639
FXUS63 KFSD 050820
AFDFSD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
320 AM CDT MON OCT 5 2026
KEY MESSAGES
- AN EXTENDED PERIOD OF WARM AND DRY CONDITIONS CONTINUES FOR
MUCH OF THE WORK WEEK.
- WARM TEMPERATURES AND OCCASIONALLY GUSTY AFTERNOON WINDS COULD
BRING SOME FIRE WEATHER CONCERNS AS FINE FUELS START DRYING
OUT.
- RAIN CHANCES MAY RETURN NEXT WEEKEND, BUT CONFIDENCE IN
DETAILS IS LOW (LESS THAN 20%).
UPDATE
ISSUED AT 316 AM CDT MON OCT 5 2026
TAKING A LOOK ACROSS THE AREA, MOSTLY CLEAR CONDITIONS CONTINUE THIS
MORNING AS A SURFACE HIGH GRADUALLY PUSHES EASTWARDS. AS WE HEAD
INTO THE START OF THE WORK WEEK, ANOTHER WARM AND BREEZY DAY IS
AHEAD. STARTING WITH THE SURFACE WINDS, WE'RE STILL ON TRACK FOR
INCREASING SOUTHERLY WINDS AS THE SPG TIGHTENS AROUND DAYBREAK. THIS
WILL LEAD TO WIND GUSTS RECURRINGLY APPROACHING THE 25-35 MPH
RANGE THROUGH THE EARLY EVENING MAINLY ALONG AND WEST OF I-29.
OTHERWISE, TEMPERATURES WILL CONTINUE TO FOLLOW A WARMING TREND
AS A WARM FRONT LIFTS THROUGH LEADING TO TEMPERATURES IN THE 70S
TO LOW 80S WITH THE WARMEST CONDITIONS WEST OF THE JAMES RIVER
VALLEY. CONTINUED THE TREND OF INCREASING OUR HIGHS AND DECREASING
DEW POINTS GIVEN THE NBMS COOL AND MOIST BIAS. LOOKING AHEAD, A
COLD FRONT WILL SWING THROUGH THE AREA STARTING TUESDAY MORNING.
HOWEVER, PRECIPITATION CHANCES ARE EXPECTED TO BE LOW (<20%)
THROUGH THE MIDWEEK.
DISCUSSION
ISSUED AT 228 PM CDT SUN OCT 4 2026
REST OF TODAY/TONIGHT: HIGH PRESSURE CONTINUES THIS AFTERNOON AND
EVENING LEADING TO AN ABSOLUTELY GORGEOUS EARLY OCTOBER DAY. SKIES
HAVE REMAINED MOSTLY CLEAR WITH A FEW HIGH CLOUDS ALONG THE MO
VALLEY. LIGHT AND VARIABLE WINDS WITH TEMPERATURES WARMING INTO THE
60S AND LOWER 70S. CONTINUED THE TREND OF THE PREVIOUS SHIFTS TO
RAISE TEMPERATURES AND LOWER DEW POINTS FROM THE NBM GIVEN RECENT
COOL/WET BIAS.
HIGH PRESSURE CONTINUES TO SLIDE EAST THIS EVENING AND OVERNIGHT,
WHICH ALLOWS SOUTHERLY FLOW TO RETURN THE AREA, ESPECIALLY WEST OF I-
29. SLIGHTLY ADJUSTED TEMPERATURES AS WE MAY STAY A BIT WARMER IN
THIS AREA. WINDS INCREASE OVERNIGHT AS THE SPG COMPRESSES BETWEEN
DEPARTING HIGH PRESSURE AND THE INCOMING FRONT MONDAY. LOWS TONIGHT
FALL INTO THE 40S AND 50S, COOLER IN THE EAST WITH CLEAR SKIES AND
LIGHT WINDS WHILE WARMER LOWS EXPECTED IN THE WEST WITH THE QUICKER
RETURN OF SOUTHERLY FLOW.
MONDAY: BASED ON THE RECENT BIAS IN THE BLEND, RAISED TEMPERATURES
AND LOWERED DEW POINTS A TOUCH FOR THE AFTERNOON/EVENING HOURS. SOME
LOCATIONS ACROSS SOUTH CENTRAL SD SHOULD WARM NEAR 80 DEGREES,
ESPECIALLY AS SOUTHERLY FLOW AND WAA INCREASE. WINDS STRENGTHEN AS
WELL, WITH GUSTS REACHING 40 MPH IN SOUTH CENTRAL SD WITH 25-35 MPH
GUSTS COMMON ELSEWHERE. WILL HAVE TO WATCH FOR STRONGER GUSTS IN THE
HIGHER ELEVATIONS OVERNIGHT INTO TUESDAY MORNING WITH THE LLJ. HIGHS
IN THE 70S FOR MOST (OUTSIDE OF SOUTH CENTRAL SD). LOWS MONDAY NIGHT
REMAIN IN THE 50S.
