243
FXUS63 KFSD 061742
AFDFSD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1242 PM CDT MON APR 6 2026
KEY MESSAGES
- LIGHT RAIN/SNOW WILL CONTINUE TO DRIFT THROUGH THE MO RIVER
VALLEY INTO THE AFTERNOON. NO ACCUMULATION EXPECTED.
- NARROW SNOW BAND EXPECTED NEAR OR MORE LIKELY SOUTH OF
HIGHWAY 20 AFTER DARK. ANY TRAVEL SOUTH OF SIOUX CITY TOWARDS
OMAHA OR DES MOINES MAY BE IMPACTED.
- A GRADUAL WARMUP THROUGH THE SECOND HALF OF THE WEEK WITH
TEMPERATURES RETURNING ABOVE NORMAL, AND EXCEEDING NORMAL
NEXT WEEKEND.
- A FEW SHOWERS MOVE THROUGH THE AREA WEDNESDAY AND AGAIN
THURSDAY NIGHT, WITH SLIGHTLY HIGHER SHOWER AND THUNDERSTORM
CHANCES THIS WEEKEND. A FEW STRONGER STORMS COULD BE POSSIBLE
BY SUNDAY.
DISCUSSION
ISSUED AT 1239 PM CDT MON APR 6 2026
THIS AFTERNOON: A VERY LIGHT RAIN/SNOW MIX DRIVEN BY 650:700 MB
FRONTOGENESIS MAY CONTINUE ALONG THE MO RIVER VALLEY THIS AFTERNOON,
THOUGH IN MOST AREAS, A DRY SUBCLOUD LAYER FOCUSED AROUND 850 MB
WILL LIMIT ANY ACCUMULATION. ELSEWHERE, VARIABLE CLOUD COVER
CONTINUES AS TEMPERATURES REMAIN 10+ DEGREES BELOW NORMAL.
TONIGHT: CAMS REALLY PICKING UP ON A GREAT NW TO SE ORIENTED
MESOSCALE BANDED FEATURE DEVELOPING AFTER DARK, MOSTLY IMPACTING
AREAS ALONG OR SOUTH OF HIGHWAY 20. GIVEN INSTABILITY WITHIN THE
BAND, ANY TRAVELERS HEADING SOUTH OF SIOUX CITY TOWARDS OMAHA WILL
NEED TO BE PREPARED FOR TRAVEL IMPACTS THROUGH DAYBREAK. THERE
REMAINS SOME VARIABILITY IN THE LOCATION OF THE FRONTOGENESIS
ASSOCIATED WITH THIS PRECIPITATION, WITH HRRR FOCUSED TOO FAR
NORTH MOST OF THIS MORNING. HAVE FAVORED THE NAM/RAP FOR UPDATES
OVERNIGHT, BUT WE'LL NEED TO WATCH THIS CLOSELY. FURTHER NORTH,
AN EASTERLY WIND AND SCATTERED CLOUD LAYER WILL ALLOW
TEMPERATURES TO DROP INTO THE 20S, SOME 10 DEGREE BELOW NORMAL.
TUESDAY: WEAK MID-LVL FLOW WILL KEEP VORTICITY STREAMING THROUGH
THE CENTRAL PLAINS ON TUESDAY. EVENTUALLY, 925:850 MB WINDS WILL
TURN SOUTHERLY, ALLOWING WARM ADVECTION TO SPREAD BACK NORTHWARD.
EVENTUALLY A DEEPER LOW LVL MOISTURE FIELD WILL TRACK NORTH, AND
WITH PERSISTENT LOW-LVL WARM ADVECTION, CAN'T RULE OUT VERY LIGHT
SNOW, DRIZZLE, OR FREEZING DRIZZLE IN THE AFTERNOON. HAVE WENT WITH
A HIGHER POP BUT LOW QPF FORECAST. THE ABUNDANCE OF CLOUDS SHOULD
AGAIN HOLD TEMPERATURES BACK BELOW NORMAL, WITH MOST AREAS
STRUGGLING TO REACH 40 DEGREES.
WEDNESDAY: BY WEDNESDAY, WE'LL BEGIN TO SEE A STRONGER UPPER TROUGH
TRACK EASTWARD THROUGH THE CANADIAN ROCKIES, ALLOWING A FRONTAL
BOUNDARY TO FORM ACROSS THE WESTERN DAKOTAS. A FEW LINGERING SPITS
MAY CONTINUE INTO WEDNESDAY MORNING AHEAD OF THIS BOUNDARY, BUT THE
GREATER STORY WILL BE THE ADVECTION OF MUCH WARMER LOW-LVL AIR
NORTHWARD. LATEST GUIDANCE HAS TIMED THE ARRIVAL OF THIS FRONT
SLIGHTLY FASTER THAN PREVIOUS SOLUTIONS, MEANING LOW-LVL MOISTURE
WILL BE SCOURED EAST QUICKLY IN THE DAY. IN THE WAKE OF THIS FRONT,
A WARM WESTERLY DOWNSLOPE WIND WILL BOTH LOWER RH VALUES INTO THE 25
TO 35 PERCENT RANGE, BUT ALLOW PROMOTE HIGHS IN THE LOWER 60S
AND GUSTY 30 MPH WINDS AT TIMES. THIS COMBINATION, ALONG WITH
DRYING OUT FINE FUELS MAY LEAD TO ELEVATED FIRE DANGER IN THE
AFTERNOON.
