318 
FXUS63 KFSD 061540
AFDFSD

AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA  
NATIONAL WEATHER SERVICE SIOUX FALLS SD
940 AM CST FRI DEC 6 2002

AS EXPECTED...A COLD AND FROSTY MORNING WITH ELEVATION AGAIN PROVING 
TO BE THE DIFFERENCE.  LOWER ELEVATION LOCATIONS ARE SITE ARE 
SEVERELY LAGGING...WHILE THE INFAMOUS BUFFALO RIDGE UP TO 10 DEGREES 
WARMER THAN IMMEDIATE SURROUNDINGS...WITH GUSTS TO 30 MPH.  HOW WARM 
IT COULD BE TODAY IS A FORMIDIBLE CHALLENGE.

SNOWCOVER A NAGGING ISSUE...AN INCH OR TWO AT BEST ACRS ALL BUT NERN 
CWA WHERE LITTLE OR NONE EXISTS. FAIRLY THICK FROST AS WELL...NOT 
SHOWING MUCH DECREASE AT CURRENT TIME IN KFSD.  NOTING FAIRLY THICK 
CI IN DIVERGENT AREA...AHEAD OF SHORT WAVELENGTH WAVE SLIDING INTO 
SWRN ND AND NWRN SD. BEST OF THIS CI DYNAMICALLY TRACKS ACRS NERN 
HALF OF CWA.  THIS TIME OF YEAR...EVEN THINNER CI IS ENOUGH TO 
SIGNIFICANTLY AFFECT TMPS.  THE PATHETIC SUN ANGLE AS WE RAPIDLY 
APPROACH THE SOLSTICE WILL NOT BE ANY HELP EITHER.  WITH CI 
TRAVERSING CWA DURG CRITICAL MIDDAY HEATING...ALL SIGNS SEEM TO 
POINT TOWARD A COOL OVERALL FORECAST.  THIS IS ALSO WELL CAPTURED IN 
PREV FCST...AND FOR NOW WL NOT DEVIATE ALL THAT MUCH. TMPS TRENDING 
TOWARD ISOTHERMAL FROM INVERSION TOP SEEM A FAIR FIRST GUESS.  WL 
BREAK OFF GREGORY CTY FOR ELEVATION EFFECTS AS WELL...AND REGROUP IN 
SW MN TO FIT SNOWCOVER/WIND CLIMATOLOGY.

GRIDS PREVIOUSLY UPDATED TO INCLUDE CI PATCH...AND INCRS WNDS A BIT 
OVER SW MN...AND SERIOUSLY SLOW LOWER ELEVATION TMP RISES THIS 
MORNING.  UPDATED ZONES OUT ARND 1530Z. 

.FSD...NONE
CHAPMAN