123
FXUS63 KFSD 231146
AFDFSD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
646 AM CDT THU APR 23 2026
KEY MESSAGES
- ISOLATED SEVERE STORMS WILL BE POSSIBLE THIS AFTERNOON OVER
PARTS OF SOUTHWEST MN AND NORTHWEST IA, ESPECIALLY ALONG AND
EAST OF HIGHWAY-60.
- NEAR CRITICAL TO CRITICAL FIRE WEATHER CONCERNS ARE EXPECTED
THIS AFTERNOON AND EVENING ESPECIALLY ACROSS MOST SOUTHEASTERN
SD AND PARTS OF SOUTHWESTERN MN. AVOID ANY OUTDOOR BURNING!
- A RETURN TO MORE SEASONABLE TEMPERATURES WITH HIGHS IN THE
MID 50S TO LOWER 60S IS EXPECTED FRIDAY THROUGH THE MIDDLE OF
NEXT WEEK.
- A VERY GOOD CHANCE (30%-60%) FOR SHOWERS AND THUNDERSTORMS
RETURNS SUNDAY INTO MONDAY. SOME LOCALLY HEAVIER RAIN WILL BE
POSSIBLE.
UPDATE
ISSUED AT 436 AM CDT THU APR 23 2026
TAKING A LOOK ACROSS THE AREA, LOW TO MID-LEVEL CLOUDS CONTINUE TO
FILTER IN AHEAD OF OUR NEXT WAVE. WITH THE PASSAGE OF A LINGERING
OUTFLOW BOUNDARY, WE'RE STARTING TO SEE A FEW SCATTERED SHOWERS
DEVELOP ACROSS THE AREA THIS MORNING. WHILE POCKETS OF LIGHT TO
MODERATE RAIN WILL BE POSSIBLE, SEVERE WEATHER IS NOT EXPECTED.
SHIFTING GEARS HERE, THE MAIN CHANGES WITH THE 00Z TO 06Z RUNS OF
GUIDANCE ARE:
1. THE PROGRESSION OF THE COLD FRONT HAS SPED UP QUITE A BIT
FROM YESTERDAY'S GUIDANCE.
2. BECAUSE OF THIS, OUR WINDOW FOR STRONGER STORMS HAS SHIFTED
TO EARLIER AND FARTHER SOUTHEASTWARDS.
3. RH VALUES HAVE TRENDED DRIER BEHIND THE COLD FRONT THIS
AFTERNOON.
4. MORE CRITICAL FIRE WEATHER CONCERNS ARE NOW EXPECTED ALONG
AND WEST OF I-29.
THE LAST TWO BULLETS WILL BE DISCUSSED FURTHER IN THE FIRE WEATHER
SECTION. AS FOR THE SEVERE WEATHER CONCERNS, WE'RE STARTING TO RUN
INTO SOME UNCERTAINTY. AS MENTIONED ABOVE, THE COLD FRONT'S
PROGRESSION HAS TRENDED FASTER THAN INITIALLY EXPECTED. AS A RESULT,
INSTEAD OF THINGS KICKING OFF BETWEEN 3-10 PM; ITS NOW STARTING TO
LOOK LIKE THE WINDOW WILL BE BETWEEN 12PM-6PM. THE MAIN QUESTIONS
THAT WE HAVE ARE HOW QUICKLY WILL THIS MORNING'S STRATUS PUSH OUT OF
OUR AREA AND HOW QUICKLY WILL WE ERODE THE CAP DEPICTED IN
SOUNDINGS. BOTH ANSWERS WILL VARY DEPENDING ON WHICH MODEL YOU
CHOOSE. WHILE THAT UNCERTAINTY CONTINUES, THE TARGET AREA CONTINUES
TO BE AREAS EAST OF I-29, MORE SPECIFICALLY ALONG AND EAST OF A
SIOUX CITY, IA TO MARSHALL, MN LINE. IF AND WHEN STORMS DO DEVELOP,
STRONGER STORMS COULD PRODUCE LARGE HAIL UP TO HALF DOLLAR SIZE AND
DAMAGING WIND GUSTS UP TO 60 MPH. WITH THIS IN MIND, WE'RE STILL
OUTLOOKED IN A DAY 1 SLIGHT (LEVEL 2 OF 5). LASTLY, THE INGREDIENTS
(CAPE/ML SHEAR) ALIGN NICELY IN NORTHWESTERN IA SO THAT WOULD BE
WHERE MY ATTENTION WOULD BE FOCUSED.
