052
FXUS63 KFSD 270004
AFDFSD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
604 PM CST FRI DEC 26 2025
KEY MESSAGES
- FOG IS LIKELY TO REDEVELOP TONIGHT, WITH THE BETTER CHANCES
NEAR AND EAST OF I-29. SOME DENSE FOG WILL REMAIN POSSIBLE.
- MUCH ABOVE NORMAL TEMPERATURES ON SATURDAY WILL TURN SHARPLY
COLDER SUNDAY ACCOMPANIED BY NORTHWEST WINDS GUSTING 30 TO 50
MPH. SUB-ZERO WIND CHILLS ARE EXPECTED SUNDAY NIGHT THROUGH
EARLY MONDAY.
- LIGHT SNOW IS LIKELY ON SUNDAY. THE LATEST MODEL RUNS ARE A
BIT MORE AGGRESSIVE ON PRODUCING AROUND AN INCH OF
ACCUMULATION, ESPECIALLY SOUTH AND EAST OF A TYNDALL TO
JACKSON MN LINE. SOME STRONG WINDS COULD CAUSE SOME BLOWING
SNOW, BUT MOST AREAS ARE COMPLETELY SNOW FREE NOW WHICH WILL
HELP KEEP THE BLOWING TO A MINIMUM.
UPDATE
ISSUED AT 558 PM CST FRI DEC 26 2025
VISIBILITY CONTINUES TO DETERIORATE THIS EVENING ACROSS THE
AREA, WITH AREAS ALONG AND NOW WEST OF I-29 DROPPING TO A HALF
MILE OR LESS. HAVE EXPANDED THE DENSE FOG ADVISORY, AND MAY NEED
TO EXPAND IN AREA AGAIN IF FOG CONTINUES TO DEVELOP OVER THE
AREA. IF TRAVELING TONIGHT, BE PREPARED FOR QUICKLY CHANGING
CONDITIONS AND DRIVE TO CONDITIONS.
DISCUSSION
ISSUED AT 205 PM CST FRI DEC 26 2025
FOG REMAINS THE MAIN CHALLENGE THROUGH TONIGHT INTO SATURDAY. A
QUICK RIDGE OF HIGH PRESSURE AT THE SURFACE WILL MOVE THROUGH, WITH
WINDS TURNING SOUTH AND SOUTHEAST THIS AFTERNOON INTO TONIGHT.
VISIBILITIES WILL IMPROVE THROUGH THE AFTERNOON, BUT AREAS
ESPECIALLY NEAR AND EAST OF I-29 WILL LIKELY SEE DENSE FOG REDEVELOP
SHORTLY AFTER SUNSET AND CONTINUE INTO THE MORNING. CONFIDENCE IS
NOT QUITE AS HIGH AS THIS MORNING AS THE MOISTURE IS BECOMING MORE
SHALLOW.
SOUTHERLY FLOW INCREASES ON SATURDAY AND BECOMES A BIT MORE
SOUTHWESTERLY WHICH SHOULD AID IN DISSIPATING THE LOW LEVEL INVERSION
AND THUS THE MOISTURE TRAPPED BELOW IT. THIS SOUTHWEST FLOW SHOULD
BRING THE AREA THE WARMEST DAY WITH HIGHS FROM THE UPPER 40S TO
AROUND 60, WARMEST IN SOUTH CENTRAL SD.
SATURDAY NIGHT INTO SUNDAY WILL SEE A WAVE MOVE THROUGH THE AREA
BRINGING THE NEXT CHANCE FOR PRECIPITATION. WHILE SOME BRIEF MIXED
PRECIPITATION WILL BE POSSIBLE WITH A SOMEWHAT DRY WARM LAYER ALOFT,
ONCE THE BETTER PRECIPITATION DEVELOPS ALL SNOW IS ANTICIPATED.
WHILE SNOWFALL AMOUNTS BY THEMSELVES WILL ONLY PRODUCE MINOR
IMPACTS, NORTHERLY WINDS GUSTING AROUND 45 MPH COULD PRODUCE SOME
BLOWING SNOW. HOWEVER, AS OPPOSED TO OUR PREVIOUS BLOWING SNOW EVENT
ABOUT A WEEK AGO WITH SOME VERY LOW VISIBILITIES, THESE WINDS WILL BE
ABOUT 15-20 MPH LOWER AND FOR THE MOST PART ALL AREAS ARE SNOW FREE.
