277  
FXUS65 KGGW 190216 AAA  
AFDGGW  
 
AREA FORECAST DISCUSSION...UPDATED  
NATIONAL WEATHER SERVICE GLASGOW MT  
816 PM MDT FRI AUG 18 2017  
   
SHORT TERM...FOR NORTHEAST MONTANA...TONIGHT THROUGH SUN
 
 
GOES IMAGERY OF NORTH AMERICA SHOWS BROAD UPPER-LEVEL TROUGH  
ACROSS ALASKA AND EXTENDING THROUGH THE YUKON TERRITORY INTO THE  
NORTHERN REACHES OF BRITISH COLUMBIA AND ALBERTA. A WAVE/COLD  
FRONT CAN BE SEEN OUT AHEAD OF THE TROUGH ADVANCING IN OUR  
DIRECTION. THIS DRY FRONT WILL REACH OUR AREA BY MORNING.  
 
TONIGHT, THERE IS A NARROW AND WEAK UPPER RIDGE IN PLACE OVER  
NORTHEAST MONTANA TO BEGIN THE EVENING WITH MOSTLY CLEAR SKIES.  
BUT BROAD BAND OF CLOUDS IS EVIDENT ON THE SATELLITE VIEW THAT  
WILL MOVE TONIGHT. SO EXPECT INCREASING CLOUDS. A SURFACE TROUGH  
OVER CENTRAL MONTANA WILL MAINTAIN MOSTLY EAST WINDS INTIALLY.  
THAT TROUGH SHIFTS EAST TONIGHT. THE RESULT WILL BE WIND IN THE  
WEST COUNTIES SHIFTING TO THE NORTHWEST BEFORE MORNING. ONLY  
EDITS WERE TO INCLUDE THE LATEST NEAR TERM GUIDANCE.  
 
TEMPLER  
 
PREVIOUS DISCUSSION -  
SYNOPTIC SETUP: HOT DESERT SOUTHWEST AIR IS MOVING UP INTOA RIDGE  
RUNNING OVER WYOMING, MONTANA, AND SASAKATCHEWAN. TO THE NORTHWEST  
A TROUGH OF COOL PACIFIC AIR IS DROPS DOWN FROM ALASAKA THROUGH  
BRITISH COLUMBIA. SOUTHWEST FLOW RESIDES OVER THE PACIFIC  
NORTHWEST AND ALBERTA.  
 
THIS AFTERNOON THROUGH TONIGHT: RIDGE ACROSS THE AREA WILL EXIT  
INTO THE DAKOTAS. SMOKE AND HAZE ACROSS THE REGION TODAY WILL  
LIKELY SETTLE IN OVERNIGHT AS CONDITIONS STABILIZE NEAR SUNDOWN.  
MEANWHILE, THE TROUGH WILL EXIT THE FRONT RANGE AND FIRMS UP A  
COLD FRONT BEHIND IT.  
 
SATURDAY: THE FRONT IS ANTICIPATED TO HIT NORTHEAST MONTANA  
BETWEEN 3 TO 9 AM AND TOMORROW WITH THE STRONGEST WINDS GUSTING  
BEHIND IT AROUND 6 TO NOON. THE FRONT ITSELF SHOULD BY DRY WITH NO  
KNOWN MOISTURE SOURCE TO ACT ON WITH THE LOW LEVEL LIFT. SMOKE  
ACROSS THE AREA SHOULD RAPIDLY EVACUATE NEAR THE SURFACE. AS RH  
WILL BE VERY LOW AND DOWNSLOPE MAY FORCE IT LOWER, WHEN COMBINED  
WITH THE WINDS HAVE DECIDED TO ADD A RED FLAG WARNING FOR THE  
SOUTHEAST TWO THIRDS OF THE CWA. GAH  
 
   
LONG TERM...SUN NIGHT THROUGH FRI
 
 
MODELS SHOWING THE PEAK FOR HIGH-BASED THUNDERSTORMS TO OCCUR  
SUNDAY NIGHT. INCREASED POPS SLIGHTLY OVER MODEL BLEND TO ACCOUNT  
FOR THIS.  
 
