141
FXUS63 KFSD 101859
AFDFSD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
159 PM CDT WED JUN 10 2026
KEY MESSAGES
- LATE TONIGHT INTO EARLY THURSDAY MORNING SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO DEVELOP ACROSS THE REGION.
STORMS WILL MOVE EAST THROUGH EARLY AFTERNOON THURSDAY.
- A FEW STRONG TO SEVERE STORMS MAY DEVELOP EARLY THURSDAY
MORNING (5-9 AM) FOR PORTIONS OF NORTHWEST IOWA. ISOLATED
WIND GUSTS TO 65 MPH AND HAIL UP TO PING PONG BALL SIZE WOULD
BE THE MAIN THREATS.
- FRIDAY THROUGH THE FIRST HALF OF NEXT WEEK WILL SEE COOLER
HIGHS IN THE 70S TO 80S AND LOWER RELATIVE HUMIDITY VALUES.
- SATURDAY WILL SEE A CHANCE OF THUNDERSTORMS OVER MAINLY
NORTHWEST IOWA. AT THIS TIME SEVERE RISK APPEARS TO BE LOW.
DISCUSSION
ISSUED AT 147 PM CDT WED JUN 10 2026
A COLD FRONT DRAPED FROM CENTRAL CANADA SOUTH THROUGH THE CENTRAL
PLAINS WILL GRADUALLY MAKE ITS WAY EAST THROUGH THE AFTERNOON TODAY.
TO THE EAST OF THE FRONT AN INFLUX OF MOISTURE ADVECTION WILL WORK
TO DESTABILIZE THE ATMOSPHERE. AS THE UPPER WAVE PASSES OVER THE
COLD FRONT IT WILL WORK AS A FOCUS FOR SHOWER AND THUNDERSTORM
INITIATION. SHORT TERM GUIDANCE IS IN FAIRLY GOOD AGREEMENT THAT ANY
STRONGER STORMS WILL BE WELL EAST OF THE REGION INTO CENTRAL IOWA
THIS AFTERNOON AND EVENING, WHERE THE BETTER DYNAMIC SETUP IS. ONE
THING TO WATCH THIS AFTERNOON IS A BAND OF VORTICITY ADVECTION AND
ENHANCED STRETCHING POTENTIAL THAT COULD RESULT IN BRIEF FUNNELS
LATE THIS AFTERNOON FOR AREAS ALONG AND EAST OF HIGHWAY 60. IF ANY
FUNNELS FORM THEY SHOULD BE WEAK AND SHORT LIVED.
LATE WEDNESDAY NIGHT INTO EARLY THURSDAY MORNING AN AREA OF WEAK WWA
COUPLED WITH AN INCREASING LLJ SWINGS THROUGH CENTRAL SOUTH DAKOTA.
THIS MAY TRIGGER SHOWERS AND THUNDERSTORMS. THESE STORMS WILL
PROGRESS NORTHEAST THROUGH EARLY THURSDAY AFTERNOON. INSTABILITY IS
LOW, LESS THAN 500 J/KG, BUT COULD BE ENOUGH FOR A FEW LIGHTNING
STRIKES. FOR AREAS NORTH OF HIGHWAY 18, SEVERE WEATHER IS NOT
ANTICIPATED, HOWEVER A FEW BRIEF, HEAVY DOWNPOURS ARE POSSIBLE.
AROUND DAYBREAK A SURFACE LOW WILL MOVE NORTHEAST OUT OF CENTRAL
NEBRASKA. INSTABILITY WILL RAPIDLY INCREASE AHEAD OF THE LOW AS 0-6
KM BULK SHEAR RAMPS UP 70-75 KTS. IN ADDITION, SYNOPTIC SUPPORT IN
THE FORM OF A JET STREAK RIGHT ENTRANCE REGION, A MID-LEVEL TROUGH
AXIS, AND CONTINUED INTENSIFICATION OF THE LLJ MAY WORK TO FOCUS
STORMS INTO A MORE ORGANIZED AREA OF SUPERCELLS. THESE WILL
THEN QUICKLY GROW UPSCALE INTO A MESOSCALE CONVECTIVE SYSTEM
(MCS). THERE REMAINS SOME UNCERTAINTY IN THE TRACK OF THE LOW,
WITH MOST GUIDANCE KEEPING THE INITIAL STRONGER SUPERCELLS JUST
TO THE SOUTH OF OUR CWA. HOWEVER, A FEW BRING ISOLATED STRONG
TO SEVERE SUPERCELLS INTO OUR NORTHEAST NEBRASKA COUNTIES AND
INTO NORTHWEST IOWA, MOSTLY EAST OF HIGHWAY 60. THESE STRONGER
STORMS WILL BE CAPABLE OF PRODUCING HAIL TO PING-PONG BALLS AND
WIND GUSTS OF 65 MPH. AS THE STRONGEST STORMS ARE EXPECTED
DURING THE MORNING COMMUTE, ROUGHLY 6 - 9 AM, WE WILL NEED TO
MONITOR THE TRENDS. ANY LINGERING SHOWERS AND THUNDERSTORMS
SHOULD BE EAST OF THE CWA BY THE EARLY AFTERNOON. HIGHS
THURSDAY AFTERNOON WILL BE COOLER THANKS TO CAA BEHIND THE WAVE,
IN THE 70S.
