120
FXUS65 KBOI 081221
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
621 AM MDT WED JUL 8 2026
UPDATE
UPDATED AVIATION DISCUSSION.
KEY MESSAGES
- ISOLATED TO SCATTERED THUNDERSTORMS THIS AFTERNOON AND EVENING
ACROSS PORTIONS OF SOUTHERN IDAHO. STORMS MAY PRODUCE OUTFLOW
WIND GUSTS UP TO 40-60 MPH, POSSIBLY MOVING THROUGH THE
TREASURE AND MAGIC VALLEYS.
- GUSTY WINDS LATE THIS AFTERNOON AND EVENING, WITH BREEZY
CONDITIONS CONTINUING EACH AFTERNOON THROUGH THE WEEK.
- HOT TEMPERATURES CONTINUE, HOTTEST FRIDAY AND SATURDAY.
- SHOWER AND THUNDERSTORM CHANCES RETURN EARLY NEXT WEEK.
SHORT TERM /THROUGH FRIDAY NIGHT/
ISSUED 348 AM MDT WED JUL 8 2026
MOISTURE WILL LINGER OVER SOUTHWEST IDAHO TODAY UNDER
SOUTHWESTERLY FLOW ALOFT, BRINGING ANOTHER ROUND OF ISOLATED TO
SCATTERED AFTERNOON AND EVENING THUNDERSTORMS. THUNDERSTORMS
WILL DEVELOP ALONG THE HIGHER TERRAIN SOUTH OF THE SNAKE RIVER
IN FAR SOUTHERN IDAHO AND LIFT NORTHEAST. STORMS ARE EXPECTED
TO WEAKEN UPON REACHING THE SNAKE BASIN, BUT A FEW STORMS WILL
PERSIST AS THEY ENTER THE MAGIC VALLEY AND SOUTHERN BOISE
MOUNTAINS. LIGHTNING AND GUSTY WINDS 40-60 MPH WILL BE THE
PRIMARY HAZARDS FROM STORMS, WITH LOCALIZED BLOWING DUST
POSSIBLE FROM OUTFLOWS. BRIEF HEAVY RAIN IS ALSO POSSIBLE IN
STRONGER STORMS. THUNDERSTORMS SHOULD TRACK TO THE EAST OF THE
BOISE METRO, BUT OUTFLOW GUSTS TO 40 MPH FROM DISTANT STORMS ARE
POSSIBLE.
OTHERWISE TODAY, EXPECT SIMILAR TEMPERATURES TO YESTERDAY WITH
HIGHS IN THE MID TO UPPER 90S IN THE LOWER ELEVATIONS WITH 80S
TO LOWER 90S IN MOUNTAIN VALLEYS. LATE THIS AFTERNOON AND
EVENING, NORTHWEST WIND GUSTS 20-35 MPH WILL DEVELOP IN MANY
AREAS AS AN UPPER TROUGH OVER BRITISH COLUMBIA TRACKS EAST AND
SENDS A WEAK, DRY COLD FRONT THROUGH OUR AREA. BREEZY CONDITIONS
WITH GUSTS 15-30 MPH WILL CONTINUE INTO THURSDAY, STRONGEST
ACROSS SOUTHERN IDAHO. BREEZY AND DRY CONDITIONS WILL RESULT IN
ELEVATED FIRE WEATHER CONDITIONS. WESTERLY FLOW ALOFT WILL PUSH
MOISTURE AND THE ACCOMPANYING THUNDERSTORM THREAT TO OUR EAST.
HIGH TEMPERATURES WILL COOL BY 3-5 DEGREES. ON FRIDAY, A STRONG
UPPER LEVEL RIDGE OVER THE DESERT SOUTHWEST WILL BEGIN TO BUILD
NORTH, BRINGING HOTTER TEMPERATURES. LOWER VALLEYS WILL REACH
THE UPPER 90S TO AROUND 100 DEGREES. FOR BOISE, THERE IS AROUND
A 50-60% CHANCE OF REACHING TRIPLE DIGITS FOR THE FIRST TIME
THIS SEASON. SOUTHWEST FLOW ALOFT WILL BRING BREEZY CONDITIONS
TO THE HIGHER TERRAIN.
