060  
FXUS65 KPIH 042209  
AFDPIH  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE POCATELLO ID  
409 PM MDT FRI SEP 4 2026  
   
KEY MESSAGES  
 
- SHOWERS AND THUNDERSTORMS WILL PERSIST ACROSS THE CENTRAL  
MOUNTAINS THROUGH SATURDAY BECOMING MORE WIDESPREAD SUNDAY AND  
LABOR DAY  
 
- LOCALLY HEAVY RAINFALL IS POSSIBLY LATER SUNDAY AND LABOR,  
POTENTIALLY CREATING ISSUES ON/AROUND STEEP SLOPES AND BURN  
SCARS  
 
- MUCH COOLER WEATHER EXPECTED ON LABOR DAY  
 
 
   
DISCUSSION  
 
ISSUED AT 1237 PM MDT FRI SEP 4 2026  
 
WE CONTINUE TO WATCH THE POTENTIAL FOR SHOWERS AND ISOLATED  
THUNDERSTORMS ACROSS THE CENTRAL MOUNTAINS THROUGH SUNDAY  
MORNING. THERE WILL BE A POTENTIAL FOR SOME LOCALLY HEAVIER  
RAINFALL, ESPECIALLY TONIGHT. THAT SAID, A MORE PROLONGED AND  
WIDESPREAD ISSUE WITH HEAVY RAIN IS NOT EXPECTED. WE WILL LET  
THE FLASH FLOOD WATCH FOR THE WAPITI BURN SCAR EXPIRE THIS  
EVENING. ACROSS THE REST OF EASTERN IDAHO, THE DRY SLOT REMAINS  
IN PLACE ALONG WITH GUSTY WINDS AT TIMES DURING THE SAME PERIOD.  
GUSTS UP TO 30-35 MPH ARE POSSIBLE, ESPECIALLY AT NIGHT WHERE  
DOWNSLOPE OCCURS OR WHERE AREAS REMAIN ABOVE ANY WEAK INVERSION,  
AND DURING THE AFTERNOON WITH FULL MIXING. TEMPERATURES WILL  
WARM UP A BIT, WITH SOME LOW TO MID 80S POPPING UP ACROSS LOWEST  
ELEVATIONS.  
 
THE FOCUS FOR THE NEXT CHANCE OF SHOWERS AND STORMS  
WILL OCCUR LATER SUNDAY THROUGH LABOR DAY. THE LOW THAT HAS  
BEEN SITTING ALONG THE COAST WILL SWING ACROSS THE STATE ON  
MONDAY. AHEAD OF THAT, WE WILL PULL IN SOME MONSOON MOISTURE TO  
HELP FUEL THIS ROUND OF SHOWERS AND STORMS. IT LOOKS LIKE AT THE  
MOMENT, ANY MOISTURE FROM MARIE WILL GET PUSHED TO OUR  
SOUTHEAST. WE WILL LIKELY GET A SMALL BOOST, ESPECIALLY CLOSER  
TO THE WYOMING BORDER. OTHERWISE, RAINFALL WILL COME FROM  
WHATEVER MOISTURE IS WRAPPING AROUND THE MAIN LOW  
ITSELF...SEPARATE FROM THE MONSOON PUSH. THE BEST CHANCE OF RAIN  
WILL BE SUNDAY NIGHT AND LABOR DAY, WITH A VERY STRONG DRY SLOT  
WRAPPING BACK INTO EASTERN IDAHO LATER IN THE DAY. RAINFALL  
AMOUNTS ACROSS THE SNAKE PLAIN, MAGIC VALLEY, AND SOUTH  
HILLS/ALBION MOUNTAINS WILL RANGE FROM A FEW HUNDREDTHS TO CLOSE  
TO 0.25" NORTH OF IDAHO FALLS. RAINFALL ACROSS THE CENTRAL  
MOUNTAINS SHOULD RANGE FROM 0.10-0.30", EXCEPT ACROSS THE HIGHER  
RANGES (SAWTOOTHS, LOST RIVER, AND LEMHI) WHERE UP 0.60" IS  
POSSIBLE. TEMPERATURES MAY BE COLD ENOUGH MONDAY, FOR A SHORTER  
PERIOD OF RAIN AND SNOW ACROSS THE HIGHER PEAKS LIKE BORAH, ETC.  
FOR THE EASTERN AND SOUTHEAST HIGHLANDS, AMOUNTS CURRENTLY FALL  
IN THE 0.20-0.50"...LOCALLY HIGHER AROUND ISLAND PARK WHERE UP  
TO 0.70" MIGHT FALL. IF WE SEE HEAVIER STORMS OR MULTIPLE STORMS  
OVER THE SAME AREA, WE COULD SEE SOME ISSUE WITH LOCALIZED  
FLOODING IN STEEPER SLOPE AREAS AND BURN SCARS. IT IS POSSIBLE  
WE MAY NEED TO ISSUE A FLASH FLOOD WATCH TO LATER ON TO COVER  
THE IMPACTS. WINDS WILL PICK UP ON THE BACK SIDE OF THE LOW,  
ESPECIALLY WHEN THE DRY SLOT MOVES IN. THE STRONGEST WINDS WILL  
BE ACROSS THE SNAKE PLAIN NORTH ACROSS THE BORDER INTO SOUTHWEST  
MONTANA. IT IS POSSIBLE A WIND ADVISORY IS NEEDED FOR THOSE  
AREAS. WE SHOULD FALL SHORT OF ANY THRESHOLDS FOR A LAKE WIND  
ADVISORY FOR AMERICAN FALLS RESERVOIR. TEMPERATURES SUNDAY WILL  
BE SIMILAR TO TOMORROW, BUT MUCH COOLER MONDAY WITH LOWER  
ELEVATIONS HIGHS MAYBE REACHING 70. MOUNTAIN TEMPERATURES WILL  
BE IN THE 50S AND LOW 60S, WITH HIGHEST ELEVATIONS NOT GETTING  
OUT OF THE 40S.  
 
