746
FXUS63 KFSD 140542
AFDFSD
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE SIOUX FALLS SD
1242 AM CDT THU MAY 14 2026
KEY MESSAGES
- CRITICAL FIRE WEATHER EXPECTED TO RETURN TODAY, ALONG WITH A
RISK FOR ISOLATED TO SCATTERED THUNDERSTORMS. SEVERE STORMS
ARE NOT EXPECTED.
- WINDS TODAY WILL BE STRONG, GUSTING 35-45 MPH. A FEW GUSTS MAY
APPROACH 50+ MPH. PERIODS OF BLOWING DUST IN RURAL AREAS MAY
RESULT. USE CAUTION IF TRAVELING AS VISIBILITY MAY BE
IMPACTED
- TEMPERATURES CONTINUE TO WARM THOUGH THE WEEKEND, WITH HIGH
TEMPERATURES EXPECTED TO BE 10 TO 20 DEGREES ABOVE NORMAL.
- REGIONAL RAIN CHANCES INCREASE SATURDAY AND ESPECIALLY SUNDAY.
A GREAT DEAL OF UNCERTAINTY REMAINS, BUT SIGNALS REMAIN
PRESENT FOR STRONG STORMS SUNDAY AND MONDAY.
UPDATE
ISSUED AT 910 PM CDT WED MAY 13 2026
THE FORECAST REMAINS ON TRACK WITH CRITICAL FIRE CONDITIONS EXPECTED
THURSDAY, AND NEAR CRITICAL CONDITIONS FRIDAY. TONIGHT INTO THURSDAY
MODEST MID-LEVEL MOISTURE WILL FLOW IN ON SOUTHERLY WINDS. WAA
BEHIND A WARM FRONT PROVIDES ENOUGH LIFT TO RESULT IN CLOUDS AND
POSSIBLY LIGHT ELEVATED SHOWERS TO THUNDERSTORMS THURSDAY MID-
MORNING. SHOWERS ARE MOST LIKELY TO FORM ALONG OR SLIGHTLY WEST
OF I- 29 AND MOVE EAST THROUGH THE EARLY AFTERNOON. A VERY DRY
SUBCLOUD LAYER WILL LIKELY LIMIT HOW MUCH REACHES THE GROUND.
SO, THIS IS UNLIKELY TO IMPACT FIRE CONDITIONS. BUT PERSISTENT
CLOUDS MAY LIMIT HIGHS A LITTLE BIT. HOT ON THE HEELS OF THE WAA
IS A COLD FRONT THAT WILL ENTER CENTRAL SOUTH DAKOTA AROUND
MID-DAY. WITH THE FRONT COME ADDITIONAL LOW CHANCES FOR SHOWERS
AND THUNDERSTORMS. AHEAD OF THE FRONT WINDS WILL INCREASE
RAPIDLY IN RESPONSE TO THE TIGHTENING SPG. WINDS LOOK TO REACH
THEIR PEAK IN THE LATE MORNING TO EARLY AFTERNOON WITH
WIDESPREAD GUSTS 35-45 MPH. AREAS BETWEEN THE JAMES RIVER VALLEY
AND I-29 MAY SEE OCCASIONAL GUSTS TO 50+ MPH. BEHIND THE FRONT
WINDS DROP OFF RAPIDLY FROM WEST TO EAST THROUGH THURSDAY
AFTERNOON. IN ADDITION TO THE WINDS RELATIVE HUMIDITY VALUES
WILL FALL AS LOW AS 19-25% FOR PORTIONS OF THE REGION. THE
TIMING OF THE WINDS AND LOWEST HUMIDITY REMAIN SLIGHTLY OFFSET
FOR AREAS ALONG AND WEST OF THE JAMES RIVER. HERE THE GUSTY
WINDS WILL EASE BEFORE THE LOWEST HUMIDITY IS MET, THEREFORE
THIS REGION REMAINS OUT OF THE RED FLAG WARNING AT THIS TIME.
EAST OF THE JAMES RIVER VALLEY THE STRONGEST WINDS AND LOWEST
HUMIDITY VALUES WILL BE BETTER ALIGNED. DESPITE THE LOW RAIN
CHANCES, THE RED FLAG WARNING FROM 10 AM UNTIL 7 PM THURSDAY
LOOKS TO BE IN GOOD SHAPE.
FOR FRIDAY WINDS WILL BE OUT OF THE NORTHWEST AND BREEZY WITH GUSTS
15-25 MPH. VERY DRY SURFACE CONDITIONS CONTINUE WITH MINIMUM
RELATIVE HUMIDITY VALUES OF 15-19% FOR THE ENTIRE REGION. NEAR
CRITICAL FIRE CONDITIONS WILL BE POSSIBLE FOR AREAS ALONG AND NORTH
OF HIGHWAY 34, WHERE THE STRONGEST GUSTS ARE EXPECTED. AT THIS TIME
NO CHANGES ARE NEEDED FOR THE FIRE WEATHER WATCH IN EFFECT FROM 9 AM
UNTIL 7 PM FRIDAY.
