559
FXUS63 KFSD 212332
AFDFSD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
532 PM CST SUN DEC 21 2025
KEY MESSAGES
- CONFIDENCE REMAINS HIGH IN AN EXTENDED PERIOD OF WARMER
WEATHER THROUGH THE HOLIDAY TRAVEL WEEK. TEMPERATURES MAY
APPROACH OR SURPASS RECORD VALUES MID TO LATE WEEK, INCLUDING
CHRISTMAS DAY.
- DRY WEATHER IS EXPECTED FOR THE VAST MAJORITY OF THE UPCOMING
WEEK. THE EXCEPTION IS THIS EVENING AS LIGHT MIX PRECIPITATION
SHOWERS ARE POSSIBLE (15-25% CHANCE) ALONG AND NORTH OF
HIGHWAY-14.
- ELEVATED FIRE DANGER MAY BE POSSIBLE ON BREEZIER DAYS IN SNOW-
FREE AREAS, MAINLY ACROSS SOUTH CENTRAL SOUTH DAKOTA THROUGH
THE MISSOURI RIVER VALLEY.
DISCUSSION
ISSUED AT 243 PM CST SUN DEC 21 2025
HIGH LEVEL CIRRUS CONTINUES TO STREAM IN FROM THE NORTHWEST THIS
AFTERNOON. HIGHS HAVE WARMED TO THE UPPER 30S AND 40S WHILE WINDS
REMAIN MARGINALLY BREEZY WITH GUSTS UP TO 20-30 MPH. LOCATIONS ALONG
THE MISSOURI RIVER, ESPECIALLY IN FAR NORTHEASTERN NEBRASKA, ARE
SEEING THE WARMEST TEMPERATURES WHICH HAS LOWERED HUMIDITY VALUES
DOWN TO AROUND 30%. THESE LOWER HUMIDITY VALUES AND BREEZY WINDS IS
MAKING FOR ELEVATED FIRE DANGER IN THIS AREA. THE ELEVATED FIRE
DANGER WON'T LAST TOO MUCH LONGER THOUGH GIVEN THE EARLY SUNSET THIS
EVENING. WARM AIR ADVECTION (WAA) WILL STRENGTHEN THIS EVENING AND
MAY RESULT IN VERY LIGHT MIXED PRECIPITATION SHOWERS IN THE FORMS OF
LIGHT SNOW, FREEZING RAIN, AND PLAIN RAIN. THIS LOOKS TO TAKE PLACE
ALONG AND NORTH OF HIGHWAY-14. HOWEVER, THE LOW LEVELS REMAIN QUITE
DRY AND WITH WAA IN PLACE, THINK THAT THE LOW LEVELS MAY BE TOO DRY
FOR THE VAST MAJORITY OF PRECIPITATION TO REACH THE SURFACE. HAVE
KEPT SLIGHT CHANCE POPS (15-25%) IN THE FORECAST. ANY CHANCE FOR
PRECIPITATION WILL PUSH EAST/NORTHEAST OF THE AREA BY 3 AM TONIGHT.
LOW TEMPERATURES WILL FALL TO THE 20S AND 30S.
MONDAY WILL BE THE FIRST WARM DAY THIS WEEK AS AN UPPER LEVEL RIDGE
BUILDS OVER THE CENTRAL AND SOUTHERN CONUS. A WARM FRONT WILL PUSH
INTO THE AREA AND LIE JUST ABOUT ALONG THE MISSOURI RIVER VALLEY.
THIS WILL MAKE FOR A MORE STARK TEMPERATURE GRADIENT ACROSS THE AREA
AS HIGHS IN THIS AREA WILL WARM TO THE 50S AND 60S, WARMEST ACROSS
SOUTH CENTRAL SOUTH DAKOTA, AND THE 40S ELSEWHERE. SMALL SHIFTS IN
THE FRONTS POSITION MAY RESULT IN WARMER AND COOLER TEMPERATURES
DEPENDING ON HOW IT SETS UP. AREAS WITH REMAINING SNOW PACK WILL
REMAIN ON THE COOLER SIDE. THERE COULD BE SOME ELEVATED FIRE DANGER
ACROSS SOUTH CENTRAL SOUTH DAKOTA THOUGH THANKFULLY HUMIDITY LEVELS
AND WINDS WILL NOT REACH CRITICAL THRESHOLDS. OVERNIGHT LOWS WILL
ALSO BE QUITE MILD, ONLY FALLING TO THE 20S AND 30S. FOR REFERENCE,
THESE LOW TEMPERATURES ARE NEAR OUR NORMAL HIGHS FOR THIS TIME OF
YEAR.
