617  
FXUS65 KGGW 171944  
AFDGGW  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GLASGOW MT  
144 PM MDT FRI JUL 17 2026  
   
KEY MESSAGES  
 
- UPPER RIDGING WILL KEEP ABOVE AVERAGE TEMPERATURES IN PLACE  
THROUGH THE WEEKEND. ON SUNDAY, AN ISOLATED 100 DEGREE  
TEMPERATURE IS POSSIBLE IN THE YELLOWSTONE RIVER VALLEY. HEAT  
RELATED EFFECTS ARE POSSIBLE ESPECIALLY SATURDAY WHEN THE  
HUMIDITY IS A FACTOR.  
 
- THERE IS A LOW CHANCE OF THUNDERSTORMS THROUGH SUNDAY BUT TIMING  
AMOUNTS AND PLACEMENTS ARE LOW CONFIDENCE.  
 
- A BRIEF COOLDOWN IS EXPECTED MONDAY.  
 
 
   
DISCUSSION  
 
WEATHER PATTERN OVERVIEW:  
 
UPPER RIDGING WILL CONTINUE TO BRING VERY WARM TEMPERATURES TO THE  
REGION THROUGH THE WEEKEND. ISOLATED TRIPLE DIGIT HEAT IS POSSIBLE  
IN THE YELLOWSTONE CORRIDOR FROM TERRY TO SIDNEY. THE HEAT COULD  
BRING ADVISORY EFFECTS SATURDAY WITH THE ADDED HUMIDITY.  
 
WEAK EMBEDDED SHORTWAVES WILL CONTINUE TO TAP DEEP MONSOONAL  
MOISTURE TO OFFER DAILY CHANCES FOR THUNDERSTORMS. HIGH  
PRECIPITABLE WATER VALUES WILL MEAN ANY GIVEN STORM COULD BE A  
PROLIFIC RAINFALL PRODUCER. IN ADDITION, THE SPC HAS INCLUDED THE  
WESTERN ZONES OF PHILLIPS AND PETROLEUM COUNTIES FOR TODAY IN A  
MARGINAL RISK FOR SEVERE THUNDERSTORMS BUT THE LATEST CAMS ARE  
SHOWING LOW CHANCES FOR OUR CWA, SO COULD BE A DRY NIGHT.  
 
OFF AND ON CHANCES FOR STORMS WILL CONTINUE THROUGH SUNDAY BUT WE  
COULD BE TOO CAPPED FOR ANYTHING TO FIRE UP. IN OTHER WORDS,  
CONFIDENCE IS QUITE LOW THAT ANYTHING WILL HAPPEN.  
 
NIGHTTIME FOG CHANCES WILL BE LOW BUT WINDS MIGHT BE TOO STRONG  
FOR IT'S FORMATION.  
 
ON MONDAY, AN UPPER LOW WILL DROP SOUTHEAST INTO SOUTH-CENTRAL  
CANADA. THIS WILL BRING A BREEZY DAY SO A LAKE WIND ADVISORY WILL  
LIKELY BE NEEDED. BUT IT WILL FEEL REFRESHING FOR MOST.  
 
THE UPPER RIDGE RETURNS NEXT WEEK AND THAT WILL ALLOW TEMPS TO  
REBOUND BACK INTO THE MID 80S TO MID 90S BY THE END OF THE WEEK.  
 
FORECAST CONFIDENCE & DEVIATIONS:  
 
SOME MASSAGING OF POPS WERE MADE TO TRY TO REFLECT WHAT THE CAMS  
MODELS WERE SHOWING THROUGH SATURDAY MORNING. TFJ  
 
 
   
AVIATION  
 
UPDATED: AT 1945Z.  
 
FLIGHT CATEGORY: VFR.  
 
DISCUSSION: DRY WEATHER CONDITIONS ARE EXPECTED THROUGH THIS  
EVENING. LATE TONIGHT, ISOLATED TO SCATTERED THUNDERSTORMS PUSHING  
IN FROM THE WEST MAY LEAD TO BRIEF REDUCTIONS IN CEILINGS.  
 
WIND: EAST TO SOUTHEAST WINDS WILL PREVAIL AT 5 TO 15 KTS MOST OF  
THE TIME WITH OCCASIONAL GUSTY CONDITIONS NEAR ANY THUNDERSTORMS.  
 
 
   
GGW WATCHES/WARNINGS/ADVISORIES  
 
NONE.  
 
 
 
 
WEATHER.GOV/GLASGOW  
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