012
FXUS63 KFSD 230204
AFDFSD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
904 PM CDT FRI MAY 22 2026
KEY MESSAGES
- SCATTERED SHOWERS AND ISOLATED STORMS MAINLY EAST OF I-29 WILL
CONTINUE TO MOVE OUT AND WEAKEN THROUGH THE MID-EVENING HOURS.
- PERIODIC CHANCES FOR RAIN REMAIN IN THE FORECAST FOR MUCH OF
THE UPCOMING WEEK. HOWEVER, DETAILS ARE UNCERTAIN AT THIS
TIME.
- BELOW NORMAL TEMPERATURES WILL CONTINUE THROUGH SATURDAY
BEFORE WARMER CONDITIONS RETURN FROM SUNDAY ONWARDS.
UPDATE
ISSUED AT 902 PM CDT FRI MAY 22 2026
A LOW PRESSURE SYSTEM OVER EAST-CENTRAL SOUTH DAKOTA
CONTINUES TO LIFT TO THE NORTH AND EAST. A BOUNDARY WITH THIS SYSTEM
STRETCHES ROUGHLY FROM DE SMET, SD TO LUVERNE, MN TO CHEROKEE, IA,
WITH SOME SHOWERS AND ISOLATED THUNDERSTORMS ALONG AND AHEAD OF IT.
THESE THUNDERSTORMS WILL WEAKEN OVER THE NEXT HOUR OR SO AS
INSTABILITY WANES AND THE UPPER LEVEL LOW CONTINUES TO LIFT
NORTHEASTWARD.
PATCHY LIGHT FOG/VERY LOW STRATUS HAS ALSO DEVELOPED OVER PARTS
OF SOUTHWEST MINNESOTA AND EASTERN SOUTH DAKOTA NORTH OF I-90
AHEAD OF THIS BOUNDARY WHERE COOLER TEMPERATURES HAVE ALREADY ALLOWED
THE AIR TO DROP TO THE DEW POINT. AS THIS BOUNDARY CONTINUES TO
MOVE EASTWARD ACROSS THE AREA, WESTERLY WINDS ARE LEFT IN ITS
WAKE AND THIS MAY HELP CLEAR OUT SOME OF THAT LIGHT FOG AS DRIER
AIR MOVES IN BEHIND IT. HOWEVER; WITH ALL THE MOISTURE LEFT
BEHIND FROM TODAY'S RAIN, FOG MAY REDEVELOP AGAIN LATER TONIGHT
AS CLOUDS CLEAR AND WINDS BECOME LIGHTER. WIDESPREAD FOG ISSUES
ARE NOT EXPECTED BY DAYBREAK AT THIS TIME AS WINDS MAY STAY JUST
ELEVATED ENOUGH THROUGH THE NIGHT.
NOT MUCH IN THE WAY OF COLD AIR ADVECTION BEHIND THIS SYSTEM,
SO ONLY SLIGHTLY BELOW NORMAL TEMPERATURES ARE EXPECTED TONIGHT
WITH LOWS MAINLY IN THE 40S, COOLEST IN SOUTH-CENTRAL SOUTH
DAKOTA WHERE CLOUDS HAVE ALREADY MOSTLY CLEARED OUT.
DISCUSSION
ISSUED AT 238 PM CDT FRI MAY 22 2026
RAIN IS TAPERING OFF THIS AFTERNOON FROM THE SOUTHWEST TO THE
NORTHEAST. THE REMAINING AREAS OF PRECIPITATION ALONG AND NORTH OF I-
90 WILL CONTINUE TO TAPER OFF AND MOVE NORTHEAST OVER THE NEXT FEW
HOURS. AN ADDITIONAL LINE OF WEAK SHOWERS IS FORMING ALONG THE
LEADING EDGE OF AN OCCLUDING FRONT JUST WEST OF THE JAMES RIVER
VALLEY. NO SEVERE WEATHER IS EXPECTED FROM THIS LINE. HOWEVER, THE
SOUTHERN PORTION AS IT PASSES THROUGH AREAS SOUTH OF HIGHWAY 18 MAY
PRODUCE SOME THUNDER AND GUSTY WINDS TO 45 MPH. AS FAR AS RAINFALL
TOTALS ARE CONCERNED, AN ADDITIONAL TENTH OR TWO IS POSSIBLE ALONG
AND NORTH OF I-90.
