536
FXUS63 KFSD 060214
AFDFSD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
914 PM CDT MON OCT 5 2026
KEY MESSAGES
- WARM AND PREDOMINANTLY DRY CONDITIONS CONTINUE THROUGH MOST
OF THE WORK WEEK. LOW (LESS THAN 25%) FOR SHOWERS LATE WEEK
NEAR THE US HIGHWAY 20 CORRIDOR.
- WARM AND DRY CONDITIONS AND OCCASIONALLY GUSTY AFTERNOON WINDS
COULD BRING SOME FIRE WEATHER CONCERNS AS GRASSES DRY OUT.
- WIDESPREAD RAIN CHANCES LOOK TO RETURN LATE NEXT WEEKEND AND
EARLY NEXT WEEK, BUT CONFIDENCE IN DETAILS REMAINS LOW (LESS
THAN 30%).
UPDATE
ISSUED AT 914 PM CDT MON OCT 5 2026
STILL A FEW LOCATIONS SEEING SOUTH WINDS GUSTING 20-25 MPH EARLY
THIS EVENING, BUT GUSTS ARE LOWER AND LESS WIDESPREAD THAN WE SAW
PRIOR TO SUNSET. THESE SPORADIC GUSTS MAY CONTINUE INTO THE LATE
EVENING, BUT FOR MOST LOCATIONS, GUSTINESS SHOULD DIMINISH AS
TEMPERATURES CONTINUE TO COOL AND THE SURFACE-BASED INVERSION
STRENGTHENS. THE EXCEPTION WILL BE ALONG AND DOWNSTREAM OF OUR
HIGHER ELEVATION AREAS IN SOUTH-CENTRAL SOUTH DAKOTA AND SOUTHWEST
MINNESOTA WHERE A LOW LEVEL JET MAY HELP MAINTAIN OCCASIONAL GUSTS
IN THE 20-30 MPH RANGE.
OVERALL, PREVIOUS FORECAST IS ON TRACK AND WILL CONTINUE TO ADJUST
FOR RECENT NBM COOL/MOIST BIAS BY BLENDING WARMER/DRIER GUIDANCE
INTO DAYTIME TEMPERATURES/DEW POINTS, RESPECTIVELY. THE MOIST BIAS
ALSO SEEMS TO HAVE SOME IMPACT ON NIGHTTIME LOWS, ESPECIALLY ON
THE CLEAR SKY/LIGHT WIND NIGHTS OF LATE. AS SUCH, WILL NUDGE LOW
TEMPERATURES TOWARD THE COOLER SIDE OF GUIDANCE FOR AT LEAST THE
NEXT COUPLE OF NIGHTS.
DISCUSSION
ISSUED AT 235 PM CDT MON OCT 5 2026
REST OF TODAY/TONIGHT: SHAPING UP TO BE ANOTHER GORGEOUS EARLY
OCTOBER DAY WITH TEMPERATURES IN THE 70S AND LOWER 80S. SURFACE HIGH
PRESSURE SLIDES EAST TODAY, WITH TIGHTENING SPG AHEAD OF DEVELOPING
TROUGH ACROSS THE WESTERN DAKOTAS AND SOUTHERN CANADA, WERE SEEING
GUSTS 25-35 MPH. SOME GUSTS AROUND 40 MPH POSSIBLE IN SOUTH CENTRAL
SD. SOUTHERLY FLOW AND WAA CONTINUES TO KEEP CONDITIONS WARMER AND
DRIER, SO RAISED HIGHS AND LOWERED DEW POINTS AGAIN FOR TODAY AS NBM
REMAINS TOO COOL/MOIST. WARMER TEMPERATURES, DRY CONDITIONS, AND
STRONGER WINDS COULD LEAD TO SOME VERY LOCALLY ELEVATED FIRE
CONCERNS THIS AFTERNOON AND EARLY EVENING FOR ANYWHERE FUELS HAVE
BEGUN TO DRY.
WEAK MID LEVEL WAVE MOVES THROUGH THIS EVENING INTO TONIGHT. BREEZY
CONDITIONS CONTINUE INTO THE OVERNIGHT HOURS, ALTHOUGH SOME GUSTS
AROUND 30 MPH REMAIN POSSIBLE NEAR/ALONG THE BUFFALO RIDGE WITH THE
LLJ INCREASING. MAY SEE SOME LOWER CLOUDS DEVELOP OVERNIGHT AHEAD OF
A BOUNDARY BUT NO PRECIPITATION IS EXPECTED. LOWS TONIGHT REMAIN
MILD, ONLY FALLING INTO THE LOWER AND MID 50S.
