377
FXUS63 KFSD 051726
AFDFSD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1226 PM CDT FRI JUN 5 2026
KEY MESSAGES
- MODELS ARE TRENDING THE SEVERE CHANCES FARTHER SOUTH TODAY. A
FEW STRONG TO SEVERE STORMS WILL BE POSSIBLE, BUT WILL LIKELY
BE CONFINED TO ROUGHLY SOUTH OF AN ELK POINT TO SIOUX RAPIDS
LINE AND POSSIBLY SOUTH OF THE AREA ENTIRELY.
- A SYSTEM WRAPS NORTH SUNDAY INTO MONDAY AND MAY BRING
SCATTERED SHOWERS AND THUNDERSTORMS TO THE AREA. CURRENTLY
SEVERE WEATHER CHANCES ARE LOW.
- TEMPERATURES HEAT UP THIS WEEKEND INTO NEXT WEEK. THERE IS AN
INCREASING CHANCE (30-60%) OF HIGHS EXCEEDING 95 DEGREES
ESPECIALLY NEAR AND WEST OF THE JAMES RIVER BY WEDNESDAY AND
THURSDAY. BE PREPARED TO ENACT ANY HEAT RELATED SAFETY
MEASURES.
UPDATE
ISSUED AT 146 AM CDT FRI JUN 5 2026
A DECAYING MCS WILL CONTINUE TO DRIFT EAST THROUGH THE EARLY MORNING
HOURS. ADDITIONAL RAINFALL AMOUNTS WILL BE ON THE LIGHTER SIDE.
MODEL TRENDS CONTINUE TO PUSH THE CHANCES FOR STRONGER UPDRAFTS TO
THE SOUTH OF THE AREA FOR THIS AFTERNOON AND EVENING IN THE WAKE OF
THIS MCS, SO OTHER THAN ROUGHLY NEAR AND SOUTH OF A SIOUX CITY TO
STORM LAKE LINE THE CHANCES FOR ANY SEVERE WEATHER TODAY ARE VERY
LOW. A FEW UPDRAFTS COULD DEVELOP IN OTHER PARTS OF MAINLY NORTHWEST
IA WITH A VERY SMALL CHANCE TO REACH SEVERE LEVELS. OTHERWISE A
FAIRLY PLEASANT SUMMER DAY IS AHEAD FOR MOST LOCATIONS WITH HIGHS IN
THE 80S AND FAIRLY LIGHT WINDS.
THIS WILL LEAD INTO A QUIET AND WARMER SATURDAY AS A NOSE OF HIGH
PRESSURE DIPS SOUTH INTO THE AREA. HIGHS FROM THE UPPER 80S TO MID
90S IN MOST LOCATIONS.
DISCUSSION
ISSUED AT 336 PM CDT THU JUN 4 2026
SEVERAL BOUNDARIES, SOME LEFT BEHIND FROM YESTERDAY'S
STORMS, ARE NOTED ACROSS THE AREA BY AGITATED LINES OF CU AND
ONGOING THUNDERSTORMS. AMPLE SUNSHINE IN THESE AREAS PRIOR TO
DEVELOPMENT HAS LED TO 1,500-2,000 J/KG TO DEVELOP WITH MID-
LEVEL LAPSE RATES AROUND 7.5 C/KM. SHEAR IS ON THE WEAKER SIDE,
BUT LARGE HAIL TO PING PONG BALLS WILL STILL BE POSSIBLE GIVEN
THE LAPSE RATES. AND WITH THE MYRIAD BOUNDARIES IN PLACE, WILL
HAVE TO WATCH FOR THE THE THREAT OF TORNADOES. THE MAIN BOUNDARY
THAT WILL BE THE FOCUS OF STORMS THROUGH THIS EVENING INTO
TONIGHT STRETCHES FROM WESTERN SOUTH DAKOTA INTO THE EAST-
CENTRAL PART OF THE STATE. AS A SHORTWAVE EMBEDDED WITHIN THE
OTHERWISE ZONAL FLOW MOVES ACROSS THE NORTHERN PLAINS THROUGH
THIS EVENING, THERE SHOULD BE AN UPTICK IN THUNDERSTORM
DEVELOPMENT. THE STORMS CURRENTLY ONGOING AT THE EASTERN END OF
THIS BOUNDARY ARE GOING TO CONTINUE TO LIFT NORTH AND CONTINUE
TO DEVELOP WITH WESTWARD EXTENT AS THE SHORTWAVE ENCROACHES THE
AREA. THE OTHER CONCERN WITH THESE STORMS WILL BE THE HEAVY RAIN
THREAT AS AREAS NEAR AND NORTH OF HIGHWAY 14 ALREADY HAVE
SATURATED GROUNDS. THIS COULD LEAD TO SOME FLASH FLOODING IF
STORMS MOVE TOO SLOWLY OVER AN AREA. AND HEAVY RAIN TO OUR NORTH
MAY ALSO CAUSE SOME MINOR RIVER FLOODING ISSUES DOWNSTREAM
DEPENDING ON HOW MUCH RAIN IS SEEN.
