264  
FXUS63 KFSD 242343  
AFDFSD  
 
AREA FORECAST DISCUSSION  
NATIONAL WEATHER SERVICE SIOUX FALLS SD  
543 PM CST WED DEC 24 2025  
   
KEY MESSAGES  
 
- AREAS OF FOG, SOME DENSE, WILL CONTINUE THROUGH TONIGHT  
ESPECIALLY EAST OF I-29 OVER NORTHWEST IOWA AND SOUTHWEST  
MINNESOTA. LOCALLY DENSE FOG IS POSSIBLE ALL THE WAY WESTWARD  
INTO SOUTH-CENTRAL SOUTH DAKOTA TONIGHT AS WELL.  
 
- AS TEMPERATURES DROP TO NEAR AND JUST BELOW FREEZING TONIGHT  
MAINLY NORTH OF I-90, PATCHY FREEZING DRIZZLE AND FREEZING FOG  
COULD RESULT IN SOME PATCHY SLICK SPOTS MAINLY ON UNTREATED  
AND ELEVATED SURFACES. USE EXTRA CAUTION ON THE ROADS AND  
CHECK ROAD CONDITIONS BEFORE TRAVELING.  
 
- TEMPERATURES REMAIN ABOVE NORMAL THROUGH THE END OF THIS WEEK,  
BUT WE TURN WINDY AND COLDER THIS WEEKEND. WIND CHILLS LIKELY  
DROP BELOW ZERO BY SUNDAY MORNING NORTH OF I-90 AND THEN AREA-  
WIDE BY MONDAY MORNING.  
 
- PRECIPITATION CHANCES FRIDAY-SATURDAY ARE LOW, BUT MAY HAVE  
TO WATCH FOR SCATTERED FLURRIES SUNDAY AS COLDER AIR MOVES IN.  
 
- ELEVATED FIRE DANGER WILL BE POSSIBLE ON BREEZIER DAYS IN  
SNOW- FREE AREAS, MAINLY ACROSS SOUTH CENTRAL SOUTH DAKOTA  
THROUGH THE MISSOURI RIVER VALLEY.  
 
 
   
DISCUSSION  
 
ISSUED AT 315 PM CST WED DEC 24 2025  
 
AREAS OF DENSE FOG WILL CONTINUE THROUGH THIS AFTERNOON INTO TONIGHT  
UNDERNEATH THE CURRENT STRATUS DECK, LOCATED FROM ROUGHLY ARLINGTON  
TO SIOUX FALLS TO LE MARS AND POINTS EAST. THIS AREA OF STRATUS WILL  
CONTINUE TO ERODE ON ITS WESTERN EDGE THROUGH THIS AFTERNOON, BUT  
EXPAND WESTWARD AGAIN OVERNIGHT. DENSE FOG WILL CONTINUE INTO  
TONIGHT, BUT ALSO EXPAND WESTWARD AS WELL. MOST OF THE AREA SEES FOG  
TONIGHT, THOUGH THE OVERALL "THICKNESS" OF THE FOG WILL  
DECREASE WITH WESTWARD EXTENT. IN OTHER WORDS, AREAS EAST OF  
I-29 INTO PORTIONS OF SOUTHWEST MINNESOTA AND NORTHWEST IOWA  
HAVE THE BEST CHANCE OF WIDESPREAD DENSE FOG CONTINUING THROUGH  
TONIGHT INTO TOMORROW MORNING, HENCE THE DENSE FOG ADVISORY THAT  
WILL BE IN EFFECT THROUGH 9 AM. FURTHER EXPANSION WESTWARD OF  
THE ADVISORY MAY BE NEEDED TONIGHT, SO KEEP UP TO DATE WITH THE  
LATEST FORECAST! AS TEMPERATURES COOL OFF TONIGHT, MANY OF US  
LOOK TO DROP TO AROUND FREEZING MAINLY NORTH OF I-90, SO ANY FOG  
COULD FREEZE TO MAINLY ELEVATED SURFACES SUCH AS OVERPASSES,  
BRIDGES, AND TREES.  
 
ANOTHER THING TO WATCH FOR TONIGHT WILL BE THE CHANCE OF  
DRIZZLE AND FREEZING DRIZZLE. REPORTS OF DRIZZLE TODAY HAVE BEEN  
SPOTTY AT BEST AS THE STRATUS LAYER IS ONLY MARGINALLY  
SUPPORTIVE OF IT. HOWEVER, CONFIDENCE WAS HIGH ENOUGH TO AT  
LEAST CONTINUE THE MENTION OF DRIZZLE OVERNIGHT TONIGHT. STILL  
SOME UNCERTAINTY AS TO HOW WIDESPREAD ANY DRIZZLE, INCLUDING  
FREEZING DRIZZLE, WILL BE, BUT ANY FREEZING DRIZZLE THAT DOES  
FORM (AGAIN MAINLY NORTH OF I-90), MAY CAUSE A GLAZE OF ICE TO  
FORM MAINLY ON UNTREATED SURFACES. ALL THIS TO SAY, FOR THOSE  
WITH TRAVEL PLANS EITHER LATE TONIGHT OR ON EARLY CHRISTMAS  
MORNING, BE SURE TO USE EXTRA CAUTION ON THE ROADS AND CHECK  
ROAD CONDITIONS BEFORE YOU LEAVE! MOST OF THE AREA WILL BE STUCK  
UNDER STRATUS CHRISTMAS DAY, KEEPING HIGHS MAINLY IN THE  
UPPER-30S TO LOW-40S. SO STILL MILD FOR THIS TIME OF YEAR, BUT  
NOT RECORD BREAKING. HIGHS WILL BE A BIT WARMER AS YOU HEAD WEST  
OF THE JAMES RIVER, WITH HIGHS IN SOUTH- CENTRAL SOUTH DAKOTA  
IN THE UPPER-50S TO NEAR 60.  
 
