454  
FXUS65 KBYZ 110053  
AFDBYZ  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE BILLINGS MT  
653 PM MDT WED SEP 10 2025  
   
KEY MESSAGES  
 
- ABOVE NORMAL TEMPERATURES THROUGH THURSDAY.  
 
- PERIODS OF ISOLATED TO SCATTERED SHOWERS AND THUNDERSTORMS TODAY  
AND THURSDAY. BEST CHANCE OF PRECIPITATION IS THURSDAY.  
 
- A FEW THUNDERSTORMS COULD BECOME STRONG TO SEVERE ON THURSDAY  
AFTERNOON AND EVENING. MAIN THREAT IS STRONG WINDS AND HAIL.  
 
- INCREASED CHANCE FOR PRECIPITATION (50-80% CHANCE >0.25IN,  
GREATEST EAST OF BILLINGS) AND COOLER TEMPS FRIDAY INTO SUNDAY.  
 
 
   
UPDATE  
 
CONVECTION OVER THE SOUTH IS FINALLY LIFTING OFF THE BEARTOOTH-  
ABSAROKA FOOTHILLS (AND SURVIVING) AS OF 645PM. FORCING IS QUITE  
WEAK BUT THERE SEEMS TO BE ENOUGH TO KEEP AT LEAST WEAK CONVECTION  
GOING FOR THE NEXT SEVERAL HOURS. MLCAPES ARE 500-1000 J/KG AND  
BULK SHEAR IS ONLY ~25 KTS, AND LOW LEVEL SHEAR IS CURRENTLY VERY  
WEAK, BUT OVER THE NEXT FEW HOURS AS T-STORM POTENTIAL SHIFTS EAST  
OF BILLINGS THERE WILL BE A MODEST SOUTHEASTERLY LOW LEVEL JET TO  
HELP THINGS OUT. NOW THAT WE HAVE SEEN STORMS INITIATE AND TRACK  
OFF THE FOOTHILLS, THERE IS CONFIDENCE FOR SCATTERED ACTIVITY THRU  
THE BILLINGS AREA IN THE NEXT 1-2 HOURS, THEN ACROSS OUR EAST  
THRU THE LATE EVENING AND INTO THE OVERNIGHT HOURS. STORMS SEEN  
MOVING OFF THE SOUTHERN BIGHORNS AND INTO SOUTHEAST SHERIDAN  
COUNTY COULD TRACK INTO SOUTHEAST MT FAIRLY SOON AS WELL. MAIN  
RISK FROM ALL STORMS THIS EVENING IS GUSTY WINDS. HEADS UP IF YOU  
HAVE OUTDOOR PLANS. HAVE ADJUSTED POPS UP TO ACCOMMODATE HIGHER  
CONFIDENCE BETWEEN NOW AND ~08Z. JKL  
 
 
   
DISCUSSION  
 
THROUGH THURSDAY NIGHT...  
 
OUR CURRENT SYNOPTIC PATTERN CONTINUES TO BE DOMINATED BY A RIDGE  
OF HIGH PRESSURE TO OUR EAST AND A LARGE LOW PRESSURE SYSTEM TO  
OUR WEST. AS THE LOW PRESSURE SYSTEM TO OUR WEST GRADUALLY  
APPROACHES OUR REGION THROUGH THURSDAY, WE WILL SEE INCREASINGLY  
DIFFLUENT MID LEVEL FLOW, INCREASED ATMOSPHERIC MOISTURE BOTH AT  
THE SURFACE AND ALOFT, AND MULTIPLE DISTURBANCES TRACK NORTHEAST  
THROUGH THE AREA. THIS WILL BRING PERIODS OF ISOLATED TO SCATTERED  
SHOWERS AND THUNDERSTORMS TO THE AREA, WITH THE BEST CHANCE OF  
PRECIPITATION EXISTING ON THURSDAY (15 TO 70 PERCENT, GREATEST  
OVER SOUTH-CENTRAL MONTANA WHERE THE UPPER LEVEL SUPPORT IS  
STRONGEST). A FEW THUNDERSTORMS MAY BECOME STRONG TO SEVERE  
THURSDAY AFTERNOON AND EVENING WITH STRONG WINDS AND HAIL BEING  
THE MAIN THREATS.  
 