ANOTHER AREA OF STORMS WILL DEVELOP OFF TO OUR WEST. THE BEST SHEAR
IS LOCATED OVER WESTERN SOUTH DAKOTA ON THE WESTERN END OF THE
MAIN BOUNDARY. GUIDANCE SHOWS STORMS DEVELOPING OUT THERE LATE
THIS AFTERNOON/EARLY EVENING MAY TAKE ON SOME BOWING SEGMENTS AS
IT MOVES EASTWARD TOWARDS OUR AREA, ARRIVING BY 9-10 PM WEST OF
THE JAMES RIVER. THIS IS WHERE THE BEST CHANCE OF DAMAGING WIND
GUSTS TO 70 MPH WILL BE, THOUGH STORMS SHOULD GRADUALLY WEAKEN
AS THEY MOVE EASTWARD AS INSTABILITY WANES THROUGH THE NIGHT. IN
OTHER WORDS, AFTER ABOUT MIDNIGHT TO 1 AM, THE SEVERE WEATHER
THREAT SHOULD COME TO AN END. A FEW SHOWERS WILL BE POSSIBLE
HEADING INTO FRIDAY MORNING, BUT NOTHING SEVERE EXPECTED.
ANOTHER UPPER-WAVE MOVES ACROSS THE NORTHERN GREAT LAKES REGION
TOMORROW AFTERNOON AND EVENING, AND THIS COULD SET OFF SOME
ISOLATED THUNDERSTORMS MAINLY NEAR AND EAST OF I-29 AND
ESPECIALLY TOWARDS THE HIGHWAY 20 CORRIDOR. CAN'T RULE OUT SOME
STRONG TO SEVERE THUNDERSTORMS WITH THIS ACTIVITY, BUT THIS WILL
BE HIGHLY DEPENDENT ON HOW STORMS DEVELOP TONIGHT. ALSO, THE
GREATER INSTABILITY WILL ALSO BE SOUTH OF THE AREA, LIKELY
KEEPING THE GREATEST THREAT TO OUR SOUTH.
RIDGING ALOFT BUILDS IN SATURDAY AND SO WE SHOULD FINALLY HAVE A DRY
DAY. THIS WILL BE QUICKLY REPLACED WITH ANOTHER ACTIVE UPPER PATTERN
HEADING INTO EARLY NEXT WEEK, WHICH WILL LEAD TO INCREASED SHOWER
AND STORM CHANCES SUNDAY AND MONDAY. JUST LIKE THE PAST FEW EVENTS,
ENSEMBLES SHOW THE INSTABILITY SUFFICIENT FOR SEVERE WEATHER LARGELY
IN PLACE, BUT THERE WILL BE QUESTIONS ON HOW MUCH SHEAR THERE
WILL BE WITH AND OF COURSE ANY OTHER MESOSCALE FEATURES THAT
CAN'T BE RESOLVED THIS FAR OUT. HEAT ALSO LOOKS TO BUILD IN NEXT
WEEK, ESPECIALLY BY WEDNESDAY AND THURSDAY WHEN LREF
PROBABILITIES OF HIGHS EXCEEDING 95 DEGREES ARE AROUND 30-60%
NEAR AND WEST OF THE JAMES RIVER, WITH A 10-30% OF HIGHS EVEN
EXCEEDING 100 DEGREES IN THESE AREAS. RECENT RAINFALL MAY MEAN
THAT THE FORECAST MODELS COULD BE OVERDOING POTENTIAL HEATING,
BUT THIS WILL BE SOMETHING THAT NEEDS TO BE WATCHED CLOSELY OVER
THE NEXT COUPLE OF DAYS.
AVIATION /18Z TAFS THROUGH 18Z SATURDAY/
ISSUED AT 1225 PM CDT FRI JUN 5 2026
ISOLATED SHOWERS AND STORMS ARE POSSIBLE INTO THIS EVENING OVER
SOUTHWEST MINNESOTA AND THE HIGHWAY 20 CORRIDOR IN NORTHWEST
IOWA/FAR NORTHEAST NEBRASKA. COVERAGE OF STORMS IS EXPECTED TO
BE LOW ENOUGH TO PRECLUDE ANY THUNDER MENTION AT KSUX AT THIS
TIME, BUT TRENDS WILL BE MONITORED. COULD SEE SOME FOG DEVELOP
TONIGHT INTO TOMORROW MORNING, BUT THE CHANCE OF THIS OCCURRING
IS ROUGHLY 20-30% ACROSS THE AREA, TOO LOW TO INCLUDE MENTION IN
THE TAFS AT THIS TIME. WINDS WILL BE FAIRLY LIGHT THROUGH THE
PERIOD, INCREASING TOWARDS TOMORROW AFTERNOON OUT OF THE EAST-
SOUTHEAST.
FSD WATCHES/WARNINGS/ADVISORIES
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
UPDATE...08
DISCUSSION...SAMET
AVIATION...SAMET
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