DISCUSSION
ISSUED AT 155 PM CDT WED MAY 13 2026
THIS AFTERNOON: AN ABSOLUTELY BEAUTIFUL AFTERNOON ACROSS THE REGION
AS WINDS REMAIN LIGHT AND VARIABLE, TEMPERATURES HAVE RISEN INTO THE
70S AND PLENTY OF SUNSHINE IS AROUND. EXPECT THESE CONDITIONS TO
PERSIST INTO THE EVENING.
TONIGHT: SHORTWAVE RIDGING MOVES EAST OF I-29 BY DAYBREAK
THURSDAY, WITH MODEST LOW-LVL MOISTURE CONVERGENCE ON THE NOSE
OF A 50 KNOT LLJ TRYING TO FOCUS ALONG I-29 BY MID-MORNING. THE
OVERNIGHT HOURS ARE EXPECTED TO REMAIN DRY BUT WITH A MIXY WIND,
TEMPERATURES MAY FAIL TO FALL BELOW 50 DEGREES.
THURSDAY: MULTIPLE HAZARDS LIKELY ON THURSDAY. EARLY IN THE
MORNING, GUIDANCE SHOWS A NARROW TONGUE OF LOW-MID LVL MOISTURE
STREAMING UP I-29. CAMS ARE A BIT SPLIT IN FURTHER DEVELOPMENT
OF THIS MOISTURE INTO A FEW SHOWERS/SPRINKLES BUT FEEL POTENTIAL
IS HIGH ENOUGH TO WARRANT SLIGHT CHC POPS INTO NW IOWA AND SW
MN FOR A BRIEF PERIOD OF TIME. MEANWHILE A SURFACE FRONT WILL
APPROACH CENTRAL SD BY DAYBREAK, GRADUALLY MOVING EAST THROUGH
THE DAY. A CHANNEL OF 50+ KNOTS OF LOW-LVL FLOW AHEAD OF THIS
BOUNDARY WILL BEGIN TO MIX DOWNWARD QUICKLY IN THE MORNING. HAVE
TRENDED WIND GUSTS TOWARDS THE 90TH PERCENTILE OF THE NBM WHICH
ALIGNED WELL WITH WINDS ON TUESDAY. PEAK GUSTS MAY BREAK THE 45
MPH MARK AT TIMES INTO THE AFTERNOON. SURFACE BASED MOISTURE
WILL BE EXTREMELY LIMITED AHEAD OF THIS BOUNDARY, BUT ANOTHER
WEDGE OF ELEVATED MOISTURE MAY BE ENOUGH TO PRODUCE HIGH BASED
SPRINKLES TO SHOWERS AS THIS FRONT PASSES EAST INTO THE
AFTERNOON. SLIGHT INHIBITION AT 850 MB WILL LIKELY PREVENT ANY
SURFACE BASED CONVECTION FROM FORMING. THE COMBINATION OF STRONG
WINDS THURSDAY WILL ALSO PRODUCE SOME PATCHY BLOWING DUST AND
MINOR AIR QUALITY ISSUES IN THE AFTERNOON. FOR FIRE WEATHER
CONCERNS, PLEASE SEE SEPARATE DISCUSSION BELOW.
THURSDAY NIGHT-FRIDAY NIGHT: THE AFOREMENTIONED BOUNDARY WILL BE
EAST OF THE CWA BY DAYBREAK FRIDAY, WITH WINDS SWITCHING TO THE
WEST NORTHWEST BEHIND THE BOUNDARY THURSDAY NIGHT. VERY DRY AIR
WILL ADVECT SOUTHEAST BEHIND THIS BOUNDARY, SETTING THE STAGE
FOR RH VALUES NEAR 15% IN THE AFTERNOON OF FRIDAY. LATEST TRENDS
HAVE PUSHED THE STRONGEST WIND POTENTIAL ALONG OR NORTH OF
HIGHWAY 14 IN THE AFTERNOON AS HIGH TEMPERATURES RISE INTO THE
80S. ONE THING TO MONITOR FOR FRIDAY EVENING WILL BE THE ON/OFF
POTENTIAL IN GUIDANCE OF SOME WEAK LOW-LVL CONVERGENCE ACROSS
NORTHERN NEBRASKA AND WESTERN IOWA IN THE EVENING. THIS AREA
WILL BE ON THE EDGE OF SOME SLIGHTLY DEEPER MOISTURE AND MUCAPE
AOA 800-1000 J/KG. WHILE ITS AN INTERMITTENT SIGNAL IN CAMS,
CAN'T DISCOUNT A THUNDERSTORM OR TWO TRYING TO FORM SOUTH OF
I-90 OR TOWARDS HIGHWAY 20 IF WE SOMEHOW REACH CONVECTIVE TEMPS
IN THE LOW 90S.
