933
FXUS63 KFSD 082321
AFDFSD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
621 PM CDT WED APR 8 2026
KEY MESSAGES
- DRY AND WARM CONDITIONS COUPLED WITH NORTHWEST WINDS GUSTING
25-35 MPH HAVE RESULTED IN ELEVATED FIRE WEATHER CONDITIONS
THIS AFTERNOON. PLEASE USE CAUTION AND REPORT ANY FIRES
IMMEDIATELY.
- MULTIPLE CHANCES FOR SHOWERS AND THUNDERSTORMS ARE IN THE
FORECAST FROM THURSDAY ONWARD. A FEW STRONGER STORMS MAY BE
POSSIBLE SATURDAY AFTERNOON INTO EARLY SUNDAY MORNING.
- A GRADUAL WARMUP IS EXPECTED THURSDAY THROUGH THE WEEKEND.
ABOVE AVERAGE TEMPERATURES ARE EXPECTED FRIDAY THROUGH MONDAY.
- A SHARP DROP IN TEMPERATURES LIKELY MONDAY INTO TUESDAY.
DISCUSSION
ISSUED AT 118 PM CDT WED APR 8 2026
BREEZY NORTHWEST WINDS GUSTING 25-35 MPH WILL USHER IN A MUCH DRIER
AIR MASS THIS AFTERNOON. RELATIVE HUMIDITY LEVELS WILL FALL TO NEAR
CRITICAL TO CRITICAL FOR A BRIEF PERIOD THIS AFTERNOON. WHILE NO
FIRE HEADLINES ARE PLANNED AT THIS TIME, CAUTION IS STILL NEEDED TO
PREVENT THE SPREAD OF WILDFIRE. THIS AFTERNOON A LOW CHANCE (<25%)
OF ISOLATED TO SCATTERED LIGHT RAIN IS POSSIBLE OVER NORTHWEST IOWA.
IF SHOWERS CAN OVERCOME THE DRY BOUNDARY LAYER, VERY LITTLE IF ANY
ACCUMULATION IS EXPECTED. HIGHS THIS AFTERNOON WILL CLIMB INTO THE
50S TO 60S, WITH THE HIGHEST TEMPERATURES OVER NORTHWEST IOWA. WINDS
BECOME LIGHT AND VARIABLE OVERNIGHT WITH CLEAR SKIES. THIS WILL HELP
LOWS COOL DOWN TO THE 20S.
AN ACTIVE PATTERN LOOKS TO BE THE STORY FOR THE REST OF THE WEEK AND
INTO NEXT WEEK. THURSDAY A SHORTWAVE PASSES THROUGH THE REGION
BRINGING WEAK ELEVATED INSTABILITY AND MODERATE WAA IN THE MID-
LEVELS. THIS MAY BE ENOUGH TO TRIGGER SHOWERS AND POSSIBLY
THUNDERSTORMS. WHILE ISOLATED TO SCATTERED STORMS ARE POSSIBLE
ACROSS THE REGION, ANY THUNDERSTORMS WILL MOST LIKELY REMAIN ALONG
AND SOUTH OF HIGHWAY 20. SEVERE WEATHER IS NOT EXPECTED, HOWEVER A
FEW STRONGER STORMS MAY PRODUCE WIND GUSTS OF 40-50 MPH AND SMALL
HAIL TO THE SIZE OF DIMES.
FRIDAY AN UPPER RIDGE AND SURFACE HIGH PRESSURE BUILD INTO THE
REGION. AS IT DOES SO WINDS WILL BECOME EASTERLY TO SOUTHEASTERLY.
SUBSIDING AIR WILL WARM AND DRY OUT CONDITIONS AT THE SURFACE.
MINIMUM RELATIVE HUMIDITY VALUES ARE EXPECTED TO FALL TO AROUND 30%
FRIDAY AFTERNOON. HIGHS WILL BE IN THE 50S WITH LIGHT WINDS. THANKS
TO THE MILDER TEMPS AND LIGHT WINDS FIRE DANGER WILL REMAIN LOW TO
MODERATE FOR MOST OF THE FORECAST AREA. THE EXCEPTION WILL BE
SOUTH CENTRAL SOUTH DAKOTA, WHERE THE HIGH CATEGORY MAY BE
REACHED. THOUGH FIRE RISKS ARE LOWER, PLEASE CONTINUE TO USE
CAUTION.
