843
FXUS65 KBOI 240928
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
328 AM MDT FRI OCT 24 2025
SHORT TERM...TODAY THROUGH SUNDAY NIGHT
ONE LAST DAY OF DRY,
MILD WEATHER BEFORE A DEEP GULF OF ALASKA UPPER TROUGH COMES IN
THIS WEEKEND. THE TROUGH WILL SEND A SURFACE COLD FRONT ACROSS
OUR CWA SATURDAY THROUGH SATURDAY EVENING, BRINGING COLDER AIR
AND WIDESPREAD RAIN AND SNOW, HEAVIEST IN NORTHERN AREAS, ALSO
ISOLATED THUNDERSTORMS, AND STRONG WIND GUSTS IN SOUTHEAST
OREGON AND THE OWYHEE MOUNTAINS SATURDAY AFTERNOON AND EVENING.
WIND MAY BE THE MOST IMPACTFUL FEATURE WITH MODELS AVERAGING 40
TO 50 MPH GUSTS FROM THE SOUTHWEST, ENOUGH FOR A WIND ADVISORY
IN HARNEY AND MALHEUR COUNTIES AND THE OWYHEE MOUNTAINS. THE
HRRR MODEL HAS 50 TO 60 MPH GUSTS OVER ALL OF EASTERN OREGON
AND ABOUT HALF OF WESTERN IDAHO BUT THAT MODEL IS A HIGH-END
OUTLIER. OUR ADVISORY REFLECTS THE MODEL CONSENSUS. TOTAL
FORECAST PCPN LATE TONIGHT THROUGH MONDAY EVENING HASN'T CHANGED
MUCH SINCE YESTERDAY, STILL RANGING FROM 1.00 TO 2.00 INCHES IN
IDAHO NORTH OF THE SNAKE BASIN, AND .30 TO .60 INCH ELSEWHERE
WITH .60 TO 1.00 INCH IN THE MOUNTAINS. SOUTHWEST WINDS ALOFT
MAY CAUSE SHADOWING IN THE SNAKE BASIN, BUT EVEN THERE AT LEAST
.30 INCH OF RAIN IS EXPECTED. SNOW LEVEL WILL STAY ABOVE 6500
FEET MSL THROUGH SATURDAY EVENING, THEN LOWER SATURDAY NIGHT
BEHIND THE COLD FRONT TO 4000 FEET NORTH TO 5000 FEET SOUTH
SUNDAY THROUGH MONDAY. SNOW WILL THEN ACCUMULATE 4 TO 12 INCHES
IN THE IDAHO MOUNTAINS NORTH OF THE SNAKE BASIN, WITH POST-
FRONTAL PCPN CONTINUING SUNDAY INTO MONDAY. MCCALL/ID SHOULD GET
3-4 INCHES NEW SNOW, WITH THE MAIN SNOWFALL SUNDAY NIGHT. HIGH
TEMPS TODAY WILL BE GENERALLY 60 TO 70 DEGREES, THEN 10 TO 15
DEGREES COLDER SATURDAY, AND ANOTHER 4 TO 8 DEGREES COLDER
SUNDAY. CLOUDS AND WINDS WILL KEEP LOW TEMPS FROM BECOMING TOO
COLD, GENERALLY UPPER 30S THROUGH 40S SATURDAY MORNING, UPPER
20S AND 30S SUNDAY, AND 20S TO MID 30S MONDAY.
LONG TERM...MONDAY THROUGH FRIDAY
PRECIPITATION CHANCES
WILL REMAIN ELEVATED COME MONDAY, AS DETERMINISTIC AND ENSEMBLE
GUIDANCE HINT AT A SHORTWAVE CROSSING OVER OUR AREA. THIS
SHORTWAVE, PAIRED WITH LINGERING MOISTURE OVER THE AREA, WILL
ALLOW FOR A 20-40% CHANCE OF PRECIPITATION SOUTHWEST OF A LINE
ROUGHLY FROM CENTERVILLE,ID TO CAMBRIDGE,ID. NORTHEAST OF THAT
LINE, CHANCES OF PRECIPITATION WILL RANGE FROM 40-60%. FOLLOWING
THE COLD FRONTAL PASSAGE IN THE SHORT TERM, SNOW LEVELS WILL BE
AT 4000-5000 FT MSL. THROUGHOUT THE DAY MONDAY, ELEVATIONS
ABOVE 5500 FT MSL IN THE WEST CENTRAL MOUNTAINS HAVE A 40-70%
CHANCE OF SEEING AT LEAST AN ADDITIONAL 4 INCHES OF SNOW
(CHANCES INCREASING WITH ELEVATION). ISOLATED SHOWERS WILL
CONTINUE OVER BAKER, VALLEY, AND ADAMS COUNTIES THROUGH
WEDNESDAY MORNING. OTHERWISE, OUR AREA IS LOOKING TO REMAIN
DRY AS A LOW-AMPLITUDE RIDGE BUILDS OVER THE GREAT BASIN.
