000 
FXUS63 KFSD 132153
AFDFSD

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
353 PM CST FRI DEC 13 2013

.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 353 PM CST FRI DEC 13 2013

UPPER LEVEL SUPPORT AND LOWER AND MID LEVEL MOISTURE WILL GRADUALLY 
INCREASE THROUGH THE EVENING RESULTING IN FLURRIES AND LIGHT SNOW. 
WHILE SIGNIFICANT AMOUNTS ARE HIGHLY UNLIKELY A HALF AN INCH TO AN 
INCH OF SNOW IS PRETTY LIKELY NORTH OF INTERSTATE 90. THE BETTER 
CHANCES FOR THIS WILL BE FROM ABOUT 2Z THROUGH 12Z FROM WEST TO EAST 
ACROSS THE CWA AS THE BEST UPPER LEVEL SUPPORT SWINGS THROUGH. WITH 
THE ADDITIONAL EXPECTED CLOUD COVER DID RAISE LOWS A DEGREE OR TWO 
BUT NO BIG CHANGES. CLOUDS WILL GRADUALLY CLEAR ON SATURDAY AND WITH 
THE SHARP LOW LEVEL THERMAL GRADIENT TO THE WEST DID RAISE HIGHS 
JUST A TOUCH TO THE WEST OF THE JAMES RIVER VALLEY. CONTINUED WITH 
HIGHS OF MAINLY 10 TO 15 ALONG AND EAST OF THE JAMES RIVER VALLEY AS 
COLD AIR SHOULD REMAIN LOCKED IN AND LOW LEVEL TEMPERATURES ARE IN 
THE TEENS BELOW ZERO. SOME PATCHY LIGHT SNOW POSSIBLE IN THE FAR 
EASTERN CWA BEFORE 15Z BUT A PRETTY SMALL THREAT AT THIS TIME.

.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 353 PM CST FRI DEC 13 2013

THE EXTENDED WILL FEATURE THE BATTLE OF THE WARM AIR VS ARCTIC 
EXPRESS.  ON SATURDAY INTO SUNDAY...THE DOME OF COOLER AIR ACROSS 
THE REGION GRADUALLY SHIFTS EAST...HOWEVER...WAVE DROPS SOUTH ON 
SUNDAY AND FEEDS OFF OF THERMODYNAMIC BOUNDARY ACROSS THE AREA. AS A 
RESULT IT LOOKS LIKE THERE WILL BE LIGHT SNOW ACROSS SOUTHWEST 
MINNESOTA.  HAVE CONTINUED THE TREND OF INCREMENTING POPS 
HIGHER...FOR WHAT APPEARS TO BE A HIGH POP LOW QPF EVENT.  IN 
GENERAL...EXPECT SNOW AMOUNTS TO REMAIN AROUND AN INCH OR 
LESS...WITH THE SOUTHWEST HALF OF THE FORECAST AREA REMAINING DRY.  
WHERE THE CLOUDS ARE PREVALENT...IT WILL BE A STRUGGLE TO WARM...AND 
HAVE COOLED FORECAST HIGHS SLIGHTLY.  

MONDAY INTO TUESDAY LOOK MILD AND DRY...AND HAVE KEPT TEMPS FAIRLY 
MILD BUT TEMPERED HIGHS SLIGHTLY WHERE DEEPER SNOW FIELD WILL 
LIMIT.  MONDAY APPEARS TO BE THE WARMER OF THE TWO DAYS WITH WEAK 
LOW LEVEL COLD AIR ADVECTION ACROSS THE AREA ON TUESDAY AS SUBTLE 
ARCTIC INTRUSION WORKS INTO THE GREAT LAKES REGION.  

SOUTHERLY FLOW DEVELOPS ON WEDNESDAY AS LOW PRESSURE DEEPENS ALONG 
THE EAST SIDE OF THE ROCKIES. THE WAVE IS SOMEWHAT INTERESTING IN 
THAT A PIECE OF ENERGY BREAKS OFF NORTHERN STREAM WAVE AND PHASES 
WITH THE NORTHERN STREAM ENERGY DROPPING DOWN IN NORTHWEST FLOW.  
OVERALL...THE DYNAMICS APPEAR TO BE FOCUSED TO THE WEST OF THE 
FORECAST AREA.  HAVE SOME LIGHT POPS FOR LIGHT SNOW OR FLURRIES AS 
ARCTIC PUSH THURSDAY NIGHT INTO FRIDAY RESULTS IN FALLING 
TEMPERATURES. BY FRIDAY NIGHT APPEARS AS THROUGH THE REGION WILL BE 
BACK INTO THE ARCTIC FREEZE WITH 925 HPA TEMPERATURES PLUMMETING 
DOWN TO AROUND -25 C. 

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1229 PM CST FRI DEC 13 2013

VFR CONDITIONS FOR THE NEXT FEW HOURS THEN MVFR CEILINGS WILL
SETTLE IN AND CONTINUE THROUGH THE NIGHT. IT DOES LOOK LIKE FROM
ABOUT 15Z THROUGH 18Z TOMORROW THESE LOWER CEILINGS COULD SCOUR
OUT AND WENT TO SCATTERED MVFR DECK DURING THIS TIME. THERE WILL
ALSO BE A LIGHT SNOW THREAT THIS EVENING WITH THE BETTER CHANCES
IN HON FROM 2Z THROUGH 6Z AND FSD FROM 5Z THROUGH 8Z.


&&

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

$$

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