Area Forecast Discussion
Issued by NWS Sioux Falls, SD

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FXUS63 KFSD 291130
AFDFSD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
530 AM CST MON DEC 29 2014

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 252 AM CST MON DEC 29 2014

STEADY DRYING WITH THE ARCTIC AIR INFLUX WILL CONTINUE TO ERODE THE
SNOW FALLING OVER THE AREA. HAVE ALREADY NOTICE THIS EFFECT A LITTLE
STRONGER THAN FORECAST IN THE LIGHT SNOW/FLURRY PATCHES NORTHWEST OF
THE AREA WHICH WERE MOVING SOUTHEAST...AND NOW ARE SHOWING MORE OF
AN APPARENT SOUTHERLY MOVEMENT AS THEY WEAKEN. OVERALL THE LIGHT
SNOW FORECAST GRIDS WE HAVE BEEN CARRYING HAVE BEEN SUPERB...JUST
ABLE TO CUT DOWN A LITTLE MORE ON THE LINGERING CHANCES FOR
MEASURABLE SNOW. SNOW/LIQUID RATIOS HAVE BEEN PRETTY LOW CONSIDERING
THE TEMPERATURES..BUT THIS IS TO BE EXPECTED WITH THIS LIGHT NON
DENDRITIC SNOWFALL...OR LACK OF FLUFF.

AS THE LINGERING LIGHT SNOW ENDS...WITH VERY LIGHT ACCUMULATIONS...
AND CLOUDS DECREASE TODAY AND EVENING...THE ATTENTION TURNS TO THE
ARCTIC AIR INFLUX. THERE MAY BE A VERY SLIGHT BUMP UP OF A DEGREE OR
TWO AS SKIES CLEAR TODAY BUT HIGHS WILL STILL BE AT THE START OF THE
MORNING. WILL GO WITH THE LONG APPARENT SUSPICION OF THE NEED FOR A
WIND CHILL ADVISORY AND ISSUE FOR TONIGHT AND TUESDAY MORNING FOR
ALL OF THE AREA...STARTING MID EVENING EXCEPT MIDNIGHT SOUTHEAST
INCLUDING MOST OF NORTHWEST IOWA. THE ARCTIC AIR WILL HAVE NO
TROUBLE SPREADING THROUGHOUT THE AREA IN THIS PATTERN...AND THE
SLOWER CLEARING OVER OUR SOUTHWEST CORNER WILL NOT CAUSE TOO MUCH
RESTRAINT ON TEMPERATURE DROP THERE.

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 252 AM CST MON DEC 29 2014

TUESDAY WILL BE DARN COLD AS ARCTIC HIGH PRESSURE DROPS SOUTH DOWN
THE EASTERN SLOPES OF THE ROCKIES. WITH FRESH SNOW AND THE COLD AIR
MASS MAY EVEN SEE A FEW SITES NOT REACH ZERO ON TUESDAY AFTERNOON.
TEMPERATURES TUESDAY NIGHT INTO WEDNESDAY MORNING A LITTLE TRICKY AS
TIMING OF WESTERLY RETURN FLOW WILL MAKE A BIG DIFFERENCE ON LOWS
AND WHERE TEMPERATURES WILL BE ON WEDNESDAY MORNING. WILL GO
SOMEWHAT NON DIURNAL WITH TEMPERATURES AS A FAIRLY STRONG WEST TO
SOUTHWEST WIND DEVELOPS OVERNIGHT. THIS WILL UNFORTUNATELY JUST MEAN
ANOTHER NIGHT WITH SOME PRETTY COLD WIND CHILL VALUES BUT IF
TEMPERATURES WARM MORE THAN EXPECTED WITH THE STRONG FLOW THEY MAY
STAY OUT OF ADVISORY CRITERIA.

WEDNESDAY WILL STILL BE BELOW NORMAL BUT NOT AS COLD AS TUESDAY. OF
COURSE WITH THE WIND ABOUT 10 TO 15 MPH HIGHER WEDNESDAY REALLY WILL
NOT FEEL ANY BETTER. HIGHS MAINLY SINGLE DIGITS TO TEENS.

IN THE OUTER PERIODS(THURSDAY THROUGH SUNDAY)...A HINT OF A SMALL
WARM UP...OR AT LEAST RETURN TO NORMAL BEFORE WHAT APPEARS TO BE
ANOTHER FAIRLY STRONG ARCTIC SURGE DROPS SOUTH. VARIOUS MODELS HAVE
COME INTO MARGINAL AGREEMENT ON LESS COLD TEMPERATURES THURSDAY INTO
SATURDAY WITH LITTLE IF ANY REAL THREAT FOR PRECIPITATION. WILL
STICK CLOSE TO THE SUPERBLEND OUTPUT UNTIL HIGHER CONFIDENCE IS
REACHED WITH THIS POSSIBLE RETURN TO LESS COLD AIR. SO BASICALLY
LOOKING AT HIGHS IN THE 20S THURSDAY AND FRIDAY...THE TEENS AND 20S
SATURDAY AND THEN DEPENDING UPON TIMING TEENS OR COLDER ON SUNDAY.
BEST CHANCE FOR LIGHTER SNOW WILL BE ALONG AND AHEAD OF THIS ARCTIC
SURGE SO NO BIGGER POPS AT THIS TIME.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 530 AM CST MON DEC 29 2014

A FEW CEILINGS AROUND 3K FEET AND VISIBILITIES 3-5SM IN LIGHT SNOW
FROM INTERSTATE 90 AND SOUTH WILL IMPROVE TO VFR FROM THE NORTH
12Z-18Z. OTHERWISE VFR OVER THE AREA THROUGH 30/12Z. THROUGH
30/00Z A FEW SURFACE GUSTS FROM THE NORTH OF 20 TO 25 KNOTS OVER
THE AREA.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...WIND CHILL ADVISORY FROM 9 PM THIS EVENING TO NOON CST TUESDAY
     FOR SDZ038>040-050-052>070.

     WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST TUESDAY
     FOR SDZ071.

MN...WIND CHILL ADVISORY FROM 9 PM THIS EVENING TO NOON CST TUESDAY
     FOR MNZ071-072-080-081-089-097-098.

     WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST TUESDAY
     FOR MNZ090.

IA...WIND CHILL ADVISORY FROM 9 PM THIS EVENING TO NOON CST TUESDAY
     FOR IAZ001.

     WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST TUESDAY
     FOR IAZ002-003-012>014-020>022-031-032.

NE...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST TUESDAY
     FOR NEZ013-014.

&&

$$

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



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