464  
FXUS65 KPIH 010311  
AFDPIH  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE POCATELLO ID  
911 PM MDT MON AUG 31 2026  
   
KEY MESSAGES
 
 
- SHOWERS AND THUNDERSTORMS WILL RETURN AND CONTINUE THROUGH THE  
NEXT SEVERAL DAYS  
 
- CRITICAL TO NEAR-CRITICAL FIRE CONDITIONS FOR THUNDERSTORMS  
EXPECTED TUESDAY FOR THUNDERSTORMS AND WIND/HUMIDITY WEDNESDAY  
 
- COOLER TEMPERATURES EXPECTED FROM WEDNESDAY ONWARD AS LOW  
PRESSURE SETTLES IN ACROSS THE WESTERN U.S.  
 

 
   
DISCUSSION
 
 
ISSUED AT 104 PM MDT MON AUG 31 2026  
 
A WEAK "WAVE" WILL LIFT NORTH ACROSS EASTERN IDAHO  
THROUGH TOMORROW MORNING, BRINGING AN INCREASE IN SHOWERS AND  
THUNDERSTORMS INCLUDING A FEW STORMS OVERNIGHT. THE BEST CHANCE OF  
RAIN WILL BE GENERALLY EAST OF AN OAKLEY TO ISLAND PARK LINE.  
WE MAY SEE A FEW LIGHT SHOWERS TO THE NORTHWEST OF THAT, BUT CHANCES  
ARE CURRENTLY UNDER 20%. WE COULD SEE SOME BRIEF HEAVIER DOWNPOURS  
FARTHER EAST, ESPECIALLY OUTSIDE OF THE SNAKE PLAIN.  
THERE IS A 10-50% CHANCE OF GUSTS OVER 35 MPH, WITH HIGH END  
APPROACHING 45 MPH. BY TOMORROW AFTERNOON, THE NEXT ROUND OF SHOWERS  
AND STORMS WILL ALREADY BE DEVELOPING. THE BULK OF THIS ROUND WILL  
INITIALLY FORMING ACROSS THE CENTRAL MOUNTAINS SOUTH THROUGH THE  
MAGIC VALLEY AND SOUTH HILLS/ALBION MOUNTAINS.  
EXPECT SOME HEAVY DOWNPOURS AND ALSO A 40-90% FOR GUSTS OVER 35 MPH,  
PUSHING 50-55 MPH. THIS SHIFTS QUICKLY TO THE NORTHEAST TOMORROW  
NIGHT. AS LOW PRESSURE ALONG THE COAST, ANOTHER "WAVE" RACES NORTH  
ON WEDNESDAY. THIS WILL KEEP OFF ANOTHER ROUND OF SHOWERS AND  
THUNDERSTORMS, WITH THE MAIN FOCUS BEING ACROSS THE CENTRAL  
MOUNTAINS. THERE IS A 10-40% CHANCE OF GUSTS OVER 35 MPH AS CURRENT  
TIMING PUSHES ANY RISK OF STRONG/SEVERE STORMS INTO MONTANA. A  
COUPLE OF HIGHER RESOLUTION MODELS HAVE ISOLATED STORMS EAST OF I-15  
AND AROUND ISLAND PARK, BUT WE CURRENTLY HAVE THAT POTENTIAL UNDER  
10% IN THE FORECAST. THE BIGGER ISSUE WILL LIKELY BE INCREASING  
WINDS ACROSS THE ENTIRE FORECAST AREA.  
THE STRONGEST WINDS WOULD BE ACROSS PORTIONS OF THE CENTRAL  
MOUNTAINS, ARCO DESERT/INL AND ALONG THE MONTANA BORDER. WE PUSHED  
THE BLEND OF MODELS FORECAST TOWARD THE HIGHEST END OF THE RANGE  
BASED ON TRENDS AND THE PATTERN, WHICH PUTS US CLOSE TO WIND  
ADVISORY THRESHOLDS. TEMPERATURES WILL REMAIN IN THE UPPER 70S TO  
MID 80S FOR HIGHS AGAIN TUESDAY, BUT DROP BACK INTO 70S, EVEN  
MID/UPPER 60S FOR HIGHER VALLEYS WITH THE FRONT ON WEDNESDAY.  
 
