110
FXUS65 KBOI 112335 CCA
AFDBOI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
534 PM MDT MON MAY 11 2026
UPDATE
UPDATED AVIATION DISCUSSION. CORRECTED WORDING.
KEY MESSAGES
- VERY HOT TUESDAY. RECORD HIGH TEMPERATURES IN THE 90S IN THE
LOWER VALLEYS.
- BECOMING VERY WINDY AND TURNING MUCH COOLER FROM WEST TO EAST
WEDNESDAY, WITH SHOWERS AND CHANCE OF THUNDERSTORMS ALONG AND
BEHIND A STRONG PACIFIC COLD FRONT.
- SLIGHTLY WARMER FRIDAY, THEN TURNING COOLER AGAIN SATURDAY
AND SUNDAY, WITH LIGHT SNOW POSSIBLE ABOVE 6000 FEET IN
NORTHERN MOUNTAINS.
SHORT TERM /THROUGH WEDNESDAY NIGHT/
ISSUED 213 PM MDT MON MAY 11 2026
AFTER TODAY'S SLIGHT COOLING, TUESDAY WILL BE ABOUT 10 DEGREES
HOTTER AS AN ANOMALOUSLY STRONG UPPER RIDGE PASSES DIRECTLY
OVERHEAD. MODELS HAVE COME INTO CLOSE AGREEMENT ON HIGH TEMPS
FOR TUESDAY, WITH 90S IN SOUTHERN VALLEYS AND 80S ELSEWHERE,
HOT ENOUGH TO SET RECORDS FOR THE DATE. THE RIDGE WILL EXIT
EAST TUESDAY EVENING AS A DEEP PACIFIC UPPER LOW, LOCATED NEAR
43N/143W AT 18Z, MOVES DUE EAST. THE LOW IS FORECAST TO REACH
THE OREGON COAST AROUND 12Z WEDNESDAY WHEN THE SLOWER-MOVING
RIDGE IS ALONG THE CONTINENTAL DIVIDE. A STEEP HEIGHT AND
THERMAL GRADIENT WILL DEVELOP BETWEEN THE RIDGE AND THE LOW
RESULTING IN FORMATION OF A STRONG SURFACE COLD FRONT. THE
FRONT IS FORECAST TO REACH WESTERN HARNEY COUNTY 10 AM PDT
WEDNESDAY, THE OR/ID BORDER AROUND 3 PM MDT WEDNESDAY, AND
SOUTH-CENTRAL IDAHO 6-8 PM MDT WEDNESDAY EVENING. THE FORWARD
SPEED OF THE FRONT, TOGETHER WITH THE STEEP THERMAL GRADIENT
ACROSS THE FRONT, WILL PRODUCE STRONG WINDS AND SHARP COOLING
AS THE FRONT PASSES, ESPECIALLY IN SOUTHERN AREAS. WE HAVE
ISSUED A WIND ADVISORY FOR THIS EVENT, EXPECTING 25 TO 35 MPH
SUSTAINED WINDS WITH GUSTS TO 55 MPH. RISING AIR AHEAD OF THE
FRONT WILL SUPPORT A CHANCE OF SHOWERS AND THUNDERSTORMS RIGHT
ALONG THE FRONT. BLOWING DUST MAY REDUCE VISIBILITY IN AREAS
THAT DON'T RECEIVE RAIN. BEHIND THE FRONT TEMPERATURES WILL
LOWER FURTHER WHILE WEST WINDS CONTINUE 15 TO 30 MPH INTO
WEDNESDAY EVENING. HIGH TEMPS WEDNESDAY WILL BE AS MUCH AS 30
DEGREES COOLER THAN TUESDAY'S HIGHS IN HARNEY COUNTY, WITH LESS
COOLING ON THE IDAHO SIDE, WHERE THE REMAINING COOLING WILL
COME THURSDAY. MORE SHOWERS WILL PASS THROUGH OUR CWA WEDNESDAY
NIGHT, MOST NUMEROUS IN NORTHERN AREAS, WITH SNOW ON THE HIGHER
PEAKS BY THURSDAY MORNING.
LONG TERM /THURSDAY THROUGH MONDAY/
ISSUED 213 PM MDT MON MAY 11 2026
AN UPPER LEVEL TROUGH WILL MOVE EAST OF THE AREA ON THURSDAY
LEAVING THE AREA UNDER DRIER NORTHWEST FLOW ALOFT AND 20 PERCENT
CHANCE OF SHOWERS OVER THE MOUNTAINS OF SW IDAHO. BREEZY WEST
TO NORTHWEST WINDS THURSDAY ESPECIALLY ACROSS THE MAGIC VALLEY
WITH DAYTIME HIGHS AROUND NORMAL. DRY ZONAL FLOW ON FRIDAY WITH
TEMPERATURES TRENDING UP A FEW DEGREES. MODELS DISPLAY SOME
VARIATION OF TROUGHING OVER THE REGION SATURDAY/SUNDAY. THIS
WILL BRING COOLER WEATHER AND A 20-30 PERCENT CHANCE OF
RAIN/SNOW SHOWERS TO THE NORTHERN MOUNTAINS WITH SNOW LEVELS
5000-6000 FEET MSL. WEEKEND TEMPERATURES EXPECTED TO BE 5 TO 10
DEGREES BELOW NORMAL WITH BREEZY NORTHWEST WINDS ACROSS THE
UPPER TREASURE AND MAGIC VALLEYS. DRY ON MONDAY WITH
TEMPERATURES TRENDING UP UNDER WEST TO NORTHWEST FLOW ALOFT.
AVIATION /00Z TUESDAY THROUGH WEDNESDAY/
ISSUED 527 PM MDT MON MAY 11 2026
VFR, WITH SCATTERED HIGH CLOUDS ABOVE 20KFT. WINDS NW 5-15 KT
WITH HIGHER GUSTS INTO THE EARLY EVENING, BECOMING LESS THAN 10
KT OVERNIGHT, THEN INCREASING TO ESE TUESDAY AFTERNOON. ESE
WINDS STRONGEST OVER THE MAGIC VALLEY OF IDAHO, WITH VALUES OF 10-20
KT WITH GUSTS TO 25+ KT POSSIBLE. HIGH DENSITY ALTITUDE POSSIBLE 20-
23Z TUESDAY.
KBOI...VFR. SOME HIGH CLOUDS. WINDS BECOMING SE OVERNIGHT LESS
THAN 10 KT, INCREASING TO SE 8-10 KT WITH GUSTS TO 15 KT AFTER
20Z TUESDAY. HIGH DENSITY ALTITUDE POSSIBLE 20-23Z TUESDAY.
BOI WATCHES/WARNINGS/ADVISORIES
ID...WIND ADVISORY FROM NOON WEDNESDAY TO MIDNIGHT MDT WEDNESDAY
NIGHT FOR IDZ012-014>016-028>030.
OR...WIND ADVISORY FROM NOON MDT /11 AM PDT/ WEDNESDAY TO MIDNIGHT
MDT /11 PM PDT/ WEDNESDAY NIGHT FOR ORZ063-064.
WWW.WEATHER.GOV/BOISE
INTERACT WITH US VIA SOCIAL MEDIA:
WWW.FACEBOOK.COM/NWSBOISE
WWW.X.COM/NWSBOISE
AVIATION.....MC
SHORT TERM...LC
LONG TERM....TL
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