WWUS20 KWNS 212103
SEL1
SPC WW 212103
ARZ000-OKZ000-TXZ000-220500-

URGENT - IMMEDIATE BROADCAST REQUESTED
Tornado Watch Number 1
NWS Storm Prediction Center Norman OK
305 PM CST Sun Jan 21 2018

The NWS Storm Prediction Center has issued a

* Tornado Watch for portions of 
  Western Arkansas
  Eastern Oklahoma
  Northeastern Texas

* Effective this Sunday afternoon and evening from 305 PM until
  1100 PM CST.

* Primary threats include...
  A few tornadoes possible
  Scattered damaging wind gusts to 70 mph possible

SUMMARY...Thunderstorms will continue to slowly increase in coverage
and intensity this afternoon into this evening from north and
northeastern Texas into southeastern Oklahoma and western Arkansas
in advance of a strong storm system progressing eastward over the
Great Plains.  The storm environment will support some threat for
semi-discrete supercells for the next few hours, and then convection
should gradually grow upscale into more of a squall line tonight.  A
few tornadoes with the supercells and/or embedded circulations, as
well as damaging winds with bowing segments, will be possible.

The tornado watch area is approximately along and 65 statute miles
east and west of a line from 30 miles west northwest of Harrison AR
to 50 miles south southwest of Tyler TX. For a complete depiction of
the watch see the associated watch outline update (WOUS64 KWNS
WOU1).

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.

&&

AVIATION...Tornadoes and a few severe thunderstorms with hail
surface and aloft to 0.5 inches. Extreme turbulence and surface wind
gusts to 60 knots. A few cumulonimbi with maximum tops to 400. Mean
storm motion vector 22040.

...Thompson