283 
FXUS63 KFSD 231609
AFDFSD

AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA 
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1010 AM CST SUN NOV 23 2008

.DISCUSSION...
CDFNT MOVG THRU JAMES VALLEY ATTM AND SHUD PUSH ALL OF CWA BY EARLY 
EVE. PLENTY OF CLOUDS ACRS CWA TODAY AND WL KEEP SKIES MOCLDY. 
PRECIP MAY BE HARD TO COME BYB THIS AFTN WITH LOW LEVELS QUITE DRY. 
MAY END UP BEING VIRGA WITH SPRINKLES AT WORST. OTHERWISE NO REASON 
TO CHANGE CURRENT FCST FOF THIS AFTN.

&&
.AVIATION...
VFR THRU 12Z MON.

&&

.PREVIOUS DISCUSSION...
AREAS OF FOG IN PLACE GENERALLY E OF I29 EARLY THIS MORNING. A FEW 
LOCATIONS REPORTING VISIBILITIES AS LOW AS 1/4 MILE IN NW IA. MID TO 
HIGH CLOUDS ARE RAPIDLY ADVANCING EAST SHOULD MITIGATE FURTHER FOG 
DEVELOPMENT...AND MAY DIMINISH FOG ALL TOGETHER BY SUNRISE. HAVE FOG 
IN THE GRIDS THROUGH 15Z...BUT WILL NEED TO REMOVE SHOULD VISBYS 
IMPROVE DUE TO CLOUD COVER. 

OTHERWISE FOR TODAY...ANOTHER QUICK MOVING WESTERLY FLOW WAVE TO 
SHIFT ACROSS THE CWA. GFS AND NAM HAVE THE SAME GENERAL IDEA BUT 
THERE ARE SOME SUBTLE DIFFERENCE THAT AFFECT THE FORECAST. LEANING 
MORE TOWARDS THE GFS THROUGH THIS AFTERNOON AS RADAR RETURNS OUT OF 
ERN MT CLOSER RESEMBLE QPF FROM THE GFS THAN NAM. GFS FORCING IS 
MUCH STRONGER AS NOTED BY OMEGA FIELDS FROM 700-500 MB...WHICH IS 
LIKELY WHY IT IS PRODUCING QPF THIS AFTERNOON...WHILE THE NAM IS 
NOT. MOISTURE IS ONCE AGAIN LACKING IN THE LOW LEVELS...SO IT WILL 
TAKE SOME TIME JUST TO SATURATE. MAIN CHANCES FOR MEASURABLE 
PRECIPITATION WILL BE IN THE N...MAINLY ALONG STATE HIGHWAY 
14...WITH NOT MUCH MORE THAN A FEW HUNDREDTHS EXPECTED. 
PRECIPITATION TYPE IS IN QUESTION. PLENTY OF COLD ALOFT FOR 
SNOW...BUT NEAR THE SURFACE IT IS MORE QUESTIONABLE AS PROGGED 
SOUNDINGS INDICATE TEMPERATURES AT OR SLIGHTLY ABOVE FREEZING. MOST 
LIKELY PRECIPITATION TYPE WILL BE DECIDED BY THE RATE. WILL LIKELY 
NEED HIGHER RATES TO SUFFICIENTLY COOL THE COLUMN ENOUGH TO INHIBIT 
MELTING...THEREFORE PRODUCING SNOW. EITHER WAY IT IS A CLOSE CALL ON 
TYPE...SO WENT WITH A MENTION OF RAIN AND SNOW. BEST CHANCES FOR 
ACCUMULATION OF SNOW WILL BE INTO SW MN LATE THIS AFTERNOON AND 
EARLY EVENING. ANY ACCUMULATIONS SHOULD BE UNDER 1 INCH...WITH 
MAINLY JUST A DUSTING EXPECTED. AHEAD OF THE SFC TROUGH... 
TEMPERATURES COULD WARM MORE THAN CURRENTLY ANTICIPATING. NAM A GOOD 
DEAL WARMER WITH 925 MB TEMPERATURES THAN GFS E OF THE TROUGH INTO 
SW MN AND NW IA. HAVE UPPER 30S TO MID 40S GOING FOR HIGHS IN THESES 
AREAS...BUT COULD EASILY GO ANOTHER 5 DEGREES WARMER...SHOULD MIXING 
REACH ONLY A FEW HUNDRED FEET HIGHER INTO THE INVERSION.    


DRY FORECAST IN PLACE FOR THE BEGINNING OF THE WORK WEEK...RIGHT 
THROUGH THANKSGIVING DAY AND INTO FRI. TEMPERATURES WILL START THE 
WEEK OUT A BIT BELOW NORMAL...BUT BY MID WEEK AND THANKSGIVING... 
SHOULD BE AT TO SLIGHTLY ABOVE NORMAL FOR DAYTIME TEMPERATURES.  
      

&&

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

&&

$$