DISCUSSION
ISSUED AT 109 PM CDT WED APR 22 2026
STRONG WINDS WILL CONTINUE INTO THE EVENING, BUT THE LOWER
HUMIDITIES WILL DIMINISH AROUND SUNSET. IT SHOULD BE NOTED
HOWEVER THAT FAIRLY STRONG SOUTHERLY FLOW WILL CONTINUE THROUGH
THE NIGHT. OTHERWISE, A CLUSTER OF SHOWERS AND THUNDERSTORMS
WILL BECOME LIKELY IN CENTRAL SD LATER THIS EVENING INTO THE
OVERNIGHT HOURS. WITH 1000-1500 J/KG CAPE POTENTIAL AND SOME
DRIER LOW LEVELS HAIL TO THE SIZE OF HALF DOLLARS AND WIND GUSTS
TO 65MPH WILL BE POSSIBLE. THESE STORMS SHOULD BE CONFINED TO
AREAS WEST OF THE JAMES RIVER AND POSSIBLY MAINLY CLOSER TO THE
MISSOURI RIVER IN CENTRAL SD. THE WEAK MID AND UPPER LEVEL WAVE
ASSOCIATED WITH THIS DEVELOPMENT DRIFTS EAST THROUGH THE NIGHT,
BUT INSTABILITY WANES TOWARDS I-29, SO EXPECT ANY STRONGER
STORMS TO GENERALLY WEAKEN AS THEY HEAD EAST LATE TONIGHT INTO
EARLY THURSDAY MORNING.
THE LATE TONIGHT AND EARLY MORNING ACTIVITY WILL DIMINISH
THROUGH THE MORNING, BUT GIVEN THE AMOUNT OF CLOUDS LEFT BEHIND
AS WELL AS THE PROGRESSION OF THE PRE-FRONTAL TROUGH, THE THREAT
FOR SEVERE WEATHER SEEMS PRETTY LIMITED FOR THURSDAY AFTERNOON
AND LIKELY SHIFTED A BIT EAST. FOR NOW, THE BEST CHANCE FOR
ISOLATED SEVERE STORMS WILL BE MID TO LATE AFTERNOON AND MAINLY
EAST OF A MARSHALL TO SIOUX CITY LINE. IF WE CAN BREAK OUT OF
THE CLOUD COVER AND WARM ENOUGH, THERE WILL BE ABOUT 1000 J/KG
CAPE WITH ABOUT 30 KNOTS OF SHEAR SO THE POTENTIAL FOR HALF
DOLLAR HAIL AND 60 MPH WINDS WILL EXIST.
FRIDAY LOOKS COOL AND DRY WITH WINDS REMAINING MOSTLY BELOW 15 TO 20
MPH, SO NOT TOO BAD OF A DAY. HIGHS MAINLY IN THE 60S.
ON SATURDAY, LOW PRESSURE TO THE NORTHWEST WILL DRIFT EAST BUT NOT
MOVE VERY MUCH, AS JET ENERGY WRAPS AROUND THE SOUTHERN EDGE INTO
THE AREA. SATURDAY INTO SUNDAY A SOUTHERN STREAM JET WILL ALSO
SPREAD INTO THE CENTRAL PLAINS AND BRING ADDITIONAL UPPER LEVEL
SUPPORT TO THE AREA. WHAT THIS MEANS IS THAT FROM ROUGHLY SATURDAY
INTO EARLY MONDAY THE AREA WILL SEE PERIODS OF MODERATE TO STRONG
MID LEVEL WARM ADVECTION, WHICH WILL BRING PERIODIC CHANCES FOR
SHOWERS AND THUNDERSTORMS. THE STRONGEST PERIOD OF LIFT APPEARS TO
ARRIVE ON SUNDAY BUT FOR NOW THE VARIOUS MODELS FOCUS IS ALL OVER
THE PLACE SO CONFIDENCE IS A BIT LOW ON THE EXACT LOCATION OF THE
MORE ORGANIZED SHOWERS AND STORMS. OF NOTE THE CANADIAN ENSEMBLE AND
EURO ENSEMBLE INDICATE MOST OF THE AREA WILL SEE A 60-90
PERCENT CHANCE FOR A HALF AN INCH OR MORE OF RAIN WHILE THE GEFS
INDICATES SOMETHING SIMILAR, JUST TO THE SOUTHEAST OF THE AREA.
