333
FXUS63 KFSD 011136
AFDFSD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
636 AM CDT SAT AUG 1 2026
KEY MESSAGES
- PATCHY FOG WILL IMPACT AREAS NEAR AND WEST OF I-29 EARLY THIS
MORNING, ESPECIALLY IN AREAS WHICH RECEIVED MORE SUBSTANTIAL
RECENT RAINFALL. ANY FOG SHOULD BURN OFF BY MID-MORNING.
- DRY CONDITIONS AND SEASONABLE TEMPERATURES WILL PREVAIL
THROUGH THE WEEKEND.
- SHOWER AND STORM CHANCES RETURN MONDAY NIGHT INTO WEDNESDAY.
AN ISOLATED STRONG TO SEVERE STORM IS POSSIBLE IN PORTIONS OF
SOUTHEAST SOUTH DAKOTA MONDAY EVENING, IF STORMS CAN DEVELOP.
UPDATE
ISSUED AT 405 AM CDT SAT AUG 1 2026
SEEING PATCHY FOG DEVELOPING VIA SATELLITE AND SURFACE OBS,
MAINLY WEST THROUGH NORTH OF SIOUX FALLS WHERE MORE SUBSTANTIAL
RAINFALL WAS REPORTED OVER THE PAST 24-36 HOURS. AT THIS TIME,
DENSE FOG IS NOT EXPECTED TO BECOME WIDESPREAD ENOUGH TO WARRANT
ANY HEADLINES.
OTHERWISE NO SIGNIFICANT FORECAST CHANGES EARLY THIS MORNING. A
LEVEL 1 OF 5 RISK FOR SEVERE STORMS WAS INTRODUCED IN THE DAY 3
OUTLOOK, MAINLY FOR MONDAY EVENING AS A COLD FRONT PUSHES INTO
SOUTHEAST SD. IF STORMS CAN DEVELOP ALONG THE BOUNDARY, THERE
MAY BE ENOUGH OVERLAP BETWEEN INSTABILITY AHEAD OF THE FRONT
AND GREATER WIND SHEAR BEHIND TO SUPPORT AN ISOLATED STRONG TO
SEVERE STORM. CONFIDENCE REMAINS LOW AT THIS TIME, THOUGH, SO IF
YOU HAVE OUTDOOR PLANS MONDAY EVENING, CONTINUE TO MONITOR THE
FORECAST FOR THE LATEST UPDATES.
DISCUSSION
ISSUED AT 247 PM CDT FRI JUL 31 2026
A NEARLY STACKED LOW PRESSURE SYSTEM WILL CONTINUE TO DRIFT
SOUTHEASTWARD INTO CENTRAL IOWA THROUGH THE REMAINDER OF THE
AFTERNOON, AND WITH THE SURFACE LOW DEEPENING, LOOK FOR WINDS TO
INCREASE A BIT MORE MAINLY EAST OF I-29 THROUGH THE EARLY EVENING
HOURS. MOST SPOTS TOP OUT WITH WIND GUSTS BETWEEN 35 AND 40
MPH, BUT ISOLATED POCKETS OF GUSTS TO AROUND 45 MPH WILL BE
POSSIBLE OVER NORTHWEST IOWA THROUGH ABOUT 7 TO 8 PM THIS
EVENING. THIS SHOULD REMAIN IN SHORT DURATION AND ISOLATED AND
SO DECIDED AGAINST WIND HEADLINES. MOISTURE ALSO CONTINUES TO
WRAP AROUND THIS LOW WHICH WILL KEEP MAINLY LIGHT RAIN IN THE
FORECAST THROUGH THIS EVENING PRIMARILY EAST OF I-29. SOUNDINGS
SHOW A LITTLE BIT OF ELEVATED INSTABILITY OVER PARTS OF
NORTHWEST IOWA, SO CAN'T RULE OUT A RUMBLE OF THUNDER THIS
AFTERNOON, BUT CHANCES FOR THIS ARE LOOKING LESS AND LESS
LIKELY. THE LAST OF THE SHOWERS SHOULD EXIT NORTHWEST IOWA BY 10
PM TO MIDNIGHT TONIGHT, LEADING TO DRY CONDITIONS HEADING INTO
THE WEEKEND.