PRECIPITATION CHANCES WILL BEGIN TO INCREASE FRIDAY AS THE NEXT
SYSTEM APPROACHES. HOWEVER, THERE IS MUCH TO BE RESOLVED IN THE
DAYS TO COME. TEMPERATURES ON MONDAY WILL BE 5-10 DEGREES BELOW
NORMAL, BEFORE INCREASING TO MORE SEASONABLE VALUES TUESDAY AND
BEYOND.
AVIATION
VFR. INCREASING HIGH CLOUDS OVERNIGHT. SURFACE
WINDS: VARIABLE UNDER 10 KT OVERNIGHT, BECOMING S-SE 10-15 KT
WITH GUSTS 20-25 KT LATE THIS MORNING/EARLY AFTERNOON. WINDS
ALOFT AT 10KFT MSL: W-NW 5-10KT, BECOMING SW 10-30 KT FRI/18Z.
KBOI...VFR. SURFACE WINDS: SE 5-10 KT OVERNIGHT, INCREASING
TO 10-15 KT WITH GUSTS UP TO 25 KT AFTER 16Z.
WEEKEND OUTLOOK...WIDESPREAD RAIN AND SNOW LATE FRIDAY NIGHT
THROUGH SUNDAY NIGHT. SNOW LEVELS LOWERING TO 4000-5000 FEET
MSL SUNDAY. AREAS OF MVFR/IFR FLIGHT CATEGORIES IN LOW CLOUDS
AND PRECIPITATION. MOUNTAINS FREQUENTLY OBSCURED. SLIGHT CHANCE
OF THUNDERSTORMS SATURDAY EVENING. PATCHY FOG IN VALLEYS THROUGH
OVERNIGHT/EARLY MORNING HOURS. SURFACE WINDS SW-SE 10-15 KT
WITH GUSTS 20-30 KT FOR MOST AREAS. LLWS POSSIBLE SATURDAY
MORNING. STRONGEST GUSTS UP TO 40 KT EXPECTED ALONG EASTERN
OR AND MOUNTAINS THROUGH SATURDAY.
PRELIMINARY POINT TEMPS/POPS
BAKER CITY 64 42 55 31 / 0 50 100 30
BOISE 70 50 61 40 / 0 10 90 90
BURNS 68 38 56 26 / 0 70 90 20
CALDWELL 70 48 62 39 / 0 20 80 70
FAIRFIELD 63 35 51 29 / 0 0 90 90
IDAHO CITY 70 37 54 29 / 0 20 100 100
JEROME 65 43 57 36 / 0 0 30 70
MCCALL 60 35 44 28 / 0 80 100 90
MOUNTAIN HOME 70 47 62 38 / 0 10 60 70
ONTARIO 66 46 62 38 / 0 30 90 60
ROME 72 44 62 32 / 0 30 60 40
TWIN FALLS 65 46 59 37 / 0 0 30 70
BOI WATCHES/WARNINGS/ADVISORIES
ID...WIND ADVISORY FROM 3 PM TO 9 PM MDT SATURDAY IDZ029.
OR...WIND ADVISORY FROM 3 PM MDT /2 PM PDT/ TO 9 PM MDT /8 PM PDT/
SATURDAY ORZ061-063.
WWW.WEATHER.GOV/BOISE
INTERACT WITH US VIA SOCIAL MEDIA:
WWW.FACEBOOK.COM/NWSBOISE
WWW.X.COM/NWSBOISE
SHORT TERM...LC
LONG TERM....NF
AVIATION.....NF
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