306
FXUS65 KBOI 222350
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
550 PM MDT THU OCT 22 2026
UPDATE
UPDATED AVIATION DISCUSSION.
KEY MESSAGES
- WIDESPREAD PRECIPITATION THROUGH FRIDAY MORNING, ALONG WITH
ISOLATED TO SCATTERED THUNDERSTORMS.
- THUNDERSTORMS THROUGH THIS EVENING WILL BE CAPABLE OF
PRODUCING GUSTY WINDS AND BRIEF HEAVY RAIN, AND SMALL HAIL IN
SOUTHWEST IDAHO.
- WINDY CONDITIONS WILL DEVELOP LATE TONIGHT AND TOMORROW
BEHIND A COLD FRONT, WITH MUCH COOLER CONDITIONS FRIDAY AND
SATURDAY.
SHORT TERM /THROUGH SATURDAY NIGHT/
ISSUED 254 PM MDT THU OCT 22 2026
AN AREA OF SHOWERS AND THUNDERSTORMS HAS DEVELOPED ACROSS SW
IDAHO THIS AFTERNOON, EXTENDING FROM THE OR/ID BORDER INTO
S-CENTRAL IDAHO. THE MID-LEVEL FEATURE TRIGGERING THIS ACTIVITY
WILL CONTINUE NORTHWARD THROUGH THIS EVENING, EXTENDING THE
COVERAGE OF SHOWERS/STORMS ALONG ITS PATH. THE SHOWERS/STORMS
WILL BRING GUSTY WINDS AND MODERATE RAINFALL. WHILE THE SEVERE
WIND THREAT HAS DIMINISHED SOME, STRONGER THUNDERSTORMS WILL BE
CAPABLE OF WIND GUSTS TO 50 MPH AND BRIEF HEAVY RAIN THROUGH
EARLY EVENING. SHOWERS CONTINUE OVERNIGHT, WITH A 10-15% CHANCE
OF THUNDERSTORMS OVER PORTIONS OF SW IDAHO (MAINLY THE W-CENTRAL
ID MTNS). WHILE THE WIND THREAT DIMINISHES THIS EVENING, BRIEF
HEAVY RAIN WILL STILL BE POSSIBLE FROM STORMS OVERNIGHT AND THE
THREAT FOR FLOODING OR DEBRIS FLOWS ON BURNS SCARS REMAINS A
RISK.
THE SURFACE COLD FRONT WILL CROSS THE AREA LATER TONIGHT,
ARRIVING WITH GUSTY NORTHWEST WINDS. WIDESPREAD GUSTS OF 30 TO
40 MPH, WILL DEVELOP ACROSS SE OREGON AND SW IDAHO FROM THE
SNAKE PLAIN TO THE NV BORDER. LOCAL GUSTS OF 45 TO 55 MPH WILL
IMPACT WINDIER LOCATIONS OF BAKER AND NORTHERN MALHEUR COUNTIES
THROUGH SUNRISE FRIDAY. THE UPPER LOW LIFTS TO THE NORTHEAST ON
FRIDAY WITH PRECIPITATION TAPERING OFF FROM W-E DURING THE
AFTERNOON. POST FRONTAL NORTHWEST WINDS WILL REMAIN GUSTY WITH
SPEEDS OF 30-40 MPH THROUGH EVENING. SNOW LEVELS WILL DROP TO
BETWEEN 4500-6000 FEET OVER OREGON AND BETWEEN 6-8KFT OVER SW
IDAHO AS PRECIPITATIONS WRAPS UP ON FRIDAY. MINOR ACCUMULATIONS
ARE POSSIBLE OVER HIGHER PEAKS.
SATURDAY WILL SEE DRY AND COOL CONDITIONS WITH BREEZY NORTHWEST
WINDS. IT COULD START OFF FROSTY AT LOWER ELEVATIONS, THOUGH
THE BREEZY WINDS COULD KEEP IT LOCALIZED.