LONG TERM /SATURDAY THROUGH WEDNESDAY/
ISSUED 348 AM MDT WED JUL 8 2026
THE CENTER OF A STRONG UPPER LEVEL RIDGE WILL MOVE ACROSS THE
ROCKY MOUNTAINS AND INTO THE NORTHERN PLAINS THIS WEEKEND INTO
EARLY NEXT WEEK. TEMPERATURES WILL REMAIN VERY HOT ON SATURDAY
WITH LOWER VALLEY HIGHS AROUND 100 DEGREES. TEMPERATURES SHOULD
COOL A COUPLE DEGREES FOR THE REST OF THE PERIOD AS THE RIDGE
AXIS MOVES EAST. HOWEVER, A SLIGHT SHIFT WEST OF THE RIDGE WOULD
PRODUCE HOTTER TEMPERATURES. EXPECT LOCALLY BREEZY CONDITIONS
EACH AFTERNOON.
ENSEMBLES ARE IN EXCELLENT AGREEMENT THAT MONSOONAL MOISTURE
WILL WORK ITS WAY NORTH AROUND THE RIDGE INTO OUR AREA EARLY
NEXT WEEK. THIS WILL REINTRODUCE THE POTENTIAL FOR SHOWERS AND
THUNDERSTORMS, ESPECIALLY ACROSS THE HIGHER TERRAIN. AN INCREASE
OF CLOUDS AND PRECIPITATION WILL ALSO LIKELY AID IN THE SLIGHT
COOLDOWN. ENSEMBLE MEAN PRECIPITABLE WATER VALUES CLIMB TO
150-200% OF NORMAL, OR ABOVE THE 90TH PERCENTILE. HEAVY RAINFALL
AND FLASH FLOODING ESPECIALLY ON RECENT BURN SCARS COULD BE A
CONCERN WITH DEEP MOISTURE IN PLACE. ADDITIONALLY, AFTER A
PERIOD OF HOT, DRY CONDITIONS, LIGHTNING ON DRY FUELS COULD BE
A CONCERN FOR NEW FIRE STARTS, ESPECIALLY IF SIGNIFICANT
RAINFALL ENDS UP BEING MORE LIMITED.
AVIATION /12Z WEDNESDAY THROUGH THURSDAY/
ISSUED 605 AM MDT WED JUL 8 2026
MAINLY VFR. ISOLATED TO SCATTERED THUNDERSTORMS THIS AFTERNOON
AND EVENING, MAINLY ACROSS FAR SOUTHWEST AND SOUTH-CENTRAL
IDAHO, IMPACTING THE MAGIC VALLEY TERMINALS. STORMS CAPABLE OF
30-50 KT OUTFLOWS, BRIEF HEAVY RAIN, AND BLOWING DUST. LOCALIZED
TERRAIN OBSCURATION FROM WILDFIRE SMOKE. HIGH DENSITY ALTITUDE
THIS WEEK DUE TO HEAT. SURFACE WINDS OUTSIDE OF STORMS: VARIABLE
LESS THAN 10 KT THIS MORNING, BECOMING W-NW 5-15 KT THIS
AFTERNOON. GUSTS TO 25 KT LATE AFTERNOON AND EVENING, EXCEPT
25-35 KT KBKE-KONO. WINDS ALOFT AT 10KFT MSL: VARIABLE OR SW-W
5-15 KT.
KBOI...VFR. A 30% CHANCE OF SHOWER/THUNDERSTORM OUTFLOWS (30-40
KT) REACHING KBOI AFTER WED/23Z. MINOR VISIBILITY REDUCTIONS
DUE TO WILDFIRE SMOKE THIS MORNING, WITH FOOTHILLS OBSCURED IN
SMOKE AT TIMES FROM FIRE ACTIVITY. HIGH DENSITY ALTITUDE THIS
WEEK DUE TO HEAT. SURFACE WINDS: SE 5-10 KT THIS MORNING,
BECOMING NW 8-13 KT WITH GUSTS TO 20 KT BY WED/21Z. WINDS ALOFT
AT 10KFT MSL OVER KBOI: SW-W 10-15 KT.
BOI WATCHES/WARNINGS/ADVISORIES
ID...RED FLAG WARNING FROM 1 PM THIS AFTERNOON TO 8 PM MDT THIS
EVENING FOR IDZ423-426.
OR...NONE.
WWW.WEATHER.GOV/BOISE
INTERACT WITH US VIA SOCIAL MEDIA:
WWW.FACEBOOK.COM/NWSBOISE
WWW.X.COM/NWSBOISE
AVIATION.....ST
SHORT TERM...ST
LONG TERM....ST
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