TUESDAY-WEDNESDAY: NORTHWESTERLY FLOW ALOFT PROMOTES A COUPLE OF
WEAK WAVES THROUGH THE NORTHERN AND CENTRAL PLAINS; HOWEVER, LACK OF
MOISTURE KEEPS DRY CONDITIONS IN PLACE. SURFACE BOUNDARY CONTINUES
TO SLIDE EAST DURING THE DAY TUESDAY INTO THE EVENING, WITH HIGH
PRESSURE MOVING IN FOR WEDNESDAY.
CONTINUED THE TREND OF RAISING HIGHS AND LOWERING LOWS AND DEW
POINTS FROM THE NBM GIVEN THE CONTINUED COOL AND WET BIAS. CONSSHORT
IN ADDITION TO THE 90TH (HIGHER) AND 10TH (LOWER) NBM PERCENTILES
WERE INCORPORATED IN TO MAKE THOSE CHANGES. HIGHS NEAR AND ABOVE 80
FOR MOST OF THE AREA TUESDAY, WHICH IS ABOUT 10-15 DEGREES ABOVE
SEASONAL AVERAGES. SLIGHTLY COOLER WEDNESDAY THANKS TO MORE
NORTHWESTERLY SURFACE FLOW AND CAA. HIGHS IN THE 70S AND LOWS IN THE
UPPER 40S AND LOWER 50S.
THURSDAY-FRIDAY: SURFACE HIGH SLIDES EAST THURSDAY, WITH CONTINUED
NORTHWESTERLY FLOW ALOFT. BY THURSDAY NIGHT, MOST GUIDANCE SHOWS A
SURFACE WARM FRONT MOVE NORTH. GUIDANCE IS SPLIT ON THE TRACK AND
STRENGTH OF ANY LOWER AND MID LEVEL WAVES THROUGH FRIDAY, SO
CONFIDENCE IS LOWER DURING THIS TIME. IN ADDITION TO TIMING AND
TRACK DIFFERENCES, NEXT BIGGEST QUESTION IS THE DEPTH OF ANY
MOISTURE RETURN. GFS/GEFS REMAIN MORE BULLISH ON THE POTENTIAL FOR
MEASURABLE PRECIPITATION, WITH MODERATE TO HIGH CHANCES (OVER 40%),
WITH THE ECMWF ENSEMBLE LOWER (40% OR LESS). GEFS ALSO HAS THE
HIGHEST (30% OR LESS) PROBABILITY OF A TENTH OF AN INCH OF RAIN WITH
OTHER ENSEMBLES EVEN LOWER. TEMPERATURES GENERALLY NEAR TO ABOVE
NORMAL.
THE WEEKEND/EARLY NEXT WEEK: ALTHOUGH GUIDANCE VARIES ON THE
DETAILS, ALL DETERMINISTIC MODELS POINT TO A SHIFT IN THE PATTERN
THROUGH NEXT WEEKEND AND INTO EARLY NEXT WEEK. A QUICK SHORT WAVE
MOVES THROUGH EARLY IN THE WEEKEND. BY SUNDAY, RIDGING ALOFT SHIFTS
EAST WITH TROUGHING DIGGING INTO THE WESTERN CONUS, BRINGING
SOUTHWESTERLY FLOW TO THE REGION. LOW PRESSURE STRENGTHENS AND MOVES
EAST INTO THE EARLY PART OF THE WEEK BRINGING MORE WIDESPREAD
PRECIPITATION CHANCES. ENSEMBLE PROBABILITIES FROM THE GFS AND ECMWF
SHOW MODERATE TO HIGH (OVER 50%) CHANCES FOR AT LEAST A TENTH OF AN
INCH OF PRECIPITATION INTO EARLY TUESDAY.
AVIATION /00Z TAFS THROUGH 00Z WEDNESDAY/
ISSUED AT 640 PM CDT MON OCT 5 2026
SOUTH WINDS GUSTING 20-25KT WILL DIMINISH WITHIN 2-3 HOURS AFTER
SUNSET IN MOST LOCATIONS TONIGHT. HOWEVER, A SOUTHWESTERLY LOW
LEVEL JET WILL MAINTAIN MODERATE GUSTS IN OUR HIGHER ELEVATIONS,
NAMELY SOUTHWEST MINNESOTA AND SOUTH-CENTRAL SOUTH DAKOTA,
THROUGH THE NIGHTTIME HOURS.
THIS LOW LEVEL JET WILL ALSO RESULT IN A PERIOD OF LOW LEVEL
WIND SHEAR AT TAF LOCATIONS AS IT SHIFTS EAST ACROSS THE REGION
OVERNIGHT. THE LOW LEVEL WIND JET AND ASSOCIATED WIND SHEAR WILL
DECREASE BY 13Z-14Z, WITH LESS GUSTY WINDS GRADUALLY TURNING TO
THE WEST AND NORTHWEST ON TUESDAY AS A WEAK BOUNDARY MOVES EAST.
VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD.
FSD WATCHES/WARNINGS/ADVISORIES
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
UPDATE...JH
DISCUSSION...SG
AVIATION...JH
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