ZOOMING OUT AND LOOKING AT THE OVERALL PATTERN WE SEE A LARGE TROUGH
DIGGING SOUTH OVER THE PACIFIC NORTHWEST. AS IT DOES SO, VORTICITY
WAVES PROPAGATE OFF THE PARENT WAVE, COMPRESSING THE PRESSURE
GRADIENTS FROM THE SURFACE THROUGH THE MID-LEVELS. THE LLJ AND
SURFACE WINDS WILL INCREASE IN RESPONSE. AFTERNOON WIND GUSTS OF 25-
35 MPH ARE EXPECTED WITH LOCALLY HIGHER GUSTS POSSIBLE. GOOD MIXING
AND WAA WILL HELP AFTERNOON HIGHS CLIMB INTO THE 60S AND 70S.
DEWPOINTS WILL ALSO INCREASE, REACHING THE MID TO UPPER 50S. IT MAY
BEGIN TO FEEL A BIT MUGGY BY SATURDAY AFTERNOON. IN ADDITION,
CHANCES FOR THUNDERSTORMS CREEP INTO THE AREA. THE GENERAL TREND
ACROSS MULTIPLE MODELS HAS BEEN AN INCREASE IN THE POTENTIAL
INSTABILITY ACROSS THE REGION. COUPLE THIS WITH MODERATE TO STEEP
LAPSE RATES, AND ROUGHLY 30 KTS OF 0-6 KM BULK SHEAR AND THE
POTENTIAL IS THERE FOR STRONG TO SEVERE THUNDERSTORMS SATURDAY
EVENING INTO SUNDAY MORNING.
STORMS CLEAR OUT FOR SUNDAY AFTERNOON AND MOST OF MONDAY. HIGHS
WILL CLIMB TO THE 70S AND 80S SUNDAY, SLIGHTLY COOLER IN THE
70S FOR MONDAY. MONDAY EVENING STORM CHANCES RETURN AGAIN, AND
CONTINUE PERIODICALLY THROUGH THE FIRST HALF OF NEXT WEEK AS THE
PREVIOUSLY MENTIONED UPPER TROUGH BEGINS TO MOVE OUT OVER THE
CENTRAL UNITED STATES. AT THIS TIME IT IS TOO EARLY TO SAY FOR
CERTAIN WHEN OR WHERE OR IF STORMS WILL BECOME SEVERE. BUT THE
POTENTIAL IS THERE BEGINNING THIS WEEKEND AND CONTINUING INTO
NEXT WEEK. THIS INCREASE IN THUNDERSTORM ACTIVITY IS TYPICAL FOR
APRIL IN THE MIDWEST. IT'S IMPORTANT THAT YOU KNOW HOW TO
RESPOND SHOULD SEVERE WEATHER APPROACH YOUR AREA. KNOW WHERE THE
NEAREST SHELTER IS LOCATED. HAVE MULTIPLE WAYS TO RECEIVE
WARNINGS, ESPECIALLY AT NIGHT HAVE AT LEAST ONE METHOD THAT WILL
WAKE YOU UP! IF YOU HAVE OUTDOOR PLANS BE SURE TO MONITOR THE
FORECAST CLOSELY FOR UPDATES.
AVIATION /00Z TAFS THROUGH 00Z FRIDAY/
ISSUED AT 621 PM CDT WED APR 8 2026
VFR CONDITIONS ARE EXPECTED FOR THE TAF PERIOD. BREEZY
WEST/NORTHWEST FLOW PREVAILS THIS EVENING IN THE WAKE OF A PASSING
COLD FRONT. GUSTS UP TO 20-30+ KNOTS IS CURRENTLY BEING OBSERVED
ACROSS THE AREA. THESE WINDS ARE EXPECTED TO WEAKEN THROUGH THE REST
OF THE EVENING HOURS BEFORE REMAINING LIGHT OUT OF THE WEST/NORTHWEST
FOR THE OVERNIGHT HOURS. WINDS WILL TURN TO OUT OF THE NORTHEAST BY
TOMORROW AFTERNOON WITH SPEEDS REMAINING LIGHT AT 5-15 KNOTS. CLOUD
COVER WILL THICKEN THROUGHOUT THE DAY TOMORROW AS LIGHT RAIN SHOWERS
RETURN TO THE AREA. AS OF NOW, THE SHOWERS MAY AFFECT ALL TAF SITES
BUT CONFIDENCE IN HIGHEST IN KSUX SEEING LIGHT SHOWERS TOMORROW
AFTERNOON. CEILINGS AND VISIBILITIES ARE EXPECTED TO REMAIN VFR IN
THE LIGHT SHOWERS. THE LIGHT SHOWERS WILL FINISH OUT THE TAF PERIOD.
FSD WATCHES/WARNINGS/ADVISORIES
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
DISCUSSION...AJP
AVIATION...MEYERS
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