PROBABILITIES OF AN INCH OR MORE ARE RUNNING ABOUT 30-40
PERCENT. LONG STORY SHORT, WILL NEED TO WATCH TRENDS TO SEE IF
WE CAN REALLY GET SOME MEANINGFUL RAINFALL IN THE AREA.
LOW PRESSURE WRAPS UP TO THE NORTH TUESDAY INTO WEDNESDAY, LEAVING
THE AREA IN FASTER WEST TO NORTHWEST FLOW AND LIKELY MOSTLY DRY
CONDITIONS. THERE WILL BE SOME SPOTTY CHANCES FOR SHOWERS AND
THUNDERSTORMS BUT FOR NOW THAT LOOKS LIKE A VERY ISOLATED THREAT.
TEMPERATURES WILL BE NEAR THE SEASONAL NORMALS.
AVIATION /12Z TAFS THROUGH 12Z FRIDAY/
ISSUED AT 642 AM CDT THU APR 23 2026
A MIX OF VFR AND MVFR CONDITIONS WILL TRANSITION TO MAINLY VFR
CONDITIONS THIS AFTERNOON. TAKING A LOOK AT SATELLITE IMAGERY, A
MIX OF VFR TO MVFR STRATUS CONTINUES TO PROGRESS THROUGH THE
AREA THIS MORNING WITH A FEW EMBEDDED SHOWERS. SHOULD SEE MOST
OF THIS ACTIVITY GRADUALLY ERODE INTO THE AFTERNOON LEAVING
BEHIND MOSTLY CLEAR SKIES FOR THE SECOND HALF OF THE DAY.
OTHERWISE, SOUTHERLY SURFACE WINDS THIS MORNING WILL BECOME MORE
WESTERLY THIS AFTERNOON THEN NORTHWESTERLY THIS EVENING BEHIND
A COLD FRONT. LASTLY, SCATTERED SHOWERS AND THUNDERSTORMS WILL
BE POSSIBLE EAST OF I-29 THIS AFTERNOON. USED A TEMPO GROUP IN
KSUX TO EMPHASIZE WHEN THE HIGHEST CONFIDENCE WAS.
FIRE WEATHER
ISSUED AT 436 AM CDT THU APR 23 2026
FIRE WEATHER: LOOKING INTO THE FIRE WEATHER SIDE OF THINGS, NEAR
CRITICAL TO CRITICAL CONCERNS ARE EXPECTED THIS AFTERNOON/EVENING.
SIMILAR TO YESTERDAY, SURFACE WINDS WILL BE ON THE BREEZIER SIDE AS
THE SPG TIGHTENS AHEAD AND BEHIND THE PREVIOUSLY MENTIONED
FRONT. NOT ONLY WILL THIS HELP GRADUALLY SHIFT OUR SURFACE WINDS
FROM SOUTHERLY THIS MORNING TO MORE WESTERLY THIS AFTERNOON
THEN MORE NORTHWESTERLY THIS EVENING, WE'LL ALSO SEE AN UPTICK
IN SPEEDS DIRECTLY BEHIND THE FRONT WITH WIND GUSTS BETWEEN
30-40 MPH EXPECTED. THIS ALONG WITH DEEPER MIXING WILL HELP
TRANSPORT WARMER AND DRIER AIR TO THE SURFACE LEADING TO
RELATIVE HUMIDITY VALUES IN THE 12-20 PERCENT RANGE. WITH ALL
THIS IN MIND AND COLLABORATION WITH OUR NEIGHBORING OFFICES, A
RED FLAG WARNING HAS BEEN ISSUED FOR MOST OF SOUTHEASTERN SD AND
PORTIONS OF SOUTHWESTERN MN. LASTLY, MAKE SURE TO AVOID ANY
OUTDOOR BURNING AS THE CONDITIONS COULD HELP A FIRE QUICKLY
SPREAD OUT OF CONTROL!
FSD WATCHES/WARNINGS/ADVISORIES
SD...RED FLAG WARNING FROM 1 PM THIS AFTERNOON TO 8 PM CDT THIS
EVENING FOR SDZ039-040-054>056-060>062-065>069.
RED FLAG WARNING FROM 11 AM THIS MORNING TO 5 PM CDT THIS
AFTERNOON FOR SDZ038-050-052-053-057>059-063-064.
MN...RED FLAG WARNING FROM 1 PM THIS AFTERNOON TO 8 PM CDT THIS
EVENING FOR MNZ071-072-097.
IA...NONE.
NE...NONE.
UPDATE...05
DISCUSSION...08
AVIATION...05
FIRE WEATHER...05
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