453  
FXUS65 KTFX 012300  
AFDTFX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GREAT FALLS MT  
500 PM MDT TUE JUL 1 2025  
 
AVIATION SECTION UPDATED.  
   
KEY MESSAGES
 
 
- VERY WARM TO HOT CONDITIONS CONTINUE THROUGH THURSDAY  
WITH TEMPERATURES COOLING CLOSER TO AVERAGE HEADING INTO THE  
WEEKEND.  
 
- SCATTERED SHOWERS AND THUNDERSTORMS DEVELOP OVER SOUTHWEST  
MONTANA THIS AFTERNOON AND EVENING WITH SOME STORMS CAPABLE OF  
LOCALIZED WIND GUSTS OVER 50 MPH.  
 
- SCATTERED SHOWERS AND THUNDERSTORMS ARE EXPECTED FOR  
MOST LOCATIONS ON WEDNESDAY, THE STRONGER STORMS MAY PRODUCE  
STRONG, GUSTY WINDS, HAIL, AND BRIEF DOWNPOURS.  
 
- DAILY ROUNDS OF SHOWERS AND THUNDERSTORMS CONTINUE HEADING  
INTO THE WEEKEND.  
 

 
   
DISCUSSION
 
 
/ISSUED 202 PM MDT TUE JUL 1 2025/  
 
- METEOROLOGICAL OVERVIEW:  
 
RIDGING ALOFT WILL BRING VERY WARM TO HOT CONDITIONS OVER THE  
NEXT COUPLE DAYS WITH AFTERNOON TEMPERATURES PEAKING ON WEDNESDAY  
IN THE LOWER AND MIDDLE 90S FOR MOST LOWER ELEVATION LOCATIONS. A  
WEAK SHORTWAVE IS EXPECTED TO UNDERCUT THE RIDGE AND INTERACT WITH  
STRONG DIURNAL HEATING FOR WIDELY SCATTERED SHOWER AND  
THUNDERSTORM DEVELOPMENT OVER SOUTHWEST MONTANA THIS AFTERNOON AND  
EVENING. DRY SUB-CLOUD LAYERS AND INVERTED V PROFILES IN A WEAKLY  
SHEARED ENVIRONMENT WILL MAKE LOCALIZED STRONG TO SEVERE WIND  
GUSTS THE PRIMARY CONCERN.  
 
SOUTHWESTERLY FLOW ALOFT WILL BECOME MORE ESTABLISHED OVER THE  
NORTHERN ROCKIES ON WEDNESDAY WHILE A TROUGH DIGS INTO THE PACIFIC  
NW AND PUSHES THE RIDGE AXIS FARTHER EAST. A SHORTWAVE WILL PASS  
THROUGH THE SOUTHWESTERLY FLOW AND BRING 25 TO 35 KTS OF BULK  
SHEAR TO AN ENVIRONMENT WITH MLCAPE AROUND 800 TO 1,200 J/KG AND  
PRECIPITABLE WATER APPROACHING THE ONE INCH MARK. THUNDERSTORM  
HAZARDS FOR WEDNESDAY WILL INCLUDE HAIL AND BRIEF HEAVY DOWNPOURS,  
BUT LOCALIZED STRONG TO SEVERE WIND GUSTS WILL ONCE AGAIN BE THE  
PRIMARY HAZARD. THE MOST WIDESPREAD STORMS AND THREAT FOR SEVERE  
WEATHER WILL BE FOR LOCATIONS EAST OF I15.  
 
