352  
FXUS63 KFSD 281106  
AFDFSD  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SIOUX FALLS SD  
506 AM CST MON NOV 28 2022  
   
SHORT TERM
 
(TODAY AND TONIGHT)  
ISSUED AT 358 AM CST MON NOV 28 2022  
 
THE CALM BEFORE THE STORM, WITH A RELATIVELY MILD DAY IN STORE  
ACROSS THE AREA. CURRENT MESOANALYSIS INDICATES A SURFACE LOW  
SLIDING EASTWARD ACROSS THE CANADIAN PRAIRIE PROVINCE, WITH A COLD  
FRONT EXTENDING SOUTHWARD INTO WESTERN SD. OUT AHEAD OF THIS  
FEATURE, A STRENGTHENING SURFACE PRESSURE GRADIENT IS PRODUCING A  
GRADUAL INCREASE IN SOUTHERLY WINDS ACROSS OUR AREA. WITH THAT,  
TEMPERATURES HAVE BEEN SLOWLY RISING FROM WEST TO EAST OVERNIGHT.  
THIS TREND WILL CONTINUE THROUGH THE MORNING HOURS, WITH  
TEMPERATURES EVENTUALLY RISING INTO THE LOWER 40S TO LOWER 50S BY  
AFTERNOON. THE AFOREMENTIONED COLD FRONT WILL WORK SLOWLY ACROSS THE  
AREA DURING THE DAY, THOUGH NOT FULLY MAKING IT OUT OF OUR AREA  
UNTIL TONIGHT. WINDS WILL ACTUALLY DROP OFF DURING THE AFTERNOON AS  
THE FRONT SLIDES IN AND THE SPG DECREASES.  
 
BY TONIGHT, A DEEPENING SURFACE LOW OVER CO BEGINS TO MOVE TO THE  
NORTHEAST, BEING CENTERED OVER NORTHEASTERN KS BY TUESDAY MORNING.  
AT THE SAME TIME, AN UPPER LEVEL TROUGH OVER THE ROCKIES BEGINS TO  
DRIFT EASTWARD INTO THE PLAINS. BY LATER TONIGHT, FRONTOGENESIS WILL  
BEGIN TO INTENSIFY FROM AROUND 800-700 MB ORIENTED APPROXIMATELY  
FROM SOUTH CENTRAL SD/CENTRAL MO RIVER CORRIDOR INTO SOUTHWESTERN  
MN. WITH THAT, LIGHT SNOW WILL DEVELOP IN THAT VICINITY (WITH SOME  
SLIGHT VARIATION AMONG CAMS) AS UPPER LEVEL LIFT INCREASES PER 300-  
500 MB DIV Q. SNOWFALL AMOUNTS PRIOR TO 12Z ON TUESDAY WILL BE LIGHT  
- GENERALLY LESS THAN HALF AN INCH. LOW TEMPERATURES OVERNIGHT WILL  
RANGE FROM NEAR 20 OUR WESTERN AND NORTHERN AREAS TO UPPER 20S OVER  
NORTHWESTERN IA.  
   
LONG TERM
 
(TUESDAY THROUGH SUNDAY)  
ISSUED AT 358 AM CST MON NOV 28 2022  
 
BY TUESDAY MORNING, FRONTOGENESIS CONTINUES TO INTENSIFY WITH UPPER  
LEVEL DIVERGENCE INCREASING IN THE LEFT EXIT REGION OF AN UPPER  
LEVEL JET STREAMING NORTHWARD THROUGH EASTERN NE INTO IA. THERE ARE  
SOME INDICATIONS THAT THERE MAY BE A BIT OF INSTABILITY ABOVE THE  
FRONTAL CIRCULATION FOR A BRIEF TIME BETWEEN 12Z TO 15Z, AND WITH  
THAT WE WILL SEE SNOWFALL PICK UP IN A BAND GENERALLY LOCATED IN A  
LINE ROUGHLY FROM YANKTON TO LUVERNE TO WINDOM. OBVIOUSLY THE  
HEAVIER BAND MAY SHIFT SLIGHTLY IN FUTURE MODEL RUNS, BUT PRESENTLY  
CAMS AND GLOBAL MODELS ARE IN DECENT AGREEMENT ON THE GENERAL  
LOCATION OF THE BAND. SOUNDINGS ARE INDICATING THAT THERE COULD BE A  
BRIEF PERIOD OF FREEZING RAIN/DRIZZLE OVER NORTHWESTERN IA AT THE  
ONSET OF PRECIPITATION PRIOR TO 18Z WITH LACK OF SATURATION IN THE  
DENDRITIC LAYER, THOUGH ANY ICE ACCUMULATION IS EXPECTED TO BE  
MINIMAL DUE TO THE SHORT DURATION. BY AFTERNOON, FRONTOGENESIS  
BEGINS WEAKEN AND SHIFT TO THE SOUTHEAST WITH NO INSTABILITY NOTED  
ABOVE THE FRONT. IN RESPONSE, SNOWFALL AMOUNTS WILL TREND DOWNWARD  
THROUGH 00Z. OVERALL, ENSEMBLE PLUMES CONTINUE TO SHOW SOME  
CLUSTERING IN THE VICINITY OF THE HEAVIER BAND AT THE RANGE OF  
APPROXIMATELY 2 TO 4 INCHES - WITH LIGHTER AMOUNTS ON EITHER SIDE OF  
THIS BAND.  
 