FRIDAY AND SATURDAY LOOK TO BE MILD DAYS, BUT A STRONG COLD FRONT IS  
STILL SET TO MOVE IN LATE SATURDAY INTO SUNDAY, BRINGING MUCH COOLER  
AIR TO THE AREA. LOWS BY SUNDAY MORNING ARE NOT LOOKING AS COLD, BUT  
WE STILL LOOK TO DROP INTO THE TEENS FOR MOST OF THE AREA. SUNDAY  
NIGHT/MONDAY IS NOW TRENDING TOWARDS BEING THE COLDEST NIGHT  
OVER THE PERIOD, WITH LOWS IN THE SINGLE DIGITS AND WIND CHILLS  
DROPPING TO THE NEGATIVE TEENS ESPECIALLY NORTH OF I-90. WE LOOK  
TO SEE A RETURN TO MILDER TEMPERATURES BY TUESDAY OF NEXT.  
PRECIPITATION-WISE, STILL LOOKING AT ONLY LOW-END LIGHT  
PRECIPITATION MAINLY ON SUNDAY WHEN LIGHT SNOW/FLURRIES LOOK  
POSSIBLE, BUT NOTHING TOO IMPACTFUL EXPECTED AT THIS TIME.  
 
 
   
AVIATION /00Z TAFS THROUGH 00Z FRIDAY/  
 
ISSUED AT 542 PM CST WED DEC 24 2025  
 
LATEST SATELLITE SHOWS LOW LEVEL STRATUS AND FOG SITTING MAINLY  
ALONG AND EAST OF I-29. CEILINGS IN THE STRATUS ARE ALL THE WAY DOWN  
TO LIFR LEVELS WITH VISIBILITIES RANGING FROM MVFR/IFR/LIFR. THUS,  
FOG IS PRESENT WHERE VISIBILITIES HAVE FALLEN BELOW A HALF A MILE.  
THIS STRATUS/FOG IS EXPANDING WESTWARDS EARLY THIS EVENING AND IS  
EXPECTED TO REACH KHON. TO GO ALONG WITH THE STRATUS AND FOG, LIGHT  
DRIZZLE AND FREEZING DRIZZLE IS POSSIBLE BENEATH THE STRATUS/IN THE  
FOG, MAINLY LATE THIS EVENING THROUGH THE OVERNIGHT HOURS. CURRENTLY  
THINK ANY FREEZING DRIZZLE WILL MOST LIKELY BE CONFINED TO AREAS  
NORTH OF I-90 WHERE TEMPERATURES ARE EXPECTED TO DROP BELOW  
FREEZING. FOG AND LOW STRATUS WILL PERSIST THROUGH THE MORNING HOURS  
TOMORROW BEFORE THE FOG LOOKS TO RETREAT EASTWARDS COME THE  
AFTERNOON. HOWEVER, THIS REDUCTION IN THE FOG LOOKS TO ONLY WORK  
EASTWARDS TO ABOUT I-29 BEFORE STOPPING AND REMAINING SETTLED FOR  
THE REST OF THE PERIOD. GIVEN A SLIGHT STRENGTHENING OF THE WINDS  
ALONG WITH TEMPERATURES WARMING, THINK THAT THE FOG MAY LIFT, THOUGH  
STILL LEAVE VISIBILITIES DOWN TO MVFR LEVELS. CEILINGS LOOK TO  
REMAIN PERSISTENT AT LIFR THRESHOLDS TO END THE PERIOD.  
 
 
   
FSD WATCHES/WARNINGS/ADVISORIES  
 
SD...DENSE FOG ADVISORY UNTIL 6 PM CST THIS EVENING FOR SDZ040-055-  
056-062.  
MN...DENSE FOG ADVISORY UNTIL 9 AM CST THURSDAY FOR MNZ071-080-081-  
089-090-097-098.  
IA...DENSE FOG ADVISORY UNTIL 9 AM CST THURSDAY FOR IAZ001>003-  
012>014-020>022-032.  
NE...NONE.  
 
 
 
 
 
DISCUSSION...SAMET  
AVIATION...MEYERS  
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