FXUS63 KUNR 270232
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
732 PM MST THU NOV 26 2009

.DISCUSSION...02Z SURFACE ANALYSIS HAD TROUGH FROM CENTRAL MT INTO
THE NE PANHANDLE. WATER VAPOUR MOVIE HAD UPPER RIDGE FROM AZ INTO
MT. CI SPILLING OVER RIDGE CREATING PARTLY CLOUDY SKIES...AND THUS
WILL BRING UP CLOUDS A BIT WITH UPDATE. REST OF FORECAST IN FINE SHAPE.

&&

.PREV DISCUSSION... /ISSUED 235 PM MST THU NOV 26 2009/ 

DISCUSSION...CURRENT SURFACE ANALYSIS SHOWS LOW PRESSURE OVER 
SOUTHERN SK...WITH WARM FRONT ACROSS THE WESTERN DAKOTAS. UPPER 
LEVEL ANALYSIS HAS RIDGE COVERING THE ROCKIES REGION...WITH TROF OFF 
THE WEST COAST. SKIES ARE MOSTLY SUNNY...WITH SOME THIN CIRRUS 
PASSING OVER THE AREA. TEMPS ARE MOSTLY IN THE 50S. SOUTHWEST WINDS 
ARE BREEZY BEHIND THE WARM FRONT ACROSS PARTS OF NORTHEASTERN WY. 

DRY AND MILD WX WILL CONTINUE ACROSS THE AREA THROUGH FRIDAY NIGHT. 
COLD FRONT PASSAGE LATE FRIDAY NIGHT AND SATURDAY MORNING WILL BRING 
MORE SEASONABLE TEMPS FOR THE WEEKEND. NOT MUCH...IF ANY...PCPN IS 
EXPECTED WITH THE FRONT AND ASSOCIATED UPPER LEVEL WAVE. HOWEVER... 
GUSTY NORTHWEST WINDS ARE EXPECTED ACROSS MUCH OF THE PLAINS ON 
SATURDAY.   

FOR TONIGHT...SKIES WILL BE MAINLY CLEAR WITH LOWS IN THE 20S AND 
30S...COOLEST IN THE VALLEYS OF THE SD PLAINS. BRISK SOUTHWEST WINDS 
ARE STILL EXPECTED ACROSS PORTIONS OF NORTHEASTERN WY AND FAVORED 
TERRAIN OF THE BLACK HILLS. SKIES WILL BE MOSTLY SUNNY ON FRIDAY 
WITH TEMPS SIMILAR TO TODAY...50S AND LOWER 60S. 

COLD FRONT WILL CROSS THE AREA LATE FRIDAY NIGHT AND SATURDAY 
MORNING. UPPER LEVEL TROF WILL SPLIT AS IT CROSSES THE WESTERN CONUS 
FRIDAY...WITH MOST OF THE ENERGY DIVING SOUTH INTO THE SOUTHWEST 
CONUS AND WEAKER NORTHERN STREAM WAVE ACCOMPANYING THE FRONT. THE 
WAVE WILL LAG BEHIND THE FRONT A BIT AND CROSS SATURDAY INTO 
SATURDAY NIGHT. THE LOWER ATMOSPHERE WILL BE QUITE DRY AS THE WAVE 
CROSSES...SO ANY RAIN AND SNOW SHOWERS THAT DEVELOP WILL LIKELY BE 
LIGHT AND RATHER ISOLATED. GUSTY NORTHWEST WINDS WILL DEVELOP BEHIND 
THE FRONT ON SATURDAY...ESPECIALLY ACROSS THE NORTHWEST AND WEST 
CENTRAL SD PLAINS. HIGHS WILL BE IN THE UPPER 30S AND 40S. MAIN 
CHANCES FOR SHOWERS INTO SATURDAY NIGHT WILL BE ACROSS THE 
SOUTHERN CWA AS WAVE BEGINS TO MOVE SOUTH AND EAST OF THE AREA.     

EXTENDED...TROF AXIS WILL SLIDE TO THE EAST ON SUNDAY...WITH DRY 
WEATHER RETURNING. NEXT TROF WILL MOVE IN FROM THE NORTHWEST TOWARDS 
MID-WEEK...THOUGH MOST OF THE PRECIP WITH THIS SYSTEM SHOULD REMAIN 
NORTH AND SOUTH OF THE AREA. TEMPERATURES WILL WARM SOME FOR THE 
BEGINNING OF THE WORK WEEK...BEFORE RETURNING TO NEAR NORMAL FOR 
MID-WEEK.
 

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

&&

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

$$

HELGESON