080
FXUS63 KFSD 090536
AFDFSD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1236 AM CDT TUE JUN 9 2026
KEY MESSAGES
- MODERATE TO MAJOR HEAT RISK TUESDAY (ALL AREAS) AND WEDNESDAY
(SOUTHEAST) INDICATES A POTENTIAL FOR HEAT-RELATED ILLNESS FOR
THOSE WITHOUT ADEQUATE COOLING AND HYDRATION. PROTECT YOURSELF
AGAINST THE HEAT AND CHECK ON MORE VULNERABLE INDIVIDUALS SUCH
AS THE ELDERLY, CHILDREN AND THOSE WITH CHRONIC ILLNESSES.
- A HEAT ADVISORY HAS BEEN ISSUED FOR MOST AREAS NEAR AND SOUTH
OF I-90 FROM 1 PM TO 9 PM TUESDAY AS HEAT INDICES CLIMB ABOVE
100 DEGREES.
- TUESDAY LOOKS TO BRING THE GREATER SEVERE THREAT OF THE NEXT 3
DAYS, WITH A LARGE HAIL THREAT TOWARD CENTRAL SOUTH DAKOTA AND
NEBRASKA IN THE EVENING TRANSITIONING TO DAMAGING WINDS UP TO
75 MPH FARTHER EAST LATE EVENING INTO THE NIGHT. ISOLATED
TORNADOES ARE POSSIBLE.
- THE COLD FRONT TRIGGERING STORMS ON WEDNESDAY IS TRENDING
FASTER, WITH THE ASSOCIATED SEVERE STORM THREAT SHIFTING EAST
INTO MAINLY MINNESOTA AND IOWA.
UPDATE
ISSUED AT 934 PM CDT MON JUN 8 2026
TAKING A LOOK ACROSS THE AREA, THE WINDOW FOR OUR SEVERE WEATHER
RISK CONTINUES TO WANE THIS EVENING AS A LINGERING CAP AND
INCREASING CLOUD COVER CONTINUE TO INHIBIT THE INITIATION OF
STORMS. WHILE SOME HIGH-RESOLUTION GUIDANCE CONTINUES TO SUGGEST
THAT THERE COULD BE A LINGERING ISOLATED THREAT ACROSS
SOUTHWESTERN MN THROUGH 03Z-06Z (10PM TO 1AM), CONFIDENCE IN
THIS SCENARIO CONTINUES TO BE LOW ESPECIALLY WITH THE LOSS OF
DIURNAL HEATING. WITH THIS IN MIND, EXPECT THE QUIETER
CONDITIONS TO CONTINUE OVERNIGHT AS LOWS DECREASE INTO THE LOW
TO UPPER 60S FOR THE NIGHT. LOOKING AHEAD, MUCH WARMER
CONDITIONS ARE INSTORED FOR TUESDAY AS SOUTHERLY SURFACE WINDS
AND A LIFTING WARM FRONT HELP HIGHS APPROACH THE 90S TO
POTENTIALLY LOW 100S. WITH THIS IN MIND, WE'RE STILL ON TRACK
FOR MODERATE TO MAJOR HEAT RISK ALONG AND SOUTH OF I-90 AND THUS
A HEAT ADVISORY HAS BEEN ISSUED FOR THESE AREAS FROM 1 PM TO 9
PM.
OTHERWISE, WE'RE STILL ON TRACK FOR THE RETURN OF SHOWER AN
THUNDERSTORM CHANCES BY TUESDAY AFTERNOON/EVENING. LOOKING ALOFT,
SHOULD SEE SCATTERED SHOWERS AND THUNDERSTORMS DEVELOP BY LATE
AFTERNOON ACROSS CENTRAL SD AS A PROGRESSING COLD FRONT INTERSECTS A
DECENTLY STRONG SHORTWAVE. SEMI-DISCRETE CELLS TO CLUSTERS WILL
BEGIN TO CONGEAL WITH EASTWARD EXTENT EVENTUALLY BECOMING EITHER A
BROKEN QLCS OR TWO SEPARATE BOWING SEGMENTS AS THE NOCTURNAL
LLJ STRENGTHENS. FROM HERE, SHOULD SEE AN UPTICK IN PROGRESSION
AS THINGS QUICK PUSH OUT OF OUR AREAS BY LATE EVENING. WITH ALL
THIS IN MIND, ALL HAZARDS WILL BE POSSIBLE WITH UP TO 2 INCH+
HAIL EXPECTED WITH THE SEMI-DISCRETE CELLS AND DAMAGING WINDS UP
TO 75 MPH ALONG WITH ISOLATED TORNADOES POSSIBLE AS THINGS GROW
MORE UPSCALE. LASTLY, ANOTHER WARM NIGHT IS EXPECTED WITH LOWS
MAINLY IN THE MID 60S TO LOW 70S.