WE GET A BRIEF BREAK MIDWEEK, BUT SOUTHWEST FLOW RETURNS AND WE  
SEE SOME MONSOON MOISTURE MOVING BACK INTO STATE AFTER THAT.  
EXPECT HIGHS TO RETURN TO THE 70S AND 80S AND AT LEAST A LOW END  
POTENTIAL (FOR NOW) OF SHOWERS AND THUNDERSTORMS.  
 
 
   
AVIATION /00Z TAFS THROUGH 00Z SATURDAY/  
 
ISSUED AT 408 PM MDT FRI SEP 4 2026  
 
A FEW SHOWERS CAN BE FOUND AROUND SUN TONIGHT. ALTHOUGH  
NO SIGNIFICANT IMPACTS ARE EXPECTED. A FEW HOURS OF BREEZY  
CONDITIONS ARE EXPECTED TONIGHT AT MOST TAF SITES BUT THEN WINDS  
SHOULD DIMINISH BY SATURDAY MORNING.  
 
 
   
FIRE WEATHER  
 
ISSUED AT 1237 PM MDT FRI SEP 4 2026  
 
SHOWERS AND ISOLATED THUNDERSTORMS WILL REMAIN CONFINED TO THE  
CENTRAL MOUNTAINS THROUGH SUNDAY MORNING. THERE IS A LOW CHANCE  
OF LOCALLY HEAVIER RAINFALL MAINLY NORTH OF STANLEY AND ACROSS  
THE FRANK CHURCH. OTHERWISE, GUSTY WINDS WILL REMAIN ACROSS THE  
REST OF EASTERN IDAHO THROUGH THE SAME PERIOD. WE WILL SEE  
NEAR-CRITICAL TO LOCALLY CRITICAL FIRE WEATHER CONDITIONS DUE TO  
THE WIND AND AFTERNOON HUMIDITY DROP TO NEAR 15 PERCENT. THROUGH  
THIS EVENING, THIS WILL BE AN ISSUE ACROSS THE SOUTHEAST CORNER  
(ZONE 413), AND TOMORROW ACROSS ZONES 410, 413, 427 AND MOST OF  
ZONE 425. WE MAY ALSO SEE THIS BE AN ISSUE SUNDAY AHEAD OF THE  
MONSOON PUSH ACROSS THE SNAKE PLAIN (410) AND MOST, IF NOT ALL  
OF ZONES 425 AND 427.  
 
SHOWERS AND THUNDERSTORMS WILL INCREASE SUNDAY NIGHT AND  
CONTINUE THROUGH MOST OF LABOR DAY, ALTHOUGH THIS WILL QUICKLY  
SHUT OFF ACROSS THE SNAKE PLAIN (410), MAGIC VALLEY AND SOUTH  
HILLS/ALBION MOUNTAINS (425 AND 427) AS A DRY SLOT QUICKLY WRAPS  
BACK INTO EASTERN IDAHO. IT LOOKS LIKE THE SUPER MAJORITY OF THE  
MOISTURE FROM MARIE STAYS TO OUR SOUTHEAST, WITH A VERY SMALL  
AMOUNT PULLED INTO AREAS EAST OF I-15. THERE IS A SEPARATE  
BATCH OF MOISTURE WRAPPING AROUND THE LOW ITSELF THAT WILL BE  
THE SOURCE OF PRECIPITATION AS THE LOW CROSSES THE CENTRAL  
MOUNTAINS AND PANHANDLE. FOR ZONES 410, 425, AND 427 LOOK FOR  
AMOUNTS FROM A FEW HUNDREDTHS UP TO 0.25", HIGHEST ACROSS THE  
NORTH END OF ZONE 410. ACROSS THE CENTRAL MOUNTAINS (422, 475,  
AND 476), AMOUNTS OF 0.10-0.30" ARE POSSIBLE, BUT CLOSER TO  
0.60" ACROSS HIGHER ELEVATIONS NORTH OF STANLEY AND ZONES  
475/476. THERE EVEN COULD BE A RAIN/SNOW MIX FOR PEAKS LIKE BORAH,  
ETC. FOR HIGHER ELEVATIONS EAST OF I-15, LOOK FOR 0.20-0.50"  
EXCEPT AROUND ISLAND PARK WHERE UP TO 0.70" IS POSSIBLE. THIS  
COULD CAUSE SOME ISSUES FOR ANY BURN SCARS OR STEEPER SLOPE  
AREAS.  
 
 
   
PIH WATCHES/WARNINGS/ADVISORIES  
 
NONE.  
 
 
 
 
 
DISCUSSION...KEYES  
AVIATION...13  
FIRE WEATHER...KEYES  
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