Area Forecast Discussion
Issued by NWS Sioux Falls, SD

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000
FXUS63 KFSD 232156
AFDFSD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
356 PM CST SUN NOV 23 2014

.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 356 PM CST SUN NOV 23 2014

FRONTOGENETIC BAND OF PRECIPITATION IS EXPECTED TO SHIFT EAST OF THE
AREA THROUGH THE LATE AFTERNOON HOURS.  STRONG NORTHWEST WINDS ARE
EXPECTED ACROSS THE AREA THROUGH MUCH OF THE OVERNIGHT.  WITH THE
WIND ADVISORY CONDITIONS ACROSS CENTRAL AND NORTHWEST SOUTH DAKOTA
AND WINDS APPROACHING ADVISORY CRITERIA OVER THE NEXT FEW HOURS...AM
GOING TO CONTINUE THE WIND ADVISORY FOR CENTRAL PORTIONS OF SOUTH
DAKOTA.  WILL ALSO ISSUE A WIND ADVISORY ALONG THE SPINE OF THE
BUFFALO RIDGE TONIGHT INTO MONDAY AS STRONG COLD AIR ADVECTION
COMBINED WITH NORTHWEST FLOW ALOFT WILL CREATE ADVISORY CONDITIONS.
THE COLD AIR ADVECTION IS EXPECTED TO DECREASE SOME DURING THE DAY
ON MONDAY...BUT MIXING WILL COUNTERACT THE REDUCED EFFECT OF THE
COLD AIR ADVECTION...SO WILL KEEP THE HEADLINE GOING THROUGH THE DAY
ON MONDAY.

SHORTWAVE DROPPING THROUGH FROM THE NORTH TONIGHT ACROSS SOUTHWEST
MINNESOTA...BUT LIMITED AMOUNTS OF MOISTURE IN THE LOW LEVELS WILL
CREATE A LIMITED PERIOD ON WHEN SNOW COULD POTENTIALLY FORM.  THE
DENDRITIC LAYER REMAINS UNSATURATED MOST OF THE TIME...AND THEREFORE
KEPT POPS FAIRLY LOW. ANY PRECIPITATION IS EXPECTED TO REMAIN
LIGHT...TOTALING A FEW HUNDREDTHS OF AN INCH OR LESS IN MOST
LOCATIONS.  TEMPERATURES WILL RETURN BACK TO BELOW NORMAL
LEVELS...WITH WIND CHILLS IN THE SINGLE DIGITS ABOVE AND BELOW ZERO.


.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 356 PM CST SUN NOV 23 2014

ACTIVE NORTHWEST FLOW...TURNING QUASI-ZONAL LATE IN THE PERIOD WILL
BRING SOME FLUCTUATING TEMPERATURES AND A FEW CHANCES FOR PRECIPITATION
IN THE MID AND LONG RANGE.

THE FIRST SUCH WAVE MANIFESTS AS A FAST MOVING CLIPPER SYSTEM...LIKELY
DROPPING THROUGH THE REGION ON TUESDAY NIGHT INTO WEDNESDAY MORNING.
THE GFS REMAINS QUITE A BIT FASTER THAN THE OTHER MODELS BY NEARLY 12
HOURS...WHILE THE GEM IS THE FURTHEST NORTH...KEEPING BRUNT OF THE
FORCING AND SNOW NORTH OF THE CWA. TRIED TO FOLLOW SOMETHING CLOSER TO
THE MIDDLE OF THE ROAD ECMWF IN TIMING AND TRACK. SCATTERED LIGHT
FLURRIES ARRIVING WITH INCREASING WARM AIR ADVECTION CLOUDS ON TUESDAY
MORNING WILL GIVE WAY TO A CHANCE OF ACCUMULATING LIGHT PRECIPITATION.
PERHAPS INITIALLY A RAIN AND SNOW MIX IN CENTRAL SD TUESDAY AFTERNOON
WILL QUICKLY CHANGE ENTIRELY TO SNOW AND TRACK THROUGH OUR NORTHERN AND
EASTERN FORECAST AREA OVERNIGHT. GREATEST ACCUMULATIONS LOOK TO BE IN
SOUTHWEST MINNESOTA WHERE A QUICK INCH AND A HALF IS POSSIBLE...WITH
LIGHTER AMOUNTS ELSEWHERE. TEMPERATURES WILL WARM NICELY EVEN WITH
INCREASING CLOUDS ON TUESDAY AS SOME DECENT WARM AIR ADVECTION ARRIVES
AHEAD OF THE CLIPPER. HIGHS WILL BE ABOVE FREEZING FOR ALL BUT THE FAR
NORTHEAST CORNER...AND WILL NEAR 40 IN SOUTH CENTRAL SD.

