603
FXUS65 KBOI 231734
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
1134 AM MDT THU JUL 23 2026
UPDATE
UPDATED AVIATION DISCUSSION.
KEY MESSAGES
- SCATTERED SHOWERS AND THUNDERSTORMS TODAY ACROSS FAR EASTERN
OREGON AND FAR WESTERN IDAHO, WITH GUSTY WINDS, LIGHTNING,
BRIEF HEAVY RAIN, AND SMALL HAIL POSSIBLE.
- VERY HOT, DRY, AND BREEZY TO END THE WEEK.
- AREAS OF SMOKE WILL CONTINUE THROUGH THE WEEK.
SHORT TERM /THROUGH SATURDAY NIGHT/
ISSUED 353 AM MDT THU JUL 23 2026
AN UPPER LEVEL LOW WILL SPIN OFF THE COAST TODAY WHILE AN UPPER
LEVEL RIDGE BEGINS TO MOVE TO THE EAST. THIS WILL USHER IN
SOUTHWESTERLY FLOW ALOFT, WHICH WILL BEGIN TO PUSH OUT DEEPER
MONSOONAL MOISTURE. HOWEVER, AN AREA OF MOISTURE AND INSTABILITY
LOCATED OVER CENTRAL OREGON THIS MORNING WILL MOVE OVER THE
IDAHO/OREGON BORDER THIS AFTERNOON AND EARLY EVENING BEFORE
DRIER AIR ARRIVES. STRONG DAYTIME HEATING WILL ALLOW SCATTERED
SHOWERS AND THUNDERSTORMS TO DEVELOP ACROSS FAR EASTERN OREGON
AND FAR WESTERN IDAHO, THEN DRIFT NORTHEAST. FORECAST SOUNDINGS
REVEAL HIGHER INSTABILITY IN THE TREASURE VALLEY TODAY THAN
PREVIOUS DAYS, INDICATING POTENTIAL FOR STORMS TO REACH THE
BOISE METRO AREA. GUSTS UP TO 40-60 MPH WILL BE POSSIBLE ALONG
WITH FREQUENT LIGHTNING, BRIEF HEAVY RAIN, AND SMALL HAIL.
SOUTHWEST FLOW WILL ALSO BRING HOTTER TEMPERATURES WITH LOWER
VALLEYS REACHING 100-105 DEGREES, WITH A HEAT ADVISORY BEGINNING
THIS AFTERNOON DUE TO HEAT-RELATED IMPACTS. WINDS WILL BECOME
BREEZY ACROSS SOUTH-CENTRAL OREGON THIS AFTERNOON WITH GUSTS TO
25 MPH. WILDFIRE SMOKE WILL PERSIST ACROSS THE AREA TODAY WITH
SOME IMPROVEMENT IN THE AFTERNOON.
ON FRIDAY AND SATURDAY, VERY DRY AIR WILL ARRIVE FROM THE WEST
AS THE LOW SLOWLY APPROACHES THE COAST AND SOUTHWEST FLOW ALOFT
INCREASES. WINDS WILL BECOME BREEZY EACH AFTERNOON, STRONGEST
ON SATURDAY AS THE UPPER LEVEL LOW MOVES INTO WESTERN
WASHINGTON. GUSTS SATURDAY ACROSS SOUTHEAST OREGON AND THE
HIGHER ELEVATIONS OF SOUTHWEST IDAHO COULD REACH 30-40 MPH. VERY
DRY AIR COMBINED WITH GUSTY WINDS MAY BRING CRITICAL FIRE
WEATHER CONDITIONS. TEMPERATURES WILL REMAIN VERY HOT,
ESPECIALLY ON FRIDAY WHEN SOME LOWER VALLEY LOCATIONS WILL
APPROACH 107 DEGREES. SHOWER AND THUNDERSTORM POTENTIAL (10-20%
CHANCE) WILL BE LIMITED TO SOUTH-CENTRAL IDAHO, WHERE MONSOONAL
MOISTURE WILL HANG ON FOR A COUPLE MORE DAYS. WILDFIRE SMOKE
WILL LINGER OVER THE AREA, MAINLY EACH NIGHT AND MORNING WITH
DAYTIME MIXING IMPROVING AFTERNOON CONDITIONS.
LONG TERM /SUNDAY THROUGH THURSDAY/
ISSUED 353 AM MDT THU JUL 23 2026
THE PATTERN THROUGH THE EXTENDED WILL BE VERY SIMILAR TO LATE
THIS WEEK, BUT MORE MODERATED WITH SLOW DAY-TO-DAY CHANGES. AN
UPPER LEVEL TROUGH ALONG/OFF THE COAST AND UPPER LEVEL RIDGING
TO OUR EAST WILL CONTINUE DRY SOUTHWEST FLOW ACROSS THE AREA.
