041  
FXUS63 KFSD 220431  
AFDFSD  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SIOUX FALLS SD  
1031 PM CST THU NOV 21 2024  
   
KEY MESSAGES  
 
- SOME PATCHY DENSE FOG IS POSSIBLE THIS MORNING. ANY FOG THAT  
FORMS IS EXPECTED TO BE SHALLOW, AND BURN OFF SHORTLY AFTER  
SUNRISE.  
 
- DRY CONDITIONS ARE EXPECTED FOR THE REST OF THE WEEK AND  
WEEKEND. HIGH TEMPERATURES WILL WARM BACK TO THE 30S AND 40S  
FRIDAY THROUGH SUNDAY.  
 
- A COLDER HOLIDAY WEEK IS EXPECTED WITH HIGH TEMPERATURES VERY  
LIKELY (90%+ CHANCE) TO REMAIN BELOW 32 DEGREES F. LIGHT  
PRECIPITATION IS POSSIBLE (40-70% CHANCE) WEDNESDAY AND  
THURSDAY, THOUGH THIS CHANCE CAN CHANGE WITH TIME.  
 
 
   
DISCUSSION  
 
ISSUED AT 236 PM CST THU NOV 21 2024  
 
QUIET CONDITIONS PERSIST ACROSS THE FORECAST AREA THIS AFTERNOON.  
SURFACE RIDGING IS SLIDING THROUGH THE NORTHERN PLAINS, WHICH IS  
PUSHING THE TIGHTEST SURFACE PRESSURE GRADIENT (SPG) EAST OF THE  
AREA. THIS WILL PUT AN END TO THE BREEZY CONDITIONS THAT LOCATIONS  
EAST OF I-29 ARE CURRENTLY SEEING BY THIS EVENING. OVERNIGHT LOW  
TEMPERATURES LOOK TO FALL TO THE TEENS TO LOW 20S BUT COULD FALL  
FURTHER IF EFFICIENT RADIATIONAL COOLING IS ACHIEVED. THE MAIN  
CAVEAT STOPPING THIS IS UPPER LEVEL CIRRUS THAT WILL PUSH INTO THE  
NORTHERN PLAINS TONIGHT. IF EFFICIENT RADIATION COOLING IS ACHIEVED  
TONIGHT, FOG WILL ALSO BE POSSIBLE. THINK THAT IT WILL MOST LIKELY  
BE WEST OF I-29 DUE TO THE RECENT SNOWPACK THAT FELL YESTERDAY.  
 
FRIDAY WILL SEE A CONTINUATION OF QUIET CONDITIONS AS THE PREVIOUSLY  
MENTIONED SURFACE RIDGING SITS OVER THE AREA. WITH UPPER LEVEL  
RIDGING ALOFT, HIGH TEMPERATURES WILL WARM TO THE MID 30S TO UPPER  
40S, WARMEST ACROSS SOUTH CENTRAL SOUTH DAKOTA. WITH THE RIDING IN  
PLACE, WINDS WILL BE LIGHT AND VARIABLE THROUGHOUT THE DAY. LOW  
TEMPERATURES WILL FALL TO UPPER TEENS AND 20S OVERNIGHT.  
 
DRY CONDITIONS LOOK TO PERSIST THROUGH THE WEEKEND DUE TO LACKING  
MOISTURE ACROSS THE AREA. HOWEVER, AN UPPER LEVEL JET WILL PUSH INTO  
THE REGION, RESULTING IN WARM AIR ADVECTION (WAA) ALOFT. THE WAA  
WILL PUSH 850 MB TEMPERATURES UP TO THE SINGLE DIGITS ON SATURDAY  
AND MAY REACH UP TO THE LOW TEENS ON SUNDAY. WINDS WILL BE LIGHT,  
OUT OF THE SOUTHEAST ON SATURDAY BUT A SURFACE TROUGH WILL PUSH  
THROUGH THE AREA ON SUNDAY, TURNING THE WINDS TO OUT OF THE  
NORTHWEST. THIS WILL BRING A RETURN OF BREEZY WINDS WITH GUSTS UP TO  
ABOUT 30 MPH POSSIBLE. LOW TEMPERATURES WILL FALL TO 20S AND 30S  
SATURDAY NIGHT AND TEENS TO 20S SUNDAY NIGHT.  
 
A COLDER AIRMASS LOOKS TO USHER INTO THE NORTHERN PLAINS FOR THE  
MAJORITY OF NEXT WEEK. THIS AIRMASS MAY BE THE FIRST ONE TO FEEL  
MUCH MORE WINTER LIKE AS BELOW AVERAGE HIGH TEMPERATURES ARE LIKELY.  
ENSEMBLES SUPPORT THIS AS THEY SHOW A NEAR 100% CHANCE FOR  
TEMPERATURES TO BE BELOW 32 DEGREES F MONDAY THROUGH THURSDAY. WINDS  
LOOK TO BE ON THE LIGHTER SIDE BUT ANY WIND WILL RESULT IN COLD WIND  
CHILLS, POTENTIAL DOWN TO THE TEENS F. WHILE THE BEGINNING OF NEXT  
WEEK LOOKS DRY, COULD SEE A RETURN OF PRECIPITATION ON WEDNESDAY AND  
THURSDAY. AS OF NOW, ANY PRECIPITATION THAT MAY FALL LOOKS TO BE  
LIGHT, WITH ONLY A 40-70% CHANCE FOR EXCEEDING A HUNDREDTH OF AN  
INCH PER ENSEMBLE ANALYSIS. WILL CERTAINLY KEEP AN EYE ON ANY LIGHT  
PRECIPITATION FOR THIS PERIOD OF TIME. ALL IN ALL, THE HOLIDAY WEEK  
LOOKS TO BE COLD WITH SOME POTENTIAL FOR LIGHT PRECIPITATION RIGHT  
BEFORE AND ON THANKSGIVING DAY.  
 
 
   
AVIATION /06Z TAFS THROUGH 06Z SATURDAY/  
 
ISSUED AT 1030 PM CST THU NOV 21 2024  
 
WINDS WILL BE LIGHT AND VARIABLE WITH VFR CONDITIONS FOR THE PERIOD  
AT THE THREE TAF SITES. A NARROW NORTH/SOUTH ORIENTED DECK OF  
STRATUS IS PRESENT OVER WESTERN MINNESOTA AND IOWA. UNDER THIS DECK  
MVFR CEILINGS AROUND 2000 FT AGL ARE PRESENT. THESE CLOUDS  
SHOULD SLOWLY ERODE OVER THE NEXT FEW HOURS.  
 
PATCHY DENSE FOG IS POSSIBLE THIS MORNING, BUT CONFIDENCE IN  
FORMATION IS LOW DUE TO A CIRRUS DECK THAT LOOKS TO MOVE INTO THE  
AREA AFTER 22.08Z. THESE HIGH CLOUDS MAY BE ENOUGH TO PREVENT FOG  
FORMATION. IF ANY FOG SHOULD DEVELOP, IT IS EXPECTED TO BE SHALLOW  
AND BURN OFF SHORTLY AFTER SUNRISE.  
 
 
   
FSD WATCHES/WARNINGS/ADVISORIES  
 
SD...NONE.  
MN...NONE.  
IA...NONE.  
NE...NONE.  
 
 
 
 
 
DISCUSSION...AJP  
AVIATION...MEYERS  
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