CONFIDENCE REMAINS HIGH THAT AN UPPER LEVEL RIDGE WILL PERSIST FOR
THE MAJORITY OF THE WORK WEEK. TUESDAY WILL BE A BIT COOLER OF A DAY
WITH HIGHS ONLY WARMING TO THE MID 30S AND 40S AS A WEAK COLD FRONT
WILL SLIDE THROUGH THE AREA. BUT MUCH WARMER TEMPERATURES WILL BE
QUICK TO RETURN ON WEDNESDAY AS WAA RESTRENGTHENS ALOFT. HIGHS WILL
REBOUND BACK TO THE 40S, 50S, AND 60S. THURSDAY LOOKS TO BE EQUALLY
AS WARM THOUGH SOME UNCERTAINTY REMAINS DUE TO SOME OF THE MEDIUM
RANGE MODELS SUGGESTING A STRONG COLD FRONT COULD PUSH THROUGH THE
AREA ON CHRISTMAS DAY. HAVE LEFT NBM TEMPERATURES IN PLACE BUT WILL
CONTINUE TO MONITOR THIS POTENTIAL. ELEVATED FIRE DANGER IS ALSO
POSSIBLE THROUGH THIS PERIOD OF TIME THOUGH WINDS AND HUMIDITY
VALUES LOOK TO AGAIN NOT REACH CRITICAL VALUES. THE EXCEPTION WILL
BE THURSDAY IF THE PREVIOUSLY MENTIONED COLD FRONT SPEEDS UP AND
BRINGS STRONGER WINDS TO THE AREA. OVERNIGHT LOW TEMPERATURES WILL
ALSO BE QUITE MILD IN THE 20S AND 30S. WEDNESDAY NIGHT LOOKS TO BE
THE WARMEST WITH LOWS ONLY FALLING TO THE 30S AND 40S. THUS, THERE
REMAINS THE POTENTIAL FOR RECORD WARM HIGHS AND RECORD WARM LOWS.
TEMPERATURES BEGIN TO COOL DOWN ON FRIDAY AS THE THERMAL RIDGE
PUSHES OFF TO THE SOUTHEAST OF THE NORTHERN PLAINS. THIS WILL BEGIN
TO TREND TEMPERATURES CLOSER TO SEASONABLE WITH HIGHS ONLY MAKING IT
TO THE 30S, 40S, AND 50S ON FRIDAY AND 30S AND 40S FOR NEXT WEEKEND.
STILL EXPECTING A DRY FORECAST THROUGH THE END OF THE WEEK BUT A
MAJORITY OF THE MEDIUM RANGE DETERMINISTIC AND MACHINE LEARNING
MODELS SUGGEST AN AMPLIFYING UPPER LEVEL WAVE COULD BRING ANOTHER
COOL DOWN NEXT WEEKEND. THE ENSEMBLES SUPPORT THIS AS THEY SHOW A 40-
70% CHANCE FOR 850 MB TEMPERATURES TO DROP BELOW FREEZING. TOO FAR
OUT TO MAKE ANY MEANINGFUL CHANGES TO THE FORECAST BUT SOMETHING TO
WATCH THROUGHOUT THIS WEEK.
AVIATION /00Z TAFS THROUGH 00Z TUESDAY/
ISSUED AT 525 PM CST SUN DEC 21 2025
VFR CONDITIONS WILL PERSIST ACROSS THE AREA THIS TAF PERIOD.
TAKING A LOOK AT SATELLITE IMAGERY, A MID TO UPPER LEVEL DECK
CONTINUES TO FILL IN ACROSS THE AREA THIS EVENING WITH POCKETS
OF RAIN AND/OR SNOW. AS THIS DECK CONTINUE TO GRADUALLY PROGRESS
EASTWARDS, COULD GET A FEW HOURS OF WINTRY MIX AT BOTH KHON &
KFSD TONIGHT. OTHERWISE, THE DEVELOPING AREA OF PRECIPITATION
WILL LIFT NORTHEASTWARDS GIVING WAY TO QUIETER CONDITIONS.
OTHERWISE, A STRENGTHENING LLJ WILL LEAD TO SEVERAL HOURS OF
LLWS SOUTH OF I-90 MAINLY AFFECTING KSUX. LASTLY, SOUTHEASTERLY
WINDS FOR MOST OF THE DAY ON MONDAY WILL BECOME MORE NORTHWESTERLY
BY MONDAY EVENING TO END THE TAF PERIOD.
FSD WATCHES/WARNINGS/ADVISORIES
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
DISCUSSION...MEYERS
AVIATION...05
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