MOSTLY ZONAL FLOW ALOFT AND DRY CONDITIONS ARE EXPECTED FOR FRIDAY.
AT THE SURFACE WEST WINDS BECOME SOUTHERLY THROUGH THE DAY. A STRONG
PUSH OF WAA WILL WARM AFTERNOON HIGHS IN TO THE 80S AND 90S. FRIDAY
OVERNIGHT A WEAK COLD FRONT PUSHES THROUGH THE REGION, BRINING LOW
CHANCES (<25%) OF RAIN TO AREAS ALONG AND NORTH OF HIGHWAY 14. AS
THE FRONT PROGRESSES TO THE SOUTHEAST THERE WILL BE ADDITIONAL LOW
TO MEDIUM CHANCES (<40%) FOR LIGHT RAIN OVER PORTIONS OF SOUTHEAST
SOUTH DAKOTA, NORTHEAST NEBRASKA, AND NORTHWEST IOWA FROM ROUGHLY
DAYBREAK THROUGH THE AFTERNOON. HIGHS SATURDAY WILL BE SLIGHTLY
COOLER IN THE UPPER 70S TO MID-80S. NORTHWESTERLY FLOW IN THE MID-
LEVELS KEEP COOLER TEMPERATURES IN THE FORECAST FOR SUNDAY AS WELL,
WITH HIGHS IN THE LOW TO MID 70S. THIS TREND OF 70S FOR HIGHS
CONTINUES INTO THE FIRST HALF OF NEXT WEEK. DEW POINTS DURING THIS
TIME WILL ALSO BE LOWER, IN THE 40S TO LOW 50S. IF YOU HAVE ANY
OUTDOOR PROJECTS, THIS WOULD BE A GREAT TIME TO WORK ON THEM WITHOUT
THE HEAT AND HUMIDITY.
MONDAY NIGHT INTO TUESDAY A STRONG UPPER WAVE WILL WORK THROUGH THE
REGION BRINGING CHANCES OF RAIN TO THE AREA. DETAILS ON INSTABILITY
AND POTENTIAL FOR STRONG STORMS ARE UNCERTAIN AT THIS TIME.
AVIATION /18Z TAFS THROUGH 18Z THURSDAY/
ISSUED AT 1234 PM CDT WED JUN 10 2026
MOSTLY CLEAR SKIES WILL PREVAIL FOR THE FIRST HALF OF THIS PERIOD.
BEHIND THE COLD FRONT WINDS WILL BECOME NORTHWESTERLY AND BREEZY.
AFTERNOON GUSTS OF OF 25-30 KTS ARE EXPECTED WITH THE HIGHEST GUSTS
OVER CENTRAL SOUTH DAKOTA. WINDS WILL DECREASE AFTER SUNSET BECOMING
LIGHT AND VARIABLE.
SHORTLY BEFORE MIDNIGHT TONIGHT CLOUDS BEGIN TO BUILD IN AHEAD AN
AREA OF SHOWERS AND THUNDERSTORMS. FOR AREAS NORTH OF HIGHWAY
81, SEVERE WEATHER IS NOT ANTICIPATED. HOWEVER, A FEW STORMS MAY
PRODUCE BRIEF HEAVY DOWNPOURS. FOR AREAS TO THE SOUTH OF
HIGHWAY 81, AND ESPECIALLY TO THE EAST OF HIGHWAY 60, CHANCES
FOR STRONG TO SEVERE THUNDERSTORMS RETURN BETWEEN ROUGHLY 10-15Z
THURSDAY MORNING. STORMS MAY BE CAPABLE OF PRODUCING LARGE HAIL
TO THE SIZE OF A PING-PONG BALL AND WIND GUSTS UP TO 60 KTS.
SHOWERS AND STORMS CONTINUE THROUGH THE END OF THE PERIOD.
FSD WATCHES/WARNINGS/ADVISORIES
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
DISCUSSION...AJP
AVIATION...AJP
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