

153 

WWUS20 KWNS 121707

SEL1

SPC WW 121707

PAZ000-130000-



URGENT - IMMEDIATE BROADCAST REQUESTED

Severe Thunderstorm Watch Number 431

NWS Storm Prediction Center Norman OK

110 PM EDT Thu Aug 12 2021



The NWS Storm Prediction Center has issued a



* Severe Thunderstorm Watch for portions of

  Much of central Pennsylvania



* Effective this Thursday afternoon and evening from 110 PM until

  800 PM EDT.



* Primary threats include...

  Scattered damaging wind gusts to 70 mph likely

  Isolated large hail events to 1 inch in diameter possible



SUMMARY...Multiple clusters of storms are expected to intensify and

move eastward through the afternoon from west central into central

Pennsylvania.  The storm environment favors damaging winds of 60-70

mph as the primary threat, though isolated large hail near 1 inch

diameter may occur with the strongest storms.



The severe thunderstorm watch area is approximately along and 45

statute miles north and south of a line from 15 miles northwest of

Latrobe PA to 25 miles east southeast of Williamsport PA. For a

complete depiction of the watch see the associated watch outline

update (WOUS64 KWNS WOU1).



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.



&&



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

1 inch. Extreme turbulence and surface wind gusts to 60 knots. A few

cumulonimbi with maximum tops to 550. Mean storm motion vector

28030.



...Thompson

