318
FXUS65 KBOI 101730
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
1130 AM MDT SAT OCT 10 2026
UPDATE
UPDATED AVIATION DISCUSSION.
KEY MESSAGES
- MUCH COOLER TEMPERATURES SATURDAY. SUNDAY AND MONDAY WILL SEE
TEMPERATURES 5 TO 10 DEGREES BELOW NORMAL.
- ACTIVE PATTERN BRINGING PRECIPITATION CHANCES SATURDAY THROUGH
TUESDAY. SNOW SHOWERS IN ELEVATIONS ABOVE 6000-8000 FEET THIS
WEEKEND.
- SIGNIFICANT RAINFALL POSSIBLE IN SOUTH-CENTRAL AND SOUTHEAST
IDAHO LATE SATURDAY THROUGH TUESDAY.
- RETURN OF WARMER AND DRIER CONDITIONS WEDNESDAY THROUGH LATE
WEEK.
SHORT TERM /THROUGH MONDAY NIGHT/
ISSUED 312 AM MDT SAT OCT 10 2026
THE CLOSED UPPER LOW WILL DIG FURTHER INTO THE NORTHWEST REGION
TODAY THROUGH SUNDAY, WITH THE LOW CENTER SLOWLY MOVING INTO CENTRAL
OR. MUCH COOLER CONDITIONS, ALONG WITH SOME BREEZY NORTHWEST WINDS,
ARE EXPECTED THROUGHOUT THE WEEKEND. THE LOW'S EAST SIDE WILL
STEER ABUNDANT MOISTURE FROM THE REMNANTS OF TROPICAL STORM
RACHEL INTO THE GREAT BASIN AND UPPER ROCKIES REGIONS, WITH THE
BULK OF THE MOISTURE EXPECTED TO ARRIVE OVER EASTERN/CENTRAL ID
LATE SATURDAY AND CONTINUING THROUGH MONDAY. THE HEAVIEST
PRECIPITATION IS STILL EXPECTED OVER THE EASTERNMOST PORTIONS OF
OUR CWA, MAINLY OVER THE WESTERN MAGIC VALLEY, THE BOISE
MOUNTAINS, AND THE SOUTHERN ID HIGHLANDS IN PARTICULAR. FROM
SATURDAY TO LATE MONDAY, THE AFOREMENTIONED AREAS WILL
POTENTIALLY SEE TOTAL RAINFALLS OF 0.70- 0.90 INCHES. WITH SNOW
LEVELS EXPECTED TO DROP INTO THE 4000-5500 FT MSL RANGE IN
EASTERN OR AND THE 6000-8500 FT MSL RANGE IN SOUTHWEST ID BY
SUNDAY, SNOW/WINTRY MIX SHOWERS ARE STILL EXPECTED OVER HIGH
TERRAIN AREAS MAINLY ON THE ID SIDE, WITH ACCUMULATIONS HEAVILY
LIMITED TO HIGH PEAKS.
LATE SUNDAY INTO EARLY MONDAY, THERE REMAINS SOME GUIDANCE
UNCERTAINTY OVER THE UPPER LOW'S MOVEMENT PATTERN, BUT IT WILL
GENERALLY DIG FURTHER DOWN INTO THE GREAT BASIN AS IT TREKS
EAST. BOTH SUNDAY AND MONDAY WILL SEE TEMPERATURES 5 TO 10
DEGREES BELOW NORMAL FROM THIS PATTERN. THE UPPER LOW'S
MOISTURE ADVECTION WILL GRADUALLY WEAKEN THROUGH MONDAY. THE
MAGIC VALLEY AND THE SOUTH-CENTRAL ID MOUNTAINS WILL GENERALLY
SEE LOWER PRECIPITATION CHANCES (30-40%) BY LATE MONDAY.
LONG TERM /TUESDAY THROUGH SATURDAY/
ISSUED 312 AM MDT SAT OCT 10 2026
COME TUESDAY, THE CLOSED UPPER LOW WILL SIT JUST SOUTH OF OUR
AREA OVER THE GREAT BASIN AS IT SLOWLY STEERS OUT EAST. THERE IS
SOME UNCERTAINTY TO THE EXTENT OF REMNANT MOISTURE CARRIED BY
THE SHIFTING LOW, BUT TUESDAY WILL GENERALLY SEE A 15-35% CHANCE
OF PRECIPITATION ACROSS THE WESTERN MAGIC VALLEY, BOISE
MOUNTAINS, AND SOUTHERN IDAHO HIGHLANDS AS IT MOVES OFF TO THE
EAST. THANKS TO THE SOUTHERLY FLOW ALOFT, HIGHER SNOW LEVELS
WILL LIMIT ANY DUSTING OF SNOW TO ELEVATIONS ABOVE 7000 FEET,
WITH LITTLE ACCUMULATION ANTICIPATED.
A WARMING AND DRYING TREND WILL SET IN BEYOND TUESDAY AS A FOLLOWING
RIDGE BUILDS INTO THE AREA. A SHORTWAVE TROUGH FROM BRITISH COLUMBIA
WILL DIG NORTH OF OUR AREA LATE WEDNESDAY THROUGH THURSDAY, BUT KEEP
OUR AREA ON THE DRY SIDE. THURSDAY THROUGH SATURDAY, A HIGHLY
AMPLIFIED PACIFIC RIDGE WILL BUILD IN AND RETURN A SLOW WARMING
TREND. TEMPERATURES 5 TO 10 DEGREES ABOVE NORMAL WILL BE POSSIBLE
FRIDAY AND SATURDAY.
AVIATION /18Z SATURDAY THROUGH SUNDAY/
ISSUED 1130 AM MDT SAT OCT 10 2026
GENERALLY VFR. ISOLATED SHOWERS THIS AFTERNOON IN SW-IDAHO, WITH
ISOLATED THUNDER MAINLY S-E OF KTWF. PRECIPITATION INCREASING
FROM SE TO NW SUN/AM INTO SUN/PM, MAINLY EAST AND SOUTH OF A
KMYL/KONO/KBNO LINE. MVFR AND MTN OBSCURATION POSSIBLE IN
PRECIP. SURFACE WINDS: W-NW 5-15 KT WITH GUSTS TO 20-25 KT.
WINDS ALOFT AT 10 KFT MSL: SW 20-30 KT.
KBOI...VFR UNDER FEW TO SCT CLOUDS THIS AFTERNOON, CLOUDS
INCREASING THIS EVENING. A 30% CHANCE OF RAIN THIS EVENING.
SURFACE WINDS: NW 5-15 KT THROUGH THE PERIOD, WITH GUSTS TO
AROUND 22 KT THIS AFTERNOON.
SUNDAY OUTLOOK...PRECIPITATION EXPANDING FROM THE ID-NV BORDER
THROUGH S-CENTRAL AND CENTRAL IDAHO SUNDAY. PERIODS OF
SNOW/WINTRY MIX OVER HIGHER TERRAIN. MVFR/IFR CONDITIONS AND
MOUNTAIN OBSCURATION POSSIBLE IN PRECIP. SNOW LEVELS: 6-9 KFT
MSL IN SW IDAHO. SURFACE WINDS: SURFACE WINDS: W-N 5-15 KT WITH
GUSTS 20-30 KT.
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
AVIATION.....NF
SHORT TERM...JY
LONG TERM....JY
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