524  
FXUS65 KTFX 010005  
AFDTFX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GREAT FALLS MT  
600 PM MDT SUN MAY 31 2020  
   
..UPDATED AVIATION SECTION AND NEAR TERM UPDATE
 
 
   
SYNOPSIS
 
 
A PASSING COLD FRONT HAS LEFT GUSTY WESTERLY WINDS BUT DRIER  
CONDITIONS IN ITS WAKE. THE WINDS ARE EXPECTED TO DIMINISH THIS  
EVENING. ANOTHER ROUND OF SHOWERS AND SOME THUNDERSTORMS ARE  
EXPECTED OVER THE CENTRAL AND SOUTHWEST FOR MONDAY AFTERNOON AND  
EVENING. BREEZY AND DRIER CONDTIONS ARE THEN EXPECTED THROUGH LATE  
WEEK FOR MOST AREAS.  
 

 
   
DISCUSSION
 
 
600 PM UPDATE...WESTERLY WINDS, THOUGH STILL FAIRLY STRONG, ARE  
DECREASING SOMEWHAT OVER THE ROCKY MOUNTAIN FRONT AND OUT ONTO THE  
ADJACENT PLAINS. THE WINDS SHOULD GENERALLY REMAIN BELOW HIGH WIND  
CRITERIA THROUGH THE EVENING AS THEY CONTINUE TO DECREASE, SO HAVE  
ALLOWED THE HIGH WIND WARNING FOR THAT AREA TO EXPIRE. COULSTON  
 
REMAINDER OF THIS AFTERNOON THROUGH MONDAY NIGHT...A PACIFIC COLD  
FRONT HAS JUST CLEARED THE FAR EASTERN PORTIONS OF THE CWA, LEAVING  
GUSTY WINDS AND MILD, DRIER CONDITIONS IN ITS WAKE. HOWEVER, THERE  
ARE A FEW LEFT OVER ISOLATED SHOWERS ALONG THE DIVIDE. THE STRONG  
WINDS THAT BROUGHT BLOWING DUST IN SOME AREAS HAVE DIMINISHED  
SOMEWHAT BUT ARE STILL ON THE STRONGER SIDE, ESPECIALLY ALONG THE  
ROCKY MOUNTAIN FRONT AND THE ADJOINING PLAINS. WILL KEEP THE HIGH  
WIND WARNING GOING THROUGH THE 0Z EXPIRATION AS THERE IS STILL A  
CHANCE OF 50 KT H700 WINDS MIXING DOWN TO THE SURFACE IN THESE  
AREAS. TONIGHT WINDS ARE EXPECTED TO DIMINISH AS SHORTWAVE RIDGING  
BRIEFLY PASSES THROUGH THE REGION. LOW TEMPERATURES WILL BE MUCH  
COOLER COMPARED TO LAST NIGHT BUT WILL STILL BE NEAR OR ABOVE THE  
SEASONAL AVERAGE FOR MOST LOCATIONS. MONDAY WILL BEGIN DRY BUT  
ANOTHER DISTURBANCE WILL DISPLACE THE AFOREMENTIONED SHORTWAVE  
RIDGING AND WILL BRING SOME SHOWERS AND THUNDERSTORMS TO CENTRAL AND  
SOUTHWESTERN AREAS BY MONDAY AFTERNOON. SEVERE STORMS ARE NOT  
EXPECTED AT THIS TIME BUT A FEW CAN BE ON THE STRONG SIDE WITH GUSTY  
WINDS AND SMALL HAIL SINCE THERE WILL BE SOME UPPER LEVEL SUPPORT  
AND INSTABILITY WITH THIS SYSTEM. BY MONDAY NIGHT, THIS ACTIVITY IN  
MOVE NORTHEASTWARD TOWARD THE EASTERN PORTIONS ON CENTRAL/NORTH-  
CENTRAL MONTANA WHILE WEAKENING AND EVENTUALLY MOVING OUT OF THE  
AREA. RCG  
 
TUESDAY THROUGH SUNDAY...WESTERLY FLOW WILL THEN TAKE SHAPE  
THROUGH THURSDAY, BRINGING MORE THE WESTERLY WINDS AND MOSTLY DRY  
CONDITIONS. THEN, A BROAD LOW PRESSURE TROUGH IS EXPECTED TO BRING  
A MORE CYCLONIC WESTERLY TO SOUTHWESTERLY FLOW ALOFT INTO NEXT  
WEEKEND. ALTHOUGH THIS WILL LIKELY NOT IMPACT TEMPERATURES  
SIGNIFICANTLY (STILL LOOKING AT TEMPERATURES AROUND 5 TO 10  
DEGREES ABOVE NORMAL), THE GREATER IMPACT WILL BE AN INCREASE IN  
THE CHANCE FOR SHOWERS AND THUNDERSTORMS ACROSS MUCH OF NORTH-  
CENTRAL AND SOUTHWEST MONTANA. RCG/CC  
 

 
   
AVIATION
 
 
UPDATED 600 PM MDT SUN MAY 31 2020 (01/00Z-02/00Z TAF ISSUANCE)  
 
VFR CONDITIONS WILL CONTINUE OVER MUCH OF THE FORECAST AREA THROUGH  
AT LEAST THE NEXT 24 HOURS. LINGERING MOUNTAIN TOP OBSCURING SHOWERS  
ON THE ROCKY MOUNTAIN FRONT WILL DECREASE THROUGH 06Z. MOST OF THE  
AREA WILL REMAIN MOSTLY CLEAR FOR MUCH OF THE PERIOD, AS THE STRONG  
WESTERLY WINDS GUSTING BETWEEN 35 AND 45 KT DECREASE THROUGH 06Z.  
HOWEVER, A DISTURBANCE WILL SPREAD HIGH AND MID LEVEL CLOUDINESS  
INTO SOUTHWEST MONTANA AFTER 06Z AND OVER CENTRAL AND NORTH CENTRAL  
MONTANA THROUGH THE REMAINDER OF THE PERIOD. THIS DISTURBANCE MAY  
ALSO BRING SCATTERED SHOWERS AND THUNDERSTORMS TO PORTIONS OF  
SOUTHWEST MONTANA AFTER 18Z, POSSIBLY CAUSING PERIODS OF MVFR  
CONDITIONS. COULSTON  
 
NOTE: AMENDMENTS NOT SCHEDULED FOR ENNIS (KEKS) DUE TO ONGOING  
RUNWAY CLOSURE.  
 

 
   
HYDROLOGY
 
 
THERE HAVE BEEN WATER LEVEL RISES ON BADGER CREEK BELOW FOUR  
HORNS CANAL NEAR BROWNING, AND THE SAINT MARY RIVER AT  
INTERNATIONAL BOUNDARY. A FLOOD ADVISORY HAS BEEN ISSUED FOR THE  
AREAS ALONG BADGER CREEK BELOW FOUR HORNS CANAL NEAR BROWNING  
THROUGH MONDAY AFTERNOON.  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
GTF 46 76 47 76 / 0 0 30 0  
CTB 45 72 44 73 / 0 0 10 0  
HLN 48 79 48 78 / 0 20 40 10  
BZN 46 82 50 77 / 0 20 40 20  
WYS 41 76 43 70 / 0 0 20 30  
DLN 46 78 48 76 / 0 30 20 20  
HVR 48 79 50 78 / 0 0 30 0  
LWT 48 75 48 72 / 0 10 60 10  
 

 
   
TFX WATCHES/WARNINGS/ADVISORIES
 
 
NONE  
 

 
 

 
 
HTTP://WWW.WEATHER.GOV/GREATFALLS  
 
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