THURSDAY-FRIDAY: THE AFOREMENTIONED UPPER WAVE TRACKS INTO THE GREAT
LAKES BY THE END OF THE WEEK, PUSHING COOLER CANADIAN AIR SOUTHWARD
INTO THE PLAINS. HIGH TEMPERATURES ONLY RETREAT SLIGHTLY INTO THE
MIDDLE 50S, NEAR CLIMATOLOGICAL NORMALS. MEDIUM RANGE MODELS BEGIN
TO DIVERGE A BIT AT THE END OF THE WEEK, SUGGESTING AN INCREASING
RISK OF SHOWERS AND ISOLATED THUNDERSTORMS THURSDAY NIGHT INTO
FRIDAY OVER THE SOUTHEASTERN 1/3 OF THE CWA. THE LATEST NBM WOULD
SUGGEST AROUND A 50% PROBABILITY OF >0.10" OF QPF ALONG AND
SOUTHEAST OF A LINE FROM YANKTON TO JACKSON INTO FRIDAY MORNING. THE
REMAINDER FRIDAY SHOULD BE DRY, AS HIGH PRESSURE ONCE AGAIN PUSHES
DRIER AIR SOUTHEASTWARD.
NEXT WEEKEND: WE'RE CONTINUING TO SEE INCREASED POTENTIAL FOR A
PATTERN SHIFT BY NEXT WEEKEND AND INTO THE FOLLOWING WEEK. MID-LVL
HEIGHTS ARE PROJECTED TO RISE OVER THE SOUTHEASTERN US, ALLOWING
MORE PERSISTENT TROUGHING TO DEVELOP ALONG AND WEST OF THE ROCKIES.
THIS SHIFT IN MID-LVL FLOW SHOULD RESULT IN ABOVE NORMAL
TEMPERATURES AS WELL AS INCREASED SHOWER AND THUNDERSTORM POTENTIAL
ACROSS THE PLAINS INTO NEXT WEEK. THAT SAID, THERE REMAINS QUITE A
BIT OF SPREAD IN TEMPERATURE GUIDANCE FOR SATURDAY AND SUNDAY, WITH
THE DETERMINISTIC NBM PUSHED TOWARDS THE 75TH PERCENTILE. HOWEVER
ON SUNDAY, THE NBM IS SUGGESTING A 10-15 DEGREE SPREAD IN HIGH
TEMPERATURES, WITH THE DETERMINISTIC NEAR THE 25TH PERCENTILE IN THE
MID-70S. SHOULD DEEP SOUTHWESTERLY FLOW DEVELOP, THEN MUCH WARMER
TEMPERATURES INTO THE 80S ARE POSSIBLE.
AS FAR AS PRECIPITATION IS CONCERNED, WE'RE AT LEAST BEGINNING TO
SEE SIGNS OF MORE INSTABILITY TRACKING NORTHEAST OVER THE
WEEKEND GIVEN THE MORE MERIDIONAL LOW-LVL FLOW TRAJECTORIES.
WHILE A GREAT DEAL OF SPREAD CONTINUES IN ENSEMBLE GUIDANCE,
SEVERAL MACHINE LEARNING CONVECTIVE OUTLOOK MODELS ARE
INDICATING RISING POTENTIAL FOR SEVERE STORMS MOVING NORTHWARD
INTO THE PLAINS AND UPPER MIDWEST BY THE END OF THE WEEKEND.
AVIATION /18Z TAFS THROUGH 18Z TUESDAY/
ISSUED AT 1140 AM CDT MON APR 6 2026
IN MOST AREAS VFR CONDITIONS CONTINUE AT MID-DAY AS A LIGHT TO
OCCASIONALLY BREEZY NORTH WIND BEGINS TO TURN TO THE NORTHEAST.
VERY LIGHT RAIN/SNOW MAY LINGER ALONG THE MO RIVER VALLEY
TOWARDS SUX, BUT IN MOST AREAS THIS PRECIPITATION IS NOT
REACHING THE GROUND, BUT INSTEAD IS VISIBLE AS VIRGA.
WE'LL SEE CEILINGS REMAIN AT VFR LEVELS IN THE OVERNIGHT HOURS
AS THE MAIN FOCUS FOR PRECIPITATION SHIFTS SOUTH OF THE
MISSOURI RIVER AND HIGHWAY 20. MODELS SHOW A VERY NARROW SNOW
BAND DEVELOPING AFTER DARK NEAR OR LIKELY SOUTH OF HIGHWAY 20.
AVIATION INTERESTS NEAR SUX WILL NEED TO MONITOR THIS BAND, AS
IT WOULD HAVE IMPACTS IF IT DRIFTS NORTHWARD. ATTM, WILL ONLY
INCLUDE A PROB30 GIVEN BETTER FOCUS TO THE SOUTH.
FSD WATCHES/WARNINGS/ADVISORIES
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
DISCUSSION...DUX
AVIATION...DUX
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