TUESDAY-WEDNESDAY: MID LEVEL WAVE AND SURFACE TROUGH SLIDE THROUGH
TUESDAY MORNING. EXPECT DRY CONDITIONS WITH A LACK OF APPRECIABLE
MOISTURE. NORTHWESTERLY FLOW ALOFT AND TUESDAY AT THE SURFACE MAY
KEEP TEMPERATURES A COUPLE OF DEGREES COOLER ON TUESDAY, BUT STILL
ABOVE AVERAGE. STRONGER PUSH OF CAA WITH ANOTHER MID LEVEL WAVE
THROUGH THE NORTHWESTERLY FLOW COOLS TEMPERATURES SLIGHTLY AGAIN ON
WEDNESDAY. HIGHS IN THE 70S TO NEAR 80 (TUESDAY) AND 70S (WEDNESDAY)
WITH LOWS IN THE 40S AND 50S.
THURSDAY-FRIDAY: NORTHWESTERLY FLOW REMAINS OVER THE CENTRAL US AS
RIDGING SLOWLY BREAKS DOWN OVER THE WESTERN US BY THE END OF THE
WEEK. A COUPLE OF WAVES MOVE THROUGH DURING THIS TIME, BRINGING SOME
LOW END PRECIPITATION CHANCES. DETERMINISTIC AND ENSEMBLE GUIDANCE
HAS BACKED OFF A BIT ON THE POTENTIAL FOR PRECIPITATION THURSDAY
WITH LESS CERTAINTY IN THE PATTERN AND LOCATION OF ANY ELEVATED
FRONTS. GIVEN THE UNCERTAINTY, LEFT THE NBM FOR NOW.
AS FOR FRIDAY, GUIDANCE IS IN A BIT BETTER AGREEMENT WITH A SURFACE
WARM FRONT LIFTING NORTH AND A MORE DEFINED 700 MB WAVE AS FLOW
ALOFT SHIFTS WESTERLY. LOWER LEVEL MOISTURE IS BETTER THURSDAY NIGHT
INTO FRIDAY THAN THURSDAY MORNING/AFTERNOON WITH MORE SOUTHEASTERLY
FLOW. HOWEVER, ENSEMBLE PROBABILITY FOR MORE THAN 0.01" OF RAIN IN A
24 HOUR PERIOD REMAINS LOW, AT 25% OR LESS. CONFIDENCE IS LOW GIVEN
QUESTIONS ABOUT FORCING. QUITE A BIT OF UNCERTAINTY IN TEMPERATURES
AS WELL, WITH A 10 OR MORE DEGREE SPREAD BETWEEN THE DETERMINISTIC
ECMWF (WARMER) AND THE GFS (COOLER). BREEZY CONDITIONS RETURN FRIDAY.
NEXT WEEKEND: PATTERN SHIFT CONTINUES INTO NEXT WEEKEND WITH SPLIT
MID AND UPPER LEVEL FLOW. EXPECT WARMER TEMPERATURES WITH
SOUTHWESTERLY FLOW. A BREEZY TO GUSTY WEEKEND IS EXPECTED, WITH THE
STRONGEST WINDS ON SATURDAY. GUIDANCE IS QUITE VARIED ON WHEN/WHERE
ANY PRECIPITATION CHANCES WOULD BE, WITH THE GFS QUICKEST WITH QPF.
ENSEMBLE PROBABILITIES OF 24 HOUR PRECIPITATION OF 0.10" ARE LOW (AS
HIGH AS 30%) INTO EARLY MONDAY MORNING.
AVIATION /00Z TAFS THROUGH 00Z TUESDAY/
ISSUED AT 959 PM CDT SUN OCT 4 2026
VFR CONDITIONS WITH LIGHT WINDS CONTINUE THROUGH DAYBREAK. A
SCATTERED TO BROKEN MID-LVL CLOUD FIELD WILL DEVELOP ALONG AND
NORTH OF I-90 THIS MORNING, GRADUALLY MOVING EAST INTO MINNESOTA
BY MID-DAY MONDAY. A VERY LIMITED RISK FOR SHALLOW VALLEY,
RIVER, LAKE FOG WILL CONTINUE THROUGH DAYBREAK.
SOUTHEASTERLY WINDS INCREASE BY MID-MORNING, TURNING SOUTHERLY
AND GUSTING TO 25 KNOTS AT TIMES IN THE AFTERNOON. SKIES WILL
REMAIN CLEAR INTO MONDAY EVENING, WITH A GUSTY SOUTHERLY WIND
PERSISTING.
FSD WATCHES/WARNINGS/ADVISORIES
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
UPDATE...05
DISCUSSION...SG
AVIATION...DUX
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