117  
FXUS63 KUNR 140436  
AFDUNR  
 
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY  
NATIONAL WEATHER SERVICE RAPID CITY SD  
1036 PM MDT TUE APR 13 2021  
   
DISCUSSION
 
(THIS EVENING THROUGH TUESDAY)  
ISSUED AT 224 PM MDT TUE APR 13 2021  
 
BROAD UPPER LEVEL TROUGHING WILL DOMINATE MOST OF THE PERIOD,  
SUPPORTING BELOW NORMAL TEMPS WITH UNSETTLED AND BREEZY CONDS AT  
TIMES. DOUBLE BARREL UPPER LOW OVER THE NORTHERN CONUS IS  
SUPPORTING COOL, BREEZY AND MOSTLY CLOUDY CONDS OVER MUCH OF THE  
REGION TODAY. EASTERN CLOSED LOW WILL PULL AWAY WED, WITH THE  
WESTERN CONUS TROUGH SLOWLY BEGINNING TO PROGRESS EAST. THIS WILL  
ALLOW FOR MUCH LESS WIND WED, WITH SLIGHTLY WARMER TEMPS. WESTERN  
CONUS TROUGH WILL SHIFT EAST WED AS A NORTHERN STREAM UPPER TROUGH  
PHASES ACROSS THE NORTHERN PLAINS, ALLOWING FOR AN OVERALL SLOW  
PROGRESSION OF LOW HEIGHTS OVER THE REGION. ASSOCIATED MAIN SFC  
LOW REFLECTION AND STORM TRACK WILL REMAIN WELL SOUTH OF THE FA,  
AS WELL AS THE BEST MOISTURE. HENCE, THE MAJORITY OF THE PRECIP  
WILL REMAIN SOUTH OF THE FA, WITH ONLY THE FAR SW HALF TO THIRD  
EXPECTED TO SEE ANY APPRECIABLE AMOUNTS. DRY AIR WILL ALSO ENTRAIN  
INTO THIS SYSTEM OVER THE NE HALF WITH NOT MUCH EXPECTED THERE AS  
THE SYSTEM PROGRESSES EAST WED NIGHT INTO FRIDAY. STILL EXPECTING  
SNOW ACCUMS WITH THIS SYSTEM, BEST CHANCE OVER SOUTHERN CAMPBELL,  
WESTON, AND FALL RIVER COUNTIES, AS WELL AS THE CENTRAL AND  
SOUTHERN BLACK HILLS WHERE 3-5 INCHES WILL BE POSSIBLE, MAINLY ON  
GRASSY SFCS. VERY COOL TEMPS EXPECTED THUR AND FRI WITH  
LOCATIONS STRUGGLING OUT OF THE 30S WHERE CLOUDS AND PRECIP  
LINGER. THINGS WILL DRY OUT FRIDAY NIGHT, WITH SHORTWAVE RIDGING  
ENSUING AND WARMING INTO SUNDAY. SUNDAY LOOKS TO BE THE WARMEST  
DAY IN THE PERIOD WITH TEMPS AROUND SEASONAL NORMS IN THE 50S.  
HOWEVER, ANOTHER COLD FRONT WILL SLIDE DOWN THE FRONT OF THE  
WESTERN NOAM RIDGE, SUPPORTING MORE BELOW NORMAL TEMPS EARLY NEXT  
WEEK, ALONG WITH CHANCES FOR SNOW SHOWERS.  
 

 
   
AVIATION
 
(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)  
ISSUED AT 1035 PM MDT TUE APR 13 2021  
 
AREAS MVFR CIGS WILL PERSIST OVER PARTS OF NORTHEAST WY INTO  
NORTHWEST SD THROUGH THE FORECAST PERIOD AS CYCLONIC FLOW AND LOW  
LEVEL MOISTURE COMBINE. REST OF THE REGION WILL SEE VFR CONDITIONS  
THROUGH THE PERIOD.  
 

 
   
UNR WATCHES/WARNINGS/ADVISORIES
 
 
SD...NONE.  
WY...NONE.  

 
 

 
 
DISCUSSION...JC  
AVIATION...HELGESON  
 
CLICK HERE TO GO TO PREVIOUS BULLETINS.

The Nexlab SD Page
The Nexlab WY Page Main Text Page