ZCZC SPCSWOMCD ALL
ACUS11 KWNS 310435 
SPC MCD 310435 
IAZ000-NEZ000-310600-

Mesoscale Discussion 1656
NWS Storm Prediction Center Norman OK
1135 PM CDT Mon Aug 30 2021

Areas affected...portions of eastern NE and extreme western IA

Concerning...Severe Thunderstorm Watch 479...

Valid 310435Z - 310600Z

The severe weather threat for Severe Thunderstorm Watch 479
continues.

SUMMARY...A threat of large hail and gusty winds continues across WW
479. Local watch extension may be needed for a small portions of
eastern Nebraska.

DISCUSSION...A couple of intense supercells, potentially producing
very large hail, are ongoing in the vicinity of Pierce and Stanton
counties in northeast NE near a stationary surface boundary draped
across eastern NE. The 00z RAOB from OAX indicated very steep
midlevel lapse rates amid strong instability. This will help
maintain well-organized cells amid 35-40 kt 0-6 km shear, and an
increasing southerly low-level jet (per latest OAX VWP data). While
these supercells are moving rather slow at around 15-20 kt, a local
aerial extension of the watch may be needed for portions of eastern
NE in the Omaha CWA given potential for a continued hail threat just
downstream from WW 479.

..Leitman.. 08/31/2021

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...FSD...OAX...GID...

LAT...LON   42479739 42399673 42169613 41509552 41039565 40879600
            40819663 41059731 41459773 41879790 42209773 42479739 

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