DISCUSSION
ISSUED AT 254 PM CDT MON JUN 8 2026
LOW STRATUS HAS HELPED SPLIT OUR AREA TEMPERATURE WISE, WITH
TEMPERATURES MAINLY IN THE 70S WEST OF I-29; MEANWHILE NEAR AND EAST
OF I-29, WE'RE IN THE 80S WHERE LESS CLOUD COVER HAS BEEN
TODAY. THESE AREAS THAT HAVE CLEARED OUT THE STRATUS COULD SEE
AN ISOLATED THUNDERSTORM THROUGH THE EARLY EVENING WHERE
1,500-2,000 J/KG OF MLCAPE HAS DEVELOPED. THE BETTER SHEAR IS
WEST OF THIS AREA, SO SEVERE WEATHER CHANCES LOOK QUITE LOW
THROUGH THIS EVENING. BUT IF AN UPDRAFT COULD MAINTAIN ITSELF,
60 MPH WINDS AND HALF DOLLAR SIZED HAIL WOULD BE THE MAIN
THREATS. THESE STORMS SHOULD MOSTLY BE DIURNALLY DRIVEN, SO
EXPECT A WEAKENING TREND AFTER THE SUNSETS. CAN'T RULE OUT SOME
PATCHY FOG TONIGHT; BUT OVERALL, A QUIET NIGHT IS AHEAD FOR US.
A MORE ACTIVE TUESDAY NIGHT IS EXPECTED, MORE ON THAT BELOW.
RAIN-WISE, MOST OF THE DAYTIME HOURS TUESDAY SHOULD BE QUIET. THE
MAIN STORY WILL BE THE BUILDING HEAT AND HUMIDITY. ANY MORNING FOG
OR LOW STRATUS SHOULD ERODE QUICKLY, ALLOWING FOR DAYTIME HEATING TO
TAKE OFF QUICKLY INTO THE AFTERNOON. LOOK FOR HIGHS TO BE IN THE 90S
FOR THE MAJORITY OF THE AREA, WITH DEW POINTS INTO THE 70S OVER
NORTHWEST IOWA, FAR NORTHEAST NEBRASKA, AND ADJACENT AREAS OF
SOUTHEASTERN SOUTH DAKOTA. THIS WILL BRING HEAT INDICES INTO THE
TRIPLE DIGITS FOR AREAS ESPECIALLY NEAR AND SOUTH OF I-90. FOR
THIS REASON, DID GO AHEAD AND ISSUE A HEAT ADVISORY FOR PORTIONS
OF OUR AREA FROM 1 PM TO 9 PM TUESDAY. THE BEST OVERLAP OF HOT
TEMPERATURES AND HIGHER DEW POINTS WILL BE IN THE SIOUX CITY
METRO WHERE HEAT INDICES COULD BE BRIEFLY AS HIGH AS 105
DEGREES. MAKE SURE TO STAY HYDRATED OUT THERE AND TAKE FREQUENT
BREAKS IF YOU HAVE TO WORK OUTDOORS OR IF YOU HAVE ANY OUTDOOR
ACTIVITIES PLANNED.
THE HEAT AND HUMIDITY WILL ALSO PRIME THE ATMOSPHERE FOR STRONG
TO SEVERE STORMS HEADING INTO TUESDAY NIGHT. AN UPPER TROUGH
WILL BEGIN TO DIG IN FROM THE CANADIAN ROCKIES AND SEND WAVES OF
VORTICITY OUR WAY TUESDAY INTO TUESDAY NIGHT. CAN'T RULE OUT A
STRAY THUNDERSTORM IN THE AFTERNOON, BUT THE BETTER CHANCES
ARRIVE IN THE EVENING AS STORMS LIKELY DEVELOP OFF TO OUR WEST
AND THEN MOVE THROUGH OUR AREA INTO THE NIGHT. THERE WILL BE
PLENTY OF INSTABILITY EVEN AS WE LOSE DAYTIME HEATING TUESDAY
NIGHT, ON THE ORDER OF 2,000-3,000+ J/KG OF CAPE. BULK SHEAR
VALUES WON'T BE AS IMPRESSIVE, AROUND 30 KTS OR SO, BUT THIS
SHOULD BE SUFFICIENT TO MAINTAIN STRONG TO SEVERE STORMS. WITH
THE HIGHLY UNSTABLE ATMOSPHERE AND SOUNDINGS SHOW SOME MID-
LEVEL DRY AIR, DAMAGING WINDS LOOK TO BE THE MAIN THREAT AND
COULD BE AS STRONG AS 75 MPH. MID-LEVEL LAPSE RATES UP TO 8.5
C/KM AND LARGE CAPE PROFILES WILL LEAD TO A SECONDARY THREAT OF
LARGE HAIL TO THE SIZE OF A HEN EGG (2 INCHES) OR SLIGHTLY
LARGER. LASTLY, TORNADOES WILL ALSO BE POSSIBLE ESPECIALLY IN
THE EVENING AS HODOGRAPHS SHOW SOME DECENT LOW LEVEL CURVATURE
IN PLACE AND STORMS HAVE A BETTER CHANCE AT BEING ROOTED TO THE
SURFACE. THE TORNADO THREAT WILL BE MAINTAINED OVERNIGHT AS
STRENGTHENING LOW LEVEL JET SPREADS INTO THE AREA. WITH ALL
MODES OF SEVERE WEATHER POSSIBLE DURING THE OVERNIGHT HOURS, BE
SURE TO HAVE A WAY FOR WARNING ALERTS TO WAKE YOU UP AT NIGHT!
