FXUS63 KFSD 120921
AFDFSD

AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA 
NATIONAL WEATHER SERVICE SIOUX FALLS SD
321 AM CST SAT DEC 12 2009

.DISCUSSION...
MAIN CONCERNS THIS PACKAGE WILL BE INCOMING ARCTIC AIR AND WHETHER 
OR NOT WE GET SOMETHING CLOSE TO AN ADVISORY TYPE SYSTEM ON SUNDAY 
NIGHT.

BEFORE THIS THOUGH...TODAY LOOKS LIKE A RELATIVELY MILD AND SOMEWHAT 
PLEASANT DAY FOR MOST LOCATIONS. A MODERATE SOUTHERLY GRADIENT WILL 
SEE WINDS AROUND 10 TO 15 MPH...SLOWLY TAPERING OFF IN THE WEST 
THROUGH THE AFTERNOON. THE BIGGEST CHALLENGE WILL BE THE STRATUS 
BLOB OVER EASTERN KANSAS AND JUST HOW FAR NORTH AND EAST IT REACHES. 
WILL STILL PLAN ON THIS AREA MAKING IT INTO NW IA AND WITH THE FLOW 
TURNING A LITTLE MORE SOUTHWEST IN AND AROUND THE CLOUD LAYER THIS 
AFTERNOON...SHOULD KEEP THE BULK OF THE CLOUD COVER SOUTHEAST OF THE 
AREA. OVERALL...WILL RAISE HIGHS JUST A SMIDGE...BUT KEEP THEM IN 
THE 20S. MAYBE SOMETHING CLOSER TO FREEZING AROUND CHAMBERLAIN AND 
GREGORY.

AS A WEAK WAVE PASSES TONIGHT COLD AIR CURRENTLY OVER SOUTHERN 
CANADA AND NORTHWEST ND WILL LEAK SOUTH AND AFFECT NORTHERN PARTS OF 
THE AREA LATE TONIGHT. OVER MAINLY NW IA AND EXTREME SE SD...MODEL 
SOUNDINGS CONTINUE TO HINT AT THE POTENTIAL FOR A LITTLE FOG OR 
LIGHT FREEZING DRIZZLE...SO WILL KEEP THIS IN THE FORECAST AND BACK 
IT A LITTLE FARTHER TO THE WEST. LOWS SHOULD RANGE FROM NEAR ZERO 
AROUND HON AND BKX TO THE MID TEENS AROUND SLB.

SUNDAY SHOULD PROVE TO BE A COLD BUT QUIET DAY AS THE AREA SEES WEAK 
UPPER LEVEL RIDGING AHEAD OF THE NEXT WAVE PROGGED FOR SUNDAY NIGHT. 
LATEST NAM/GFS/EC/GEM ALL IN PRETTY GOOD AGREEMENT WITH AMOUNT OF 
COLD AIR EXPECTED...SO LOWERED HIGHS QUITE A BIT...RANGING FROM 
AROUND 5 NORTH TO 15 TO 20 SOUTH. A COMBINATION OF COLD TEMPERATURES 
AND NORTH TO NORTHEAST WINDS AROUND 10 TO 15 MPH WILL LEAD TOWARDS 
WIND CHILL VALUES AROUND 15 BELOW IN SOME SPOTS...SO A COLD SUNDAY.

WENT AHEAD AND UPPED POPS A LITTLE ON SUNDAY NIGHT AND INCREASED 
SNOW AMOUNTS A LITTLE AS WELL. VERY COLD AIR MASS IN PLACE AS WAVE 
MOVES THROUGH AND PRETTY MUCH BANKING ON ALL SNOW. LATEST GEM THE 
MOST AGGRESSIVE IN THE WARM SECTOR AND WOULD ALMOST HINT AT THE 
POTENTIAL FOR SLEET WITH 850MB T AROUND ZERO NEAR I90 AND AROUND -16 
C AT 925MB. NONE OF THE OTHER MODELS THIS AGGRESSIVE...SO WILL 
MAINTAIN ALL SNOW AT THIS TIME. WILL AIM FOR ABOUT 1-2 INCHES ALONG 
AND NORTH OF HIGHWAY 14...NEAR AN INCH DOWN I90 AND LESS THAN A HALF 
AN INCH ALONG THE MO RIVER INTO NW IA. LOWS FROM ZERO TO 5 BELOW 
NORTH TO 5 TO 10 ABOVE IN NW IA.

WILL KEEP SOME LOW POPS IN THE EAST ON MONDAY MORNING AS WAVE 
EXITS...BUT EXPECTING DRY AND COLD CONDITIONS MONDAY NIGHT INTO 
TUESDAY. HIGHS MAINLY IN THE SINGLE DIGITS MONDAY AND TUESDAY WITH 
LOWS MOSTLY BELOW ZERO.

&&

.AVIATION...
CLEAR SKIES EARLY THIS MORNING...WITH A FEW PATCHES OF CIRRUS. 
ATTM...SOME IFR STRATUS ALONG THE MO/IA BORDER AND INTO FAR SE NE. 
WILL SEE THIS LIFT NWRD THROUGH THE MORNING...REACHING THE SE CWA 
SOMETIME AFTER SUNRISE. GENERALLY EXPECTING STRATUS TO REMAIN ALONG 
AND E OF I29. MORE CONCERNED WITH THE POSSIBILITY OF MVFR STATUS 
DEVELOPING LATE TODAY...AND MORE SO TONIGHT. OTHERWISE LITTLE IN THE 
WAY OF AVIATION CONCERNS UNTIL SUNDAY NIGHT...WHEN AN UPPER LEVEL 
DISTURBANCE WILL SPREAD SNOW ACROSS PORTIONS OF THE FORECAST AREA. 
THERE IS ALSO THE POTENTIAL OF A BRIEF PERIOD OF FREEZING RAIN MORE 
TOWARDS THE SUX AREA. 

&&

.FSD WATCHES/WARNINGS/ADVISORIES...

SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.

&&

$$