541
FXUS63 KFSD 051938
AFDFSD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
238 PM CDT MON OCT 5 2026
KEY MESSAGES
- BREEZY SOUTHERLY WIND GUSTS 25 TO 35 MPH INTO THE EVENING.
GUSTS AS HIGH AS 40 MPH IN SOUTH CENTRAL SOUTH DAKOTA. WIND
GUSTS 20 TO 30 MPH MAY CONTINUE TONIGHT IN HIGHER ELEVATIONS.
- 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%).
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 /18Z TAFS THROUGH 18Z TUESDAY/
ISSUED AT 1226 PM CDT MON OCT 5 2026
VFR CONDITIONS THROUGH THE PERIOD; HOWEVER, SOME GUIDANCE HINTS
AT SOME LOWER VFR TO UPPER LEVEL MVFR CLOUDS NEAR/EAST OF I-29
LATE TONIGHT INTO EARLY TUESDAY MORNING. THAT SAID, NOT
EXPECTING MORE THAN FEW/SCT COVERAGE AT THIS TIME.
MAIN CONCERN THROUGH THE PERIOD REMAINS WINDS. SOUTHERLY WINDS
GUST THIS AFTERNOON AND EVENING OF 20 TO 30 KNOTS, UP TO 35
KNOTS IN SOUTH CENTRAL SD. WINDS MAY STILL GUST AROUND 25 KNOTS
OVERNIGHT, STRONGER ACROSS THE HIGHER ELEVATIONS OF THE BUFFALO
RIDGE. LLJ STRENGTHENS OVERNIGHT MAINLY ALONG/EAST OF THE JAMES
RIVER WHICH BRINGS LLWS TO AREAS NEAR I-29 AND EAST WHERE THE
LLJ IS STRONGEST. WINDS BEGIN TO SHIFT TO THE WEST/NORTHWEST
THROUGH TUESDAY MORNING AND EARLY AFTERNOON.
FSD WATCHES/WARNINGS/ADVISORIES
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
DISCUSSION...SG
AVIATION...SG
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page