PATCHY FOG IS POSSIBLE WHERE WINDS CAN GO VERY LIGHT TO CALM BY
EARLY TOMORROW MORNING, BUT IT DOES LOOK LIKE WINDS SHOULD REMAIN
ELEVATED ENOUGH TO PREVENT WIDESPREAD DEVELOPMENT. TRENDS WILL BE
MONITORED. OTHERWISE, A PLEASANT DAY IS IN STORE FOR TOMORROW
WITH HIGHS IN THE UPPER 70S TO LOWER 80S WITH DEW POINTS DOWN
INTO THE MID 50S WEST TO LOW 60S EAST. THESE LOWER DEW POINTS
WILL LEAD TO MORE COMFORTABLE CONDITIONS OUT THERE ESPECIALLY
WHEN COMPARED TO THE PAST FEW DAYS. THE HUMIDITY RELIEF WILL BE
SHORT-LIVED HOWEVER, AS SOUTHERLY FLOW RETURNS ON SUNDAY AND
ALLOWS DEW POINTS TO RISE THROUGH THE 60S AND POTENTIALLY AS
HIGH AS THE LOWER 70S IN THE AFTERNOON. IT WON'T BE NEARLY AS
HOT AS IT HAS BEEN THOUGH AS HIGHS WILL STILL REMAIN MAINLY IN
THE 80S WITH A FEW POCKETS OF HIGHS NEAR 90 IN SOUTH-CENTRAL
SOUTH DAKOTA. THOSE HOTTER AREAS WILL LIKELY BE OFFSET FROM THE
HIGHER DEW POINTS THOUGH, SO HEAT INDICES WON'T GET TOO HIGH.
TEMPERATURES WILL CONTINUE TO WARM ON MONDAY AND THIS WILL BE
OUT AHEAD OF OUR NEXT COLD FRONTAL PASSAGE. THIS COLD FRONT MAY
BRING A CHANCE OF STRONGER THUNDERSTORMS TO THE AREA, BUT THE
OVERNIGHT TIMING OF THE FRONTAL PASSAGE AND THE FACT THE BETTER
UPPER LEVEL SUPPORT WILL BE DISPLACED TO OUR NORTH LEADS TO A
LOW CONFIDENCE FORECAST FOR SEVERE WEATHER.
THIS FRONTAL BOUNDARY MAY STALL OUT OR SLOW DOWN NEAR OR SOUTH
OF THE HIGHWAY 20 CORRIDOR AS A LARGE UPPER WAVE PIVOTS SLOWLY
ACROSS THE REGION. THIS WILL KEEP RAIN AND STORM CHANCES IN THE
FORECAST MAINLY SOUTH OF I-90 THROUGH THE DAY ON TUESDAY AND
POTENTIALLY INTO WEDNESDAY AS WELL DEPENDING ON WHERE THE
FRONTAL BOUNDARY STALLS. WILL HAVE TO WATCH THIS FOR PERHAPS
SOME HEAVY RAIN POTENTIAL AS SOME OF THE LOWER RESOLUTION GLOBAL
MODELS SUCH AS THE 31.12Z ECMWF AND CANADIAN MODEL 48 HOUR QPF
ALREADY SHOWS A STRIPE OF 1 TO 3+ INCHES EITHER NEAR HIGHWAY 20
OR NEAR I-80 DEPENDING ON THE MODEL. SO WE'LL SEE WHAT THE
HIGHER RESOLUTION MODELS COME UP WITH AS WE GET CLOSER, BUT
THESE AREAS SOUTH OF I-90 DIDN'T RECEIVE AS MUCH RAIN WITH THIS
MOST RECENT SYSTEM, SO THE FLOOD THREAT MAY STILL REMAIN LOW
ANYWAY. COOLER WEATHER IMMEDIATELY FOLLOWS THE COLD FRONTAL
PASSAGE, WITH HIGHS LIKELY ONLY STAYING IN THE 70S TUESDAY AND
WEDNESDAY BEFORE GRADUALLY WARMING UP THROUGH THE END OF NEXT
WEEK.
AVIATION /12Z TAFS THROUGH 12Z SUNDAY/
ISSUED AT 635 AM CDT SAT AUG 1 2026
PATCHY FOG PRODUCING SPORADIC MVFR-LOCALLY IFR VISIBILITY AS WE
START THIS TAF PERIOD, THOUGH NOT DIRECTLY IMPACTING TAF SITES
AT THIS TIME. CONDITIONS SHOULD QUICKLY IMPROVE TO VFR BY 14Z.
NORTH WINDS INCREASE SLIGHTLY THROUGH THE MORNING, MOST NOTABLY
ALONG/EAST OF I-29 WERE OCCASIONAL GUSTS 15-20KT ARE EXPECTED
THROUGH THE AFTERNOON. ANY GUSTS QUICKLY DIMINISH BY SUNSET WITH
LIGHT/VARIABLE WINDS BECOMING LIGHT SOUTH INTO SUNDAY MORNING.
FSD WATCHES/WARNINGS/ADVISORIES
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
UPDATE...JH
DISCUSSION...SAMET
AVIATION...JH
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