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FXUS63 KUNR 092149
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
250 PM MST TUE FEB 9 2010

.DISCUSSION...CURRENT SURFACE ANALYSIS HAS LOW PRESSURE CENTERED
OVER THE GREAT LAKES AREA...WITH ARCTIC HIGH PRESSURE OVER SOUTH
CENTRAL CANADA INTO THE EASTERN DAKOTAS. ARCTIC BOUNDARY STRETCHES
ACROSS CENTRAL MT... CENTRAL WY...AND INTO CO. UPPER LEVEL ANALYSIS
HAS ONE SYSTEM OVER THE MID MS RIVER VALLEY...WITH ANOTHER ALONG THE
CA COAST. SKIES ARE MAINLY CLEAR ACROSS THE AREA...WITH THE
EXCEPTION BEING SOME LINGERING LOW CLOUDS ACROSS TRIPP CO. TEMPS ARE
MOSTLY IN THE TEENS...WITH 20S ACROSS PORTIONS OF NORTHEASTERN WY
AND THE HIGHER BLACK HILLS. WINDS ARE GENERALLY LIGHT FROM THE SOUTH
TO SOUTHEAST...EXCEPT A LITTLE BRISK IN THE GCC AND RAP AREAS.

MILDER WEATHER CAN BE EXPECTED FOR THE MIDDLE PART OF THE WEEK AS
ARCTIC AIR IS GRADUALLY SCOURED OUT OF THE AREA FROM SOUTHWEST TO
NORTHEAST. TEMPS WILL GET BACK CLOSER TO AVERAGE LEVELS BY
THURSDAY...BUT WITH SNOWCOVER IN PLACE ACROSS MOST OF THE AREA...
THEY SHOULD GENERALLY REMAIN BELOW AVERAGE.

SKIES WILL BE MOSTLY CLEAR TONIGHT WITH LOWS DOWN TO AROUND ZERO AT
MOST LOCATIONS...WARMEST ACROSS NORTHEASTERN WY AND PORTIONS OF THE
HILLS...AND BELOW ZERO IN MANY VALLEY AREAS. WIND CHILLS OF 10 BELOW
TO 20 BELOW CAN BE EXPECTED ACROSS A GOOD PORTION OF THE SD PLAINS.
FRONTAL BOUNDARY WILL LIFT NORTHEASTWARD INTO THE CWA LATER TONIGHT
AND WEDNESDAY...LIKELY STALLING OUT OVER THE HILLS AREA. HIGHS
WEDNESDAY SHOULD GENERALLY BE IN THE LOW TO MID 30S ACROSS
NORTHEASTERN WY AND FAR SOUTHWESTERN SD...UPPER TEENS AND 20S TO THE
NORTH AND EAST OF THE HILLS.

THURSDAY WILL BE EVEN MILDER...WITH MOST LOCATIONS EXPECTED TO GET
INTO THE 30S. FAR NORTHERN AND EASTERN AREAS WILL LIKELY STAY IN
THE 20S. WEAK UPPER LEVEL ENERGY IN NORTHWEST FLOW IS PROGGED TO
CROSS THE AREA...BRINGING CLOUDINESS AND POSSIBLY A FEW SNOW SHOWERS
NEAR THE FRONTAL BOUNDARY THURSDAY INTO THURSDAY NIGHT. THR FRONTAL
BOUNDARY WILL LIKELY REMAIN SOMEWHERE ACROSS THE CENTRAL OR EASTERN
CWA.

EXTENDED...GUIDANCE HAS BECOME CONSISTENT IN DROPPING A VIGOROUS
UPPER LOW OUT OF CANADA AND THRU THE NRN PLAINS LATE FRIDAY AND
SATURDAY. THIS WILL BRING ANOTHER SHOT OF ARCTIC AIR BACK INTO OUR
AREA ALONG WITH A CHANCE FOR LIGHT SNOW. HAVE TRENDED TEMPS TO THE
LOWEST OF THE GFS ENSEMBLES...BUT THIS MAY STILL NOT BE COLD ENOUGH.
COOL BUT DRIER CONDITIONS WILL PREVAIL FOR THE END OF THE WEEKEND
AND EARLY NEXT WEEK...WITH A SLOW MODERATING TREND INTO THE MIDDLE
OF NEXT WEEK AS AN UPPER RIDGE BUILDS THRU THE NRN ROCKIES.

&&

.AVIATION...LINGERING MVFR CIGS OVR CNTRL SD SHOULD GRADUALLY
DISSIPATE LATER THIS AFTN/EVE. VFR CONDITIONS WILL CONTINUE AT BOTH
KGCC AND KRAP TERMINALS NEXT 24 HOURS.

&&

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

$$