971  
FXUS65 KBOI 171603  
AFDBOI  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE BOISE ID  
1003 AM MDT WED SEP 17 2025  
   
DISCUSSION  
SUNNY, DRY, AND WARM WEATHER TODAY WITH AN UPPER  
IN PLACE OVER THE REGION. SUNRISE WEBCAMS SHOWING SMOKE LAYERS  
ALOFT AND SEEING IT ACROSS THE REGION ON MORNING GEOCOLOR  
SATELLITE IMAGERY AS WELL. THE SMOKE IS ENTERING THE REGION FROM  
THE NORTHEAST AS IT WRAPS AROUND THE UPPER HIGH. TODAY'S  
TEMPERATURES WILL BE SEVERAL DEGREES WARMER THAN YESTERDAY WITH  
VALLEY HIGHS INTO THE MID-80S THIS AFTERNOON. NO UPDATES TO THE  
CURRENT FORECAST.  
 
 
   
AVIATION  
VFR. LAYERS OF SMOKE ALOFT. LOCAL IFR IN MOUNTAIN  
VALLEY FOG UNTIL 17/15Z. SURFACE WINDS: E-S 5-15KT. WINDS ALOFT  
AT 10KFT MSL: VARIABLE UP TO 10 KT.  
 
KBOI...VFR WITH LIGHT WINDS. SMOKE LAYERS ALOFT.  
 
 
   
PREV DISCUSSION  
 
SHORT TERM...TODAY THROUGH FRIDAY NIGHT...SUNNY, WARMER DAYS, AND  
CLEAR COOL NIGHTS WILL CONTINUE THROUGH THURSDAY EVENING UNDER HIGH  
PRESSURE ALOFT. THE RIDGE AXIS WILL SHIFT EAST OF OUR CWA THURSDAY  
NIGHT AND SOUTHWEST FLOW ALOFT WILL THEN DRAW MOISTURE NORTHWARD  
THROUGH THE CALIFORNIA SIERRA NEVADA AND BRING HIGH CLOUDS INTO  
EASTERN OREGON BY FRIDAY MORNING. THE CLOUDS WILL SLIGHTLY RAISE  
LOW TEMPERATURES IN OREGON. THURSDAY AND FRIDAY WILL BE THE  
WARMEST DAYS THIS WEEK WITH HIGHS ABOUT 10 DEGREES ABOVE NORMAL.  
WINDS WILL BE LIGHT DIURNAL THROUGH THE PERIOD EXCEPT SOUTHEAST  
GUSTS 15 TO 20 MPH MIDDAY TODAY NEAR MOUNTAIN HOME AND GLENNS  
FERRY, ID. WILDFIRE SMOKE WILL BE NEGLIGIBLE NEAR THE SURFACE.  
 
LONG TERM...SATURDAY THROUGH WEDNESDAY...SEVERAL DEGREES COOLER  
(BUT STILL ABOVE NORMAL) THIS WEEKEND AS A WEAK UPPER TROUGH COMES  
INLAND FROM THE GULF OF ALASKA AND ANOTHER WEAK UPPER TROUGH COMES  
INLAND ACROSS CALIF AND NEVADA. THE SOUTHERN TROUGH WILL BRING A  
15-20 PERCENT CHANCE OF SHOWERS TO THE ID/NV BORDER SATURDAY  
AFTERNOON. BY SUNDAY BOTH TROUGHS WILL BE EAST OF US BUT THE  
SOUTHERN ONE WILL LEAVE CLOUDS NEAR THE ID/NV BORDER, WHILE  
NORTHERN AREAS BECOME SUNNY AGAIN. SUNDAY NIGHT A STRONGER NORTH  
PACIFIC UPPER TROUGH WILL COME INLAND, WITH A DRY COLD FRONT  
PASSING THROUGH OUR CWA OVERNIGHT AND MONDAY MORNING. THE FRONT  
WILL BRING CLOUDS, GUSTY WEST/NORTHWEST WINDS, AND BRIEFLY COOLER  
TEMPS. BY TUESDAY FORECAST MODELS SHOW THE TROUGH AND COOLER AIR  
ALREADY WELL EAST OF US, WITH THE NEXT STRONG UPPER RIDGE  
BUILDING OVER THE INTERIOR WESTERN US BRINGING SUNNY, WARMER  
WEATHER AGAIN. ON WEDNESDAY GFS AND ECM DIFFER ON THE APPROACH  
OF THE NEXT NORTH PACIFIC UPPER TROUGH. GFS BRINGS IT STRONGLY  
INLAND TO OREGON WHILE ECM ALLOWS ONLY A WEAK TROUGH INLAND  
WHILE KEEPING THE MAIN TROUGH OFF THE COAST. FOR NOW WE WILL  
CAUTIOUSLY ALLOW A 15 TO 25 PERCENT CHANCE OF SHOWERS INTO OUR  
CWA WEDNESDAY.  
 
 
   
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  
 
DISCUSSION...DG  
AVIATION.....DG  
SHORT TERM...LC  
LONG TERM....LC  
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