SHOWERS AND THUNDERSTORMS ACTIVITY WILL CONTINUE ON THURSDAY, BUT  
WEST TO NORTHWESTERLY FLOW IN THE WAKE OF WEDNESDAY'S SHORTWAVE  
LOOKS TO PUSH THE MOST WIDESPREAD ACTIVITY A LITTLE FARTHER SOUTH  
INTO CENTRAL AND SOUTHWEST MONTANA. FORECAST SOUNDINGS CURRENTLY  
SHOW PROFILES WITH LONG/THIN CAPE WITH DEEP SATURATION. ALSO  
RELATIVE HUMIDITY VALUES CLIMB SOME WHILE TEMPERATURES FALL A FEW  
DEGREES. THIS GIVES THE EXPECTATION FOR MORE RAINFALL PRODUCTIVE  
SHOWERS AND STORMS WITH SOME INSTANCES OF HAIL AND STRONG WIND  
GUSTS.  
 
A COUPLE OF DEEPER SHORTWAVES MOVES THROUGH FOR THE FRIDAY  
THROUGH MONDAY PERIOD AND BRING ADDITIONAL ROUNDS OF SHOWERS AND  
THUNDERSTORMS WITH NEAR AVERAGE TEMPERATURES. SIMILAR TO THURSDAY,  
THIS ACTIVITY LOOKS TO BE MORE PRODUCTIVE RAINFALL WISE, BUT  
THERE WILL STILL BE SUFFICIENT CAPE AROUND FOR AT LEAST SOME  
INSTANCES OF HAIL AND THUNDERSTORM WIND GUSTS. - RCG  
 
- FORECAST CONFIDENCE & SCENARIOS:  
 
MODERATE HEAT RISK THROUGH THURSDAY...  
 
NOT MUCH HAS CHANGED IN REGARDS TO THE HEAT RISK EXPECTED TODAY  
THROUGH THURSDAY. TEMPERATURES ARE STILL EXPECTED TO PEAK ON  
WEDNESDAY WITH HIGHS IN THE LOWER TO MID- 90S FOR MOST LOWER  
ELEVATION LOCATIONS. AREAS SOUTHEAST OF THE HIGHWAY 87 CORRIDOR  
BETWEEN GREAT FALLS AND HAVRE (EXCLUDING THE LEWISTOWN AREA) WILL  
HAVE THE GREATEST RISK WHERE OVERNIGHT TEMPERATURES WILL HOVER  
AROUND 60 DEGREES OR HIGHER IN ADDITION TO THE AFTERNOON HEAT.  
NORTHERN FERGUS AND SOUTHERN BLAINE COUNTIES CURRENTLY HAVE AN 80  
TO 100% CHANCE FOR LOWS ABOVE 60 DEGREES. LOCALIZED AREAS WITH  
MAJOR HEAT IMPACTS ARE EXPECTED, ALTHOUGH IT WILL BE ONLY FOR A 24  
TO 36 HOUR PERIOD. NO HEAT PRODUCTS ARE ANTICIPATED AT THIS TIME,  
BUT THE SITUATION WILL CONTINUE TO BE MONITORED.  
 
PERIODS OF SHOWERS AND THUNDERSTORMS THROUGH THE WEEKEND...  
 
MOST OF THE MOISTURE WILL BE IN THE MIDDLE AND UPPER LEVEL TODAY  
WITH VERY DRY SURFACE CONDITIONS. THIS SETUP IS FAVORABLE FOR HIGH  
BASED SHOWER AND THUNDERSTORM DEVELOPMENT WITH LIMITED WIND SHEAR  
FOR STORM MAINTENANCE. LOCALIZED STRONG, GUSTY WINDS IN EXCESS OF  
50 MPH AND OCCASIONAL LIGHTNING WILL BE THE PRIMARY HAZARD TO  
WATCH FOR THIS AFTERNOON AND EVENING. THE LATEST HREF GUIDANCE  
HIGHLIGHTS MUCH OF SOUTHWEST MONTANA WITH A 70% + CHANCE FOR  
THUNDERSTORMS WIND GUSTS UP TO AND OVER 35 MPH AND A 10% CHANCE  
FOR GUSTS 58 MPH OR GREATER. STORMS WILL MOSTLY IMPACT AREAS SOUTH  
OF I90 AND THEN BEGIN TO DIMINISH AND END AS THEY MOVE  
NORTH/NORTHEASTWARD IN CENTRAL MONTANA. TO THIS EFFECT, THE STORM  
PREDICTION CENTER HAS INCLUDED US IN A MARGINAL RISK FOR SEVERE  
STORMS THIS AFTERNOON (A 5% CHANCE OF SEEING WIND GUSTS OVER 58MPH  
WITHIN 25 MILES OF ANY GIVEN LOCATION) FOR SOUTHWESTERN MONTANA.  
 
