987
FXUS65 KBOI 231202
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
602 AM MDT SAT MAY 23 2026
UPDATE
UPDATED AVIATION DISCUSSION.
KEY MESSAGES
- MOSTLY DRY WITH TEMPERATURES 10 TO 15 DEGREES ABOVE NORMAL
THROUGH MEMORIAL DAY.
- GUSTY WINDS MONDAY AHEAD OF A PACIFIC COLD FRONT, RESULTING
IN ELEVATED FIRE WEATHER CONDITIONS.
- MUCH COOLER WITH GUSTY WINDS AND A CHANCE OF SHOWERS AND
THUNDERSTORMS TUESDAY AND WEDNESDAY. SHOWERS IN IDAHO
THURSDAY, THEN DRYING AND WARMING FRIDAY.
SHORT TERM /THROUGH MONDAY NIGHT/
ISSUED 310 AM MDT SAT MAY 23 2026
NO CHANGE TO CURRENT WARMING FORECAST THROUGH MONDAY (MEMORIAL
DAY). MOST AREAS WILL ALSO BE GRADUALLY DRIER, BUT ISOLATED
THUNDERSTORMS WILL DEVELOP LATE TODAY/EVENING NEAR THE OR/NV
BORDER, AND ALONG ALL OF THE NORTHERN NV BORDER SUNDAY
AFTERNOON/EVENING AND AGAIN MONDAY AFTERNOON/EVENING. THE HOT,
DRY AIR, AND ISOLATED THUNDERSTORMS WILL INCREASE FIRE DANGER
IN SOUTHERN MALHEUR COUNTY WHERE GRASSES HAVE ALREADY BECOME
CRITICALLY DRY. A DEEP UPPER LOW FROM THE GULF OF ALASKA WILL
PUSH A STRONG COLD FRONT ACROSS SOUTHEAST OR MONDAY EVENING AND
WESTERN ID OVERNIGHT, BRINGING A WIND SHIFT FROM SOUTHEAST TO
STRONGER NORTHWESTERLY, RAPID COOLING, AND A 20-40 PERCENT
CHANCE OF POST-FRONTAL SHOWERS AND THUNDERSTORMS. THE SUPPORTING
UPPER LOW IS FORECAST TO TRACK FROM JUST WEST OF VANCOUVER
ISLAND MONDAY AFTERNOON TO WESTERN OR MONDAY NIGHT, SLIGHTLY
WEST OF PREVIOUS FORECASTS. MONDAY NIGHT SHOULD THEREFORE BE
WARMER THAN PREVIOUSLY FORECAST ESPECIALLY ON THE IDAHO SIDE.
LONG TERM /TUESDAY THROUGH SATURDAY/
ISSUED 310 AM MDT SAT MAY 23 2026
THE STRONG COLD FRONT SHOULD BE IN WESTERN IDAHO EARLY TUESDAY
MORNING AND THE WESTERN MAGIC VALLEY BEFORE NOON. BUT WITH THE
SUPPORTING UPPER LOW HEADING SSE INTO NEVADA, THE FORWARD SPEED
OF THE FRONT WILL BE SLOWED AND WINDS NOT AS STRONG AS IF THE
UPPER LOW WERE TO PUSH THE FRONT DUE EASTWARD. EVEN SO, THE AIR
BEHIND THE FRONT WILL BE 20 TO 25 DEGREES COOLER THAN AHEAD OF
IT AND WILL BE STRONGLY FELT TUESDAY. SHOWERS AND AFTERNOON
THUNDERSTORMS WILL BE MORE NUMEROUS TUESDAY AND WEDNESDAY BUT
RAINFALL AMOUNTS WILL STILL BE RELATIVELY LIGHT, RANGING FROM
LESS THAN .10 INCH IN THE SNAKE BASIN AND MOST OF EASTERN OR,
TO .10 TO .25 INCH IN SOUTHERN HIGHLANDS AND MOUNTAINS, AND
.25 TO .50 INCH IN VALLEY COUNTY, ID, HEAVIEST IN EASTERN
VALLEY COUNTY. SHOWERS WILL CONTINUE INTO THURSDAY ON THE IDAHO
SIDE WHEN THE UPPER LOW IS STILL IN CENTRAL NV. IN FACT,
LATEST MODELS HAVE THURSDAY AFTERNOON/EVENING EVEN WETTER THAN
TUESDAY. BUT FRIDAY AND SATURDAY LOOK DRIER AND WARMER AS THE
UPPER LOW SHOULD THEN BE IN COLORADO.
AVIATION /12Z SATURDAY THROUGH SUNDAY/
ISSUED 602 AM MDT SAT MAY 23 2026 VFR. MOSTLY CLEAR SKIES
THROUGH 20Z. ISOLATED THUNDERSTORMS NEAR THE OR/NV BORDER 23/21Z
THROUGH 24/03Z. SURFACE WINDS:
VARIABLE OR SE LESS THAN 10 KT THROUGH 18Z, THEN W-NW 5-15 KT
UNTIL 24/01Z, WITH GUSTS TO 20 KT IN SE OR AND MAGIC VALLEY.
KBOI...VFR. CLEAR SKY. SURFACE WINDS: SE 5-10KT UNTIL 18Z,
THEN NW 7-12 KT UNTIL 24/00Z.
SUNDAY OUTLOOK...VFR. MOSTLY CLEAR SKIES THROUGH 24/20Z.
ISOLATED THUNDERSTORMS NEAR THE NV BORDER 24/20Z-25/06Z.
SURFACE WINDS: SE OR VARIABLE 5-10 KT UNTIL 24/20Z, THEN
W-NW 5-15 KT UNTIL 25/00Z.
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.....LC
SHORT TERM...LC
LONG TERM....LC
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