LONG TERM /SUNDAY THROUGH THURSDAY/
ISSUED 254 PM MDT THU OCT 22 2026
A SHORT LIVED HIGH PRESSURE SYSTEM WILL CONTINUE TO BUILD IN
OVER THE REGION SUNDAY, BRINGING SLIGHTLY WARMER TEMPERATURES
AND DRY CONDITIONS THROUGH MONDAY MORNING. CLEAR SKIES OVERNIGHT
PAIRED WITH THE RECENT PRECIPITATION WILL ALLOW FOR VALLEY FOG
TO FORM LATE SUNDAY NIGHT AND AGAIN ON MONDAY NIGHT, BUT IT
SHOULD DISSIPATE BY THE LATE MORNING. A CUT OFF LOW PRESSURE
SYSTEM FROM THE GULF OF ALASKA WILL MOVE IN LATE MONDAY-EARLY
TUESDAY, BRINGING WIDESPREAD PRECIPITATION AND COOLER
TEMPERATURES TO THE REGION. DISAGREEMENT IN THE TIMING OF THE
LOW PRESSURE SYSTEM EXISTS, WITH MOST MODELS PUSHING
PRECIPITATION AND COOLER TEMPERATURES LATE MONDAY, WHILE A FEW
OUTLIER SOLUTIONS DELAY THE ARRIVAL TO TUESDAY MORNING. CURRENT
FORECAST FAVORS HIGH TERRAIN IN NORTHEAST OREGON AND CENTRAL
IDAHO FOR THE BEST CHANCE OF PRECIPITATION (30-50% CHANCE)
THROUGH THURSDAY, WITH SNOW LEVELS ANTICIPATED TO BE AROUND
6000-7000 FEET. THE LOW WILL THEN PUSH TO THE EAST, ALLOWING FOR
ANOTHER RIDGE OF HIGH PRESSURE TO BUILD IN BY THURSDAY,
BRINGING ANOTHER SLIGHT WARMING AND DRYING TREND FOR THE REGION.
AVIATION /00Z FRIDAY THROUGH SATURDAY/
ISSUED 548 PM MDT THU OCT 22 2026
WIDESPREAD RAIN SHOWERS AND SCATTERED T-STORMS MOVING FROM
SOUTH TO NORTH THIS EVENING, WITH WIDESPREAD RAIN SHOWERS
CONTINUING THROUGH FRIDAY AFTERNOON. GUSTY OUTFLOW WINDS UP TO
50 KT, SMALL HAIL, AND HEAVY RAINFALL WILL REMAIN POSSIBLE IN
STRONGER T-STORMS, MAINLY IN SOUTHWEST ID. MOUNTAINS OBSCURED IN
RAIN AND LOWERING CEILINGS. SURFACE WINDS:
S-E 5-12 KT WITH GUSTS 20-25 KT. COLD FRONT TONIGHT SHIFTING
WINDS OUT OF THE W-NW 15-25 KT WITH GUSTS 30-40 KT AFTER
FRI/06Z. WINDS ALOFT AT 10KFT: S 15-30 KT.
KBOI...VFR. WIDESPREAD RAIN SHOWERS AND ISOLATED EMBEDDED
THUNDERSTORMS THROUGH THE EVENING. HEAVY RAIN, SMALL HAIL, AND
GUSTY OUTFLOW WINDS NEAR 40 KT POSSIBLE IN STRONGER STORMS.
SURFACE WINDS: SE 8-15 KT WITH GUSTS 20-25 KT IN THE EVENING,
SHIFTING NW 10-15 KT WITH GUSTS UP TO 25 KT FOLLOWING COLD FRONT
LATE TONIGHT AND AFTER.
WEEKEND OUTLOOK...AREAS OF MVFR-IFR IN RAIN/SNOW MIX ACROSS SW
IDAHO THROUGH SATURDAY AM. SNOW LEVELS BEHIND THE FRONT WILL
DROP TO 5000-6500 FT MSL, WHILE PRECIPITATION TAPERS OFF LATE
FRIDAY. AREAS OF VALLEY FOG WILL FORM EACH MORNING, OTHERWISE
VFR. SURFACE WINDS: W-NW 10-20 KT WITH GUSTS 30-40 KT FRIDAY,
THEN LIGHT AND VARIABLE UNDER 12 KTS THROUGH SUNDAY.
BOI WATCHES/WARNINGS/ADVISORIES
ID...FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR IDZ013.
OR...NONE.
WWW.WEATHER.GOV/BOISE
INTERACT WITH US VIA SOCIAL MEDIA:
WWW.FACEBOOK.COM/NWSBOISE
WWW.X.COM/NWSBOISE
AVIATION.....JY
SHORT TERM...DG
LONG TERM....SA
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