505
FXUS63 KFSD 261120
AFDFSD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
520 AM CST THU FEB 26 2026
KEY MESSAGES
- PATCHY AREAS OF LOCALLY DENSE FOG WILL CONTINUE MAINLY ACROSS
PORTION OF NORTHWESTERN IA AND THE MN/IA STATE LINE THROUGH
MID-MORNING BEFORE GRADUALLY DISSIPATING.
- THE RETURN OF MILD AND BREEZY CONDITIONS WILL LEAD TO ELEVATED
FIRE WEATHER CONCERNS THIS AFTERNOON WITH THE FOCUS ACROSS
SOUTHCENTRAL SD. MORE WIDESPREAD CONCERNS ARE EXPECTED BY
FRIDAY.
- CONFIDENCE CONTINUES TO INCREASE IN PERIODS OF LIGHT TO
MODERATE SNOW RETURNING FROM FRIDAY NIGHT INTO SATURDAY. WHILE
OVERALL AMOUNTS ARE STILL UNCERTAIN, THE U.S. HIGHWAY-14
CORRIDOR AND PORTIONS OF SOUTHWESTERN MN LOOK TO BE THE AREAS
OF FOCUS.
UPDATE
ISSUED AT 304 AM CST THU FEB 26 2026
TAKING A LOOK ACROSS THE AREA, MOSTLY CLEAR CONDITIONS HAVE RETURNED
THIS MORNING WITH LIGHTER SURFACE WINDS. WITH THIS AND LINGERING LOW-
LEVEL MOISTURE IN PLACE, PATCHY AREAS OF LOCALLY DENSE FOG HAVE
DEVELOPED ALONG THE MN/IA STATE LINE AND PORTIONS OF NORTHWESTERN
IA. WITH MANY SURFACE OBSERVATIONS ACROSS NORTHWESTERN IA NOW
STARTING TO REPORT VISIBILITIES OF 1/2 MILE OR LESS, HAVE DECIDED TO
ISSUE A DENSE FOG ADVISORY FOR THESE AREAS. WITH THIS IN MIND, MAKE
SURE TO SLOW DOWN AND BE PREPARED FOR RAPID CHANGES IN VISIBILITY ON
THOSE MORNING COMMUTES! HEADING INTO TODAY, MORE MILD AND DRY
CONDITIONS ARE EXPECTED AS WEST-NORTHWEST SURFACE WINDS AND A WEAK
WARM FRONTAL PASSAGE HELP TEMPERATURES PEAK IN THE LOW TO UPPER 50S
FOR THE DAY. WITH BREEZIER CONDITIONS (20-30 MPH GUSTS) EXPECTED
THIS AFTERNOON, ELEVATED FIRE WEATHER CONCERNS WILL RETURN FOR MOST
AREAS AS RH VALUES GRADUALLY DECREASE INTO THE 25%-35% RANGE WITH
THE DRIEST CONDITIONS ACROSS SOUTHCENTRAL SD. HOWEVER, WITH THESE
CONDITIONS BEING LIMITED TO SHORT WINDOW OF 3-4 HOURS; DECIDED TO
FORGO ANY FIRE HEADLINES AT THIS TIME.
LOOKING AHEAD, FRIDAY LOOKS TO BE A BETTER FIRE WEATHER DAY WITH
MILDER TEMPERATURES IN THE 50S TO MID 60S AND RHS IN THE 20%-30%
RANGE. WITH THIS IN MIND, NOT ONLY IS MOST OF OUR AREA OUTLINED IN
THE VERY HIGH CATEGORY OF THE GFDI; BUT MOST AREAS ARE ALSO OUTLINED
IN THE 95TH PERCENTILE OF THE HDWI PROBABILITIES. AS A RESULT, WE'LL
PROBABLY NEED SOME TYPE OF FIRE WEATHER HEADLINE. HOWEVER, WE'LL
FORGO IT AT THIS TIME UNTIL WE GET MORE SHORT-RANGE GUIDANCE.
OTHERWISE, CONFIDENCE CONTINUES TO INCREASE IN PERIODS OF LIGHT TO
MODERATE SNOW RETURNING TO THE HIGHWAY-14 CORRIDOR AND PORTIONS OF
SOUTHWESTERN MN FROM FRIDAY NIGHT INTO SATURDAY. WHILE OVERALL
AMOUNTS ARE STILL QUESTIONABLE AT THIS TIME, MOST ENSEMBLE GUIDANCE
SHOWS LOW TO MODERATE CONFIDENCE (20%-50%) IN AT LEAST 1 INCH OF
SNOW AND LOW CONFIDENCE (20% OR LESS) IN 2 INCHES OR MORE. BASED ON
WHAT IS BEING DEPICTED IN THE LATEST 00Z/06Z DETERMINISTIC GUIDANCE,
EXPECT THESE PROBABILITIES TO INCREASE OVER THE COMING RUNS WITH
SOME MODELS (CANADIAN AND NAM) SHOWING THE POTENTIAL FOR 3+ INCHES
IN SOME SPOTS. WITH THIS IN MIND, MAKE SURE TO FOLLOW YOUR LOCAL
FORECAST AS THE POTENTIAL AMOUNTS AND TRACK OF THIS SYSTEM ARE
SUBJECT TO CHANGE.
