547  
FXUS65 KGGW 210153  
AFDGGW  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE GLASGOW MT  
753 PM MDT SAT JUL 20 2019  
   
DISCUSSION
 
 
EVENING UPDATE...  
ONLY MADE MINOR CHANGES TO POPS AND TEMPERATURES. I BROUGHT LOWS  
UP A DEGREE OR TWO, BASED ON INCREASED CLOUD COVER OVERNIGHT. THIS  
COULD ALSO KEEP HIGHS DOWN A DEGREE OR SO TOMORROW IF THEY DO  
LINGER LONGER INTO THE MORNING HOURS.  
 
AVERY  
 
PREVIOUS DISCUSSION...  
TODAY'S FORECAST PACKAGE IS WELL IN LINE WITH PREVIOUS THINKING  
OVER THE LAST FEW DAYS. ITEMS OF NOTE INCLUDE: OVERNIGHT TONIGHT  
AND SUNDAY MORNING RAIN SHOWERS, HOT TEMPERATURES FOR MONDAY  
THROUGH WEDNESDAY, AND THE NEXT STORM SYSTEM (POSSIBLY SEVERE)  
LATER WEDNESDAY THROUGH THURSDAY.  
 
SATELLITE IMAGERY EASILY SHOWS THE SHEAR IN THE ATMOSPHERE  
ROTATING THE CLOUDS ACROSS SOUTHERN ALBERTA AND SOUTHERN  
SASKATCHEWAN. THIS IS DUE TO A LINGERING LOW PRESSURE CIRCULATION  
LEFT OVER FROM THE DEPARTING TROUGH. IT WILL MOVE THROUGH MONTANA  
FROM WEST TO EAST LATER TONIGHT THROUGH SUNDAY AND WILL BRING  
FAIRLY GOOD CHANCES FOR A FEW PASSING RAIN SHOWERS TO PORTIONS OF  
NORTHEAST MONTANA, AND MAYBE AN ISOLATED THUNDERSTORM.  
 
BUILDING HIGH PRESSURE QUICKLY MOVES INTO THE REGION IN THE WAKE  
OF THAT DISTURBANCE. THE HOT HIGH PRESSURE RIDGE DOMINATES THE  
WEATHER PATTERN FROM LATE SUNDAY THROUGH WEDNESDAY. EXPECT HIGH  
TEMPERATURES WELL INTO THE MID 90S WITH OVERNIGHT TEMPERATURE  
RECOVERY NOT DROPPING MUCH BELOW THE MID TO UPPER 60S. WILL NEED  
TO KEEP A CLOSE WATCH ON FORECAST HUMIDITIES TO SEE IF NBM SHOWS  
ACCURATE VALUES WHEN COMPARED TO OBSERVATIONS. THIS WILL BE A  
SIGNIFICANT CHANGE INTO A MUCH DRIER PATTERN THAN WE HAVE HAD OVER  
THE PREVIOUS SEVERAL DAYS.  
 
BY WEDNESDAY AFTERNOON, THE NEXT LOW PRESSURE TROUGH ALOFT QUICKLY  
PINWHEELS INTO THE CANADIAN ROCKIES AND TURNS THE FLOW ALOFT OVER  
US MORE FROM THE SOUTHWEST. AS THE TROUGH SUDDENLY CLOSES OFF INTO  
A LOW CENTER, IT POPS BACK NORTHWARD FOR A BIT. WHEN THE ENTIRE  
TROUGH FINALLY PASSES THROUGH OUR REGION BY THURSDAY NIGHT, SOME  
SHOWERS AND THUNDERSTORMS LOOK POSSIBLE, AND MAY BECOME SEVERE,  
DEPENDING ON THE TIMING AND ORIENTATION OF THE TROUGH AXIS.  
 
---BMICKELSON  
 

 
   
AVIATION
 
 
FLIGHT CATEGORY: VFR  
 
WINDS: GENERALLY LIGHT (LESS THAN 10 KTS) AND VARIABLE THROUGH  
TONIGHT AND SUNDAY.  
 
DISCUSSION: SOME SHOWERS MAY STRAY NEAR THE TAF SITES OVERNIGHT  
TONIGHT AND EARLY SUNDAY, SO ADDED VCSH TO EACH LOCATION. IF  
SHOWERS GET CLOSER AND PRODUCE THUNDER, AN AMENDMENT OR TWO MAY BE  
NEEDED. CEILINGS SHOULD LIFT BY SUNDAY AFTERNOON.  
 
AVERY  
 

 
   
GLASGOW WATCHES/WARNINGS/ADVISORIES
 
NONE.  
 

 
 

 
 
WEATHER.GOV/GLASGOW  
 
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