721
FXUS63 KFSD 120149
AFDFSD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
849 PM CDT SUN OCT 11 2026
KEY MESSAGES
- PATCHY FOG MAY BUILD INTO THE BUFFALO RIDGE TONIGHT. SOME
UNCERTAINTY REMAINS, BUT BE PREPARED TO FOLLOW THE NECESSARY
SAFETY PRECAUTIONS SHOULD IT DEVELOP.
- EXTREME TEMPERATURE RANGES MONDAY: A STALLED COLD FRONT WILL
CREATE A SHARP CONTRACT IN TEMPERATURES MONDAY. 50S ARE
POSSIBLE NEAR HURON, WHILE THE 80S WILL BE LIKELY NEAR SIOUX
CITY/STORM LAKE.
- DRY MID-WEEK WITH RAIN RETURNING THURSDAY: NEAR NORMAL
TEMPERATURES AND DRY CONDITIONS LIKELY THROUGH WEDNESDAY.
SCATTERED RAIN BY THURSDAY WITH A 60% PROBABILITY OF GREATER
THAN 0.10" OF RAIN BY FRIDAY.
- TURNING COLDER: TEMPERATURES INTO NEXT WEEKEND FALL BELOW
NORMAL INTO THE 50S.
UPDATE
ISSUED AT 845 PM CDT SUN OCT 11 2026
A COLD FRONT CONTINUES TO PUSH THROUGH THE FORECAST AREA THIS
EVENING. THE FRONT IS CURRENTLY VISIBLE ON SATELLITE IMAGERY AND MAY
BEGIN TO SLOW DOWN SOON BEFORE STALLING FOR THE REST OF THE NIGHT.
THIS WILL LEAD TO A WIDE RANGE FOR LOW TEMPERATURES AS LOCATIONS
TOWARDS CENTRAL AND SOUTH CENTRAL SOUTH DAKOTA LOOK TO SEE LOWS FALL
TO THE 50S WHILE AREAS AHEAD OF THE FRONT, MAINLY ACROSS NORTHWEST
IOWA, WILL SEE MILD LOWS IN THE 60S. LOW LEVEL STRATUS IS ALSO
BEGINNING TO PUSH INTO THE AREA FROM THE WEST. WHILE THE STRATUS
SHOULD STAY ELEVATED, SOME MODELS SUGGEST THAT PATCHY FOG COULD
DEVELOP ALONG THE BUFFALO RIDGE IN SOUTHWEST MINNESOTA. THERE IS
CURRENTLY SOME PATCHY FOG ALONG THE RIDGE UP INTO NORTHEAST SOUTH
DAKOTA, SO WILL WATCH TRENDS IN THIS FOGS POTENTIAL THROUGH THE REST
OF THE NIGHT.
MONDAY WILL BE THE LAST DAY WITH HIGHS IN THE 80S FOR PARTS OF
SOUTHWEST MINNESOTA, FAR NORTHEAST NEBRASKA, FAR SOUTHEAST SOUTH
DAKOTA, AND NORTHWEST IOWA AS THE PREVIOUSLY MENTIONED FRONT WILL
FULLY PUSH THROUGH THE FORECAST AREA. LOCATIONS TO THE WEST OF
THE BOUNDARY WILL SEE COOLER HIGHS, ONLY WARMING TO THE 60S AND
70S. THIS WILL RESULT IN A LARGE TEMPERATURE GRADIENT ACROSS THE
FORECAST AREA. THERE STILL REMAINS THE CHANCE (15-20%) FOR
LIGHT RAIN SHOWERS PRIMARILY IN THE MORNING BEFORE ANY CHANCE
FOR LIGHT RAIN DIMINISHES FOR THE AFTERNOON AND EVENING
TIMEFRAMES. LOW TEMPERATURES WILL BE NEAR SEASONABLE TO ABOVE
AVERAGE IN THE 40S AND 50S.
SURFACE RIDGING WILL PUSH INTO THE NORTHERN PLAINS ON TUESDAY,
KEEPING DRY CONDITIONS FOR THE DAY. THIS WILL PROVIDE NORTHERLY
WINDS FOR THE DAY, KEEPING HIGH TEMPERATURES CLOSER TO SEASONABLE IN
THE 60S TO PERHAPS LOW 70S.
