266 
FXUS63 KFSD 011203
AFDFSD

AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NATIONAL WEATHER SERVICE SIOUX FALLS SD
603 AM CST WED FEB 1 2012

.AVIATION.../FOR THE 12Z TAF ISSUANCE/
OTHER THAN SOME PATCHY FOG IN SOUTHWEST MINNESOTA THROUGH ABOUT 
14Z...VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. /08

&&

.DISCUSSION.../ISSUED AT 355 AM CST/
TODAY AND TOMORROW CONTINUE TO LOOK FAIRLY WARM ACROSS THE REGION 
WITH 925 TEMPS IN THE 5 TO 6 DEGREES CELSIUS RANGE...AND AT LEAST 
SOME MIXING TO PROMOTE AFTERNOON TEMPS A TOUCH ABOVE ISOTHERMAL. 
LOWS ON WEDNESDAY NIGHT WILL BE MORE SIMILAR TO THOSE SEEN THIS 
MORNING WITH VERY LITTLE CLOUD COVER...THEN BEGINNING THURSDAY 
NIGHT...THE APPROACHING SYSTEM TO THE SOUTH BEGINS IMPACTING 
TEMPERATURES FOR THE FORECAST AREA.

MODELS ARE SETTLING ON A SOLUTION FOR THE SURFACE LOW UP THROUGH 
SATURDAY MORNING...TAKING A FAIRLY SOUTHERN TRACK THROUGH OKLAHOMA 
INTO SOUTHEAST KANSAS. THE BULK OF THE PRECIPITATION WILL LIKELY 
STAY SOUTH OF THE FORECAST AREA ON FRIDAY WITH THE BEST UPPER LEVEL 
DYNAMICS AND IMPRESSIVE INSTABILITY CONFINED TO SOUTHERN NEBRASKA 
THROUGH KANSAS...BUT HAVE INCLUDED A SLIGHT CHANCE OVER THE SOUTHERN 
EDGE OF THE AREA FOR UNCERTAINTY IN THE LOW TRACK AND A POTENTIAL 
FOR SOME OVERRUNNING NORTH OF THE 700 MB FRONT. ALTHOUGH 850 MB 
TEMPERATURES ARE ABOVE ZERO MOST OF FRIDAY...MODELS INDICATE A DRY 
LAYER THROUGH THIS LAYER...AND PRECIPITATION WILL LIKELY BRING THE 
BULK OF THE SOUNDING BELOW FREEZING...SUPPORTING MOSTLY SNOW. 
HOWEVER...NEAR SURFACE TEMPERATURES WILL HOVER A FEW DEGREES ABOVE 
FREEZING MOST OF THE DAY...ALLOWING FOR SOME MELTING IN THE LOWEST 
LEVELS AND A POTENTIAL RAIN SNOW MIX. WITH WARM GROUND AND NEAR 
SURFACE TEMPERATURES...SNOW AMOUNTS ON FRIDAY SHOULD BE MINIMAL. AS 
THE SYSTEM PUSHES NORTH AND BEGINS TO DEEPEN ON FRIDAY NIGHT... 
PRECIPITATION WILL BECOME MORE LIKELY ACROSS THE SOUTHERN EDGE OF 
THE FORECAST AREA...AND COOLER AIR WRAPPING IN TO THE NORTH WILL 
CHANGE THE PRECIPITATION TYPE TO SNOW THROUGHOUT THE AREA.

ON SATURDAY...MODEL UNCERTAINTY EXPLODES AS THE GFS QUICKLY KICKS 
THE LOW OUT TO THE EAST...EC HANGS THE LOW ACROSS THE NORTHERN 
PLAINS...AND GEM WAVERS SOMEWHERE IN BETWEEN THE TWO SOLUTIONS. 
SATURDAY MORNING STILL LOOKS FAIRLY LIKELY FOR SNOWFALL ACROSS THE 
SOUTH...AND WITH THE BEST DYNAMICS IN THE EC AND GFS LIFTING INTO 
NORTHWEST IA...HAVE FOCUSED THE HIGHEST SNOWFALL AMOUNTS FOR THIS 
PERIOD. SATURDAY AFTERNOON THROUGH SUNDAY...HAVE SLOWLY ALLOWED THE 
POTENTIAL FOR PRECIPITATION TO DECREASE AS THE SURFACE LOW BROADENS 
AND UNCERTAINTY INCREASES. TOTAL SNOW AMOUNTS FOR THIS SYSTEM SHOULD 
CUT OFF FAIRLY RAPIDLY SOMEWHERE NOT FAR FROM THE SOUTHERN BORDER OF 
THE FORECAST AREA...AND CURRENTLY HAVE NOMINAL ACCUMULATIONS NORTH 
OF A LINE FROM WAKEFIELD NEBRASKA TO STORM LAKE.

BEYOND SUNDAY...TEMPERATURES CONTINUE TO LOOK ABOVE NORMAL IN A 
QUIET WEATHER PATTERN. THE NEXT COLD PUSH SHOULD DROP INTO THE 
REGION ON TUESDAY...BUT DOES NOT LOOK VERY POTENT...ESPECIALLY IN 
THE GFS. AFTER SNOW TAPERS ON SATURDAY NIGHT OR SUNDAY...CONDITIONS 
SHOULD BE DRY THROUGH THE REMAINDER OF THE PERIOD. /LAFLIN

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

&&

$$