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000
FXUS63 KUNR 092211
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
311 PM MST MON DEC 9 2013

.SHORT TERM...THIS EVENING THROUGH TUESDAY NIGHT
ISSUED AT 311 PM MST MON DEC 9 2013

CURRENT SURFACE ANALYSIS SHOWS A FRONTAL BOUNDARY/WARM FRONT
ACROSS THE WESTERN DAKOTAS. UPPER LEVEL ANALYSIS SHOWS
NORTHWESTERLY FLOW OVER THE REGION...WITH A SHORTWAVE NOW MOVING
THROUGH NORTHERN PORTIONS OF THE CWA. STRONG UPPER JET IS ALSO IN
PLACE OVER THE NORTHERN ROCKIES REGION. SKIES HAVE BECOME MAINLY
CLOUDY ACROSS MUCH OF THE AREA NOW. WEST TO NORTHWEST WINDS HAVE
INCREASED BEHIND THE BOUNDARY ACROSS NORTHWESTERN SD. WEST TO
SOUTHWEST WINDS LINGER ELSEWHERE. TEMPS HAVE RISEN RELATIVELY
NICELY IN MOST AREAS TODAY...WITH TEENS AND LOWER 20S AT THIS TIME.

MAIN CONCERN THROUGH THIS EVENING WILL BE THE SHORTWAVE DISTURBANCE
AND FRONTAL BOUNDARY THAT WILL PASS THROUGH THE AREA. THIS WAVE WILL
CONTINUE TO BRING GUSTY WINDS AND SNOW SHOWERS TO FAR NORTHEASTERN
WY...THE NORTHERN BLACK HILLS AREA...AND MUCH OF NORTHWESTERN SD.
SNOWFALL AMOUNTS LOOK TO GENERALLY BE AN INCH OR LESS ACROSS THE
PLAINS...WITH 1 TO 4 INCHES OVER THE NORTHERN BLACK HILLS AND BEAR
LODGE MTS. THE HIGHEST AMOUNTS WILL BE OVER FAVORED WEST-NORTHWEST
FACING SLOPES OF THE NORTHERN HILLS. WEST-NORTHWEST WINDS OF 15 TO
30 MPH AND GUSTS TO AROUND 45 MPH WILL PRODUCE AREAS OF BLOWING AND
DRIFTING SNOW...ESPECIALLY ACROSS THE NORTHWEST SD PLAINS. SNOW
SHOWERS AND WIND WILL GRADUALLY TAPER OFF OVERNIGHT.

NORTHWEST FLOW ALOFT REMAINS OVER THE AREA ON TUESDAY...WITH MILDER
AIR IN PLACE ACROSS THE AREA INTO THE AFTERNOON HOURS. HIGHS WILL
MOSTLY BE IN THE 20S WITH NORTHWESTERLY WINDS BECOMING BREEZY
DURING THE MIDDAY AND AFTERNOON HOURS AS ANOTHER ARCTIC COLD FRONT
SLIDES SOUTH. THE COLDEST AIR WITH THIS SYSTEM WILL REMAIN NORTH
AND EAST OF THE BLACK HILLS TUESDAY NIGHT INTO WEDNESDAY. ANOTHER
UPPER LEVEL DISTURBANCE WILL COMBINE WITH THE FRONT TO BRING MORE
SNOW SHOWER ACTIVITY. THE BEST CHANCES WILL AGAIN BE ACROSS THE
NORTHERN BLACK HILLS DURING THE AFTERNOON AND EVENING...WHERE
ADDITIONAL LIGHT ACCUMULATIONS CAN BE EXPECTED. SNOWFALL AND WIND
WILL AGAIN TAPER OFF OVERNIGHT.

&&

.LONG TERM...WEDNESDAY THROUGH MONDAY
ISSUED AT 311 PM MST MON DEC 9 2013

PERSISTENT NW FLOW WILL PREVAIL THROUGH THE EXTENDED PERIOD. DRY
WX IS EXPECTED THROUGH THE END OF THE WORK WEEK...WITH A FEW
EMBEDDED DISTURBANCES POSSIBLE BRINGING LIGHT SNOW TO PARTS OF THE
AREA OVER THE WEEKEND INTO EARLY NEXT WEEK. MOISTURE WILL REMAIN
QUITE LIMITED SO NO SIGNIFICANT SNOWFALL IS EXPECTED. TEMPS WILL
BE A BIT MORE DIFFICULT...ESPECIALLY ON THE SD PLAINS. THE BRUNT
OF COLD AIR IS EXPECTED TO REMAIN GENERALLY EAST OF THE CWFA WHICH
WOULD LEAD TO TEMPS NEAR OR SLIGHTLY ABOVE AVERAGE FOR MOST AREAS.
THE BIGGEST QUESTION WITH REGARD TO TEMPS WILL BE OVER THE WEEKEND
WITH THE PASSAGE OF UPPER LEVEL WAVES...WHERE COLDER AIR COULD
FILTER INTO ERN PARTS OF THE CWFA.

&&

.AVIATION...FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING
ISSUED AT 311 PM MST MON DEC 9 2013

A FRONTAL BOUNDARY WILL MOVE INTO NERN WY AND NWRN SD LATER THIS
AFTN...CREATING A PERIOD OF GUSTY NW WINDS ALONG WITH MVFR CIGS
AND LIGHT SNOW/BLOWING SNOW...WITH SOME IFR CONDITIONS EXPECTED IN
UPSLOPE AREAS OF THE NRN BLKHLS. THESE CONDITIONS WILL SPREAD
SOUTH THROUGH WRN SD TONIGHT AND CONTINUE THROUGH AT LEAST TUESDAY
MORNING.

&&

.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WINTER WEATHER ADVISORY UNTIL 11 PM MST THIS EVENING FOR SDZ001-
     002-012-013-024-025.

WY...WINTER WEATHER ADVISORY UNTIL 11 PM MST THIS EVENING FOR WYZ056-
     057-071.

&&

$$

SHORT TERM...26
LONG TERM...JOHNSON
AVIATION...JOHNSON