536
FXUS63 KFSD 152324
AFDFSD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
624 PM CDT WED APR 15 2026
KEY MESSAGES
- UNSEASONABLY WARM TEMPERATURES, VERY LOW HUMIDITY, AND BREEZY
SOUTHWEST WIND GUSTS LEAD TO A CRITICAL FIRE DANGER THURSDAY.
A RED FLAG WARNING HAS BEEN ISSUED FOR SOUTH CENTRAL AND
SOUTHEAST SOUTH DAKOTA AND FAR NORTHEAST NEBRASKA. ADDITIONAL
FIRE CONCERNS POSSIBLE FRIDAY BUT CONFIDENCE IS LOW.
- A STRONG COLD FRONT MOVES THROUGH THE AREA ON FRIDAY. AHEAD OF
THE FRONT OVER PARTS OF NORTHWEST IOWA AND SOUTHWEST
MINNESOTA, AN ISOLATED SEVERE STORM IS POSSIBLE. BEHIND THE
FRONT, MUCH COOLER AIR MOVES IN AND ANY RAIN MAY BRIEFLY
CHANGE TO A WINTRY MIX AND/OR SNOW NEAR AND NORTH OF HIGHWAY
14 AS PRECIPITATION EXITS THE AREA.
DISCUSSION
ISSUED AT 220 PM CDT WED APR 15 2026
STRONG TO SEVERE THUNDERSTORMS HAVE STAYED SOUTH AND
WEST OF THE AREA THUS FAR TODAY. INSTABILITY HAS BEEN MARGINALLY
SUPPORTIVE OF AT LEAST SOME OCCASIONAL RUMBLES OF THUNDER TODAY, AND
AS WE REACH THE PEAK OF DAYTIME HEATING, A FEW MORE HUNDRED J/KG OF
CAPE WILL DEVELOP. THIS MAY LEAD TO SLIGHTLY BETTER COVERAGE OF
THUNDERSTORMS MAINLY SOUTH OF A SIOUX RAPIDS TO SIOUX CITY, IA LINE,
BUT THE CHANCES FOR SEVERE WEATHER LOOK QUITE LOW. THERE'S STILL
AROUND 45-55 KTS OF BULK SHEAR, SO IF A DECENT UPDRAFT CAN GET GOING
AND SUSTAIN ITSELF, THEN QUARTER SIZED HAIL CANNOT BE RULED OUT.
THIS THREAT ENDS AROUND 6 PM AS STORMS MOVE OFF TO THE EAST. QUIET
WEATHER EXPECTED TONIGHT AS THE MAIN UPPER WAVE RESPONSIBLE FOR THE
RAIN MOVES OFF TO OUR EAST. LOWS TONIGHT DROP TO THE MIDDLE 40S FOR
THE MOST PART ACROSS THE AREA BY THURSDAY MORNING.
WINDS START TURNING MORE SOUTHWESTERLY HEADING INTO THE DAY ON
THURSDAY, WHICH WILL HELP USHER IN WARMER AND DRIER AIR INTO THE
AREA AND LEADING TO CRITICAL FIRE WEATHER CONDITIONS. MORE ON THIS
IN THE FIRE WEATHER DISCUSSION BELOW. FOR THURSDAY NIGHT INTO THE
DAY ON FRIDAY, A DEEP TROUGH EXTENDING FROM THE NORTHERN ROCKIES
INTO THE FOUR CORNERS WILL MOVE THROUGH THE AREA. AT THE SURFACE, A
STRONG COLD FRONT WILL SWEEP ACROSS THE AREA DURING THE DAY ON
FRIDAY. BY 1 PM ON FRIDAY, DETERMINISTIC AND ENSEMBLE GUIDANCE HAS
THE FRONT EITHER JUST EAST OF THE IA/MN HIGHWAY 60 CORRIDOR OR JUST
EAST OF THE FORECAST AREA. THESE FASTER SOLUTIONS WILL LIMIT THE
POTENTIAL FOR SEVERE WEATHER IN OUR AREA AS THE BETTER INSTABILITY
WOULD DEVELOP OFF TO OUR EAST. SO STILL A LOW CONFIDENCE SEVERE
WEATHER FORECAST, BUT A VERY ISOLATED STRONG TO SEVERE STORM STILL
REMAINS POSSIBLE OVER PARTS OF NORTHWEST IOWA AND SOUTHWEST
MINNESOTA EARLY FRIDAY AFTERNOON IF THE COLD FRONT SLOWS DOWN OR A
STORM IS ABLE TO DEVELOP JUST BEFORE THE FRONT CLEARS THE AREA.