STORMS LOOK TO PUSH EAST OF THE AREA AS A COLD FRONT STARTS MOVING
INTO OUR AREA. MOST GUIDANCE NOW PUSHES THIS COLD FRONT MOSTLY EAST
OF THE AREA BY PEAK DAYTIME HEATING, SO THE THREAT FOR SEVERE
WEATHER CONTINUES TO TREND EASTWARD FOR WEDNESDAY. WILL HAVE TO
WATCH LATE WEDNESDAY NIGHT/EARLY THURSDAY MORNING AS THE MAIN WAVE
MOVES THROUGH THE AREA AS THIS COULD HELP DEVELOP SOME STORMS
MAINLY NEAR AND SOUTH OF HIGHWAY-20. INSTABILITY WILL BE THE
LIMITING FACTOR, BUT THE POTENTIAL FOR SHEAR PUSHING TOWARDS 60
KTS WILL MEAN ANY STORMS WILL BE WORTH WATCHING IF ONE COULD
EVEN GET GOING EARLY THURSDAY MORNING. LOOKING AHEAD, COOLER
TEMPERATURES AND CONTINUED BROAD, LOW-END RAIN CHANCES WILL BE
MAINTAINED HEADING INTO THE WEEKEND AS GENERAL TROUGHINESS
REMAINS IN PLACE. INSTABILITY LOOKS FAIRLY WEAK DURING THIS TIME
FRAME, SO SEVERE WEATHER CHANCES LOOK LOW. WE WILL LIKELY SEE
COOLER TEMPERATURES ESPECIALLY INTO EARLY NEXT WEEK WHEN HIGHS
IN THE 70S MAY START TO BECOME MORE WIDESPREAD.
AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/
ISSUED AT 1230 AM CDT TUE JUN 9 2026
MAINLY VFR CONDITIONS WITH OCCASIONAL MVFR TO IFR CIGS WILL BE
POSSIBLE THIS TAF PERIOD. TAKING A LOOK ACROSS THE AREA, MOSTLY
CLEAR CONDITIONS PERSIST THIS EVENING. EXPECT THESE CONDITIONS
TO CONTINUE THROUGH THE EARLY AFTERNOON ON TUESDAY BEFORE
SCATTERED SHOWERS AND THUNDERSTORMS RETURN THIS EVENING. BESIDES
PROMOTING OCCASIONAL MVFR TO IFR CIGS AND VSBYS, DECIDED TO ADD
TEMPO GROUPS TO BOTH KHON AND KFSD SINCE THESE AREAS WILL BE THE
MOST LIKELY TO BE IMPACTED WITHIN THE LATEST GUIDANCE. OTHERWISE,
SHOULD SEE THINGS CLEAR OUT BY 03Z WEDNESDAY. LASTLY, LIGHT AND
VARIABLE WINDS OVERNIGHT WILL BECOME MORE SOUTHERLY AND BREEZY
DURING THE DAY ON TUESDAY PROMOTING WINDS GUSTS BETWEEN 25-35 MPH.
FSD WATCHES/WARNINGS/ADVISORIES
SD...HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 9 PM CDT THIS
EVENING FOR SDZ059>071.
MN...NONE.
IA...HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 9 PM CDT THIS
EVENING FOR IAZ001-002-012>014-020>022-031-032.
NE...HEAT ADVISORY FROM 1 PM THIS AFTERNOON TO 9 PM CDT THIS
EVENING FOR NEZ013-014.
UPDATE...05
DISCUSSION...SAMET
AVIATION...05
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page