878  
FXUS65 KBOI 281133  
AFDBOI  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE BOISE ID  
533 AM MDT MON SEP 28 2026  
   
UPDATE
 
UPDATED AVIATION DISCUSSION.  
 

 
   
KEY MESSAGES
 
 
- CLOUDY SKIES AND ISOLATED RAIN SHOWERS CONTINUE IN SW IDAHO  
THIS MORNING, CLEARING FROM WEST TO EAST THROUGHOUT THE DAY.  
 
- FAIR SKIES AND WARMER TEMPERATURES TUESDAY THROUGH THE  
WEEKEND, RANGING 5-10 DEGREES ABOVE NORMAL.  
 
- BREEZY NORTHWEST WINDS EXPECTED THE NEXT SEVERAL AFTERNOONS,  
MAINLY IN THE UPPER TREASURE/MAGIC VALLEYS AND THE SURROUNDING  
TERRAIN.  
 

 
   
SHORT TERM /THROUGH WEDNESDAY NIGHT/
 
 
ISSUED 246 AM MDT MON SEP 28 2026  
AN ELONGATED TROUGH OVER THE WESTERN U.S. CONTINUES TO BRING  
CLOUD COVER, VIRGA, AND ISOLATED RAIN SHOWERS ACROSS FAR  
SOUTHEAST OREGON AND SOUTHWEST IDAHO THIS MORNING. SKIES WILL  
CLEAR FROM FROM WEST TO EAST THROUGHOUT THE DAY AS THE LOW AND  
SUBSEQUENT MOISTURE HEAD EASTWARD. THIS WILL ALLOW TEMPERATURES  
TO WARM FOR EASTERN OREGON AND PORTIONS OF SOUTHWESTERN IDAHO  
TODAY, WHILE SOUTH-CENTRAL IDAHO IS LIKELY TO REMAIN COOLER WITH  
THE EXTENDED INFLUENCE OF THE LOW. 500MB HEIGHTS WILL BEGIN TO  
RISE IN WEST-NORTHWEST FLOW TONIGHT THROUGH WEDNESDAY, YIELDING  
WARMER, DRIER CONDITIONS AREA-WIDE. THE W-NW FLOW WILL ALSO  
CONTRIBUTE TO BREEZY SURFACE WINDS FOR THE WESTERN SNAKE PLAIN  
AND SURROUNDING TERRAIN IN THE AFTERNOONS TODAY THROUGH  
WEDNESDAY.  
 

 
   
LONG TERM /THURSDAY THROUGH MONDAY/
 
 
ISSUED 246 AM MDT MON SEP 28 2026  
A FLATTENED RIDGE, CENTERED OVER THE SOUTHWEST U.S., WILL  
DOMINATE THE REGION THURSDAY THROUGH THE WEEKEND, WITH  
TEMPERATURES CLIMBING TO 5-10 DEGREES ABOVE NORMAL. A COUPLE OF  
WEAK DISTURBANCES MAY INFILTRATE THE RIDGE FRIDAY THROUGH  
SUNDAY, WHICH WOULD INCREASE CLOUD COVER AND BRING MORE  
UNCERTAINTY FOR TEMPERATURES. HOWEVER, PRECIPITATION CHANCES  
REMAIN BELOW 10 PERCENT DURING THIS TIME-FRAME. EARLY NEXT WEEK,  
MODELS FAVOR A STRENGTHENING RIDGE ALONG THE WEST COAST THAT  
WOULD SUPPORT DRY, WARM, AND FAIR CONDITIONS ACROSS SOUTHEAST  
OREGON AND SOUTHWEST IDAHO.  
 

 
   
AVIATION /12Z MONDAY THROUGH TUESDAY/
 
 
ISSUED 532 AM MDT MON SEP 28 2026  
 
GENERALLY VFR. DECREASING MID/HIGH CLOUDS FROM WEST TO EAST  
TODAY. VIRGA AND ISOLATED RAIN SHOWERS OVER SW IDAHO THIS  
MORNING, EXITING EAST THIS AFTERNOON. PATCHY MORNING FOG/LOW  
STRATUS IN SHELTERED MOUNTAIN VALLEYS. SURFACE WINDS: W-NW 5-15  
KT, AFTERNOON GUSTS TO 20-30 KT FROM KBOI TO THE SOUTH/EAST.  
WINDS ALOFT AT 10KFT MSL: W-NW 5-15 KT.  
 
KBOI...VFR AND VIRGA EARLY THIS MORNING, DECREASING BY LATE  
MORNING. LIGHT RAIN OVER THE NEARBY TERRAIN THROUGH MORNING.  
SURFACE WINDS: W-NW 4-10 KT, INCREASING TO 10-15 KT WITH GUSTS  
TO 20-25 KT THIS 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.....SH  
SHORT TERM...SH  
LONG TERM....SH  
 
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