COLDER AIR WILL BE RUSHING IN BEHIND THE FRONT AS GUIDANCE IS IN
GOOD AGREEMENT OF A STRONG PUSH OF COLD AIR ADVECTION (CAA)
FOLLOWING THE FRONTAL PASSAGE ON FRIDAY. THIS MEANS FOR MOST OF THE
AREA, THE MORNING WILL BE WARMER THAN THE AFTERNOON, SO DRESS
ACCORDINGLY! WITH THE COLDER AIR MOVING IN, ANY PRECIPITATION
LEFTOVER BEHIND THE FRONTAL PASSAGE COULD TURN TO A WINTRY MIX OR
SNOW AS THE SYSTEM EXITS THE AREA. LATEST GUIDANCE IS TRENDING
TOWARDS OUR AREA DRYING OUT BEFORE THE COLDEST AIR ARRIVES, LIMITING
THE CHANCE FOR WINTRY WEATHER. THERE IS A POTENTIAL WHERE AT LEAST
SOME RAIN COULD TURN TO WINTRY PRECIPITATION ALONG PORTIONS OF THE
HIGHWAY 14 CORRIDOR FRIDAY MORNING/EARLY AFTERNOON, BUT THIS WOULD
LIKELY BE SHORT-LIVED AND THUS CAUSE LITTLE IMPACTS. STILL TIME FOR
THINGS TO CHANGE, SO BE SURE TO KEEP UP TO DATE WITH THE LATEST
FORECAST! THIS PUSH OF CAA WILL ALSO LEAD TO WINDY CONDITIONS FRIDAY
INTO SATURDAY, WITH NORTHWESTERLY GUSTS TO 30 TO 40 MPH EXPECTED
BOTH DAYS, STRONGEST ON FRIDAY. TEMPERATURE-WISE, LOOK FOR LOWS DOWN
INTO THE 20S TO LOWER 30S SATURDAY MORNING AND THEN THE 20S AREA-
WIDE BY SUNDAY MORNING. HIGHS ON SATURDAY WILL STRUGGLE TO MAKE IT
TO THE 50S FOR THE MOST PART, COOLEST EAST OF THE MISSOURI RIVER.
RIDGING ALOFT LOOKS TO BUILD INTO THE AREA HEADING INTO EARLY NEXT
WEEK, WHICH WILL HELP BRING ABOUT A WARMING TREND WITH LIMITED RAIN
CHANCES THROUGH THE START OF THE NEXT WORK WEEK.
AVIATION /00Z TAFS THROUGH 00Z FRIDAY/
ISSUED AT 622 PM CDT WED APR 15 2026
VFR CONDITIONS BEGIN THE TAF PERIOD. A FEW LIGHT SHOWERS PERSIST
ACROSS PARTS OF THE AREA. HAVE ADDED A PROB30 GROUP TO KSUX TO BEGIN
THE PERIOD TO TAKE THESE LIGHT SHOWERS INTO ACCOUNT. OTHERWISE A CU
FIELD THAT HAS DEVELOPED WILL WANE WITH THE SETTING SUN. WINDS WILL
GO LIGHT AND VARIABLE FOR A BRIEF PERIOD OF TIME TONIGHT BEFORE
BEGINNING TO PICK UP OUT OF THE SOUTH. SKIES ARE EXPECTED TO REMAIN
CLEAR FOR THE DAY TOMORROW WITH WINDS FURTHER VEERING TO OUT OF THE
SOUTHWEST. WINDS WILL ALSO STRENGTHEN TOMORROW AFTERNOON WITH GUSTS
UP TO ABOUT 25 KNOTS EXPECTED. THE BREEZY WINDS WILL FINISH OUT THE
TAF PERIOD.
