729  
FXUS65 KTFX 192345  
AFDTFX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GREAT FALLS MT  
445 PM MST THU DEC 19 2024  
 
AVIATION SECTION UPDATED.  
   
KEY MESSAGES
 
 
- DRY WEATHER AND WARMER TEMPERATURES CONTINUE TODAY AND FRIDAY.  
 
- THE FORECAST PERIOD WILL BE WINDY ACROSS THE ROCKY MOUNTAIN  
FRONT AND THE NORTH CENTRAL MONTANA PLAINS, MOST NOTABLY ON  
SUNDAY AND MONDAY.  
 
- A FEW ROUNDS OF LIGHT MOUNTAIN SNOW AND LOWER ELEVATION RAIN  
ARE FORECASTED THIS WEEKEND AND NEXT WEEK.  
 

 
   
DISCUSSION
 
 
/ISSUED 127 PM MST THU DEC 19 2024/  
 
- METEOROLOGICAL OVERVIEW:  
 
THE UPPER-LEVEL RIDGING BUILDING IN TODAY WILL KEEP THE AREA  
WARMER AND DRIER, EXCEPT FOR THE HI-LINE REGION. A SURFACE  
BOUNDARY DRAPED ACROSS NORTH-CENTRAL MT WILL KEEP THE WARM  
TEMPERATURES FROM MIXING IN ALONG THE HI-LINE. A SLIGHT BREAKDOWN  
IN THIS RIDGE FRIDAY WILL BRING BREEZY WINDS ACROSS THE PLAINS.  
HOWEVER, NEXT CHANCES FOR PRECIPITATION DON'T ARRIVE UNTIL LATE  
SATURDAY AS A BROADER UPPER-LEVEL TROUGH MOVES IN. THIS WILL BRING  
LIGHT MOUNTAIN SNOW/LOWER ELEVATION RAIN. STRONGER WINDS ALOFT  
MOVE IN SUNDAY AND MONDAY MORNING, BRINGING GUSTY CONDITIONS TO  
THE ROCKY MOUNTAIN FRONT AND NORTH-CENTRAL MT PLAINS.  
 
NEXT WEEK LOOKS TO REMAIN ACTIVE FOR MAINLY THE MOUNTAINS REGIONS.  
A FEW SMALL UPPER-LEVEL WAVES PASS THROUGH THE REGION THROUGHOUT  
THE WEEK. THE FIRST ONE ON MONDAY, BRINGING CHANCES FOR LIGHT  
PRECIPITATION ALONG THE CONTINENTAL DIVIDE AND SOUTHWEST MT. A  
MORE DYNAMIC UPPER-LEVEL TROUGH BRINGS IN MORE WIDESPREAD  
PRECIPITATION CHRISTMAS EVE AND EARLY CHRISTMAS MORNING.  
TEMPERATURES REMAIN ABOVE AVERAGE THROUGH THE FORECAST PERIOD.  
 
- FORECAST CONFIDENCE & SCENARIOS:  
 
THERE IS HIGH CONFIDENCE FOR DRY WEATHER TODAY AND TOMORROW WITH  
BREEZY WINDS ON FRIDAY. GUSTY WINDS SET UP ALONG THE ROCKY  
MOUNTAIN FRONT SUNDAY AND MONDAY, WITH A 50% CHANCE AND GREATER  
FOR 55 MPH. THE OVERALL SYNOPTIC SET UP DOESN'T LOOK AS IMPRESSIVE  
FOR A HIGH WIND EVENT SO NO HIGH WIND PRODUCTS ARE ANTICIPATED AT  
THIS TIME. WITH MULTIPLE UPPER-LEVEL WAVES MOVING THROUGH NEXT  
WEEK, THERE HAS BEEN GOOD AGREEMENT IN GUIDANCE FOR BREEZY TO  
GUSTY WINDS ACROSS THE ROCKY MOUNTAIN FRONT AND NORTH-CENTRAL MT  
PLAINS MOST DAYS. WE WILL HAVE TO MONITOR TRENDS FOR A SNEAKY HIGH  
WIND SET-UP, BUT I AM NOT ANTICIPATING ANY EVENTS AT THIS TIME.  
 
IN TERMS OF PRECIPITATION FROM LATE SATURDAY TO SUNDAY, HIGHER  
END VALUES (75TH PERCENTILE NBM) GIVES 1-4" OF SNOW AT HIGHER  
TERRAIN. WITH ONLY MINOR ACCUMULATIONS, ONLY MINOR IMPACTS ARE  
ANTICIPATED FOR TRAVEL. ACROSS LOWER ELEVATIONS, THERE'S A 20% FOR  
0.05" OF PRECIPITATION ACROSS THE NORTH-CENTRAL MT PLAINS. FOR  
RAIN AT LOWER ELEVATIONS ON CHRISTMAS EVE/EARLY CHRISTMAS MORNING,  
THERE'S A 20-50% FOR 0.05" OF PRECIPITATION SOUTH OF THE MONTANA  
HIGHWAY 200 CORRIDOR. AT HIGHER ELEVATIONS, THERE'S A 30-60%  
CHANCE FOR 2" OF SNOW AT PASS LEVEL IN SOUTHWEST MT. -WILSON  
 

 
   
AVIATION
 
 
20/00Z TAF PERIOD  
 
VARYING AMOUNTS OF MID-HIGH LEVEL CLOUD COVER STREAM ACROSS THE  
REGION TONIGHT AS AN UPPER LEVEL RIDGE SHIFTS ACROSS THE NORTHERN  
ROCKIES WITH DECREASING CLOUDS ON FRIDAY. CANNOT RULE OUT SOME  
PATCHY FOG AND/OR LOW CLOUD-DEVELOPMENT NEAR THE KHVR TERMINAL  
OVERNIGHT BUT LATEST FORECAST GUIDANCE HAS DECREASED PROBABILITIES  
TO LESS THAN 20%. OTHERWISE VFR CONDITIONS PREVAIL WITH GENERALLY  
LIGHT SURFACE WINDS OVERNIGHT GIVING WAY TO BREEZY WEST TO  
SOUTHWEST WINDS ON THE PLAINS FRIDAY. HOENISCH  
 
REFER TO WEATHER.GOV/ZLC FOR MORE DETAILED REGIONAL AVIATION  
WEATHER AND HAZARD INFORMATION.  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
GTF 30 54 35 55 / 0 0 0 0  
CTB 22 49 31 49 / 0 0 0 0  
HLN 27 48 28 47 / 0 0 0 0  
BZN 23 47 25 49 / 0 0 0 0  
WYS 10 37 8 38 / 0 0 0 0  
DLN 25 47 25 45 / 0 0 0 0  
HVR 8 39 20 44 / 0 10 0 0  
LWT 25 53 33 55 / 0 0 0 0  
 

 
   
TFX WATCHES/WARNINGS/ADVISORIES
 
 
NONE.  

 
 

 
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