UNFORTUNATELY, WITH THE SPG STRENGTHENING IN RESPONSE TO THE  
AFOREMENTIONED SURFACE LOW TRACKING THROUGH IA DURING THE DAY,  
NORTHERLY WINDS WILL CRANK UP BY THE AFTERNOON, GUSTING 30 TO 35 MPH  
INTO THE EVENING. AS A RESULT, PATCHY BLOWING SNOW WILL BE POSSIBLE  
IN AREAS THAT RECEIVE HEAVIER SNOWFALL. BASED ON ALL OF THE ABOVE,  
WENT AHEAD AN ISSUED A WINTER WEATHER ADVISORY FOR PORTIONS OF  
SOUTHEASTERN SD, NORTHEASTERN NE, NORTHWESTERN IA, AND SOUTHWESTERN  
MN FOR TUESDAY.  
 
SNOW ENDS EARLY ON TUESDAY NIGHT AS THE SURFACE LOW MOVES INTO THE  
GREAT LAKES REGION. THE UPPER LEVEL TROUGH MOVES INTO THE  
MISSISSIPPI VALLEY ON TUESDAY NIGHT, THEN TO THE EASTERN SEABOARD BY  
EARLY THURSDAY. THIS PUTS OUR AREA IN A NORTHWESTERLY UPPER FLOW  
DURING THE PERIOD, AND VERY COLD AIR WILL FUNNEL INTO OUR AREA FOR  
TUESDAY NIGHT INTO WEDNESDAY NIGHT. BOTH THE NAEFS AND ECMWF  
ENSEMBLES SHOW 850 MB TEMPERATURES IN THE BOTTOM 10TH PERCENTILE OR  
LOWER WITH RESPECT TO CLIMATOLOGY, AND WE ARE LOOKING AT LOWS MAINLY  
IN THE SINGLE DIGITS FOR BOTH TUESDAY NIGHT AND WEDNESDAY NIGHT,  
WITH HIGHS ON WEDNESDAY IN THE UPPER TEENS AND 20S. WITH THE COLD  
AIR ADVECTION, A STRONG SURFACE PRESSURE GRADIENT, AND WINDS RUNNING  
AROUND 25 TO 30 KTS AT THE TOP OF THE MIXED LAYER, THE COLD WILL BE  
FURTHER AGGRAVATED BY THE STRONG NORTHWESTERLY WINDS THROUGH THAT  
PERIOD - WITH WIND CHILLS BELOW ZERO ON TUESDAY NIGHT INTO EARLY  
WEDNESDAY.  
 
A FAIRLY RAPID RECOVERY OCCURS FOR THURSDAY AND FRIDAY AS THE UPPER  
LEVEL FLOW TAKES ON A MORE SOUTHWESTERLY COMPONENT, WITH A SOUTHERLY  
FLOW AT THE SURFACE AS HIGH PRESSURE EXITS TO THE EAST AND A SURFACE  
TROUGH APPROACHES FROM THE WEST. THIS WILL THROW HIGHS BACK INTO THE  
30S AND 40S ON THURSDAY AND FRIDAY, AND IT AGAIN LOOKS TO BE A  
BREEZY TO WINDY PERIOD. A COLD FRONT SWINGS THROUGH THE REGION LATER  
ON FRIDAY, BRINGING A COOL DOWN FOR THE EARLY PART OF NEXT WEEKEND,  
BEFORE WARMING AGAIN ON SUNDAY AS THE UPPER LEVEL FLOW BECOMES MORE  
ZONAL. OUTSIDE OF THE POTENTIAL FOR LIGHT PRECIPITATION ON FRIDAY  
NIGHT, IT APPEARS TO BY DRY FOR THE END OF THE WEEK INTO THE  
WEEKEND.  
 

 
   
AVIATION
 
(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)  
ISSUED AT 458 AM CST MON NOV 28 2022  
 
WITH A LOW LEVEL JET OVERHEAD, THERE WILL BE A PERIOD OF LOW LEVEL  
WIND SHEAR AT KSUX THIS MORNING. OTHERWISE, GUSTY SOUTHERLY WINDS  
EARLY IN THE DAY WILL DIMINISH IN THE AFTERNOON, TRANSITIONING TO  
WEST/NORTHWESTERLY AS A FRONTAL BOUNDARY SLIDES ACROSS THE REGION  
INTO TONIGHT. LIGHT SNOW WILL DEVELOP THROUGH SOUTH CENTRAL SD  
EARLY TONIGHT, THEN EXPAND TO THE NORTH AND EAST THROUGH THE  
REMAINDER OF THE TAF PERIOD - AFFECTING KFSD TOWARD THE END OF THE  
PERIOD.  
 

 
   
FSD WATCHES/WARNINGS/ADVISORIES
 
 
SD...WINTER WEATHER ADVISORY FROM 6 AM TO 6 PM CST TUESDAY FOR SDZ062-  
066>071.  
 
MN...WINTER WEATHER ADVISORY FROM 6 AM TO 6 PM CST TUESDAY FOR MNZ080-  
081-089-090-097-098.  
 
IA...WINTER WEATHER ADVISORY FROM 6 AM TO 6 PM CST TUESDAY FOR  
IAZ001>003-012>014-020.  
 
NE...WINTER WEATHER ADVISORY FROM 6 AM TO 6 PM CST TUESDAY FOR NEZ013.  
 

 
 

 
 
SHORT TERM...JM  
LONG TERM...JM  
AVIATION...JM  
 
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