355
FXUS63 KFSD 112300
AFDFSD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
600 PM CDT SAT JUL 11 2026
KEY MESSAGES
- AN EXTENDED STRETCH OF HOT TEMPERATURES ARE EXPECTED THROUGH
THE NEXT WEEK. HIGHS IN THE 90S MAY APPROACH 100 DEGREES IN A
FEW LOCATIONS. THE CUMULATIVE NATURE OF THE HEAT COULD LEAD TO
SOME HEAT HEALTH CONCERNS.
- PATCHY MORNING FOG WILL BE POSSIBLE EACH DAY, BUT WIDESPREAD
DENSE FOG ISN'T LIKELY.
- MINIMAL PRECIPITATION IS EXPECTED OVER THE NEXT 7 DAYS, WITH
THE LREF PROBABILITY OF >0.25" THROUGH MONDAY THE 20TH NO
GREATER THAN 17% IN ANY ONE LOCATION.
DISCUSSION
ISSUED AT 1221 PM CDT SAT JUL 11 2026
THIS AFTERNOON: IT'S A HOT DAY ACROSS THE REGION WITH PLENTY OF
SUNSHINE. HIGH TEMPERATURES CLIMBING INTO THE 90S IN MOST
LOCATIONS, BUT WITH DEW POINTS MIXING DOWN LOWER INTO THE 60S, HEAT
INDEX VALUES REMAIN BELOW CRITICAL VALUES. THAT SAID, ANYONE
SPENDING TIME OUTDOORS OVER THE NEXT DAYS WILL NEED TO TAKE
PREVENTATIVE ACTIONS FROM A VERY HIGH UV INDEX.
TONIGHT: WINDS AGAIN TURN LIGHT AND VARIABLE THROUGH THE NIGHT. THE
NBM HAS BEEN BIASED A BIT TOO COLD WITH OVERNIGHT LOWS THE PAST
DAYS, BUT WE WILL BEGIN TO SEE DEW POINTS LOWER A BIT AT NIGHT WHICH
COULD LEAD TO SOME LOWS INTO THE UPPER 60S. HREF PROBABILITIES SHOW
LESS POTENTIAL FOR FOG THIS MORNING THAN LAST NIGHT, HOWEVER, THE
FAVORED AREAS WOULD AGAIN BE ACROSS NW IOWA FOR PATCHY MORNING FOG.
SUNDAY: PRETTY MUCH AN IDENTICAL DAY ON SUNDAY, WITH A BIT MORE
SOUTHWESTERLY WIND FETCH WEST OF I-29. THIS WILL RESULT IN HIGH
TEMPERATURE CREEPING A COUPLE DEGREES WARMEST WEST OF I-29. HOWEVER
WITH DEEPER MIXING, DEW POINT MIX DOWNWARDS FURTHER, AND WILL AGAIN
KEEP HEAT INDEX VALUES BELOW CRITICAL THRESHOLDS.
MONDAY-FRIDAY: REALLY NO MAJOR CHANGES IN THE FORECAST FOR THE
UPCOMING WORK WEEK. THE MID-LVL RIDGE CONTINUES TO BUILD THROUGH
THE NORTHERN PLAINS CENTERING ITSELF ALONG THE ND/SD BORDER BY
MONDAY AND THEN BUILDING SOUTHWARD AND BROADENING BY THE MIDDLE OF
THE WEEK ALONG I-90. THE RESULT WILL BE DAILY HIGHS IN THE 90S TO
EVEN LOWER 100S IN A FEW AREAS WEST OF I-29. THE DAILY DIRECTION OF
THE SURFACE WINDS WILL DICTATE SOME VARIANCE IN WARMING, WITH
SOUTHWESTERLY WIND FETCH ALLOWING FOR DEEPER MIXING AND SLIGHTLY
HIGHER AFTERNOON HIGHS. RECORDS THIS WEEK APPEAR TO BE SAFE EVEN
IF 100S ARE REACHED. MOST RECORDS FOR THE UPCOMING WEEK RANGE
FROM 104-113 DEGREES STEMMING FROM SOME SEVERE PAST DROUGHT
YEARS). FORTUNATELY NO EXTREME RISES IN DEW POINTS ARE
EXPECTED, WHICH WILL KEEP HEAT INDEX VALUES BELOW 100 DEGREES IN
MOST AREAS. WILL CONSIDER HEAT HEADLINES FOR PORTIONS OF THE
JAMES RIVER VALLEY AREAS AND WESTWARD BY MONDAY WHERE HIGHS DO
BEGIN TO CROSS THE 100 MARK, BUT HEAT INDEX VALUES REMAIN 1-3
DEGREES BELOW CRITERIA. ECE/GEFS PROBABILITIES CONTINUE TO
HIGHLIGHT THE JAMES RIVER VALLEY WITH A 60%+ PROBABILITY OF
EXCEEDING 100 THROUGH TUESDAY, HOWEVER AS SOUTHWESTERLY WINDS
EXPAND EASTWARD LATE IN THE WEEK, THOSE PROBABILITIES TO EXPAND
INTO THE I-29 CORRIDOR. A SIDE NOTE WITH ALL OF THE HEAT
CONCERNS THIS WEEK. DAILY RH VALUES DO FALL NEAR OR BELOW 20%
WEST OF THE JAMES RIVER INTO THE WEEK WITH AFTERNOON WIND GUSTS
APPROACHING 25 MPH. WE MAY BEGIN TO SEE SOME INCREASE IN FIRE
DANGER GIVEN THE DRY OUT OF FINE FUELS.
SATURDAY-SUNDAY: WE MAY BEGIN TO SEE SOME BREAK IN THE RIDGE BY
NEXT WEEKEND, AS A WEAK MID-LVL WAVE FLOWS NORTHWARD THROUGH THE
PLAINS AND A SECOND WAVE CROSSES NEAR THE CANADIAN BORDER. WHILE
THIS COULD BRING SOME CLOUDS TO NEXT WEEKEND, LOW-LVL MOISTURE
TRANSPORT THROUGH THE CENTRAL PLAINS VEERS OFF QUICKLY EAST, AND THE
CANADIAN WAVE IS ONLY BRINGING LIMITED PACIFIC MOISTURE WITH IT.
PRECIPITATION CHANCES REMAIN LOW AT THIS POINT, WITH LREF GUIDANCE
INDICATING NO MORE THAN A 17% PROBABILITY OF >0.25" OF PRECIPITATION
THROUGH MONDAY MORNING.
AVIATION /00Z TAFS THROUGH 00Z MONDAY/
ISSUED AT 555 PM CDT SAT JUL 11 2026
MAINLY VFR CONDITIONS WILL CONTINUE THIS TAF PERIOD. TAKING A
LOOK AT SATELLITE IMAGERY, MOSTLY CLEAR CONDITIONS CONTINUE THIS
AFTERNOON. THE ONLY AVIATION CONCERNS WILL BE SOME PATCHY RIVER
VALLEY FOG THAT DEVELOPS OVERNIGHT AS SURFACE WINDS LIGHTEN.
WHILE THIS COULD LEAD TO OCCASIONAL MVFR TO IFR VSBYS AT TIMES,
CONFIDENCE ISN'T HIGH ENOUGH TO ADD IT INTO THE TAFS YET.
LASTLY, MAINLY SOUTHERLY WINDS WILL CONTINUE WITH MARGINALLY
BREEZY CONDITIONS EXPECTED AT TIMES.
FSD WATCHES/WARNINGS/ADVISORIES
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
DISCUSSION...DUX
AVIATION...05
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page