632
ACUS11 KWNS 120301
SWOMCD
SPC MCD 120300
SDZ000-NEZ000-120430-
MESOSCALE DISCUSSION 1942
NWS STORM PREDICTION CENTER NORMAN OK
1000 PM CDT TUE AUG 11 2026
AREAS AFFECTED...PARTS OF WESTERN INTO SOUTH-CENTRAL SD AND FAR
NORTHERN NE
CONCERNING...SEVERE THUNDERSTORM WATCH 569...
VALID 120300Z - 120430Z
THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 569
CONTINUES.
SUMMARY...A SEVERE WIND AND HAIL RISK MAY CONTINUE TONIGHT INTO
SOUTH-CENTRAL SOUTH DAKOTA AND VICINITY, WITH DOWNSTREAM WATCH
ISSUANCE POSSIBLE.
DISCUSSION...A WELL ESTABLISHED SUPERCELL HAS GRADUALLY TRANSITIONED
INTO A SMALL BOWING COMPLEX ACROSS WESTERN SD OVER THE PAST HOUR OR
TWO, WITH MAINLY MEASURED SEVERE WIND GUSTS UP TO AROUND 75-80 MPH.
EVEN WITH THE ONSET OF NOCTURNAL COOLING, A RESERVOIR OF RICH
LOW-LEVEL MOISTURE (WITH UPPER 60S TO LOW 70S SURFACE DEWPOINTS) AND
STEEP MID-LEVEL LAPSE RATES ARE SUPPORTING A NARROW CORRIDOR OF
STRONG INSTABILITY PER LATEST MESOANALYSIS ESTIMATES. IT IS
PLAUSIBLE THAT THE ONGOING SMALL BOW WILL TRACK EAST-SOUTHEASTWARD
ALONG THE INSTABILITY AXIS INTO SOUTH-CENTRAL SD OVER THE NEXT FEW
HOURS WHILE CONTINUING TO POSE A THREAT FOR SEVERE GUSTS AND HAIL.
TIME-LAGGED HRRR/RRFS RUNS SUPPORT THIS SCENARIO, WITH SOME MEMBERS
SHOWING SIGNIFICANT GUST POTENTIAL (75+ MPH) PERSISTING WITH
EASTWARD EXTENT. THEREFORE, DOWNSTREAM WATCH ISSUANCE IS BEING
CONSIDERED FOR PARTS OF SOUTHERN SD AND FAR NORTHERN NE BEFORE THE
04Z EXPIRATION OF SEVERE THUNDERSTORM WATCH 569.
..GLEASON/MOSIER.. 08/12/2026
..PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT
ATTN...WFO...FSD...ABR...LBF...UNR...
LAT...LON 44090277 44620168 44400022 44149883 43639818 42909843
42819932 42880113 43230277 43960281 44090277
MOST PROBABLE PEAK TORNADO INTENSITY...UP TO 90 MPH
MOST PROBABLE PEAK WIND GUST...65-80 MPH
MOST PROBABLE PEAK HAIL SIZE...1.50-2.50 IN
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