The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
western New York
northeastern Pennsylvania
Lake Erie
Lake Ontario
* effective this Wednesday afternoon and evening from 340 PM
until 1100 PM EDT.
* Primary threats include...
several damaging wind gusts to 70 mph possible
several large hail events to 1.5 inches in diameter possible
a few tornadoes possible
The Severe Thunderstorm Watch area is approximately along and 70
statute miles north and south of a line from 30 miles west of
Buffalo New York to 15 miles southeast of Utica New York. For a
complete depiction of the watch see the associated watch outline
update (wous64 kwns wou2).
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 210... ww 211...
Discussion... large-scale forcing for upward vertical motion ahead of
a short wave impulse moving northeast of the lower Ohio Valley is
expected to contribute to increasing thunderstorm development late
this afternoon and evening. In the presence of weak to moderate
instability... deep layer shear will be supportive of organized
convective development. A window of opportunity appears to exist
for discrete supercell development... as southerly 850 mb flow
strengthens... with one or two tornadoes not out of the question.
However... this threat is expected to be short-lived and fairly
localized... as boundary layer mixing has resulted in sizable
temperature/dew point spreads... which probably will allow outflow to
quickly undercut mesocylones.
Aviation... a few severe thunderstorms with hail surface and aloft
to 1.5 inches. Extreme turbulence and surface wind gusts to 60
knots. A few cumulonimbi with maximum tops to 500. Mean storm
motion vector 26035.
... Kerr
