857
FXUS65 KBOI 221723
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
1123 AM MDT FRI MAY 22 2026
UPDATE
UPDATED AVIATION DISCUSSION.
KEY MESSAGES
- MOSTLY DRY WITH TEMPERATURES 10 TO 15 DEGREES ABOVE NORMAL
FOR MEMORIAL DAY WEEKEND.
- GUSTY WINDS MONDAY AHEAD OF A COLD FRONT, RESULTING IN
ELEVATED FIRE WEATHER CONDITIONS.
- MUCH COOLER WITH GUSTY WINDS AND A CHANCE OF SHOWERS AND
THUNDERSTORMS TUESDAY AND WEDNESDAY.
SHORT TERM /THROUGH SUNDAY NIGHT/
ISSUED 319 AM MDT FRI MAY 22 2026
A RIDGE OF HIGH PRESSURE ALOFT IN THE EASTERN PACIFIC WILL SHIFT
INLAND TODAY BUT ALSO FLATTEN, AS A FASTER MOVING TROUGH ALSO
COMES INLAND ACROSS WESTERN CANADA. STILL, THE RIDGE WILL CAUSE
FURTHER WARMING IN OUR CWA TODAY AND SATURDAY. ON SUNDAY
WESTERLY WINDS ALOFT WILL BACK TO SOUTHWESTERLY AS A DEEP UPPER
LOW IN THE GULF OF ALASKA MOVES TOWARD THE BC COAST. THIS WILL
RESULT IN EVEN MORE WARMING, AND ALSO A SLIGHT CHANCE (10-15%)
OF THUNDERSTORMS ALONG THE NV BORDER LATE SUNDAY AND SUNDAY
NIGHT.
LONG TERM /MONDAY THROUGH FRIDAY/
ISSUED 319 AM MDT FRI MAY 22 2026
MONDAY (MEMORIAL DAY) WILL BE THE WARMEST DAY OF ALL AS UPPER WINDS
INCREASE FROM THE SOUTHWEST AHEAD OF THE APPROACHING DEEP UPPER LOW,
WHICH BY LATE MONDAY WILL BE JUST OFF VANCOUVER ISLAND. BY LATE
MONDAY NIGHT THE LOW WILL BE INLAND OVER CENTRAL OREGON AND CLOSE
ENOUGH TO PUSH A STRONG COLD FRONT INTO OUR CWA, WITH GUSTY WINDS
AND AN INCREASING CHANCE OF SHOWERS IN EASTERN OREGON. MODELS
HAVE COME INTO MUCH BETTER AGREEMENT SINCE YESTERDAY AND TUESDAY
AGAIN LOOKS MUCH COOLER THAN MONDAY AS THE FRONT MOVES ACROSS
WESTERN IDAHO, WITH GUSTY WINDS AND MORE SHOWERS AND CHANCE OF
THUNDERSTORMS. THIS COLD FRONT HAS SIMILARITIES TO THE FRONT
THAT BROUGHT STRONG WINDS AND BLOWING DUST TO OUR CWA LAST WEEK,
BUT UNLIKE THAT CASE, PRE-FRONTAL TEMPERATURES WILL NOT BE AS
WARM, AND THE THERMAL GRADIENT ACROSS THE FRONT NOT AS STRONG.
IN ADDITION, THE SUPPORTING UPPER LOW WILL BE COMING IN FROM THE
NORTHWEST RATHER THAN DIRECTLY INLAND FROM THE WEST, WHICH ALSO
ARGUES FOR A WEAKER AND SLOWER FRONTAL PASSAGE. EVEN SO, THIS
COLD FRONT WILL BE SIGNIFICANT WITH AT LEAST 20 DEGREES COOLING
BEHIND IT. THE COOL, SHOWERY WEATHER WILL CONTINUE INTO
WEDNESDAY, THEN DRYING AND WARMING THURSDAY AND FRIDAY.
AVIATION /18Z FRIDAY THROUGH SATURDAY/
ISSUED 1122 AM MDT FRI MAY 22 2026
VFR. SURFACE WINDS: W-NW 5-15 KT, BECOMING VARIABLE SE LESS THAN
10 KT TONIGHT.
KBOI...VFR. SURFACE WINDS: NW 10-15 KT, BECOMING SE 5-10 KT
TONIGHT.
WEEKEND OUTLOOK...VFR WITH MOSTLY CLEAR SKIES. WINDS SE OR
VARIABLE 5-10 KT IN THE NIGHTS/MORNINGS AND W-NW 5-15 KT IN THE
AFTERNOONS. ISOLATED THUNDERSTORMS NEAR THE ID/NV BORDER SUNDAY
AFTERNOON.
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.....JM
SHORT TERM...LC
LONG TERM....LC
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