311  
FXUS65 KTFX 242308  
AFDTFX  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GREAT FALLS MT  
308 PM MDT FRI MAR 24 2017  
 
UPDATED AVIATION  
   
DISCUSSION
 
 
TONIGHT THROUGH SUNDAY...RIDGE OF HIGH PRESSURE HAS EXITED THE CWA  
AS EVIDENT BY INCREASING CLOUDS AND WINDS. INCREASING  
SOUTHWESTERLY WINDS ARE BRINGING SOME BREEZY AREAS AND MOUNTAIN  
WAVE CLOUDS THIS AFTERNOON. AS MOISTURE INCREASES WITH THE  
SOUTHWEST FLOW ASSOCIATED WITH A WEAK RIVER EVENT...RAIN SHOWERS  
AND SNOW SHOWERS ABOVE 6000 FEET...POSSIBLY LOWERING TO 5000 FEET  
LATE TONIGHT...ARE EXPECTED THROUGH THE OVERNIGHT HOURS ACROSS  
WESTERN AND SOUTHERN PORTIONS. THESE SHOWERS COULD ALSO SPREAD  
ACROSS CENTRAL PORTIONS EARLY SATURDAY MORNING WITH A WEAK  
SHORTWAVE EMBEDDED IN THE FLOW. CHANCES FOR RAIN SHOWERS AND SNOW  
SHOWERS ABOVE 5000 FEET THEN LINGER THROUGH SATURDAY ACROSS  
WESTERN AND SOUTHERN PORTIONS...WHILE SOME SCATTERED SHOWERS MAY  
RETURN ACROSS CENTRAL PORTIONS SATURDAY AFTERNOON. PRECIP COULD  
THEN LINGER ACROSS THE WEST AND SOUTH THROUGH SATURDAY  
EVENING...THEN A RIDGE OF HIGH PRESSURE WILL BRING DRYING  
CONDITIONS OVERNIGHT SATURDAY NIGHT INTO SUNDAY. A DRY AND  
SLIGHTLY BREEZY DAY IS EXPECTED FOR SUNDAY. SO OVERALL SOME ACTIVE  
BUT LOW IMPACT WEATHER IS EXPECTED ACROSS THE WEST AND SOUTH  
THROUGH SATURDAY...WITH SCATTERED SHOWERS CENTRAL...AND LITTLE  
PRECIP NORTH. THIS TIME OF YEAR IT SEEMS DIFFICULT TO ACCUMULATE  
SNOW OTHER THAN AT NIGHT. SNOW ACCUMULATIONS FROM PASS LEVELS AND  
HIGHER COULD REACH THE 2 TO 6 INCH RANGE IN SOUTHWEST  
MT...HOWEVER...IMPACTS ARE EXPECTED TO BE LOW AS THE MARCH SUN  
WILL KEEP ROADS WARM. SLIGHTLY COOLER BUT STILL ABOVE NORMAL TEMPS  
IN THE LOW TO MID 50S ARE GENERALLY EXPECTED FOR SATURDAY...WITH  
SOME 40S SOUTHWEST. WARMING TEMPS IN THE MID TO UPPER 50S ARE  
EXPECTED SUNDAY. RIVERS WILL CONTINUE TO BE MONITORED...HOWEVER NO  
WARNINGS ARE IN EFFECT CURRENTLY. FIRE DANGER HAS PROBABLY PEAKED  
TODAY...ALTHOUGH MAY INCREASE AGAIN SLIGHTLY ON SUNDAY. ANGLIN  
 
SUNDAY NIGHT THROUGH FRIDAY...THE REGION COMES UNDER  
INFLUENCE OF AN UPPER LEVEL TROUGH LATE SUNDAY INTO MONDAY, WITH THE  
POTENTIAL FOR SPLITTING UPPER LEVEL ENERGY RESULTING IN A SNOW/RAIN  
MIX ACROSS MUCH OF THE AREA, BUT ESPECIALLY ACROSS SW MT, WHERE THE  
HIGHEST PRECIPITATION CHANCES LOOK TO BE MONDAY INTO MONDAY NIGHT  
BEFORE THE SYSTEM DEPARTS TO THE EAST. CONDITIONS IMPROVE LATER  
TUESDAY THROUGH WEDNESDAY ASIDE FROM SCATTERED, MAINLY MOUNTAIN  
SHOWERS. UNCERTAINTY INCREASES WITH THE FOLLOWING SYSTEM FOR LATE-  
WEEK. THIS SYSTEM LOOKS TO PUSH A COLD FRONT SOUTH AND EAST THROUGH  
THE REGION, WITH A ROUND OF UPSLOPE FLOW AND MOISTURE THAT WOULD  
ALLOW FOR SOME ACCUMULATING SNOW ACROSS PARTS OF THE HIGH PLAINS AS  
WELL AS PARTS OF SW MT. THE GFS AND CANADIAN MODELS INDICATE A QUICK  
BURST OF SNOW IN A SHORT AMOUNT OF TIME (6 HOURS OR LESS), WHILE THE  
EUROPEAN MODEL INDICATES UP TO A 24-HOUR PERIOD OF SNOW FROM  
THURSDAY INTO FRIDAY FOR SOME PARTS OF OUR AREA. THIS SYSTEM WILL  
BEAR WATCHING THROUGH THE MIDDLE OF NEXT WEEK. CASSELL  
 

 
   
AVIATION
 
 
UPDATED 2308Z.  
 
SOUTHWESTERLY TO WESTERLY FLOW ALOFT WILL PERSIST DURING THE TAF  
PERIOD. ONE WEATHER DISTURBANCE SHOULD CROSS THE AREA BETWEEN 06Z  
AND 18Z/SAT, WHILE ANOTHER SHOULD NEAR THE CONTINENTAL DIVIDE FROM  
THE WEST BY 00Z/SUN. VFR AND BREEZY SURFACE WINDS ARE EXPECTED AT  
THE NORTH-CENTRAL MT TERMINALS DURING THE PERIOD. FARTHER SOUTH, A  
PERIOD OF MVFR TO IFR CIGS AND PERHAPS MVFR VSBY IN SHOWERS OF RAIN  
AND/OR SNOW IS POSSIBLE AT KBZN, KEKS AND KHLN, ESPECIALLY BETWEEN  
ABOUT 06Z AND 15Z/SAT. IN ADDITION, PERIODS OF MOUNTAIN  
OBSCURATION SHOULD BE EXPECTED DURING THE PERIOD.  
JASZKA  
 

 
   
PRELIMINARY POINT TEMPS/POPS
 
 
GTF 38 55 32 57 / 20 20 10 0  
CTB 35 49 29 51 / 10 10 0 0  
HLN 37 53 32 56 / 40 30 40 10  
BZN 36 51 30 54 / 50 60 30 10  
WEY 29 38 20 40 / 60 70 40 10  
DLN 35 49 28 52 / 30 30 20 0  
HVR 38 57 31 56 / 10 10 10 0  
LWT 37 51 31 52 / 20 20 20 0  
 

 
   
TFX WATCHES/WARNINGS/ADVISORIES
 
 
NONE.  

 
 

 
 
WEATHER.GOV/GREATFALLS  
 
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