047
FXUS65 KBOI 220919
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
319 AM MDT FRI MAY 22 2026
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/
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/
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 THE PREVIOUS CASE, PRE-
FRONTAL TEMPERATURES WILL NOT BE AS WARM AND THE THERMAL
GRADIENT ACROSS THE FRONT WILL BE WEAKER. 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 /06Z FRIDAY THROUGH SATURDAY/
ISSUED 1052 PM MDT THU MAY 21 2026
VFR WITH SCT-BKN HIGH CLOUDS OVERNIGHT THROUGH MORNING. SURFACE
WINDS: MOSTLY VARIABLE UNDER 10 KT OVERNIGHT THROUGH MORNING, THEN
W-NW 5-15 KT IN THE AFTERNOON.
KBOI...VFR WITH SCATTERED HIGH CLOUDS OVERNIGHT. SURFACE WINDS: S-SE
5-10 KT OR VARIABLE OVERNIGHT THROUGH MORNING, THEN NW 7-12 KT IN
THE AFTERNOON.
WEEKEND OUTLOOK...VFR WITH MOSTLY CLEAR SKIES THROUGHOUT THE
WEEKEND. WINDS SE OR VARIABLE 5-10 KT IN THE NIGHT/MORNING AND W-NW
5-15 KT IN THE AFTERNOON EACH DAY. ISOLATED AFTERNOON THUNDERSTORMS
NEAR THE NV BORDER EACH DAY.
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
SHORT TERM...LC
LONG TERM....LC
AVIATION.....LC
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