178
FXUS63 KFSD 040156
AFDFSD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
856 PM CDT SAT OCT 3 2026
KEY MESSAGES
- AN EXTENDED PERIOD OF WARM AND DRY CONDITIONS IS EXPECTED FOR
MUCH OF THE UPCOMING WORK WEEK.
- WARM TEMPERATURES AND OCCASIONALLY GUSTY AFTERNOON WINDS COULD
BEGIN LEADING TO FIRE WEATHER CONCERNS AS FINE FUELS BEGIN TO
DRY OUT.
UPDATE
ISSUED AT 849 PM CDT SAT OCT 3 2026
AFTER AN INITIAL FRONTAL BOUNDARY PASSED THROUGH THE REGION LATE
THIS AFTERNOON, WE'RE CONTINUING TO WATCH A SECONDARY BOUNDARY
SURGE SOUTHEAST. THIS SECOND BOUNDARY IS PULLING MUCH DRIER
BOUNDARY LAYER AIR SOUTHEAST, WITH DEW POINTS IN CENTRAL AND
NORTHERN SOUTH DAKOTA IN THE UPPER 30S. THIS DRIER AIR WILL
SPREAD THROUGH THE CWA OVERNIGHT ON A LIGHT NORTHEAST WIND. THE
BIG QUESTION WILL BE IF OVERNIGHT LOWS CONTINUE TO FALL TOWARDS
THESE LOWER DEW POINTS, OR IF SLOWLY INCREASING HIGH LEVEL
CLOUDS ARRIVING BY 3AM HOLD TEMPERATURES UPWARDS. FOR NOW, WILL
LOWER TEMPERATURES SLIGHTLY.
THE NBM HAS HAD BOTH A WET BIAS WITH DEW POINTS AND A COOL BIAS
IN HIGH TEMPERATURES THE PAST FEW DAYS. THIS TREND CONTINUES
INTO SUNDAY AS THERE ARE SIGNS THAT DEW POINTS WILL BE 3 TO 8
DEGREES LOWER THAN EARLIER POPULATED MODEL RUNS. ADDITIONALLY,
WILL HEDGE TOWARDS THE WARMER SIDE OF GUIDANCE AND BY 3-4PM
SUNDAY AN ABSOLUTELY SPECTACULAR DAY WILL BE ONGOING.
NO OTHER MAJOR CHANGES TO THE FORECAST AS WE HEAD INTO NEXT
WEEK. FEEL THERE WILL BE SOME TENDENCY TO REACH HIGHER FOR BOTH
WINDS AND TEMPERATURES MONDAY AND TUESDAY GIVEN ORIENTATION OF
LOW-LVL FLOW. HIGHS MAY CLIMB TOWARDS THE 80S ON TUESDAY.
DISCUSSION
ISSUED AT 217 PM CDT SAT OCT 3 2026
REST OF TODAY/TONIGHT: SPRINKLES/SHOWERS CONTINUE TO MOVE EAST THIS
AFTERNOON, MAINLY ALONG AND NORTH OF I-90. FIRST ROUND OF SHOWERS
WITH THE INITIAL WAA AND THE LLJ CONTINUES TO PUSH EAST OF I-29 THIS
AFTERNOON. THERE'S BEEN ENOUGH MUCAPE (GENERALLY 500 J/KG OR LESS)
FOR SOME LIGHTNING NEAR AND NORTH OF US HWY 14, BUT THIS RISK HAS
QUICKLY DIMINISHED WITH THE LOSS OF THE INSTABILITY. NO LIGHTNING
HAS BEEN OBSERVED IN OUR AREA FOR THE LAST HOUR OR SO, AND THINK
RISK IS NOW < 10% FOR THE REST OF THE AFTERNOON. NEXT AREA OF
SHOWERS ACROSS CENTRAL AND NORTHEASTERN SD IS TIED TO THE MID LEVEL
WAVE AND MOVES THROUGH DURING THE AFTERNOON AND EARLY EVENING HOURS,
AGAIN STAYING MAINLY NORTH OF I-90. WITH DRY SUB CLOUD LAYER AND
HIGH CLOUD BASES, ANY RAINFALL ACCUMULATION REMAINS MINIMAL TODAY.
STRONGEST WINDS HAVE DIMINISHED, SO ALLOWED THE WIND ADVISORY TO
EXPIRE AT 1 PM CDT. EXPECT SOUTHERLY GUSTS AHEAD OF THE FRONT 30-40
MPH THIS AFTERNOON. HAVE ALSO OBSERVED SOME 30-40 MPH GUSTS FROM THE
NORTHWEST JUST BEHIND THE FRONT, WHICH WILL CONTINUE INTO THE
EVENING HOURS. FRONT HAS BEEN MOVING THROUGH A LITTLE MORE QUICKLY
THAN PREVIOUSLY EXPECTED. DESPITE SHOWERS AND BREEZY CONDITIONS,
IT'S A PLEASANT EARLY OCTOBER DAY WITH TEMPS IN THE 60S AND 70S.
