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WWUS20 KWNS 212002

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OKZ000-TXZ000-220300-



URGENT - IMMEDIATE BROADCAST REQUESTED

Tornado Watch Number 503

NWS Storm Prediction Center Norman OK

300 PM CDT Sat Oct 21 2017



The NWS Storm Prediction Center has issued a



* Tornado Watch for portions of

  Western and central Oklahoma

  Northwest Texas



* Effective this Saturday afternoon and evening from 300 PM until

  1000 PM CDT.



* Primary threats include...

  A couple tornadoes possible

  Scattered large hail likely with isolated very large hail events

    to 2.5 inches in diameter possible

  Scattered damaging wind gusts to 70 mph likely



SUMMARY...Thunderstorm development is expected around 4pm, with an

increase in storm coverage/intensity into this evening.  More

isolated supercells with very large hail will be possible initially

across western Oklahoma and northwest Texas.  Storms will then grow

upscale into a more solid squall line by late evening, when damaging

winds will become the more common threat.  A tornado or two could

occur with the initial discrete supercells, as well as later this

evening with circulations embedded in the developing line across

central Oklahoma.



The tornado watch area is approximately along and 60 statute miles

east and west of a line from 45 miles west northwest of Ponca City

OK to 55 miles southwest of Wichita Falls TX. For a complete

depiction of the watch see the associated watch outline update

(WOUS64 KWNS WOU3).



PRECAUTIONARY/PREPAREDNESS ACTIONS...



REMEMBER...A Tornado Watch means conditions are favorable for

tornadoes and 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.



&&



OTHER WATCH INFORMATION...CONTINUE...WW 502...



AVIATION...Tornadoes and a few severe thunderstorms with hail

surface and aloft to 2.5 inches. Extreme turbulence and surface wind

gusts to 60 knots. A few cumulonimbi with maximum tops to 500. Mean

storm motion vector 24030.



...Thompson

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