298 
FXUS43 KFSD 311625
AFDFSD

AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1020 AM CST WED DEC 31 1997

ONLY REAL FORECAST PROBLEM TODAY IS POSITIONING THE INEVITABLE STRONG
GRADIENT IN AFTERNOON TEMPERATURES.  SFC WM PUSH CLOSE TO JAMES
VALLEY...MOVING ONLY SLOWLY EWRD TDA...WITH SOMEWHAT SHALLOW CD RIDGE
CNTRD NR SPW.  RETURN FLOW OFF WK SNOWFIELD TO E WL TEMPER WARMING E
FOR A TIME TDA.  OTHER PBLM IS LOW CLOUD BAND THU JAMES RVR ALG FNTL
BAND...AS WELL AS WEALTH OF HIGH CLDS SPILLING INTO REGION.  ABR/MPX
RAOBS DEEP INTO CD AIR.

USE SOME QUALITATIVE GUIDANCE FM 12Z RUC...BUT APPEARS MUCH TOO UNIFORM
AND SMOOTHED WITH SFC TMPS.  WL UPDT CLD CVR SW MN/NW IA...AS WELL AS
TIGHTEN TMP GRAD THRU CWA.  9H TMPS WOULD SUPPORT AS MUCH AS 30F DIFF
WEST TO EAST THIS AFTN.

.FSD...NONE

CHAPMAN