000 
FXUS63 KFSD 041001
AFDFSD

AREA FORECAST DISCUSSION FOR SOUTHEAST SD/SOUTHWEST MN/NORTHWEST IA 
NATIONAL WEATHER SERVICE SIOUX FALLS SD 
400 AM CST SUN NOV 4 2007

.DISCUSSION...

ONE FINAL DAY OF MILD CONDITIONS AHEAD OF A STRONG COLD FRONT THAT 
WILL WORK THROUGH THE REGION TONIGHT. FAIRLY STRONG JET STREAM 
ORIENTED FROM NORTHWEST TO SOUTHEAST REMAINS OVER THE AREA MUCH OF 
THE WEEK AS LOW PRESSURE SYSTEM UNDERGOES RAPID CYCLOGENESIS OVER 
THE GREAT LAKES REGION. 

A FEW BATCHES OF HIGH CLOUDS WILL SPILL INTO THE REGION TODAY...AND 
HAVE TEMPERED WARMING POTENTIAL SLIGHTLY IN THE EASTERN PORTION OF 
THE CWA AS A RESULT. DRY AIR MASS CONTINUING...AND WITH MILD TEMPS 
WILL BE A VERY HIGH FIRE DANGER ACROSS SOUTH CENTRAL SOUTH DAKOTA 
THIS AFTERNOON.  

STRONG COLD FRONT EXPECTED TO MOVE ACROSS THE AREA LATE THIS EVENING 
INTO THE OVERNIGHT.  MODEST PRESSURE RISES OF 4-5 MB COUPLED WITH 
STRONG COLD AIR ADVECTION WILL RESULT IN WINDY CONDITIONS...DESPITE 
FRONTAL TIMING. OPTED TO ISSUE A WIND ADVISORY FOR CWA WHICH WILL 
RUN THROUGH THE DAY ON MONDAY. COULD BE A BRIEF LULL IN THE WINDS 
TOWARDS DAY BREAK...BUT EXPECT IT TO BE RELATIVELY SHORT LIVED AS 
GOOD MIXING POTENTIAL DRAWS STRONGER WINDS FROM ALOFT. WINDS AT 
900-850 MB PROGGED TO BE 40-45 KNOTS...WHICH SHOULD BE ENOUGH TO 
REACH MARGINAL ADVISORY CONDITIONS. NAM ADVERTISES SECOND PUSH OF 
CANADIAN AIR DURING THE DAYTIME HOURS ON MONDAY...BUT DOES NOT 
APPEAR TO BE AS STRONG AS THE INITIAL SURGE. TEMPERATURES WILL MOVE 
LITTLE ON MONDAY AS MIXING IS OFFSET BY COLD AIR ADVECTION.  COLUMN 
COOLS ENOUGH THROUGHOUT THE DAY THAT DENDRITIC LAYER DROPS 8-10K 
FEET. BY LATE IN THE DAY...DENDRITIC LAYER COINCIDES WITH ANY 
LINGERING CLOUD COVER. COULD SEE A FEW FLURRIES ALOFT...BUT WILL 
STRUGGLE TO REACH THE SURFACE WITH DRY SUBCLOUD LAYER. 

GUSTY CONDITION WILL SLOWLY DECREASE MONDAY NIGHT AS POCKETS OF WEAK 
COLD AIR ADVECTION MOVE THROUGH THE REGION UNDER THE DIRECTIVE 
NORTHWEST FLOW. 

NORTHWEST FLOW LOOKS TO REMAIN A LITTLE LONGER ON TUESDAY THAN 
ORIGINALLY ANTICIPATED...AS HIGH PRESSURE OVER THE CENTRAL PLAINS 
STRUGGLES TO SHIFT EAST DUE TO LONG WAVE TROUGH OVER THE EAST COAST. 
HAVE KEPT FORECAST HIGHS 10-15 DEGREES BELOW NORMAL WITH 850 TEMPS 
RANGING FROM -6 TO -9 C. 

MODELS SUGGESTING WARM FRONT WILL MOVE THROUGH THE AREA ON 
WEDNESDAY...HOWEVER CLOUD COVER MAY HINDER WARMING POTENTIAL. 
TEMPERATURES CONTINUE TO MODERATE INTO THE LATER PORTION OF THE 
WEEK...BUT WITH DRY AIR MASS REMAINING...PRECIP CHANCES REMAIN 
RELATIVELY LOW.  
&&

.AVIATION...

VFR TODAY WITH ONLY SCATTERED HIGH AND MID CLOUDS. SFC WINDS MAINLY 
IN THE 5 TO 15 KT RANGE BUT STRONGER WINDS ALOFT. STRONG COLD FRONT 
SUNDAY NIGHT INCREASING SFC WIND TO 20 TO 30 WITH GUST TO 45 KTS. 
STRONG NW WIND TO CONTINUE THROUGH MONDAY.

&&

.FSD WATCHES/WARNINGS/ADVISORIES...
IA...WIND ADVISORY FROM 3 AM TO 5 PM CST MONDAY FOR IAZ001>003-     
012>014-020>022-031-032.

MN...WIND ADVISORY FROM MIDNIGHT TONIGHT TO 5 PM CST MONDAY FOR 
     MNZ071-072.

     WIND ADVISORY FROM 3 AM TO 5 PM CST MONDAY FOR MNZ080-081-089-
     090-097-098.

NE...WIND ADVISORY FROM 3 AM TO 5 PM CST MONDAY FOR NEZ013-014.

SD...WIND ADVISORY FROM MIDNIGHT TONIGHT TO 5 PM CST MONDAY FOR 
     SDZ038>040-050-052>061-063>065-068-069.

     WIND ADVISORY FROM 3 AM TO 5 PM CST MONDAY FOR SDZ062-066-067-
     070-071.
&&

$$
BT/SL