398
ACUS11 KWNS 212139
SWOMCD
SPC MCD 212138
NEZ000-SDZ000-220015-
MESOSCALE DISCUSSION 2073
NWS STORM PREDICTION CENTER NORMAN OK
0438 PM CDT FRI AUG 21 2026
AREAS AFFECTED...PARTS OF SOUTHWEST SOUTH DAKOTA AND WESTERN
NEBRASKA
CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 212138Z - 220015Z
PROBABILITY OF WATCH ISSUANCE...60 PERCENT
SUMMARY...THE AREA IS BEING MONITORED FOR AN INCREASE IN
SEVERE-THUNDERSTORM POTENTIAL. THE PRIMARY CONCERNS ARE LARGE HAIL
AND SEVERE WIND GUSTS. A WATCH ISSUANCE IS POSSIBLE.
DISCUSSION...ISOLATED THUNDERSTORMS ARE EVOLVING ALONG A
SE/NW-ORIENTED CONFLUENCE AXIS EXTENDING FROM PARTS OF NORTHWEST NE
TOWARD THE BLACK HILLS. THIS ACTIVITY IS POTENTIALLY BEING AIDED BY
A SUBTLE MIDLEVEL IMPULSE CRESTING THE RIDGE IN THE NORTHERN PLAINS.
THE UNR 18Z SOUNDING SAMPLED STEEP DEEP-LAYER LAPSE RATES AND A
LONG/MOSTLY STRAIGHT HODOGRAPH (AROUND 40 KT OF EFFECTIVE SHEAR) --
WHICH WILL SUPPORT SPLITTING SUPERCELL STRUCTURES AND ORGANIZED
CLUSTERS. THE PRIMARY CONCERN WILL BE LARGE HAIL AND ROBUST
OUTFLOW/SEVERE WIND GUSTS. GIVEN THE SUBTLE LARGE-SCALE FORCING FOR
ASCENT AND SOME LINGERING LOW-LEVEL INHIBITION, STORM COVERAGE IS
UNCERTAIN. CONVECTIVE TRENDS WILL BE MONITORED IN THE NEAR TERM, AND
A WATCH ISSUANCE IS POSSIBLE.
..WEINMAN/THOMPSON.. 08/21/2026
..PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT
ATTN...WFO...LBF...UNR...CYS...
LAT...LON 41710107 41290158 41080255 41120337 41460384 41980401
43100398 43530387 43800363 43880335 43850292 43630206
43320144 42820100 42110085 41710107
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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