540
ACUS11 KWNS 090136
SWOMCD
SPC MCD 090135
IAZ000-SDZ000-090300-
MESOSCALE DISCUSSION 2347
NWS STORM PREDICTION CENTER NORMAN OK
0835 PM CDT THU OCT 08 2026
AREAS AFFECTED...SOUTHEAST SOUTH DAKOTA INTO IOWA
CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY
VALID 090135Z - 090300Z
PROBABILITY OF WATCH ISSUANCE...20 PERCENT
SUMMARY...AN ELEVATED SUPERCELL OR TWO MAY PRODUCE ISOLATED LARGE
HAIL IN THE NEXT FEW HOURS. THE MARGINAL MAGNITUDE OF THE HAIL
THREAT WILL LIKELY PRECLUDE A WATCH.
DISCUSSION...ELEVATED CONVECTION HAS BEEN EXPANDING IN A
NORTHWEST-SOUTHEAST BAND FROM SOUTHEAST SD INTO IA. THE CONVECTION
APPEARS TO BE ROOTED INTO THE 850-700 MB LAYER IN A ZONE OF
LOW-LEVEL WARM ADVECTION ON THE NORTHEAST EDGE OF AN ELEVATED MIXED
LAYER. ISENTROPIC UPGLIDE WILL INCREASE THROUGH EARLY TONIGHT ON
THE NOSE OF A MODESTLY STRENGTHENING LOW-LEVEL JET, WHICH WILL
SUPPORT A CONTINUED INCREASE IN STORM COVERAGE THROUGH AT LEAST 04Z.
UPSTREAM LOW-LEVEL MOISTURE IS SUFFICIENT FOR MUCAPE IN EXCESS OF
1000 J/KG AND CLOUD-LAYER VERTICAL SHEAR IS STRONG ENOUGH TO SUPPORT
AN ELEVATED SUPERCELL OR TWO THE NEXT FEW HOURS FROM SOUTHEAST SD
INTO IA. RELATIVELY STEEP MIDLEVEL LAPSE RATES AND THE POSSIBILITY
OF SOME SUPERCELL STRUCTURES SUGGEST THAT THE STRONGEST STORMS COULD
PRODUCE ISOLATED LARGE HAIL NEAR 1 INCH DIAMETER. CURRENT
EXPECTATIONS ARE THAT THE HAIL THREAT WILL REMAIN TOO
ISOLATED/MARGINAL TO WARRANT A WATCH.
..THOMPSON/GLEASON.. 10/09/2026
..PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT
ATTN...WFO...DMX...FSD...
LAT...LON 41739455 42209562 42919727 43279783 43559770 43399662
42929532 42309382 41849302 41609297 41509353 41739455
MOST PROBABLE PEAK HAIL SIZE...UP TO 1.25 IN
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