TEMPERATURES WILL REMAIN HOT, ALTHOUGH SLIGHTLY COOLER THANKS TO
THE TROUGH WITH LOWER VALLEYS REACHING THE MID 90S.
TEMPERATURES MAY INCREASE SEVERAL DEGREES BY THE END OF THE
PERIOD AS THE RIDGE BUILDS BACK TO THE WEST. WINDS WILL REMAIN
BREEZY, BUT NOT AS STRONG AS SATURDAY DUE TO A WEAKER PRESSURE
GRADIENT. DRY AIR WILL KEEP SHOWER AND THUNDERSTORM CHANCES
MINIMAL, BUT WILL TICK UP ACROSS SOUTH-CENTRAL IDAHO TO 10-20%
BY MID TO LATE WEEK AS THE RIDGE EXPANDS AND ALLOWS MONSOONAL
MOISTURE BACK INTO EASTERN AREAS.
AVIATION /18Z THURSDAY THROUGH FRIDAY/
ISSUED 1134 AM MDT THU JUL 23 2026
GENERALLY VFR. AREAS OF MVFR VISIBILITY DUE TO WILDFIRE SMOKE,
IMPROVING DURING PEAK AFTERNOON HEATING. SCATTERED SHOWERS AND
THUNDERSTORMS LATE AFTERNOON/EVENING IN EASTERN OREGON AND FAR
WESTERN IDAHO, IMPACTING KEUL/KONO/KBKE/KMYL. OUTFLOW GUSTS
30-50 KT, BRIEF HEAVY RAIN, AND SMALL HAIL IN STRONGEST STORMS.
HIGH DENSITY ALTITUDE DUE TO HEAT THIS AFTERNOON. SURFACE WINDS:
VARIABLE LESS THAN 10 KT THIS MORNING, BECOMING SW-NW 5-15 KT
THIS AFTERNOON. WINDS ALOFT AT 10KFT MSL: SW 10-20 KT.
KBOI...VFR. HIGH DENSITY ALTITUDE DUE TO HEAT THIS AFTERNOON.
OUTFLOW GUSTS TO 25 KT FROM THUNDERSTORMS PASSING WEST OF KBOI
LATE AFTERNOON AND EARLY EVENING. SURFACE WINDS: VARIABLE LESS
THAN 10 KT UNTIL 21Z, THEN NW 5-10 KT 23/21Z THROUGH 24/02Z,
THEN VARIABLE LESS THAN 10 KT.
WEEKEND OUTLOOK...AREAS OF WILDFIRE SMOKE CONTINUING WITH AREAS
OF MVFR VISIBILITY DURING LATE NIGHT AND MORNING HOURS, IMPROVING
EACH AFTERNOON. HIGH DENSITY ALTITUDE DUE TO HEAT. ISOLATED
SHOWERS AND THUNDERSTORMS ACROSS THE MAGIC VALLEY EACH AFTERNOON.
MOSTLY CLEAR ELSEWHERE. SURFACE WINDS: SW-NW 5-15 KT WITH GUSTS
TO 25 KT, EXCEPT 10-20 KT WITH GUSTS TO 30 KT ON SATURDAY.
BOI WATCHES/WARNINGS/ADVISORIES
ID...AIR QUALITY ALERT UNTIL 2 PM MDT FRIDAY FOR IDZ011-012-014-033.
RED FLAG WARNING UNTIL 9 PM MDT THIS EVENING FOR IDZ400-420-
423.
FIRE WEATHER WATCH FROM FRIDAY AFTERNOON THROUGH SATURDAY
EVENING FOR IDZ401-402-423.
HEAT ADVISORY UNTIL 9 PM MDT SATURDAY FOR IDZ012-014-016-033.
OR...AIR QUALITY ALERT UNTIL 2 PM MDT /1 PM PDT/ FRIDAY FOR
ORZ061>064.
RED FLAG WARNING UNTIL 9 PM MDT /8 PM PDT/ THIS EVENING FOR
ORZ672>675.
FIRE WEATHER WATCH FROM FRIDAY AFTERNOON THROUGH SATURDAY
EVENING FOR ORZ670>675.
HEAT ADVISORY UNTIL 9 PM MDT /8 PM PDT/ SATURDAY FOR ORZ063-
064.
WWW.WEATHER.GOV/BOISE
INTERACT WITH US VIA SOCIAL MEDIA:
WWW.FACEBOOK.COM/NWSBOISE
WWW.X.COM/NWSBOISE
AVIATION.....LC
SHORT TERM...ST
LONG TERM....ST
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