTERNOON AND
EVENING. SNOW ACCUMULATIONS OF 2-4 INCHES EXPECTED THURSDAY
EVENING.
LONG TERM...FRIDAY THROUGH TUESDAY...AN ACTIVE PATTERN IS
FORECASTED FOR THIS WEEKEND. AN UPPER-LEVEL RIDGE WILL FURTHER
BUILD INTO THE EASTERN PACIFIC, WITH MOISTURE AND UPPER-LEVEL
SHORTWAVE DISTURBANCES MOVING THROUGH THE AREA THROUGH THE LONG
TERM. POPS WILL BE ACTIVE FOR MUCH OF THE LONG TERM WITH THESE
DISTURBANCES. SNOW LEVELS WILL RISE FROM AROUND 4000-6000 FEET
FRIDAY MORNING (STARTING AS SNOW IN MOUNTAIN VALLEYS) TO AROUND
5500-7000 FEET FRIDAY NIGHT, AND POSSIBLY AS HIGH AS 8000 FEET
AS THE WARM FRONT PASSES THROUGH LATE IN THE DAY. SATURDAY AND
BEYOND, SNOW LEVELS WILL FLUCTUATE SLIGHTLY WITH PASSING
SYSTEMS, BUT SHOULD AVERAGE AROUND 5000-7000 FEET. PRECIPITATION
WILL LET UP ON MONDAY AS THE UPPER-LEVEL RIDGE AXIS BUILDS
CLOSER TO THE REGION, HOWEVER PRECIPITATION LOOKS TO RETURN
TUESDAY WITH ANOTHER UPPER-LEVEL SHORTWAVE PASSAGE. TEMPERATURES
FRIDAY THROUGH TUESDAY SHOULD AVERAGE AROUND 10 DEGREES ABOVE
NORMAL, AND PASSING SYSTEMS WILL BRING BREEZY CONDITIONS.
BOI WATCHES/WARNINGS/ADVISORIES
ID...NONE.
OR...NONE.
WWW.WEATHER.GOV/BOISE
INTERACT WITH US VIA SOCIAL MEDIA:
WWW.FACEBOOK.COM/NWSBOISE
WWW.X.COM/NWSBOISE
DISCUSSION...JDS
AVIATION.....NF
SHORT TERM...KA
LONG TERM....CH
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