DISCUSSION
ISSUED AT 1242 PM CDT SUN OCT 11 2026
THIS AFTERNOON: ANOTHER VERY WARM DAY ACROSS THE TRI-STATE AREA AS
TEMPERATURES CONTINUE TO RISE INTO THE 80S. FURTHER WEST HOWEVER, A
FRONTAL BOUNDARY HAS STALLED FROM GREGORY TO NEAR HURON AND NORTH OF
WATERTOWN. NORTHWESTERLY DRAINAGE WINDS ARE DOING WHAT THEY LIKE TO
DO AND KEEPING TEMPERATURES COOLER WITH CONSIDERABLE STRATUS THROUGH
CENTRAL AND NORTHERN SOUTH DAKOTA. THIS FRONT WILL STAY NEARLY
STATIONARY INTO LATE AFTERNOON, PERHAPS SLIDING A BIT FURTHER
SOUTHEAST INTO THE MO RIVER VALLEY. TEMPERATURES WILL LIKELY FALL
SHORT OF RECORDS IN MOST LOCATIONS, HOWEVER GUSTY WINDS GREATER THAN
25 MPH IN NW IOWA COULD PROMOTE ELEVATED AGRICULTURAL RELATED FIRE
RISKS TO SUNSET.
TONIGHT: MY CONFIDENCE IS RISING THAT THE COLD FRONT WILL CONTINUE
SLIPPING SOUTHEAST THROUGH THE OVERNIGHT HOURS, THOUGH JUST HOW FAR
SOUTHEAST IS STILL IN QUESTION. SHOULD THE FRONT REACH INTO NW IOWA
AND NE NEBRASKA, THEN A SIGNIFICANT AMOUNT OF COOLER AIR MAY DRAIN
SOUTHEAST KNOCKING TEMPERATURES FURTHER INTO THE UPPER 40S TO LOWER
50S. ANTICIPATING STRATUS TO REFORM LATE TONIGHT, ESPECIALLY IN
AREAS FROM GREGORY TO BROOKINGS AND MARSHALL WHERE COOL AIR WILL
CONTINUE TO DRAIN.
MONDAY: WE'RE LIKELY TO START THE DAY WITH QUITE A BIT OF STRATUS IN
THE CWA, POTENTIALLY AS FAR SE AS SIOUX FALLS. A MID-LVL SHORTWAVE
TRACKING THROUGH THE DAKOTAS MID-MORNING TO MID-DAY WILL ACCOMPLISH
TWO TASKS, LIFTING THE COLD FRONT VERY SLIGHTLY BACK NORTHWEST, BUT
ALSO PINNING IN COOLER AND MOIST AIR IN THE DRAINAGE FLOW ON THE
BACKSIDE OF THE FRONT. THE END RESULT MAY BE AN EXTREME TEMPERATURE
GRADIENT OF THE 80S IN SIOUX CITY AND STORM LAKE/SPENCER, TO THE 50S
IN HURON. LATEST NBM WILL NOT CATCH THESE MESOSCALE TEMPERATURE
GRADIENTS, SO HAVE ADJUSTED AND BLENDED IN HIGHER RESOLUTION
GUIDANCE. HOWEVER THE GRADIENT MAY STILL BE MORE DEFINED THAN THE
CURRENT FORECAST SUGGESTS. WHILE MOISTURE IS LACKING ALOFT, A FEW
SPRINKLES TO LIGHT RAIN SHOWERS COULD DEVELOP THROUGH CENTRAL AND
NORTHEASTERN SODAK IN THE DAY. HAVE ALSO MANUALLY PUSHED UP STRATUS
THROUGH MID-DAY WEST OF I-29.
MONDAY NIGHT: NORTHWEST WINDS CONTINUE THROUGH THE OVERNIGHT HOURS
INTO TUESDAY AS QUITE A BIT OF COOLER CANADIAN AIR FILTERS SOUTHEAST
THIS WILL PUSH OVERNIGHT LOWS INTO THE 40S IN SEVERAL AREAS WITH
SOME QUESTIONS ON CLOUD COVER POTENTIAL LINGERING.