SATURDAY: A BRIEF RISE IN MID-LVL HEIGHTS AND INFLUENCE OF DRIER
CANADIAN AIRMASS WILL PREVENT MOISTURE AND MEANINGFUL INSTABILITY
FROM RACING NORTHWARD SATURDAY. FOR MOST OF US, EXPECT A DRY AND
RATHER NICE SATURDAY AS HIGHS RISE INTO THE 80S.
SATURDAY NIGHT-MONDAY: GUIDANCE IS STILL QUITE UNCERTAIN, BUT TRENDS
CONTINUE TO SHOVE A TROUGH INTO THE PLAINS SATURDAY NIGHT. THE SPEED
AT WHICH LOW-LVL FLOW TURNS MORE MERIDIONAL REMAINS IN QUESTION,
HOWEVER BOTH THE GFS/ECMWF LIFT AN ELEVATED WARM FRONT
NORTHWARD BY SUNDAY MORNING. CONVERGENCE AND UPPER DYNAMICS
WOULD SUPPORT GROWING SHOWER AND THUNDERSTORM RISKS MOVING
NORTHWARD THROUGH THE TRI-STATE AREA INTO SUNDAY MORNING. WHILE
THE SEVERE WEATHER RISKS OVERNIGHT MAY BE LOW, ELEVATED PARCELS
MIGHT HAVE UPWARDS OF 500-1000 J/KG SUPPORTING SOME HAIL GROWTH
THROUGH MID-MORNING SUNDAY.
EVEN MORE UNCERTAINTY BUILDS THROUGH THE DAY ON SUNDAY, FOCUSED ON
THE NORTHWARD PUSH OF THE WARM SECTOR INTO THE PLAINS. GFS/EC/CMC
ENSEMBLE GUIDANCE ALL REMAINS SPLIT 50/50 WITH THE WARM SECTOR OR
DEEPER INSTABILITY EITHER STAYING SOUTH OF I-90, OR ON THE FLIPSIDE
SPREADING WELL NORTH AND BRINGING EVEN MODERATE TO STRONG
INSTABILITY TOWARDS THE TRI-STATE AREA BY SUNDAY AFTERNOON. AI BASED
MODELS AND CIPS ANALOG GUIDANCE SUPPORT THE POTENTIAL THAT DOES
EXIST FOR THIS EVENT, FURTHER SUPPORTING EARLY SPC DAY 4 OUTLOOKS.
CONTINUE TO MONITOR SUNDAY'S FORECAST IF YOU HAVE OUTDOOR EVENTS
PLANNED, AS THIS REMAINS A VERY CONDITIONAL SEVERE WEATHER FORECAST.
THE UPPER TROUGH DEEPENS AND PIVOTS EASTWARD INTO MONDAY, PUSHING A
SURFACE FRONT INTO THE CWA OVERNIGHT. SEVERAL WAVES OF CONVECTION
COULD BE POSSIBLE INTO THE MORNING HOURS OF MONDAY, WITH STRONGER
CONVECTION POTENTIAL FOCUSED EAST OF I-29. A GREAT DEAL OF
UNCERTAINTY REMAINS INTO MONDAY AND IT'S CERTAINLY POSSIBLE THE
GREATEST POTENTIAL OF REDEVELOPMENT ALONG THE FRONT COULD BE PUSHED
EAST OF THE CWA.
THIS ENTIRE SYSTEM SHOULD BRING MEANINGFUL RAIN TO THE CWA BY TIME
IT EXITS THE REGION. NBM 10/90 PERCENTILE QPF OVER THE 72 HOUR
PERIOD DOES RANGE FROM A QUARTER INCH TO NEARLY 2", WITH A MEAN
AROUND 0.75" IN MOST LOCATIONS. OF COURSE CONVECTION CAN INFLUENCE
THESE LOCATIONS SIGNIFICANTLY, WHICH IS WHY THE NBM PROBABILITY OF
>0.50" IS ONLY AROUND 50% IN ANY GIVEN LOCATION.
TUESDAY-WEDNESDAY: DRIER WEATHER AND COOLER CONDITIONS ARE EXPECTED
AS WE MOVE INTO THE MIDDLE OF NEXT WEEK. HIGH TEMPERATURES TUESDAY
COULD STRUGGLE TO CLIMB THROUGH THE 60S.