THIS SHOULD LIMIT HOW MUCH SNOW WILL BLOW AND WILL OF COURSE BE
COMPLETELY LIMITED TO WHAT FALLS. THE LATEST GEFS GIVES A PRETTY
GOOD CHANCE FOR 1-2" OF SNOW WHILE THE EC AI AND EC ENSEMBLE STICK
TO AN INCH OR LESS. BOTH SUGGEST THE BETTER CHANCES WILL BE FOR AREAS
IN AND AROUND NORTHWEST IA. FOR NOW THE NAM IS AN OUTLIER BY
PRODUCING THE BETTER CHANCE FOR 1-2" OF SNOW MAINLY NORTH OF I-90.
WILL NEED TO MONITOR TRENDS OF THE SMALL VORT MAX THAT DROPS SOUTH
BEHIND THIS WAVE LATE SUNDAY AFTERNOON INTO SUNDAY NIGHT. THIS COULD
PRODUCE SOME SNOW SHOWERS WITH SOME FAIRLY STRONG WINDS, BUT
CONFIDENCE A LITTLE LOW ON WHETHER OR NOT WE GET SNOW WITH THIS
FEATURE.
THE OTHER SIDE OF THIS WAVE WILL BE THE WIND AND COLD. VERY STRONG
COLD AIR ADVECTION DEVELOPS LATE SATURDAY NIGHT INTO SUNDAY MORNING.
A SOLD CORE OF STRONG LOW LEVEL WINDS AND PRESSURE RISES SUPPORT
FREQUENT WIND GUSTS OF 40 TO 50 MPH, WHICH SHOULD CONTINUE INTO
SUNDAY NIGHT, TAPERING OFF FROM NORTHWEST TO SOUTHEAST. THESE WINDS,
WHEN COMBINED WITH THE INCOMING COLD AIR, WILL PRODUCE WIND CHILLS OF
-10 TO -20 SUNDAY INTO MONDAY MORNING.
NORTHWEST FLOW REMAINS FAIRLY STRONG OVERHEAD TUESDAY INTO FRIDAY. A
BRIEF WARM ON TUESDAY WILL BE FOLLOWED BY A MODERATELY COLD SHOT OF
AIR, BRINGING TEMPERATURES BACK BELOW NORMAL. A QUICK SHOT OF WARM
ADVECTION AHEAD OF THIS SHOT OF COLDER AIR TUESDAY NIGHT INTO
WEDNESDAY COULD BRING ANOTHER ROUND OF LIGHT SNOW.
AVIATION /00Z TAFS THROUGH 00Z SUNDAY/
ISSUED AT 558 PM CST FRI DEC 26 2025
IFR TO LIFR FOG AND STRATUS CONTINUE TO EXPAND WEST ACROSS THE
AREA. THIS MAY CONTINUE TO SPREAD WEST TO THE JAMES RIVER VALLEY
OVERNIGHT, BUT CONFIDENCE IS LOWER THE FURTHER WEST YOU GO.
EXPECT CONDITIONS TO IMPROVE LATE SATURDAY MORNING, LINGERING
LONGEST EAST OF I-29. OUTSIDE OF FOG/STRATUS, EXPECT VFR
CONDITIONS.
WINDS REMAIN SOUTHERLY THROUGH THE PERIOD, ALTHOUGH AREAS
ALONG/WEST OF THE JAMES RIVER BEGIN TO SHIFT WESTERLY TOWARD
SATURDAY EVENING. SOME MARGINAL LLWS IS POSSIBLE TOWARD
DAYBREAK, AND HAVE INCLUDED MENTION AT KFSD.
FSD WATCHES/WARNINGS/ADVISORIES
SD...DENSE FOG ADVISORY UNTIL 9 AM CST SATURDAY FOR SDZ062-067.
MN...DENSE FOG ADVISORY UNTIL 9 AM CST SATURDAY FOR MNZ089-090-098.
IA...DENSE FOG ADVISORY UNTIL 9 AM CST SATURDAY FOR IAZ001>003-
012>014-020>022-032.
NE...NONE.
UPDATE...SG
DISCUSSION...08
AVIATION...SG
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page