LOOKING A BIT CLOSER AT THE CHANCE OF PRECIPITATION, ISOLATED TO  
SCATTERED SHOWERS AND THUNDERSTORMS ARE FORECAST THIS AFTERNOON  
AND EVENING. AT THIS TIME, UNCERTAINTY REMAINS ON THE SPACIAL  
EXTENT OF THIS ACTIVITY AS THERE IS A MID- LEVEL CAP IN PLACE  
UNDER THE INFLUENCE OF THE UPPER LEVEL RIDGE TO OUR EAST. HOWEVER,  
A FEW HIGH RESOLUTION MODELS INDICATE THIS CAP MAY ERODE FOR A  
FEW HOURS THIS AFTERNOON AND EARLY EVENING, ALLOWING CONVECTION TO  
DEVELOP. SHOULD THIS OCCUR, A FEW STRONGER STORMS ARE POSSIBLE IN  
EASTERN MONTANA BEFORE SUNSET WITH GUSTY WINDS BEING THE MAIN  
THREAT. THE PROBABILITY FOR ANY SEVERE THUNDERSTORMS REMAINS LOW.  
WHILE ANY ACTIVITY THAT FORMS TODAY WILL LIKELY TAPER OFF THIS  
EVENING, A DEVELOPING LOW LEVEL JET OVER EASTERN MONTANA MAY ALLOW  
SHOWERS TO LINGER OVERNIGHT IN EASTERN MONTANA (10 TO 20 PERCENT  
CHANCE). BY THURSDAY MORNING, ANOTHER WAVE OF ISOLATED TO  
SCATTERED SHOWERS LOOKS TO LIFT NORTH OVER SOUTH-CENTRAL MONTANA.  
WITH THIS, PRECIPITATION LOOKS TO BE LIGHT. BY THURSDAY AFTERNOON  
AND EVENING, A MORE ROBUST ROUND OF PRECIPITATION IS EXPECTED.  
WITH MODEST CAPE AND SHEAR, AND THE PASSAGE OF A PACIFIC COLD  
FRONT, A FEW STRONG TO SEVERE THUNDERSTORMS COULD DEVELOP OVER THE  
PLAINS OF MONTANA AND WYOMING. AS PREVIOUSLY MENTIONED, THE MAIN  
THREATS ARE STRONG WINDS AND HAIL. WINDS COULD BE LOCALLY ENHANCED  
ALONG THE FRONT WHERE CONVECTION EXISTS. THE SHOWERS AND  
THUNDERSTORMS THURSDAY LOOK TO LIFT NORTH AND EAST OUT OF OUR AREA  
BY LATE IN THE EVENING.  
 
TEMPERATURES THURSDAY WILL REMAIN WARM IN THE UPPER 70S TO LOWER  
90S, WARMEST IN EASTERN MONTANA. OVERNIGHT LOWS WILL RANGE IN THE  
50S AND 60S TONIGHT AND 40S AND 50S THURSDAY NIGHT. ARENDS  
 
FRIDAY THROUGH TUESDAY...  
 
STRONG TROUGH AND A DEVELOPING UPPER LOW ARE SHOWN MOVING INTO  
THE REGION BY ENSEMBLES THROUGH THE WEEKEND. COOLER AND WETTER  
CONDITIONS WILL ACCOMPANY THIS SYSTEM.  
 
