934  
FXUS65 KBYZ 031506  
AFDBYZ  
 
AREA FORECAST DISCUSSION...UPDATED  
NATIONAL WEATHER SERVICE BILLINGS MT  
906 AM MDT SUN AUG 3 2025  
   
KEY MESSAGES
 
 
- THUNDERSTORM COVERAGE AND PRECIPITATION POTENTIAL DECREASES  
THROUGH WEDNESDAY.  
 
- SEASONAL TEMPERATURES IN THE UPPER 80S TO LOWER 90S THROUGH  
WEDNESDAY.  
 
- COOLER AND UNSETTLED PATTERN POSSIBLE FOR LATTER PART OF THE  
WEEK.  
 
 

 
   
UPDATE
 
 
QUICK UPDATE TO THE FORECAST THIS MORNING. LATEST CAMS BRING  
EVENING CONVECTION A BIT FURTHER NORTH THAN PREVIOUS RUNS, SO  
ADDED A SLIGHT CHANCE AS FAR NORTH AS I-90 TO COVER THIS, ALSO  
TWEAKED PRECIPITATION CHANCES A BIT FURTHER NORTH ALONG THE  
EASTERN STATE LINE TO LINE UP BETTER WITH EASTERN OFFICES  
THOUGHTS. REST OF THE FORECAST IS GOOD SHAPE FOR A QUIETER DAY  
CONVECTION WISE WITH A LOT OF SUN AND HIGHS IN THE MID TO UPPER  
80S. CHAMBERS  
 

 
   
DISCUSSION
 
 
THROUGH SUNDAY NIGHT...  
 
WEAK UPPER TROF SLIDES TO THE NORTH OF THE AREA TODAY ENHANCING  
DOWNSLOPE WESTERLY FLOW IN THE MID/UPPER LEVELS. THIS WILL RESULT  
IN A PUSH OF DRIER AIR FROM THE WEST ACROSS MUCH OF OUR FORECAST  
AREA. WE STILL HAVE A WEAK PERTURBATION PROGGED TO TRACK ALONG THE  
MT/WY BORDER. PLUS, WE HAVE SOME WEAK LOW LEVEL CONVERGENCE  
OCCURING ALONG THE DAKOTAS BORDER. THUS, WE EXPECT TO SEE MAINLY  
ISOLATED CONVECTION ALONG THE SOUTHERN AND EASTERN PERIPHERY OF  
OUR CWA, FROM THE BEARTOOTHS TO THE BIG HORNS AND INTO THE  
SOUTHEAST CORNER OF MONTANA. MLCAPE IS LESS THAN 750 J/KG IN THESE  
AREAS WITH 25-30 KTS OF SHEAR AND ONLY WEAK FORCING. SO WE DO NOT  
EXPECT SEVERE STORMS. WHILE PWATS WILL DROP TO AROUND OR UNDER  
0.75 INCHES IN OUR WEST, THEY AREA STILL >0.80 IN OUR EAST,  
INCLUDING SHERIDAN COUNTY, WY. SO THERE REMAINS A RISK OF HEAVY  
RAIN WITH A FEW STORMS THAT DEVELOP IN OUR SOUTH AND SOUTHEAST  
SECTIONS. HOWEVER, OVERALL THERE IS LIKELY TO BE MUCH LESS  
COVERAGE OF THUNDERSTORMS TODAY. CONVECTION MAY LINGER IN THE FAR  
EAST LATE IN THE EVENING BEFORE EXITING TO THE EAST.  
 
NOT MUCH CHANGE IN TEMPERATURE TRENDS WITH HIGHS TODAY IN THE  
UPPER 80S TO LOWER 90S, WITH LOWS IN THE 50S TO LOWER 60S. BT  
 
MONDAY THROUGH SUNDAY...  
 
A DISTURBANCE MOVING THROUGH THE REGION LATE MONDAY INTO TUESDAY  
WILL BRING THE BEST CHANCE OF PRECIPITATION FOR THE FIRST HALF OF  
THE WEEK. CURRENTLY, THE BEST CHANCE (30-50%) IS OVER THE WESTERN  
MOUNTAINS AND NORTH OF BILLINGS. WITH THIS SYSTEM, ATMOSPHERIC  
MOISTURE VALUES WILL BE NEAR NORMAL, SO HEAVY RAIN IS LESS OF A  
THREAT THAN IN THE PREVIOUS WEEK.  
 
BY THE END OF THE WEEK, THE RIDGE OVER THE GREAT BASIN IS EXPECTED  
TO SHIFT EASTWARD, ALLOWING A TROUGH TO MOVE INTO THE REGION.  
WHILE THE EXACT DETAILS ON THIS SYSTEM ARE STILL UNCERTAIN, A  
COOLER AND MORE UNSETTLED PATTERN CAN BE EXPECTED INTO THE  
WEEKEND.  
 
HIGH TEMPERATURES WILL BE NEAR NORMAL MONDAY THROUGH THURSDAY,  
WITH HIGHS IN THE 80S TO LOW 90S. THEN, AS THE DISTURBANCE MOVES  
IN AT THE END OF THE WEEK, TEMPERATURES ARE EXPECTED TO COOL. BY  
SATURDAY, THERE IS AT LEAST A 30% CHANCE OF HIGHS LESS THAN 75  
ACROSS THE REGION. ARCHER  
 

 
   
AVIATION
 
 
ISOLATED SHOWERS AND THUNDERSTORMS WILL DEVELOP IN THE AFTERNOON  
AND EVENING NEAR AND OVER THE MOUNTAINS AND NEAR THE DAKOTA  
BORDER. THE MAIN THREATS WITH ANY STORMS WILL BE GUSTY AND ERRATIC  
WINDS UP TO 45 KTS, SMALL HAIL, AND HEAVY RAIN. THE MOST LIKELY  
IMPACTED SITES ARE KLVM AND KSHR. OTHERWISE, VFR CONDITIONS WILL  
PREVAIL. ARCHER  
 

 
   
PRELIMINARY POINT TEMP/POPS
 
 
TDY MON TUE WED THU FRI SAT  
-------------------------------------------------------  
BIL 087 061/092 059/086 059/092 062/091 060/080 056/076  
1/U 21/U 31/U 00/U 00/B 23/T 32/W  
LVM 085 052/086 049/083 051/089 053/086 050/076 047/073  
2/T 22/T 21/U 00/U 11/B 34/T 33/T  
HDN 088 059/094 058/086 058/094 060/092 058/081 055/077  
1/U 10/U 31/U 00/U 10/B 23/T 42/W  
MLS 089 062/094 063/086 060/094 064/093 062/082 057/077  
1/U 10/U 43/T 10/U 11/B 33/T 42/T  
4BQ 086 063/091 063/086 061/093 063/095 062/082 058/075  
2/T 20/U 21/U 10/U 11/U 22/T 52/T  
BHK 085 059/089 062/084 058/090 061/090 059/081 056/076  
2/T 20/U 34/T 21/U 22/T 32/T 42/W  
SHR 083 056/091 056/085 055/093 058/094 056/081 052/074  
2/T 20/U 11/U 00/U 00/B 13/T 43/T  
 

 
   
BYZ WATCHES/WARNINGS/ADVISORIES
 
 
MT...NONE.  
WY...NONE.  
 

 
 

 
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