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WWUS20 KWNS 120101

SEL7

SPC WW 120101

NEZ000-SDZ000-120800-



URGENT - IMMEDIATE BROADCAST REQUESTED

Severe Thunderstorm Watch Number 647

NWS Storm Prediction Center Norman OK

800 PM CDT Wed Sep 11 2019



The NWS Storm Prediction Center has issued a



* Severe Thunderstorm Watch for portions of

  northeastern Nebraska

  parts of central and eastern South Dakota



* Effective this Wednesday night and Thursday morning from 800 PM

  until 300 AM CDT.



* Primary threats include...

  Scattered large hail and isolated very large hail events to 2

    inches in diameter possible

  Isolated damaging wind gusts to 70 mph possible



SUMMARY...Thunderstorms are forecast to continue increasing in

coverage this evening, across the South Dakota vicinity, with

isolated severe storms gradually evolving within the larger area of

convection.  Large hail is expected to be the primary severe risk,

though locally damaging winds -- and possibly a tornado -- will also

be a possibility this evening.



The severe thunderstorm watch area is approximately along and 60

statute miles north and south of a line from 55 miles southwest of

Pierre SD to 15 miles north northeast of Sioux Falls SD. For a

complete depiction of the watch see the associated watch outline

update (WOUS64 KWNS WOU7).



PRECAUTIONARY/PREPAREDNESS ACTIONS...



REMEMBER...A Severe Thunderstorm Watch means conditions are

favorable for severe thunderstorms in and close to the watch area.

Persons in these areas should be on the lookout for threatening

weather conditions and listen for later statements and possible

warnings. Severe thunderstorms can and occasionally do produce

tornadoes.



&&



OTHER WATCH INFORMATION...CONTINUE...WW 645...WW 646...



AVIATION...A few severe thunderstorms with hail surface and aloft to

2 inches. Extreme turbulence and surface wind gusts to 60 knots. A

few cumulonimbi with maximum tops to 600. Mean storm motion vector

24035.



...Goss

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