TUESDAY-WEDNESDAY: LATEST FORECAST GUIDANCE CONTINUES TO TREND DRIER
WITH PRECIPITATION CHANCES DURING THE MIDDLE OF THE WEEK. THE
AMPLITUDE OF MID-LVL RIDGING THROUGH THE CENTRAL AND SOUTHERN PLAINS
MAY BE STRONG ENOUGH TO PREVENT ANY CUT OFF ENERGY IN THE FOUR
CORNERS FROM MOVING EASTWARD AS QUICK AS GUIDANCE HINTED YESTERDAY.
THE END RESULT WILL BE DRY CONDITIONS TUESDAY AND WEDNESDAY WITH
HIGHS NEAR OR EVEN SLIGHTLY ABOVE SEASONAL NORMALS.
THURSDAY-SATURDAY: THE CUTOFF ENERGY IN THE FOUR CORNERS MAY
EVENTUALLY PHASE WITH A SECONDARY NORTHERN STREAM TROUGH CROSSING
THE CANADIAN ROCKIES BY THURSDAY. INCREASING WARM ADVECTION AND
MOISTURE RETURN AHEAD OF THIS TROUGH COMBINED WITH MID-LVL DPVA MAY
RESULT IN THE DEVELOPMENT OF SCATTERED RAIN BY THURSDAY. LATEST
ENSEMBLE PROBABILITIES CONTINUE TO SUGGEST LIGHT RAIN AMOUNTS WITH
60-70% PROBABILITIES OF >0.10", BUT ONLY 30% PROBABILITIES OF MORE
THAN 0.50". HIGH PRESSURE WILL QUICKLY SWING SOUTHEAST INTO THE
PLAINS FOR FRIDAY AND THE UPCOMING WEEKEND. TEMPERATURES FOR AT
LEAST A COUPLE DAYS MAY COOL BELOW SEASONAL NORMALS, BUT ONLY
SLIGHTLY.
AVIATION /00Z TAFS THROUGH 00Z TUESDAY/
ISSUED AT 621 PM CDT SUN OCT 11 2026
LATEST SATELLITE IMAGERY SHOWS HIGH LEVEL CIRRUS PUSHING THROUGH THE
FORECAST AREA ALONG WITH MVFR STRATUS DRAPED ACROSS THE WESTERN
FRINGES OF THE AREA. A COLD FRONT IS CURRENTLY PUSHING THROUGH THE
AREA AS WELL, TURNING THE WINDS TO OUT OF THE NORTHWEST IN ITS WAKE.
SHOULD SEE THE FRONT SLOWLY PUSH THROUGH THE AREA TONIGHT IF NOT
STALL OUT ALONG AND EAST OF A KMML TO KFSD TO KYKN LINE. THIS
EASTWARD PROGRESSION OF THE FRONT WILL PULL THE MVFR STRATUS
EASTWARDS. KHON IS EXPECTED TO SEE MVFR/IFR CEILINGS TONIGHT BUT
CONFIDENCE DECREASES WITH EASTERN EXTENT. HAVE INCLUDED SCATTERED
IFR CEILINGS AT KFSD TOMORROW MORNING FOR NOW. WILL BUMP UP COVERAGE
IF CONFIDENCE IN LOWER CEILINGS FOR THE TERMINAL INCREASES. LOW
LEVEL WIND SHEAR (LLWS) IS ALSO EXPECTED AT KSUX TONIGHT.
WHILE THE LLWS WILL CEASE AND THE STRATUS GENERALLY LIFTS TOMORROW
MORNING, KHON COULD STILL SEE LOWER CEILINGS LINGER FOR THE REST OF
THE TAF PERIOD. ASIDE FROM CEILINGS, WINDS WILL BE TURNING
NORTHWESTERLY THROUGH THE DAY TOMORROW TO END THE PERIOD.
FSD WATCHES/WARNINGS/ADVISORIES
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
UPDATE...MEYERS
DISCUSSION...DUX
AVIATION...MEYERS
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