FXUS63 KUNR 301001
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
300 AM MST MON NOV 30 2009

.DISCUSSION...CURRENT SURFACE ANALYSIS SHOWS HIGH PRESSURE FROM THE 
NORTHERN ROCKIES INTO WESTERN TEXAS WITH WESTERLY WINDS ACROSS THE 
FORECAST AREA. UPPER ANALYSIS SHOWS A TROUGH OVER THE MIDWEST WITH A 
RIDGE BUILDING OVER THE PACIFIC NORTHWEST. SATELLITE SHOWS AN AREA 
OF CLOUDS ACROSS ERN MT INTO NERN WY/WRN SD ASSOCIATED WITH WAA 
ALOFT.

THE WARM AIR ADVECTION WILL CONTINUE TODAY...ALLOWING TEMPS TO RISE 
MAINLY IN THE 50S WITH SOME 40S IN THE BLACK HILLS. PARTLY CLOUDY 
CONDITIONS WILL CONTINUE INTO MONDAY NIGHT...WITH SOME INCREASING 
CLOUDS FROM THE NORTH AND WEST LATE. LOWS WILL DROP INTO THE 20S AND 
30S. 

A STRONG COLD FRONT AND UPPER LEVEL SHORTWAVE WILL CROSS THE AREA ON 
TUESDAY. STRONG NORTHWEST WINDS WILL DEVELOP BEHIND THE FRONT AS CAA 
DEVELOPS. IT CONTINUES TO LOOK LIKE AT LEAST A WIND ADVISORY EVENT 
FOR PORTIONS OF THE WESTERN SD PLAINS. NOT EXPECTING MUCH...IF 
ANY...PCPN WITH THIS FRONT AS ATMOSPHERE WILL REMAIN RATHER DRY. 
MAIN CHANCES FOR ANY LIGHT SNOW WILL BE ACROSS NORTHEASTERN WY AND 
THE BLACK HILLS. HIGHS WILL BE IN THE 30S AND 40S...WITH 
TEMPERATURES FALLING IN THE AFTN.

THE WIND WILL DIMINSISH ON TUESDAY NIGHT WILL POSSIBLY A FEW 
LINGERING SNOW SHOWERS OR FLURRIES. LOW TEMPS WILL FALL INTO THE 
TEENS AT MANY LOCATIONS. WEDNESDAY WILL BE PARTLY CLOUDY WITH HIGHS 
STRUGGLING TO REACH 30F AT MANY LOCATIONS...SETTING UP AN EVEN 
COLDER NIGHT ON WEDNESDAY NIGHT. 

EXTENDED...THE DEEP UPPER TROUGH WILL CONTINUE TO SLIDE EAST 
THURSDAY WITH THE MAIN AXIS MOVING INTO THE GREAT LAKES REGION. THE 
COLDEST AIR WILL DROP SOUTH OF THE AREA WITH WARM AIR ADVECTING IN 
FROM THE WEST/NORTHWEST AS A RIDGE BUILDS OVER THE NORTHERN ROCKIES. 
DRY WEATHER IS EXPECTED THURSDAY WITH HIGHS IN THE 20S TO LOWER 30S. 
WARM AIR WILL CONTINUE TO ADVECT IN THURSDAY NIGHT INTO FRIDAY 
BRINGING TEMPS INTO THE 40S ACROSS SOME LOCATIONS. MODELS ARE 
SHOWING A CLIPPER SYSTEM APPROACHING FROM THE NORTHWEST WHICH WILL 
BRING A COLD FRONT FRIDAY NIGHT INTO SATURDAY WHICH WILL DROP TEMPS 
BACK TO BELOW SEASONAL AVERAGES. MODELS HAVE BEEN INCONSISTENT WITH 
THE PLACEMENT AND TIMING OF THIS SYSTEM...SO HAVE NOT ADDED POPS TO 
THE FORECAST. HOWEVER IF BETTER CONSISTENCY IS SEEN BETWEEN 
MODELS...POPS MAY HAVE TO BE ADDED FOR THE WEEKEND.

&&

.AVIATION...VFR CONDITIONS ARE EXPECTED THROUGH THE FORECAST PERIOD.
 
&&

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

$$