MODELS HAVE COME INTO BETTER AGREEMENT THAT THE UPPER LOW WILL  
DEVELOP ALONG THE MONTANA/CANADIAN BORDER AND LIFT NORTH. THIS HAS  
LARGE IMPLICATIONS FOR THE FORECAST AREA, WITH THE LOW LIFTING  
NORTH THE CHANCE FOR WIDESPREAD AND LONG LASTING PRECIP WILL  
DECREASE. CURRENTLY, THE CHANCE FOR PRECIPITATION WILL INCREASE  
FROM WEST TO EAST, LATE FRIDAY MORNING THROUGH THE AFTERNOON.  
OVERALL THE CHANCE FOR PRECIPITATION ON FRIDAY IS MODERATE TO HIGH  
(50-80%) ACROSS THE AREA. DEPENDING ON WHERE THE LOW DEVELOPS,  
ISOLATED TO SCATTERED THUNDERSTORMS ARE POSSIBLE WITH MODEST  
INSTABILITY REMAINING FROM THURSDAY. THE CHANCE FOR PRECIPITATION  
OVER THE WEEKEND IS CURRENTLY LOW TO MODERATE (15-40%). STORM  
TOTAL RAINFALL AMOUNTS HAVE DECREASED WITH THE LATEST FORECAST,  
THOUGH 0.1 TO 1 INCH OF RAINFALL IS DEPICTED FRIDAY MORNING  
THROUGH SATURDAY MORNING. THE BEST CHANCE FOR MORE THAN 0.25" OF  
QPF LARGELY EXISTS EAST OF BILLINGS, AND THE BEST CHANCE FOR AT  
LEAST 0.50" OF QPF EXISTS IN AND EAST OF ROSEBUD COUNTY.  
BILLINGS AND WEST WILL GENERALLY SEE AMOUNTS BETWEEN 0.1" TO  
0.25".  
 
HIGH TEMPERATURES WILL BE IN THE 70S TO LOW 80S FRIDAY, COOLING  
INTO THE UPPER 60S AND 70S SATURDAY. A CLIMB BACK INTO THE 70S AND  
80S IS SHOWN BY ENSEMBLES, SUNDAY AND MONDAY.  
 
FOR RELEVANT PRECIPITATION PROBABILITY GRAPHICS, PLEASE VISIT  
WEATHER.GOV/BYZ  
 
MATOS  
 
 
   
AVIATION  
 
THERE IS A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS THIS  
AFTERNOON AND EVENING ACROSS MUCH OF THE AREA. WHILE UNCERTAINTY  
REMAINS ON THE EXTENT OF THIS ACTIVITY, ANY SHOWER OR THUNDERSTORM  
THAT DEVELOPS COULD PRODUCE GUSTY AND ERRATIC WINDS. BY LATE THIS  
EVENING INTO TONIGHT, A LOW LEVEL JET LOOKS TO DEVELOP OVER  
EASTERN MONTANA. THIS COULD KEEP SHOWER ACTIVITY GOING INTO THE  
NIGHT, AS WELL AS BRING SOME LOW LEVEL WIND SHEAR TO AIRPORTS  
AROUND KMLS AND KBHK. OVER THE MOUNTAINS OF SOUTH- CENTRAL MONTANA  
LATE TONIGHT INTO THURSDAY MORNING, ANOTHER ROUND OF SCATTERED  
SHOWERS LOOKS TO MOVE INTO THE REGION. THE CHANCE OF SHOWERS AND  
THUNDERSTORMS THEN SPREADS ACROSS THE REGION ONCE AGAIN THURSDAY  
AFTERNOON AND EVENING. ARENDS/TS  
 
 
   
PRELIMINARY POINT TEMP/POPS  
 
THU FRI SAT SUN MON TUE WED  
-----------------------------------------------------------  
BIL 061/084 054/080 055/075 054/077 054/082 053/077 053/074  
24/T 33/T 55/T 22/W 12/W 33/W 33/W  
LVM 051/079 044/075 044/073 044/074 045/077 044/073 044/074  
25/T 34/T 45/T 22/T 13/T 34/T 33/W  
HDN 057/086 052/082 053/074 050/077 050/082 050/077 050/075  
33/T 42/T 66/T 32/W 11/U 33/W 43/W  
MLS 060/089 056/083 057/073 054/077 053/082 053/078 053/074  
32/T 52/W 77/T 53/W 21/U 32/W 43/W  
4BQ 062/088 056/082 058/072 052/074 052/080 053/077 052/072  
21/U 21/U 76/T 42/W 11/U 22/W 43/W  
BHK 057/091 054/083 054/072 050/074 050/081 050/079 049/072  
31/B 21/U 78/T 63/T 21/U 22/W 43/W  
SHR 054/086 049/079 048/071 044/074 046/080 047/076 046/073  
22/T 24/T 77/T 32/T 11/U 23/W 44/W  
 
 
   
BYZ WATCHES/WARNINGS/ADVISORIES  
 
MT...NONE.  
WY...NONE.  
 
 
 
 
WEATHER.GOV/BILLINGS  
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