EARLY SATURDAY MORNING PATCHY FOG IS POSSIBLE AS LOW TEMPERATURES
APPROACH DEW POINTS IN THE 40S. FOG IS EXPECTED TO BURN OFF BY MID-
MORNING. CLOUDS WILL SCATTER OUT THROUGH THE DAY BECOMING MOSTLY
SUNNY BY AFTERNOON. WINDS WILL BE LIGHT OUT OF THE WEST AND HIGHS
ARE EXPECTED TO CLIMB INTO THE UPPER 60S AND 70S. MODEST MID-LEVEL
MOISTURE ADVECTION AND WEAK ELEVATED INSTABILITY MAY RESULT IN
ISOLATED TO SCATTERED LIGHT SHOWERS AND THUNDERSTORMS SUNDAY. SUNDAY
WILL BE WARM WITH HIGHS IN THE UPPER 70S AND 80S. LATE SUNDAY NIGHT
INTO EARLY MONDAY MORNING BETTER DYNAMIC PARAMETERS MAY ALLOW FOR A
FEW ISOLATED STRONG TO SEVERE THUNDERSTORMS FOR AREAS ALONG AND
SOUTH OF HIGHWAY 18. THIS AREA IS CURRENTLY UNDER AN SPC DAY 3
MARGINAL OUTLOOK (LEVEL 1 OF 5). MONDAY IS EXPECTED TO BE EVEN
WARMER WITH HIGHS IN THE MID 80S TO LOW 90S, WITH THE WARMEST
TEMPERATURES EXPECTED ALONG AND WEST OF THE JAMES RIVER VALLEY.
MONDAY WILL ALSO BE ON THE MUGGY SIDE WITH DEWPOINTS IN THE MID 50S
TO LOW 60S.
PERIODIC RAIN CHANCES REMAIN IN THE FORECAST FOR THE REMAINDER OF
NEXT WEEK. THE NEXT BEST CHANCE FOR STRONGER THUNDERSTORMS LOOKS TO
BE THURSDAY, HOWEVER DETAILS AT THIS TIME ARE LACKING. HIGHS FOR
TUESDAY WILL ONCE AGAIN BE IN THE MID 80S TO LOW 90S. THE REST OF
THE WEEK HIGHS WILL GENERALLY BE IN THE 80S.
AVIATION /00Z TAFS THROUGH 00Z SUNDAY/
ISSUED AT 639 PM CDT FRI MAY 22 2026
A FEW SHOWERS AND STORMS WILL CONTINUE PRIMARILY EAST OF I-29
EARLY THIS EVENING BEFORE EXITING OFF TO OUR NORTH AND EAST. AS
THESE SHOWERS PUSH OUT OF THE AREA, IT WILL TAKE THE MVFR/IFR
CEILINGS ALONG WITH IT, LEAVING MAINLY VFR CONDITIONS THROUGH THE
PERIOD. THE EXCEPTION WILL BE AN AREA OF CLOUDS WRAPPING AROUND A
LOW PRESSURE SYSTEM AS MOVES ACROSS THE AREA MAINLY NORTH OF I-90,
WHERE BRIEF MVFR CEILINGS WILL BE POSSIBLE THROUGH TONIGHT. THESE
LOWER CLOUDS COULD BRIEFLY IMPACT KHON AND KFSD TOWARDS THE MIDDLE
OF THE NIGHT, BUT ARE MORE LIKELY TO STAY NORTH AND EAST OF THOSE
SITES.
PATCHY FOG CAN'T BE RULED OUT TONIGHT DUE TO ALL THE MOISTURE LEFT
BEHIND FROM TODAY'S RAIN AND AS WINDS TURN LIGHTER. CONFIDENCE WAS
NOT HIGH IN THE OVERALL COVERAGE AND LONGEVITY OF THIS FOG TO
INCLUDE IN THE TAFS, BUT PERHAPS THE BEST CHANCE OF THIS OCCURRING
WOULD BE AT KSUX (AROUND 25-35% CHANCE). WINDS WILL TURN MORE
WESTERLY THROUGH TONIGHT, BUT STAY ON THE LIGHTER SIDE THROUGH
THE PERIOD.
FSD WATCHES/WARNINGS/ADVISORIES
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
UPDATE...SAMET
DISCUSSION...AJP
AVIATION...SAMET
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