COLDER AIR PLUNGES BACK INTO THE REGION BEHIND THE WAVE ON WEDNESDAY
AFTERNOON AND OVERNIGHT...LEADING TO AN UNSEASONABLY COLD THANKSGIVING
DAY. STRATUS WILL PREVENT TEMPERATURES FROM PLUNGING BELOW ZERO ON
WEDNESDAY NIGHT...BUT WITH THE BAROCLINIC ZONE SETTING UP ACROSS
NORTHEAST SD INTO SOUTH CENTRAL SD AND A POSSIBLE SUBTLE IMPULSE
TRACKING IN THIS AREA...SOME LIGHT SNOWFALL CHANCES DEVELOP NEAR THE
MISSOURI VALLEY. THE EXACT EXTENT OF THIS PRECIPITATION INTO OUR
FORECAST AREA IS STILL UNCERTAIN...BUT COULD SEE AN INCH OR TWO OF
SNOWFALL. MODELS INDICATE A GRADUAL CLEARING ON THURSDAY ACROSS OUR
NORTHEASTERN HALF. CLOUDS MAY LINGER LONGER NEAR THE MISSOURI VALLEY
AND SOUTH CENTRAL SD...BUT ACCUMULATING SNOWFALL IS NOT EXPECTED.
THANKSGIVING HIGHS WILL ONLY REACH THE MID TEENS TO MID 20S.

MODELS DIVERGE A BIT MORE THURSDAY NIGHT AND ONWARD WITH EACH MODEL
SHIFTING THE BAROCLINIC ZONE NORTH AND SOUTH ACROSS THE NORTHERN
PLAINS. NOT A GREAT DEAL OF CONFIDENCE IN TEMPERATURES AND
PRECIPITATION CHANCES DURING THIS PERIOD...SO DID NOT ALTER MUCH FROM
THE ALLBLEND. IT DOES SEEM REASONABLY CERTAIN THE TEMPERATURES MODERATE
SOME ON FRIDAY...BUT MODELS ARE AGAIN COMPLETELY OUT OF PHASE THIS
WEEKEND.


&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1155 AM CST SUN NOV 23 2014

BREEZY NORTHWEST WINDS EXPECTED TO PREVAIL THROUGH THE PERIOD.
CLOUD CEILINGS WILL GRADUALLY LOWER INTO THE MVFR RANGE. COULD
HAVE SOME LIGHT SNOW OVERNIGHT...THOUGH TIMING IS STILL SOMEWHAT
SUSPECT SO HAVE LEFT OUT FOR NOW.


&&

.FSD WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY FROM MIDNIGHT TONIGHT TO 6 PM CST MONDAY FOR
     SDZ040-056.

     WIND ADVISORY UNTIL 9 PM CST THIS EVENING FOR SDZ038-050-052-053-
     057>059-063-064.

MN...WIND ADVISORY FROM MIDNIGHT TONIGHT TO 6 PM CST MONDAY FOR
     MNZ071-072-080-081-089-090-097-098.

IA...WIND ADVISORY FROM MIDNIGHT TONIGHT TO 6 PM CST MONDAY FOR
     IAZ001>003-013-014-022.

NE...NONE.
&&

$$

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


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