212  
FXUS65 KTFX 190626  
AFDTFX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GREAT FALLS MT  
1226 AM MDT TUE MAY 19 2026  
   
KEY MESSAGES
 
 
- SLIGHT CHANCE FOR AFTERNOON SHOWERS AND THUNDERSTORMS THIS AFTERNOON  
ACROSS MUCH OF THE REGION.  
 
- MORE WIDESPREAD PRECIPITATION IS EXPECTED ON WEDNESDAY THROUGH THURSDAY.  
 
- TEMPERATURES WILL GRADUALLY WARM THROUGH THE WEEK WITH THE WARMEST  
TEMPERATURES EXPECTED THIS WEEKEND.  
 

 
   
DISCUSSION
 
 
- METEOROLOGICAL OVERVIEW  
 
AFTER A COOL START TO THE MORNING, TEMPERATURES WILL WARM MODESTLY  
INTO THE 50S AND 60S. LINGERING MOISTURE ON THE BACKSIDE OF THE  
UPPER-LEVEL TROUGH COMBINED WITH MODEST INSTABILITY WILL ALLOW FOR  
POP-UP SHOWERS AND THUNDERSTORMS THROUGH THE AFTERNOON TODAY.  
 
ON WEDNESDAY ANOTHER UPPER-LEVEL TROUGH WILL ARRIVE BRINGING A  
CHANCE FOR WIDESPREAD WETTING PRECIPITATION TO THE REGION. SNOW WILL  
BE GENERALLY CONFINED TO LOCATIONS ABOVE 7,000 FEET WITH THE REST OF  
THE LOWER ELEVATIONS SEEING PRIMARILY RAIN THROUGH THE EVENT.  
 
AS THE UPPER-LEVEL TROUGH STARTS TO SLOWLY EXIT THE AREA TOWARDS THE  
END OF THE WEEK, TEMPERATURES WILL GRADUALLY START TO WARM UP AS  
UPPER-LEVEL RIDGING BEGINS BUILDING OVER THE WESTERN CONUS THROUGH  
THE WEEKEND.  
 
- FORECAST CONFIDENCE & SCENARIOS:  
 
FOR TODAY, HI-RES MODELS WERE SHOWING PRETTY SCATTERED 15-30%  
CHANCES FOR PRECIPITATION ACROSS THE REGION. IN GENERAL, MOST  
LOCATIONS WILL REMAIN DRY THROUGHOUT THE DAY EXCEPT FOR WHERE THESE  
POP-UP SHOWERS END UP DEVELOPING. THE HIGHEST CHANCES FOR  
THUNDERSTORM ACTIVITY WILL BE ACROSS NORTH-CENTRAL MONTANA WITH ANY  
PRECIPITATION IN CENTRAL AND SOUTHWEST MONTANA EXPECTED TO BE MORE  
STRATIFORM IN NATURE.  
 
THERE IS STILL GOOD AGREEMENT FOR WIDESPREAD WETTING RAINS. THE  
HEAVIEST AMOUNTS ARE CURRENTLY EXPECTED ALONG A STRETCH FROM THE  
NORTHERN ROCKIES DOWN THROUGH CENTRAL MONTANA INCLUDING GREAT FALLS  
AND HELENA INTO LEWISTOWN. PROBABILITIES OF MORE THAN 0.25" OF  
PRECIPITATION ARE CURRENTLY SITTING AT 60-80% WITH A 20-40% CHANCE  
OF 0.5" OR MORE. WHILE PRECIPITATION AMOUNTS ACROSS THE REMAINDER OF  
NORTH-CENTRAL AND SOUTHWEST MONTANA ARE NOT EXPECTED TO BE QUITE AS  
HIGH THERE IS STILL AT LEAST A 40% CHANCE FOR A TENTH OF AN INCH OR  
MORE. -THOR  

 
   
AVIATION
 
 
19/06Z TAF PERIOD  
 
VFR CONDITIONS WILL PREVAIL THROUGHOUT THE DURATION OF THE  
1906/2006 TAF PERIOD; HOWEVER, WIDELY SCATTERED SHOWERS AND  
ISOLATED THUNDERSTORMS WILL DEVELOP BETWEEN 16-19Z TUESDAY AND  
PERSIST THROUGH 03-06Z WEDNESDAY ACROSS SOUTHWEST THROUGH NORTH  
CENTRAL MONTANA. MAIN IMPACT FROM ANY SHOWER OR STORM WILL BE  
ERRATIC WINDS AND BRIEF REDUCTIONS IN CIGS TO LOW-VFR, ALONG WITH  
MOUNTAIN OBSCURATION. - MOLDAN  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
GTF 64 40 56 38 / 40 20 70 80  
CTB 63 37 53 34 / 20 30 90 40  
HLN 65 38 60 37 / 30 30 40 80  
BZN 62 33 60 34 / 0 30 20 90  
WYS 54 25 54 29 / 10 20 20 80  
DLN 61 33 61 34 / 10 20 10 70  
HVR 68 40 60 36 / 40 60 50 30  
LWT 60 36 56 35 / 20 30 70 80  
 

 
   
TFX WATCHES/WARNINGS/ADVISORIES
 
 
NONE.  

 
 

 
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