262 
FXUS63 KFSD 210749
AFDFSD

AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA 
NATIONAL WEATHER SERVICE SIOUX FALLS SD
249 AM CDT TUE SEP 21 1999

STRAIGHTFORWARD FCST WITH JUST A COUPLE OF MINOR WARTS. KABR...KOAX 
AND KBIS SNDGS SHOW SOME FAIRLY HIGH MSTR CONTINUING AT 850MB...WITH 
VERY DRY AIR ABV THIS LVL. COUPLED WITH A SHORTWV MOVG DOWN THE EAST 
SIDE OF THE RIDGE AS PER THE IR PIX...BLV THE ERN HALF OF CWA COULD 
BECOME PCLDY THIS AFTN DURING MAX HTG. MIXING TEMPS DOWN FM AROUND 
800MB AT THE SUBSIDENCE INVERSION LEVEL...REVEALS HIGHS OF ABOUT 65 
TO 70 IN THE EAST...AND IN THE LOWER TO MID 70S IN THE WEST. 
BASICALLY...LARGE WRN U.S. RIDGE SETS UP AND CWA CAUGHT IN A NWRLY 
FLOW THRU WED. MDLS PROG ANOTHER WK SHORTWV MOVG DOWN THE FLOW 
TNGT...EAST OF THE CWA THRU THE GRTLKS. ABOUT THE ONLY AFFECT THIS 
MAY HAVE ON THE FA IS KEEPING THE LIGHT WNDS FM THE SOUTH TNGT AHD 
OF THE FRONTAL BNDRY. BUT WHAT IS INTERESTING ON WED...IS THAT BOTH 
THE NGM AND ETA SHOW A HIGH PRES CIRCULATION OVR ERN ND BEHIND THE 
WK FNT. THIS MAY TURN THE WNDS ARND TO THE N OR NE OVR MUCH OF THE 
CWA BY WED AFTN. ONE EXCEPTION TO THIS WL BE FM NR SUX TO SLB...
WHERE THE WK BNDRY HANGS UP. SO OPTED TO WORD VARIABLE IN THIS ZONE.
FOR TEMPS...KEPT HIGHS SLIGHTLY ABV THE FWC OVERALL. FOLLOWED ETA 
LLVL TEMPS THIS TIME ARND. PLENTY OF WAA AT 850MB TDAY AND TNGT...
WITH NEUTRAL ADVECTION ON WED.

.FSD...NONE
FUHS