FIRE WEATHER
ISSUED AT 220 PM CDT WED APR 15 2026
WINDS REMAIN LIGHT ACROSS THE AREA THIS AFTERNOON, SO FIRE
WEATHER CONCERNS ARE NOT EXPECTED INTO THIS EVENING. SOUTH-
SOUTHWESTERLY WINDS WILL INCREASE ON THURSDAY AS A STORM SYSTEM
DEEPENS OFF TO OUR WEST. RELATIVE HUMIDITY VALUES LOOK TO DROP
AS LOW AS 15-20% ACROSS THE AREA IN THE AFTERNOON AS
TEMPERATURES WARM INTO THE LOWER TO MIDDLE 80S. THIS DRY AIR
WILL COMBINE WITH GUSTS OF 25-30 MPH TO LEAD TO CRITICAL FIRE
WEATHER CONDITIONS ACROSS A LARGE PART OF THE AREA. FOR THIS
REASON, UPGRADED THE FIRE WEATHER WATCH FOR SOUTH CENTRAL AND
SOUTHEASTERN SOUTH DAKOTA AND FAR NORTHEASTERN NEBRASKA TO A RED
FLAG WARNING.
A LITTLE UNCERTAINTY REMAINS ON HOW FAR EAST THE STRONGEST
WINDS MAKE IT, BUT ENOUGH CONFIDENCE TO ISSUE A FIRE WEATHER
WATCH FOR PARTS OF SOUTHWEST MINNESOTA INTO ADJACENT AREAS OF
NORTHWEST IOWA WHERE RH VALUES WILL DROP TO AROUND 20-25%.
FARTHER SOUTH TO THE HIGHWAY 20 CORRIDOR IN NORTHWEST IOWA, WENT
WITH A FIRE WEATHER WATCH INSTEAD OF A RED FLAG WARNING DUE TO
UNCERTAINTY REGARDING HOW MUCH RAIN WE SEE DOWN THERE TODAY. IF
WE COULD GET MORE OF A STEADY RAIN DEVELOP AND/OR A COUPLE OF
THUNDERSTORMS MOVE THROUGH THIS AFTERNOON, THAT MAY PRECLUDE A
GREATER FIRE DANGER DESPITE THE LOW RH AND BREEZY WINDS
EXPECTED.
WINDS REMAIN ELEVATED AND EVEN INCREASE ON FRIDAY AS A COLD FRONT
MOVES THROUGH THE AREA AND TURNS WINDS FROM THE SOUTH TO OUT OF THE
NORTHWEST. DRIER AIR WILL FILTER IN BEHIND THIS FRONT, DROPPING RH
VALUES BY FRIDAY AFTERNOON. THIS WILL LEAD TO A PRIMARILY WIND
DRIVEN HIGH TO VERY HIGH GFDI ACROSS THE AREA; HOWEVER COLDER
TEMPERATURES MOVING IN AND CLOUD COVER PRECLUDES A GREATER FIRE
WEATHER THREAT AT THIS TIME.
FSD WATCHES/WARNINGS/ADVISORIES
SD...RED FLAG WARNING FROM NOON TO 8 PM CDT THURSDAY FOR SDZ038>040-
050-052>071.
MN...FIRE WEATHER WATCH FROM THURSDAY AFTERNOON THROUGH THURSDAY
EVENING FOR MNZ071-072-080-089-097-098.
IA...FIRE WEATHER WATCH FROM THURSDAY AFTERNOON THROUGH THURSDAY
EVENING FOR IAZ001-012-020-031.
NE...RED FLAG WARNING FROM NOON TO 8 PM CDT THURSDAY FOR NEZ013-014.
DISCUSSION...SAMET
AVIATION...MEYERS
FIRE WEATHER...SAMET
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