143
FXUS65 KBOI 272010
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
210 PM MDT SUN SEP 27 2026
KEY MESSAGES
- CLOUDY SKIES AND ISOLATED LIGHT RAIN SHOWERS TONIGHT AND
MONDAY.
- CLEARING MONDAY NIGHT, THEN SUNNY WARMER DAYS TUESDAY THROUGH
FRIDAY.
- BREEZY NORTHWEST WINDS AFTERNOONS AND EVENINGS IN THE SNAKE
BASIN EAST OF BOISE THE NEXT SEVERAL DAYS.
SHORT TERM /THROUGH TUESDAY NIGHT/
A WEAK NORTHWARD-MOVING WARM FRONT HAS SPREAD CLOUDS OVER OUR CWA,
WITH A FEW LIGHT RAIN SHOWERS DETECTED BY RADAR IN NORTHERN MALHEUR
COUNTY. THIS FRONT WAS THE FORMER COLD FRONT THAT PASSED THROUGH
OUR CWA ON FRIDAY, BUT RETURNED NORTHWARD UNDER SOUTHWESTERLY FLOW
ALOFT AS A PACIFIC UPPER TROUGH REACHED THE WEST COAST. THE CURRENT
WARM FRONT DOESN'T HAVE MUCH RAIN WITH IT BUT WHAT LITTLE THERE IS
WILL BE FOCUSED OVER HARNEY COUNTY THIS EVENING, DECREASING BY
MIDNIGHT, THEN REAPPEARING OVERNIGHT AND MONDAY MORNING IN
OWYHEE COUNTY NORTHEASTWARD THROUGH THE BOISE MOUNTAINS.
INSTABILITY LOOKS TOO WEAK TO SUPPORT THUNDERSTORMS EITHER TODAY
OR MONDAY. MEANWHILE, THE UPPER TROUGH WILL CLOSE OFF A LOW AS
IT MOVES INLAND, HEADED INTO SOUTHERN CALIFORNIA MONDAY AND
ARIZONA TUESDAY. THE LOW WILL TAKE THE FRONTAL BAND EASTWARD AND
OUT OF OUR OREGON ZONES MONDAY AND OUR IDAHO ZONES MONDAY
NIGHT, BRINGING CLEARING SKIES AND COOLER NIGHTTIME TEMPS.
TUESDAY LOOKS SUNNY AND WARMER AS AN UPPER RIDGE REPLACES THE
DEPARTING LOW. WIND THIS EVENING WILL BE BREEZY NORTHWESTERLY
(15-25 MPH) BETWEEN BOISE AND TWIN FALLS, AND LIGHTER ELSEWHERE.
SIMILAR WINDS ARE EXPECTED THE NEXT SEVERAL
AFTERNOONS/EVENINGS.
LONG TERM /WEDNESDAY THROUGH SUNDAY/
HIGH PRESSURE BUILDING OFF THE FOUR CORNERS REGION WILL CONTINUE
WARM AND DRY CONDITIONS WEDNESDAY THROUGH LATE WEEK. A MOSTLY FLAT
TROUGH STEERING EAST ACROSS THE NORTHWEST REGION WILL BRING A DRY
COLD FRONT ACROSS THE AREA ON WEDNESDAY. THIS FRONTAL PASSAGE WILL
RETURN ELEVATED WIND BREEZES, MAINLY OVER THE SOUTHWEST ID SIDE.
A LARGE PACIFIC HIGH PRESSURE WILL THEN BUILD IN THURSDAY THROUGH
FRIDAY, BRINING UNSEASONABLY WARM TEMPERATURES ABOUT 10 DEGREES
ABOVE NORMAL FOR BOTH THOSE DAYS. COME LATE FRIDAY, ANOTHER MOSTLY
DRY SHORTWAVE TROUGH WILL DIG ACROSS THE NORTHWEST REGION,
RETURNING A COOLING TREND THROUGH SATURDAY. SUNDAY MAY SEE THE
RETURN OF WARMER THAN NORMAL TEMPERATURES, DEPENDING ON THE
EXTENT OF PACIFIC RIDGE BUILDING OVER THE GREAT BASIN.
AVIATION /18Z SUNDAY THROUGH MONDAY/
ISSUED 1140 AM MDT SUN SEP 27 2026
GENERALLY VFR. VIRGA AND ISOLATED RAIN SHOWERS MAINLY OVER SE
OREGON AND THE CENTRAL ID MOUNTAINS. PATCHY FOG IN SHELTERED
MOUNTAIN VALLEYS OVERNIGHT THROUGH MONDAY MORNING. SURFACE
WINDS: SW- NW 5-15 KT, WITH GUSTS TO 25 KT SOUTH/EAST OF KBOI
THIS AFTERNOON AFTER 21Z. WINDS ALOFT AT 10KFT MSL: SW 10-20 KT.
KBOI...VFR WITH DENSE MID-HIGH CLOUD COVERAGE. VIRGA/LIGHT
SHOWERS IN THE VICINITY THIS AFTERNOON.
SURFACE WINDS: NW 7-14 KT THIS AFTERNOON, WITH GUSTS TO AROUND
20 KT LATE AFTERNOON THROUGH EARLY EVENING.
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
SHORT TERM...LC
LONG TERM....JY
AVIATION.....JY
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page