FXUS63 KFSD 251629
AFDFSD

AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1029 AM CST WED NOV 25 2009

.DISCUSSION....
FORECAST IN FAIRLY GOOD SHAPE THIS MORNING WITH NO ADDITIONAL UPDATE 
PLANNED.  MODEST COLD AIR ADVECTION ALONG WITH 30-35 KNOTS OF FLOW 
AT 925 MB WILL CREATE WINDY CONDITIONS ACROSS THE AREA.  EXPECT 
WINDS WILL REMAIN NEAR WIND ADVISORY THROUGH LATE AFTERNOON...BUT 
EXPECT CONDITIONS TO GENERALLY REMAIN BELOW CRITERIA AND WILL REMAIN 
WITHOUT A HEADLINE. EXPECT TEMPERATURES TO REMAIN FAIRLY STEADY WITH 
COLD AIR ADVECTION AND CLOUD COVER.

TRICKY CLOUD COVER FORECAST TONIGHT WITH BATCH OF STRATUS ACROSS 
NORTH DAKOTA SLIDING SOUTH.  GFS NOT HANDLING CURRENT CLOUD COVER 
ALL THAT WELL...AND NAM SUGGESTS A DIURNAL TREND TO THE CLOUDS THIS 
EVENING.  CLOUDS HAVE A BIT OF A DIURNALLY DRIVEN LOOK TO THEM BASED 
ON VISIBLE SATELLITE.  TRIED TO LOOK AT A TAMDAR SOUNDING TO 
SUBSTANTIATE THIS IDEA ACROSS CENTRAL OR WESTERN NORTH DAKOTA...BUT 
NO DATA WAS AVAILABLE. WILL CONTINUE TO INTERROGATE CLOUD SITUATION 
FOR TONIGHT WITH ISSUANCE OF AFTERNOON PACKAGE. /BT

&&
.AVIATION...
AREAS MVFR CIGS AND GUSTY NWLY WINDS CAN BE EXPECTED THROUGH EARLY 
EVENING. PERIODS OF MVFR VSBYS IN -SN ARE POSSIBLE AT KHON/KFSD TAF 
LOCATIONS...WITH BETTER CHANCE OF IFR VSBYS XPCTD TO REMAIN OVER 
SWRN MN/NWRN IA. WND GUSTS OF 25-35KT WILL PERSIST MUCH OF THE 
DAY...DMNSHG AFTER 26/00Z AS HIGH PRESSURE BEGINS TO BUILD INTO THE 
AREA FROM THE WEST.

MVFR CLOUDS WILL GRADUALLY CLEAR FROM WEST TO EAST OVERNIGHT. LARGE 
BATCH OF STRATUS ACROSS NORTH DAKOTA WILL POTENTIALLY DIMINISH 
TOWARDS SUNSET LATE WEDNESDAY AFTERNOON...LEAVING MOSTLY CLEAR SKIES 
AFTER 00Z.

&&
.PREV DISCUSSION...
QUICK MOVING UPPER LEVEL LOW CURRENTLY CENTERED NEAR THE MN/ND/SD
BORDER WILL DROP SE ACROSS THE CWA TODAY...BRINGING A SHOT OF SNOW 
MAINLY TO EASTERN AREAS. THIS IS A VERY DYNAMIC SYSTEM...BUT AS IT 
IS MOVING SO QUICKLY...SNOW AMOUNTS WILL BE LIMITED. COULD BE A MIX 
OF RAIN OR SNOW INTO NW IA THIS MORNING...BUT TEMPERATURES ALOFT 
COOL ENOUGH THAT ALL PRECIPITATION SHOULD SWITCH TO SNOW...EVEN IF 
SURFACE TEMPERATURES REMAIN ABOVE FREEZING. SNOW ACCUMULATIONS WILL 
MAINLY BE CONFINED OF AREAS EAST OF INTERSTATE 29...AND GENERALLY 
EXPECTING 1 INCH OF SNOW ALONG AND EAST OF THE BUFFALO RIDGE...BUT 
WOULD NOT RULE OUT ISOLATED 2 INCH AMOUNTS IN THIS AREA. IT HAS BEEN 
TOUGH TO GAUGE THE RATE OF SNOW FALL INTO NE SD AND ERN ND THIS 
MORNING DUE TO A LACK OF OBSERVATION SITES...HOWEVER...JMS REPORTED 
5 HRS OF SN WITH VSBYS AROUND 3/4 MILE FOR A FEW HOURS. EXPECTING 
SIMILAR CONDITIONS ALONG AND EAST OF THE BUFFALO RIDGE. NOT 
EXPECTING ENOUGH SNOW ACCUMULATIONS FOR AN ADVISORY...BUT VSBYS 
COULD DROP BELOW 1/2 SM FOR A FEW HOURS IN PLACES...AND WHEN 
COMBINED WITH STRONG NW WINDS...COULD MAKE FOR TRICKY TRAVEL FOR A 
SHORT TIME TODAY. THE UPPER LEVEL DISTURBANCE RESPONSIBLE FOR THE 
SNOW WILL EXIT THE AREA JUST AS FAST AS IT APPEARED. SNOW SHOULD 
PRETTY WELL BE OVER BY SUNSET...EXCEPT MAYBE A FEW LINGERING 
FLURRIES TOWARD MJQ/SPW/SLB. ELECTED NOT TO ISSUE A WIND ADVISORY 
TODAY...BUT WINDS WILL BE MARGINAL ALONG THE MO VALLEY. 40 TO 50 KT 
NW FLOW IS IN PLACE AT 850 MB THIS MORNING...BUT DOES NOT APPEAR 
THESE WINDS WILL BE ABLE TO COMPLETELY MIX TO THE SFC. WOULD LIKE TO 
SEE SLIGHTLY STRONGER CAA FOR AN ADVISORY. STILL...SHOULD SEE SOME 
30 MPH SUSTAINED WINDS WITH GUSTS OVER 40 MPH.   

CLEARING SKIES WEST TO EAST TONIGHT AND DECREASING WINDS AS HIGH 
PRESSURE BUILDS INTO THE AREA. COOL HIGH PRESSURE REMAINS IN PLACE 
TOMORROW...WITH TEMPERATURE ONLY RISING INTO THE 30S IN THE EAST AND 
40S WEST. ALTHOUGH THIS IS SOME OF THE COOLEST AIR WE HAVE SEEN THIS 
SEASON...IT IS RIGHT AROUND NORMAL.
 
NOT MUCH GOING ON IN THE WAY OF WEATHER THOUGH EARLY NEXT WEEK. 
UPPER RIDGE TO KEEP THINGS DRY THROUGH SATURDAY. A TROUGH DROPS INTO 
THE NORTHERN PLAINS ON SUNDAY...WHICH COULD BRING SOME LIGHT SNOW 
SHOWERS TO THE AREA...HOWEVER THERE MAY NOT MUCH MOISTURE TO WORK 
AND LOOKS LIKE THE NRN STREAM WAVE MAY BE WEAK...WITH STRONGER SRN 
STREAM WAVE OVER TX. 97

&&

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

$$