Area Forecast Discussion
Issued by NWS Rapid City, SD

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000
FXUS63 KUNR 261702
AFDUNR

AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
1002 AM MST WED NOV 26 2014

.SHORT TERM...TODAY THROUGH THURSDAY NIGHT
ISSUED AT 249 AM MST WED NOV 26 2014

LATEST WATER VAPOR IMAGES AND UPPER ANALYSIS SHOW UPPER TROUGH OVER THE
MIDWEST WITH A RIDGE OVER THE PACIFIC COAST. FAST 150KT JET FLOW
IS DIVING INTO THE FORECAST AREA FROM THE NORTHWEST. THE NW-SE ORIENTED
BAROCLINIC ZONE OVER THE WESTERN PART OF THE CWA WILL INTENSIFY
TODAY WITH INCREASED MID-HIGH LEVEL WARM ADVECTION ABOVE THE
COLDER AIR AT THEE SURFACE. THE BAROCLINIC ZONE WILL GRADUALLY
MOVE NORTHEASTWARD TODAY AND TONIGHT. FRONTOGENETICAL FORCING AND
NEARLY SATURATED PROFILES WILL LEAD TO PERIODS OF LIGHT SNOW OR
FLURRIES OVER NERN WY AND PARTS OF FAR WESTERN SOUTH DAKOTA TODAY.
THE PRECIPITATION WILL SPREAD NEWD TONIGHT AS UPPER HEIGHTS
CONTINUE TO BUILD AND LOW-MID LEVEL WARM ADVECTION INTENSIFIES.
SREF PTYPE PROBABILITIES AND NAM VERTICAL PROFILES SUPPORT A
CHANCE OF SNOW WITH A SLIGHT CHANCE OF FZRA OVER PARTS OF NERN WY
AND NWRN SD LATE TONIGHT INTO THU MORNING. THERE WILL BE A WIDE
SPREAD OF TEMPERATURES ON THURSDAY AS THE COLDER AIR RETREATS TO
THE EAST AND WARMER AIR MOVES IN FROM THE SOUTHWEST. HIGHS ARE
EXPECTED TO RANGE FROM AROUND 30F TOWARD NORTH CENTRAL SOUTH
DAKOTA WITH HIGHS AROUND 50F OVER PARTS OF NORTHEASTERN WYOMING
AND SOUTHWESTERN SOUTH DAKOTA. THE PRECIPITATION OVER FAR
NORTHWESTERN SOUTH DAKOTA IN THE MORNING WILL MOVE AWAY FROM THE
AREA BY AFTERNOON...LEAVING DRY WEATHER AND VARIABLE CLOUD COVER
FOR THURSDAY AFTN.

&&

.LONG TERM...FRIDAY THROUGH TUESDAY
ISSUED AT 249 AM MST WED NOV 26 2014

UPPER FLOW WILL BECOME MORE ZONAL FOR THE END OF THE
WEEK AS WEAK RIDGING BREAKS DOWN AHEAD OF THE NEXT PACIFIC TROUGH.
WARMER AIRMASS OVER THE REGION FRIDAY WILL BRING TEMPS WELL ABOVE
SEASONAL AVERAGES. THE NEXT TROUGH WILL CROSS THE PACIFIC NORTHWEST
SATURDAY WITH STRONG COLD FRONT CROSSING THE AREA. THERE IS SOME
DISAGREEMENT BETWEEN THE ECM/GFS WITH THE TIMING OF THE FRONT. THE
GFS HAS TRENDED WARMER DELAYING THE FRONTAL PASSAGE TILL SATURDAY
NIGHT. THE ECM CONTINUES TO SHOW THE FRONT PASSING DURING THE DAY
SATURDAY. HAVE INCREASED TEMPS SOME TO ACCOUNT FOR GFS...BUT
CONFIDENCE IS LOW AT THIS TIME. SOME LIGHT SNOW IS POSSIBLE SAT
NIGHT INTO POSSIBLY SUNDAY...BUT MINIMAL QPF IS EXPECTED. COLDER AIR
WILL KEEP TEMPS MUCH COLDER EARLY NEXT WEEK...BUT SOME MODIFYING IS
POSSIBLE TOWARD MIDWEEK.

&&

.AVIATION...FOR THE 18Z TAFS THROUGH 18Z THURSDAY
ISSUED AT 1001 AM MST WED NOV 26 2014

SNOW WILL CONTINUE ACROSS MUCH OF THE AREA TODAY BRINGING
WIDESPREAD MVFR/IFR CONDITIONS...AND CONTINUE THROUGH TONIGHT.
SOME LIFR CONDITIONS EXPECTED NEAR THE BLKHLS AREA.

&&

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

$$

SHORT TERM...10
LONG TERM...13
AVIATION...POJORLIE







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