SHOWER AND THUNDERSTORM ACTIVITY BECOMES MORE EXPANSIVE ON  
WEDNESDAY AS A SHORTWAVE ADDS BETTER UPPER LEVEL SUPPORT AND  
MOISTURE. THE GREATEST MOISTURE AND INSTABILITY WILL EAST OF I15,  
PARTICULARLY FOR AREAS SOUTH AND EAST OF A GREAT FALLS TO HAVRE  
LINE. THESE AREAS HAVE AROUND A 10% CHANCE FOR WIND GUSTS 58 MPH  
OR GREATER. THERE WILL ALSO BE THE THREAT FOR MARGINALLY SEVERE  
HAIL AND BRIEF DOWNPOURS.  
 
MOST SHOWERS AND STORMS SHIFT A LITTLE FARTHER SOUTH ON THURSDAY,  
MOSTLY STAYING OVER THE SOUTHWEST AND CENTRAL AREAS SOUTH OF THE  
HIGHWAY 87/200 CORRIDOR. THIS LOOKS TO BE TEMPORARY WITH  
SOUTHWESTERLY FLOW ALOFT AND PASSING SHORTWAVES BRINGING MORE  
AREAWIDE SHOWER AND THUNDERSTORM POTENTIAL HEADING INTO THE  
WEEKEND AND BEYOND. THERE WILL BE SUFFICIENT INSTABILITY AND  
MOISTURE FOR SEVERE WEATHER AND PRODUCTIVE SHOWERS AND STORMS WITH  
THE MOST RAINFALL GENERALLY EXPECTED THURSDAY THROUGH SATURDAY.  
- RCG  
 

 
   
AVIATION
 
 
02/00Z TAF PERIOD  
 
SHRA AND TSRA WILL CONTINUE TO PUSH ACROSS SOUTHWESTERN MONTANA  
THIS EVENING, THOUGH THEY SHOULD GENERALLY STAY NEAR OR SOUTH OF A  
KHLN TO KLWT LINE. ANY SHOWERS AND STORMS SHOULD DISSIPATE BY 4Z,  
LEAVING CLEARING SKIES AND LIGHT WINDS OVERNIGHT TONIGHT. SKIES  
START OUT CLEAR ON WEDNESDAY, BUT ANOTHER, MORE WIDESPREAD ROUND  
OF SHRA AND TSRA RETURN DURING THE AFTERNOON AND EVENING HOURS  
ACROSS ALL NORTH CENTRAL AND SOUTHWESTERN MONTANA. LUDWIG  
 
REFER TO WEATHER.GOV/ZLC FOR MORE DETAILED REGIONAL AVIATION  
WEATHER AND HAZARD INFORMATION.  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
GTF 58 94 60 90 / 0 20 20 30  
CTB 56 90 58 84 / 0 10 10 10  
HLN 58 91 59 87 / 0 40 20 50  
BZN 55 94 55 87 / 30 30 20 60  
WYS 45 82 45 73 / 20 30 20 60  
DLN 53 88 54 82 / 20 40 30 70  
HVR 58 99 59 93 / 0 10 30 10  
LWT 59 90 59 84 / 0 20 30 40  
 

 
   
TFX WATCHES/WARNINGS/ADVISORIES
 
 
NONE.  

 
 

 
HTTP://WWW.WEATHER.GOV/GREATFALLS  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab MT Page Main Text Page