BEYOND THAT, GENERAL LOW PRESSURE SETTLES IN ALONG THE COAST INTO  
EARLY NEXT WEEK. INITIALLY, SHOWERS AND STORMS WILL BASICALLY  
DEVELOP ACROSS THE CENTRAL MOUNTAINS. HEADING INTO THE WEEKEND,  
SHOWERS AND STORMS WILL BECOME MORE WIDESPREAD. THE AMOUNT OF  
MONSOON MOISTURE DOES INCREASE, SO THE POTENTIAL FOR HEAVIER  
RAINFALL MAY RETURN. OF NOTE, ALTHOUGH THE MAIN GFS MODELS IS AN  
EXTREME OUTLIER, IT WANTS TO BE AGGRESSIVE WITH GRABBING THE  
REMNANTS OF TROPICAL DEVELOPMENT IN THE PACIFIC AND PULL IT  
NORTH ACROSS IDAHO. ALL OTHER MODELS (ECMWF AND IT ENSEMBLES,  
THE GEFS AND AIGFS) DO NOT SHOW THIS AT ALL. EITHER WAY,  
TEMPERATURES LOOK TO REMAIN COOLER WITH HIGHS IN THE 60S AND  
70S.  
 

 
   
AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/
 
 
ISSUED AT 911 PM MDT MON AUG 31 2026  
 
A FEW THUNDERSTORMS ARE ON THE LEADING BAND OF MOISTURE WORKING  
NORTHWARD. MOST OF THE THUNDERSTORMS SHOULD DIMINISH BY 06Z.  
SHOWERS WILL PASS THROUGH EAST IDAHO OVERNIGHT INTO TUESDAY  
MORNING. GUSTY WINDS ARE LIKELY DURING THE OVERNIGHT HOURS BUT  
SHOULD RELAX TUESDAY MORNING. ANOTHER ROUND OF CONVECTION IS  
EXPECTED TUESDAY AFTERNOON.  
 

 
   
FIRE WEATHER
 
 
ISSUED AT 135 PM MDT MON AUG 31 2026  
 
A MASS OF MOISTURE IS MOVING IN FROM THE SOUTH, ARRIVING IN  
SOUTHERN IDAHO IN THE EARLY EVENING AND IN EASTERN IDAHO AROUND  
MIDNIGHT, AND CENTRAL IDAHO AROUND TUESDAY MORNING. THUNDERSTORMS  
SHOULD DEVELOP BY AT LEAST TUESDAY AFTERNOON WITH SCATTERED  
COVERAGE IN THE CENTRAL IDAHO MOUNTAINS AND THE NORTHERN END OF  
THE SNAKE RIVER PLAIN. RED FLAG WARNING WAS ISSUED FOR THE  
NORTHER PORTIONS OF THE SAWTOOTH NF. THE HIGHER THREAT OF  
WETTING RAINS IN THE NORTHERN HALF OF THE SNAKE RIVER PLAIN HAVE  
MADE THE LIGHTNING ACTIVITY OF LOWER THREAT.  
 
THE INCOMING MOISTURE WILL MEAN CLOUDINESS THAT WILL KEEP  
TEMPERATURES RELATIVELY COOL, AND THUS HUMIDITY READINGS SHOULD  
BE WAY UP, AT LEAST FOR A LITTLE. MAY HAVE TO WATCH FIRE WEATHER  
ZONE 427 ON WED AS HUMIDITY DRIES OUT FIRST THERE, AT THE SAME  
TIME AS WIND INCREASE TO BREEZY TO WINDY CONDITIONS.  
 
WARMING AND DRYING DEVELOP FOR THE MIDDLE PART OF THE WEEK, WITH  
SUNDAY BEING THE NEXT DAY OF SIGNIFICANT SHOWER AND  
THUNDERSTORMS ACTIVITY.  
 

 
   
PIH WATCHES/WARNINGS/ADVISORIES
 
 
RED FLAG WARNING FROM 1 PM TO 9 PM MDT TUESDAY FOR IDZ422.  
 

 
 

 
 
DISCUSSION...KEYES  
AVIATION...13  
FIRE WEATHER...MESSICK  
 
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