OTHERWISE, REST OF FORECAST LOOKED GOOD. TFJ  
 
PREVIOUS DISCUSSION...  
THE NORTHEAST MONTANA FORECAST IS PICKED UP SATURDAY EVENING WITH  
ZONAL FLOW ALOFT AND A DRY COLD FRONT HAVING PASSED THROUGH THE  
AREA DURING THE DAY. SO, WIND BEHIND THE FRONT WILL BE NORTHERLY,  
BUT CALMED DOWN FROM THE DAY. WEAK DISTURBANCES ALONG THE FRONTAL  
BOUNDARY COULD GENERATE A FEW SHOWERS AND THUNDERSTORMS, BUT A  
SURFACE HIGH SHOULD KEEP MOST OF THAT SOUTH OF OUR AREA SATURDAY  
EVENING. HOWEVER AFTER MIDNIGHT, A SHORT-WAVE TROUGH MOVES IN FROM  
THE WEST TO RIDE ALONG THE FRONTAL BOUNDARY. THIS COULD INITIATE  
RAIN SHOWERS AND THUNDERSTORMS INTO SUNDAY, TAPERING OFF SUNDAY  
EVENING THROUGH MONDAY MORNING. NEAR NORMAL TEMPERATURES.  
 
MONDAY MORNING A SECOND, MORE ENERGETIC, QUICK-MOVING, TROUGH  
FROM THE WEST COULD INITIATE ANOTHER ROUND OF SHOWERS AND THUNDER  
MONDAY AFTERNOON AND EVENING. NEAR NORMAL TEMPERATURES.  
 
TUESDAY AND BEYOND, MODELS SHOW A BROAD UPPER RIDGE MOVING OVER  
THE DIVIDE FOR WARMER, QUIETER AND DRY CONDITIONS AT LEAST  
THROUGH MID-WEEK.  
 
BEYOND THAT, MODEL DIFFERENCES IN LOCATION AND TIMING OF THE NEXT  
TROUGH/STORM SYSTEM GROW. BUT BOTH THE GFS AND THE EC BRING IN A  
RATHER LARGE SYSTEM FROM THE GULF FOR THE WEEKEND WITH A RETURN TO  
NEAR NORMAL TEMPERATURES.  
 
TEMPLER  
 

 
   
AVIATION
 
 
FLIGHT CAT: VFR.  
 
SYNOPSIS: HIGH PRESSURE IS IN PLACE THIS EVENING. A COLD FRONT IS  
ANTICIPATED TO MOVE THROUGH THE AREA OVERNIGHT BUT CONDITIONS  
SHOULD REMAIN DRY.  
 
WIND: SOUTHEAST WIND AHEAD OF A FRONT THIS EVENING, BECOMING WEST  
TO NORTHWEST AT 10 TO 20 KTS BEHIND THE FRONT SATURDAY.  
 
GAH/PROTON  
 

 
   
FIRE WEATHER
 
 
AN UPPER-LEVEL TROUGH AND COLD FRONT MOVING THROUGH NORTHERN BC &  
ALBERTA CAN BE SEEN ON GOES SATELLITE IMAGERY. BECAUSE OF THIS  
FRONT, LOCALLY ENHANCED TO CRITICAL FIRE WEATHER CONDITIONS ARE  
EXPECTED FOR SATURDAY.  
 
THIS DRY COLD FRONTAL PASSAGE OUT OF CANADA IS INITIALLY EXPECTED  
TO REACH OUR AREA SATURDAY MORNING. THIS WILL SHIFT WIND AROUND  
TO THE NORTHWEST. WIND WILL BEGIN INCREASE BY MID-MORNING TO A  
GUSTY 15 TO 25 MPH. RELATIVE HUMIDITY PERCENTS WILL AGAIN DROP  
INTO THE TEENS AND LOWER 20S.  
 
WITH CONTINUED DRY FUELS, GUSTY WIND, AND LOW RELATIVE  
HUMIDITIES, CRITICAL FIRE WEATHER CONDITIONS ARE EXPECTED FOR MOST  
OF NORTHEAST MONTANA, AND A RED FLAG WARNING IS IN EFFECT FOR  
THOSE AREAS. THE NORTHWEST AREA, HOWEVER, WILL CONTINUE TO HAVE  
ENHANCED FIRE WEATHER CONDITIONS AND WILL BE MONITORED FOR  
POSSIBLE INCLUSION LATER INTO THE WARNING.  
 

 
   
GLASGOW WATCHES/WARNINGS/ADVISORIES
 
 
RED FLAG WARNING FROM 8 AM TO 8 PM MDT SATURDAY FOR  
MTZ120-122-136-137.  
 

 
 

 
 
WEATHER.GOV/GLASGOW  
 
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