001  
FXUS65 KBOU 221804  
AFDBOU  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE DENVER/BOULDER CO  
1204 PM MDT FRI OCT 22 2021  
   
UPDATE
 
 
ISSUED AT 1036 AM MDT FRI OCT 22 2021  
 
WITH MOSTLY SUNNY SKIES THIS MORNING, TEMPERATURES ARE WARMING  
CONSIDERABLY QUICKER THAN YESTERDAY. THIS KEEPS THE FORECAST ON  
TRACK FOR ABOVE NORMAL HIGHS THIS AFTERNOON. ADJUSTED THE HIGHS UP  
1- 2 DEGREES. WITH AN UPPER LEVEL RIDGE OVERHEAD, DRY CONDITIONS  
WILL PREVAIL TODAY.  
 

 
   
SHORT TERM
 
(TODAY AND TONIGHT)  
ISSUED AT 317 AM MDT FRI OCT 22 2021  
 
A FLAT UPPER LEVEL RIDGE WILL BUILD OVER THE AREA TODAY WITH THE  
FLOW ALOFT BECOMING MORE WSW. MEANWHILE, A SFC LEE TROUGH WILL  
BECOME ESTABLISHED ALONG THE FRONT RANGE. OVERALL WILL SEE LESS  
CLOUDS TODAY WITH AFTN HIGHS, OVER THE PLAINS, MAINLY IN THE  
UPPER 60S TO LOWER 70S.  
 
FOR TONIGHT WILL SEE INCREASING WSW FLOW ALOFT WITH AN INCREASE IN  
HIGHER LEVELS CLOUDS.  
   
LONG TERM
 
(SATURDAY THROUGH THURSDAY)  
ISSUED AT 317 AM MDT FRI OCT 22 2021  
 
ON SATURDAY, UPPER LEVEL HIGH PRESSURE WILL BE OVER THE CENTRAL  
PLAINS STATES WITH A FLAT UPPER LEVEL TROUGH OVER THE WESTERN U.S.  
THIS PATTERN WILL BRING WARM AND CONTINUED DRY WEATHER TO THE  
FORECAST AREA. SNOW IS EXPECTED TO INCREASE ACROSS THE HIGH COUNTRY  
SATURDAY NIGHT AND CONTINUE INTO SUNDAY MORNING AS A POTENT UPPER  
LEVEL SHORTWAVE MOVES ACROSS THE AREA. THE SNOW SHOULD GENERALLY BE  
LIGHT, HOWEVER, THERE COULD BE A BRIEF PERIOD OF MODERATE TO HEAVY  
SNOW DUE TO COLD AIR ADVECTION AND BETTER OROGRAPHICS JUST BEHIND  
THE SHORTWAVE. AT THIS TIME, SNOWFALL AMOUNTS ARE EXPECTED TO RANGE  
BETWEEN A TRACE AND 5 INCHES. THE HEAVIEST AMOUNTS SHOULD BE IN THE  
GORE AND PARK RANGES WITH LIGHTER AMOUNTS FURTHER SOUTH ACROSS THE I-  
70 CORRIDOR. FURTHER EAST ACROSS THE PLAINS, THERE COULD BE ISOLATED  
TO SCATTERED LIGHT SHOWERS WITH THE PASSAGE OF THE UPPER LEVEL  
DISTURBANCE.  
 
THE COOLER AIRMASS BEHIND THE TROUGH SHOULD RESULT IN SUNDAY'S  
TEMPERATURES BEING A FEW DEGREES COOLER THAT SATURDAY'S READINGS.  
DRIER WEATHER IS ALSO EXPECTED BY LATE MORNING AS UPPER LEVEL HIGH  
PRESSURE MOVES INTO COLORADO.  
 
ON MONDAY, UPPER LEVEL HIGH PRESSURE IS FORECASTED TO BUILD OVER THE  
CENTRAL U.S. AS ANOTHER UPPER LEVEL TROUGH APPROACHES COLORADO FROM  
THE WEST. THIS PATTERN WILL PLACE COLORADO UNDER THE INFLUENCE OF A  
DRY SOUTHWESTERLY FLOW ALOFT WHICH SHOULD RESULT IN DRY WEATHER AND  
UNSEASONABLY WARM TEMPERATURES. GUSTY WINDS COMBINED WITH THE WARM  
TEMPERATURES AND RELATIVE HUMIDITY IN THE TEENS COULD LEAD TO  
ELEVATED FIRE DANGER ACROSS PORTIONS OF THE PLAINS, SOUTHERN  
FOOTHILLS AND PALMER DIVIDE MONDAY AFTERNOON. COOLER UNSETTLED  
WEATHER IS EXPECTED MONDAY NIGHT AND TUESDAY AS THE UPPER LEVEL  
TROUGH MOVES ACROSS THE ROCKY MOUNTAIN REGION. THE MOUNTAINS SHOULD  
SEE ANOTHER ROUND OF ACCUMULATING SNOW WITH THIS SYSTEM WITH A FEW  
SHOWERS POSSIBLE ACROSS THE PLAINS.  
 
ON WEDNESDAY, THE UPPER TROUGH IS PROGGED TO MOVE INTO THE CENTRAL  
PLAINS STATES AS AN UPPER LEVEL RIDGE OF HIGH PRESSURE MOVES INTO  
THE WESTERN U.S. COLORADO WILL BE IN-BETWEEN THESE TWO SYSTEMS UNDER  
THE INFLUENCE OF A STRONG NORTHWESTERLY FLOW ALOFT. THIS IS A  
FAVORABLE OROGRAPHIC FLOW TO PRODUCE MORE SNOW IN THE MOUNTAINS.  
HOWEVER, AMOUNTS SHOULD BE LIGHT DUE TO THE MOISTURE BEING SOMEWHAT  
SHALLOW. THIS ALSO LOOKS LIKE A GOOD SETUP FOR BREEZY TO WINDY  
CONDITIONS ACROSS THE MOUNTAINS, FOOTHILLS AND EASTERN PLAINS.  
 
DRIER CONDITIONS ARE EXPECTED BY THURSDAY AS UPPER LEVEL HIGH  
PRESSURE REBUILDS OVER THE REGION.  
 

 
   
AVIATION
 
(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)  
ISSUED AT 1200 PM MDT FRI OCT 22 2021  
 
VFR CONDITIONS EXPECTED TODAY INTO SATURDAY. WINDS BECOME  
SOUTHEASTERLY THIS AFTERNOON THEN RETURNING TO DRAINAGE IN THE  
EVENING WITH SSW WINDS BY MIDNIGHT. HIGH TO MID-LEVEL CLOUDS MOVE  
IN THIS AFTERNOON/EARLY EVENING AND WILL PERSIST INTO SATURDAY.  
WINDS STAY SOUTHWESTERLY IN THE MORNING BECOMING SOUTHEASTERLY IN  
THE AFTERNOON. SHOWERS BEGIN TO DEVELOP OVER THE MOUNTAINS  
SATURDAY AFTN. CONDITIONS ARE MORE LIKELY TO STAY DRY OVER THE  
LOWER ELEVATIONS BEFORE 00Z, ALTHOUGH COULD NOT RULE OUT SOME  
VIRGA AFTER 20Z GIVEN ADEQUATE MID-LEVEL MOISTURE.  
 

 
   
BOU WATCHES/WARNINGS/ADVISORIES
 
 
NONE.  

 
 

 
 
UPDATE...MENSCH  
SHORT TERM...RPK  
LONG TERM...JK  
AVIATION...MENSCH  
 
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