SURFACE HIGH PRESSURE BEGINS TO SLIDE IN FROM THE NORTHWEST LATE
TONIGHT. WITH WINDS TAPERING DOWN OVERNIGHT AND CLEARING SKIES,
WOULD NOT BE ENTIRELY SURPRISED TO SEE SOME PATCHY RIVER VALLEY FOG
BY DAYBREAK SUNDAY. HREF PROBABILITY OF VISIBILITY BELOW 5 MILES IS
LOW (LESS THAN 30%) AND VERY ISOLATED, SO KEPT MENTION OUT OF THE
FORECAST FOR NOW. WE'LL FALL INTO THE MID 40S AND LOWER 50S.
SUNDAY: SURFACE HIGH PRESSURE REMAINS OVERHEAD TO END THE WEEKEND,
WITH NEUTRAL TO CAA AND LIGHT NORTHWESTERLY WINDS MOST OF THE DAY.
THIS SHOULD KEEP TEMPERATURES A BIT COOLER FOR MOST OF THE AREA,
WITH HIGHS IN THE MID AND UPPER 60S. LOWS FALL INTO THE MID AND
UPPER 40S AGAIN AS SURFACE HIGH MOVES EAST.
THE UPCOMING WEEK: MID/UPPER LEVEL HIGH PRESSURE REMAINS IN PLACE
THROUGH THE WORK WEEK ACROSS THE SOUTHWESTERN US. THIS KEEPS THE
CENTRAL AND NORTHERN PLAINS IN NORTHWESTERLY FLOW, ALLOWING A FEW
SHORT WAVES TO TRACK ACROSS THE REGION. HIGHS IN THE 60S AND 70S
WITH LOWS GENERALLY IN THE 40S AND 50S.
MONDAY NIGHT INTO TUESDAY SEES A COUPLE OF THESE SUBTLE AND WEAK
WAVES THROUGH, AS WELL AS A COLD FRONT TUESDAY. SOUNDINGS FOR THIS
PERIOD ARE VERY DRY, SO PRECIPITATION IS NOT EXPECTED. MAIN IMPACT
WILL BE BREEZIER WINDS MONDAY AFTERNOON AND NIGHT WITH GUSTS 30-40
MPH AS THE SPG TIGHTENS AHEAD OF THE FRONT. TUESDAY LOOKS TO BE THE
WARMEST DAY OF THE UPCOMING WEEK, ALTHOUGH HOW WARM DEPENDS ON HOW
QUICKLY THE FRONT TRACKS THROUGH.
GUIDANCE IS QUITE VARIED HANDLING THE NEXT SURFACE LOW THURSDAY AND
ANY ASSOCIATED RAIN CHANCES. DETERMINISTIC GFS IS CURRENTLY THE
STRONGEST WITH THIS FEATURE AND WOULD BRING MORE WIDESPREAD
PRECIPITATION CHANCES; HOWEVER, CONFIDENCE IS LOW GIVEN MODEL SPREAD
AND ENSEMBLE PROBABILITY OF MORE THAN A TENTH OF AN INCH LESS THAN
20%, SO HAVE LEFT THE VERY LOW NBM POPS AS IS. TROUGHING BEGINS TO
DIG INTO THE WESTERN US BY NEXT WEEKEND BRINGING THE RETURN OF
SOUTHWESTERLY FLOW AND POSSIBLY MORE PRECIPITATION CHANCES.
AVIATION /00Z TAFS THROUGH 00Z MONDAY/
ISSUED AT 603 PM CDT SAT OCT 3 2026
VFR CONDITIONS ARE EXPECTED INTO SUNDAY. CLOUDS WILL CONTINUE TO
CLEAR WITH A LIGHT NORTHWEST WIND PERSISTING OVERNIGHT. THIS
NORTHWEST WIND SHOULD LIMIT ANY FOG DEVELOPMENT OUTSIDE OF VERY
SHELTERED AREAS IN NW IOWA. HIGH LEVEL CLOUDS ALSO INCREASING
AFTER 3AM WILL LIMIT OVERALL COOLING AND FURTHER REDUCE FOG
POTENTIAL.
LIGHT WINDS AND VFR CONDITIONS ARE EXPECTED THROUGH SUNDAY.
FSD WATCHES/WARNINGS/ADVISORIES
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
UPDATE...DUX
DISCUSSION...SG
AVIATION...DUX
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