DISCUSSION
ISSUED AT 149 PM CST WED FEB 25 2026
LIGHT SNOW IS CURRENTLY MOVING THROUGH THE REGION, AND IS EXPECTED
TO EXIT TO THE SOUTHEAST THIS EVENING. ADDITIONAL ACCUMULATIONS OF A
DUSTING TO A A TENTH OR TWO FOR MOST LOCATIONS. SLIGHTLY HIGHER
ADDITIONAL ACCUMULATIONS UP TO A HALF AN INCH IS POSSIBLE FOR
PORTIONS OF SOUTHWESTERN MINNESOTA AND NORTHWESTERN IOWA. CLOUDS
WILL SLOWLY SCATTER OUT THROUGH THE OVERNIGHT AND WINDS WILL BECOME
LIGHT. EARLY THURSDAY MORNING PATCHY DENSE FOG MAY DEVELOP FOR AREAS
EAST OF THE JAMES RIVER VALLEY. VISIBILITY MAY BRIEFLY BE REDUCED
DOWN TO 2 MILES OR LESS AT TIMES. FOG BURNS OFF QUICKLY AFTER DAY
BREAK.
THE REST OF THURSDAY WILL BE PLEASANT WITH CLEAR SKIES AND WARM
HIGHS IN THE UPPER 40S TO 50S. AFTERNOON WINDS WILL BE BREEZY WITH
WEST-NORTHWESTERLY GUSTS 25-30 MPH WEST OF THE JAMES RIVER. TO THE
EAST, GUSTS WILL BE LIGHTER BETWEEN 15-25 MPH. FRIDAY WILL BE EVEN
WARMER THANKS TO A STRONG PUSH OF WAA. GOOD MIXING THROUGH THE 850
MB LAYER WILL RESULT IN SURFACE HIGHS IN THE 50S AND 60S, WITH THE
WARMEST TEMPERATURES EXPECTED ALONG THE SOUTHERN MISSOURI RIVER
COUNTIES. TAKING A LOOK ALOFT A LARGE LOW PRESSURE SYSTEM WILL
MOVE THROUGH CENTRAL INTO EASTERN CANADA THURSDAY THROUGH
FRIDAY. FRIDAY AFTERNOON IT WILL DRAG A TROUGH AXIS THROUGH OUR
REGION. THIS WILL TURN WINDS TO THE NORTHWEST BY LATE MORNING.
WINDS WILL THEN INCREASE IN RESPONSE TO A TIGHTENING SPG, WITH
AFTERNOON GUSTS REACHING 25-35 MPH. WINDS DECREASE AFTER SUNSET
BUT REMAIN ON THE BREEZY SIDE, WITH GUST OF 15-20 MPH.
THE MAIN CONCERN FOR BOTH THESE DAYS IS THE HIGH TO VERY
HIGH GRASSLAND FIRE DANGER. THOUGH RELATIVE HUMIDITY VALUES WILL BE
WELL ABOVE CRITICAL THRESHOLDS, THE WARM TEMPERATURES AND BREEZY
WINDS COULD AID IN RAPID FIRE GROWTH THROUGH CURED FUELS. PLEASE USE
CAUTION, ESPECIALLY IN AREAS OF LONGER GRASS LIKE DITCHES OR DENSE
FIELD STUBBLE. SHOULD A FIRE START, REPORT IT IMMEDIATELY.
WITH THE CHANGE IN WIND DIRECTION COMES A STRONG PUSH OF CAA. THIS
WILL BRING OUR HIGH TEMPERATURES SATURDAY DOWN CLOSER TO AVERAGE IN
THE 20S AND 30S. ALONG WITH COOLER TEMPERATURES, A SUBTLE
EMBEDDED SHORTWAVE WITH IN THE LARGER LOW MENTIONED EARLIER MAY
PROVIDE JUST ENOUGH LIFT FOR LIGHT SNOW SHOWERS TO FORM. SNOW
MAY LINGER INTO SUNDAY. MANY DETAILS ARE UNCERTAIN AT THIS TIME,
BUT A AN INCH OR TWO OF ACCUMULATION MAY BE POSSIBLE. HIGHS FOR
SUNDAY WILL BE COLDER THAN AVERAGE IN THE 20S. BUT DON'T FRET,
WE BEGIN A WARMING TREND AGAIN MONDAY THAT CONTINUES THROUGH MID
WEEK.
AVIATION /12Z TAFS THROUGH 12Z FRIDAY/
ISSUED AT 514 AM CST THU FEB 26 2026
MOSTLY VFR CONDITIONS WITH OCCASIONAL MVFR TO LIFR VSBYS THIS
MORNING WITH TRANSITION TO VFR CONDITIONS BY THIS AFTERNOON.
TAKING A LOOK AT SATELLITE IMAGERY, PATCHY AREAS OF LOCALLY
DENSE FOG CONTINUE TO SIT OVER THE PORTIONS OF NORTHWESTERN IA
AND SOUTHWESTERN MN THIS MORNING PROMOTING MVFR TO LIFR VSBYS.
WHILE THESE CONDITIONS COULD PERSIST THROUGH DAYBREAK, MOST THE
FOG SHOULD GRADUALLY ERODE BY MID-MORNING. OTHERWISE, LIGHT
SOUTHWESTERLY WINDS WILL BECOME MORE WEST-NORTHWESTERLY
THROUGHOUT THE DAY AND BREEZY WITH GUSTS BETWEEN 20-30 MPH
EXPECTED.
FSD WATCHES/WARNINGS/ADVISORIES
SD...NONE.
MN...DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR MNZ089-090-
098.
IA...DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR IAZ002-003-
013-014-022.
NE...NONE.
UPDATE...05
DISCUSSION...AJP
AVIATION...05
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