AVIATION /06Z TAFS THROUGH 06Z FRIDAY/
ISSUED AT 1240 AM CDT THU MAY 14 2026
VFR CONDITIONS ARE EXPECTED TO PREVAIL THIS PERIOD. SOUTHEAST WINDS
HAVE BEGUN TO INCREASE AND WILL CONTINUE THROUGH THE OVERNIGHT AND
INTO TODAY. BY LATE MORNING WIDESPREAD GUSTS OF 35-40 KTS ARE
EXPECTED WITH A FEW GUSTS OF 47+ KTS POSSIBLE WEST OF I-29. A BRIEF
2-4 HOUR WINDOW OF MAINLY DIRECTIONAL LLWS IS POSSIBLE THIS MORNING
AS THE LLJ KICKS IN AROUND MIDNIGHT. STRONG WINDS CONTINUE THROUGH
THE AFTERNOON, GRADUALLY TAPERING OFF FROM WEST TO EAST IN THE
EVENING.
MID TO HIGH LEVEL CLOUDS FILTER IN AHEAD OF AN APPROACHING SURFACE
FRONT. A FEW ISOLATED ELEVATED SHOWERS AND THUNDERSTORMS ARE
POSSIBLE THIS MORNING. THIS AFTERNOON A BETTER CHANCE FOR SHOWERS
AND THUNDERSTORMS WILL FORM ALONG AND EAST OF I-29. CONFIDENCE IN
IMPACTS TO TAF SITES IS LOW, AND SO HAVE LEFT MENTION OUT AT THIS
TIME.
FIRE WEATHER
ISSUED AT 703 PM CDT WED MAY 13 2026
STRONG SOUTHWESTERLY WINDS WILL BEGIN THURSDAY AHEAD OF AN
APPROACHING FONT FROM THE WEST. GUSTS 40+ MPH ARE LIKELY TO DEVELOP
BY DAYBREAK AND SLIDE EASTWARD INTO MN/IA BY MID-AFTERNOON. WHILE A
FEW SPRINKLES MAY BE PRESENT AT TIMES, RELATIVE HUMIDITY VALUES WILL
STILL FALL NEAR 25 PERCENT IN AREAS EAST OF THE JAMES RIVER. WEST
OF THE JAMES RIVER, A FRONT WILL ARRIVE BY MID-DAY, TRENDING WINDS
QUICKLY DOWNWARD OR TURNING TO THE WEST. RH VALUES NEAR THE FRONT
MAY RISE SLIGHTLY LOWERING THE RISKS. RECENT DROUGHT CONDITIONS HAVE
SIGNIFICANTLY SLOWED THE SPRING GREENUP, LEADING TO INCREASED FIRE
POTENTIAL IN TALL AND EVEN SOME SHORT GRASS AREAS. WILL ISSUE A RFW
FOR AREAS WITH A LONGER DURATION OF SUSTAINED HIGH WINDS AND NEAR
CRITERIA RH.
ON FRIDAY, A VERY DRY AIRMASS WILL WORK SOUTHWARD, LOWERING
AFTERNOON RELATIVE HUMIDITY VALUES TOWARDS THE 15% MARK. WINDS WILL
BE LOWER IN MOST AREAS, BUT COULD FLIRT WITH RFW CRITERIA NORTH
OF I- 90 AND ESPECIALLY ALONG AND NORTH OF HIGHWAY 14. WILL
ISSUE A FWA TO ADVERTISE THIS POTENTIAL.
FSD WATCHES/WARNINGS/ADVISORIES
SD...RED FLAG WARNING FROM 10 AM THIS MORNING TO 7 PM CDT THIS
EVENING FOR SDZ039-040-054>056-060>062-065>071.
FIRE WEATHER WATCH FROM FRIDAY MORNING THROUGH FRIDAY EVENING
FOR SDZ038>040-052>056.
MN...RED FLAG WARNING FROM 10 AM THIS MORNING TO 7 PM CDT THIS
EVENING FOR MNZ071-072-080-081-089-090-097-098.
FIRE WEATHER WATCH FROM FRIDAY MORNING THROUGH FRIDAY EVENING
FOR MNZ071-072-080-097.
IA...RED FLAG WARNING FROM 10 AM THIS MORNING TO 7 PM CDT THIS
EVENING FOR IAZ001>003-012>014-020>022-031-032.
NE...RED FLAG WARNING FROM 10 AM THIS MORNING TO 7 PM CDT THIS
EVENING FOR NEZ013-014.
UPDATE...AJP
DISCUSSION...DUX
AVIATION...AJP
FIRE WEATHER...DUX
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