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000
FXUS63 KFSD 121903
AFDFSD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
103 PM CST THU DEC 12 2013

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 356 AM CST THU DEC 12 2013

WINDS...AND ANY LOCAL BLOWING SNOW...NEAR THE BUFFALO RIDGE IN
SOUTHWEST MN WERE DECREASING ON SCHEDULE IN THE PREDAWN HOURS. THAT
WILL LEAVE US WITH A MILD DAY AND WINDS MOSTLY 10 MPH OR LESS. AN
ASSORTMENT OF HIGH AND SOME MIDDLE CLOUDS WILL CONTINUE TO FLOW
ACROSS THE AREA FROM THE NORTHWEST TODAY AND TONIGHT...WITH SOME
GENERAL INCREASE POSSIBLE LATE TONIGHT. HOWEVER...FOR MOST OF TODAY
AND TONIGHT...SKIES SHOULD QUALIFY FOR PARTLY CLOUDY NORTHEAST AND
MOSTLY SUNNY/MOSTLY CLEAR SOUTHWEST. HIGH TEMPERATURES...THOUGH
LIMITED BY SNOW COVER TODAY...WILL REACH THE MID 20S EAST TO MID 30S
SOUTHWEST. THESE READINGS...WHICH WOULD BE CONSIDERED COLD A MONTH
AGO...WILL SEEM A RATHER BALMY AND PLEASANT BREAK FROM THE COLD
SPELL. LOWS TONIGHT SHOULD BE IN THE 3 TO 13 RANGE...ABOVE ZERO.
THIS IS NOT BAD EITHER AS WINDS SHOULD STAY 10 MPH OR LESS...EXCEPT
FOR A LITTLE INCREASE FROM THE NORTHEAST POSSIBLE IN OUR NORTH LATE
TONIGHT AS A WEAK COLD FRONT IS FORCED INTO THE AREA BY A CENTRAL
CANADIAN HIGH. NO FOG EXPECTED LATE TONIGHT AT THIS TIME...THOUGH
WOULD HATE TO SAT IT COULD NOT HAPPEN SOUTHWEST WITH SKIES POSSIBLY
STAYING MOSTLY CLEAR AFTER TODAYS HIGHS ABOVE FREEZING OVER SNOW
COVER. A STRATUS DECK COULD ALSO BE A POSSIBILITY VERY LATE TONIGHT
BEHIND THE COLD FRONT OVER THE FAR NORTH...BUT WILL KEEP CLOUD
INCREASE MODEST FOR NOW.

.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 356 AM CST THU DEC 12 2013

END OF THE WEEK STILL LOOKS TO COOL DOWN FROM RELATIVE WARMTH
EXPECTED TODAY...WITH MODELS IN PRETTY GOOD AGREEMENT PUSHING THE
DEEPER COLD AIR SOUTH INTO THE AREA FRIDAY AND FRIDAY NIGHT. STILL
SEEING SOME SIGNALS FOR A CHANCE OF LIGHT PRECIP SLIDING ACROSS THE
NORTHEAST PORTIONS OF THE CWA WITH A WEAK WAVE TRACKING THROUGH THE
NORTHERN PLAINS...SO NOT MUCH CHANGE TO POPS FOR FRIDAY NIGHT. DID
MOVE THE PRECIP EAST A LITTLE FASTER SATURDAY AS THE WAVE PULLS OUT
OF THE AREA AND SURFACE RIDGE MOVES ACROSS THE CWA. HIGHS FRIDAY AND
SATURDAY LARGELY BACK IN THE TEENS...WITH SOME LOWER 20S SOUTH ON
FRIDAY...AND FAR WEST ON SATURDAY.

TEMPERATURES SUNDAY STILL VERY MUCH IN QUESTION...WITH MODELS STILL
NOT SHOWING MUCH AGREEMENT ON TRENDS IN ONE DIRECTION OR THE OTHER.
THE 12Z ECMWF AND 00Z GFS RUNS HAD BEEN SHOWING TREND TOWARD WARMER
SOLUTIONS...BUT NEW 00Z ECMWF ALONG WITH 00Z GEM AND 06Z NAM ALL
WENT IN THE OPPOSITE DIRECTION...BRINGING A REINFORCING COLD PUSH
INTO AT LEAST THE EASTERN 2/3 OF THE FORECAST AREA LATE SATURDAY
NIGHT/SUNDAY MORNING BEFORE ALLOWING WARMER AIR TO BEGIN TO BUILD
EASTWARD. WITH SUCH VARIABILITY CONTINUING...CONFIDENCE IN FORECAST
TEMPERATURES FOR SUNDAY REMAINS LOW AND WILL CONTINUE TO STICK CLOSE
TO BROAD MODEL CONSENSUS WITH TEENS NORTHEAST AND 20S TO LOWER 30S
SOUTHWEST. IF LATEST GFS PANS OUT...COULD BE ANOTHER 5-10 DEGREES
WARMER...WITH SIMILAR SWING IN THE OTHER DIRECTION OF 00Z ECMWF/GEM
ARE CORRECT.

MONDAY CONTINUES TO LOOK LIKE BEST CHANCE FOR WARMER AIR TO SPREAD
ACROSS THE REGION WITH ALL MODELS AGAIN IN PRETTY GOOD AGREEMENT
WITH THIS WARMING SUNDAY NIGHT THROUGH MONDAY...BEFORE NEXT COLD
FRONT BEGINS TO PUSH SOUTHWARD. SNOW PACK MAY TEMPER WARMING A BIT...
BUT WITH DEEP WESTERLY FLOW FAVORABLE FOR AT LEAST FAIR MIXING...
HIGHS IN THE UPPER 20S AND 30S SEEM REASONABLE. QUESTIONS RETURN
MONDAY NIGHT THROUGH WEDNESDAY...INITIALLY WITH HOW STRONG THE COLD
PUSH WILL BE BEHIND THE FRONT FOR TUESDAY...THEN WHETHER THAT COLD
AIR WILL STICK AROUND AS PER THE GFS...OR INSTEAD QUICKLY BE SHUNTED
EAST WITH A STRONG WARMING SIGNAL AS THE ECMWF INDICATES. AS WITH
SUNDAY...ENSEMBLES AGAIN OF LITTLE HELP IN DETERMINING TREND WITH
HIGH VARIABILITY SEEN IN BOTH GFS AND ECMWF ENSEMBLE SETS. SO...LIKE
SUNDAY...OPTED TO STICK FAIRLY CLOSE TO CONSENSUS.

AS FAR AS PRECIP CHANCES THROUGH THE LONGER RANGE...DESPITE THE HIGH
VARIABILITY IN TEMPERATURES...MODELS APPEAR TO HAVE BETTER AGREEMENT
IN KEEPING PRECIP TRACK NORTH OF OUR AREA AND HAVE THUS PULLED ANY
MEASURABLE PRECIP CHANCES FROM OUR FORECAST AREA FOR SUNDAY THROUGH
WEDNESDAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 102 PM CST THU DEC 12 2013

MAINLY VFR CONDITIONS THROUGH THE PERIOD. THERE WILL BE A CHANCE
FOR SOME MVFR CEILINGS AT MAINLY FSD AND HON TOMORROW MORNING BUT
CHANCES ARE LOW ENOUGH WILL NOT INCLUDE IN THE TAF.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&

$$

SHORT TERM...
LONG TERM...JH
AVIATION...08