212
FXUS65 KBOI 230004
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
604 PM 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 202 PM MDT FRI MAY 22 2026
A VERY STABLE AND QUIET WEATHER PATTERN DOMINATES THE SHORT
TERM PERIOD AS HIGH PRESSURE ALOFT MAINTAINS CONTROL OVER THE
INTERMOUNTAIN WEST. CLEAR SKIES AND LIGHT WINDS WILL ALLOW FOR
EFFICIENT RADIATIONAL COOLING OVERNIGHT, THOUGH MORNING LOWS
WILL REMAIN ABOVE NORMAL. A STEADY WARMING TREND WILL CONTINUE
ACROSS SOUTHEAST OREGON AND SOUTHWEST IDAHO SATURDAY INTO SUNDAY
AS WEAK NORTHWESTERLY FLOW ALOFT SLOWLY TRANSITIONS TO A MORE
SOUTHWESTERLY REGIME. THIS WILL INCREASE MID LEVEL MOISTURE
ALONG THE NEVADA BORDER SATURDAY AFTERNOON, AIDING IN CU
DEVELOPMENT AND POTENTIALLY SUPPORTING A FEW ISOLATED SHOWERS
AND THUNDERSTORMS (20% CHANCE).
BY SUNDAY, TEMPERATURES WILL PUSH TO AROUND 5 TO 10 DEGREES
ABOVE SEASONAL NORMALS. A STRENGTHENING SURFACE PRESSURE
GRADIENT AHEAD OF AN APPROACHING PACIFIC LOW WILL LEAD TO
INCREASING WESTERLY WINDS ACROSS THE REGION SUNDAY AFTERNOON,
PARTICULARLY THROUGH THE SNAKE RIVER PLAIN. EXPECT GUSTS TO
REACH 20 TO 30 MPH BY LATE AFTERNOON. WHILE A SLIGHT CHANCE OF
SHOWERS AND THUNDERSTORMS WILL EXIST ALONG THE NEVADA/IDAHO
BORDER SUNDAY AFTERNOON, MOST OF THE REGION WILL REMAIN DRY
THROUGH SUNDAY NIGHT UNDER MOSTLY CLEAR SKIES.
LONG TERM /MONDAY THROUGH FRIDAY/
ISSUED 202 PM MDT FRI MAY 22 2026
THE EXTENDED PERIOD BEGINS ON MEMORIAL DAY WITH SOUTHWEST FLOW
ALOFT STRENGTHENING ACROSS THE REGION. THIS WILL PUSH DAYTIME
HIGH TEMPERATURES TO THEIR WARMEST LEVELS OF THE WEEK, TOPPING
OUT AROUND 10 TO 15 DEGREES ABOVE NORMAL FOR LATE MAY. WHILE
LOWER ELEVATIONS AND VALLEY LOCATIONS WILL REMAIN DRY, THE
INCREASED MOISTURE AND AFTERNOON INSTABILITY WILL SUPPORT
ISOLATED SHOWERS AND THUNDERSTORMS OVER THE HIGHER TERRAIN OF
SOUTHEAST OREGON AND THE WEST CENTRAL IDAHO MOUNTAINS MONDAY
AFTERNOON. BREEZY TO GUSTY CONDITIONS WILL DEVELOP AREA WIDE AS
A STRONG UPPER LEVEL TROUGH INCHES CLOSER TO THE COAST.
A MAJOR WEATHER PATTERN SHIFT TAKES HOLD ON TUESDAY AND
WEDNESDAY AS A DEEP UPPER LEVEL TROUGH MOVES INLAND. A STRONG
COLD FRONT WILL SWEEP THROUGH THE AREA, BRINGING A SHARP DROP IN
TEMPERATURES, WIDESPREAD GUSTY WINDS, AND A SIGNIFICANTLY
HIGHER CHANCE (25% TO 60%) OF PRECIPITATION. HIGH TEMPERATURES
ON TUESDAY AND WEDNESDAY WILL PLUMMET TO WELL BELOW NORMAL.
WIDESPREAD VALLEY SHOWERS AND HIGH ELEVATION MOUNTAIN SNOW
SHOWERS ARE EXPECTED, PROVIDING MUCH NEEDED MOISTURE TO THE
REGION.
THE TROUGH BEGINS TO EXIT THE REGION BY THURSDAY, ALLOWING HIGH
PRESSURE TO SLOWLY REBUILD FROM THE SOUTH AND WEST. THIS WILL
START A GRADUAL DRYING AND WARMING TREND THAT CARRIES INTO
FRIDAY, BRINGING TEMPERATURES BACK TOWARD SEASONAL AVERAGES BY
THE END OF THE WORK WEEK.
AVIATION /00Z SATURDAY THROUGH SUNDAY/
ISSUED 555 PM MDT FRI MAY 22 2026
VFR, WITH SCATTERED CUMULUS CLOUDS OVER HIGH TERRAIN THIS
EVENING. MOSTLY CLEAR OVERNIGHT THROUGH MORNING. SURFACE WINDS:
W-NW 5-15 KT, BECOMING VARIABLE OR SE LESS THAN 10 KT TONIGHT
AFTER SUNSET.
KBOI...VFR. SURFACE WINDS: NW 8-13 KT, BECOMING SE UNDER 10 KT
TONIGHT AFTER SUNSET.
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/OR/NV BORDER
SATURDAY/SUNDAY AFTERNOONS.
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.....JY
SHORT TERM...JDS
LONG TERM....JDS
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