Mesoscale Discussion 1969
NWS Storm Prediction Center Norman OK
0304 PM CDT Sat Aug 12 2023
Areas affected…eastern Ohio across Pennsylvania and into central
Concerning…Tornado Watch 634…
Valid 122004Z – 122200Z
The severe weather threat for Tornado Watch 634 continues.
SUMMARY…The threat for severe storms persists across the watch
area, and is increasing from Ohio into Pennsylvania and New York.
Isolated tornadoes remain possible, and large hail is increasingly
DISCUSSION…Widely scattered supercells currently stretch from
eastern OH across parts of northern PA and into south-central NY,
and several of these are severe, including a tornadic cell over
eastern OH. The strongest instability currently exists over OH where
the PWAT has increased substantially this afternoon. Some of this
more unstable air is spreading into northwest PA and southern NY as
well, and this trend should continue for several hours.
Deep-layer shear remains favorable for molding storms into
supercells, with winds veering with height below 700 mb, and
increasing speeds in the mid to upper levels. In addition,
temperatures aloft may cool further.
Aside from the lake breeze influence and cold front from northern OH
into IN, storms farther east over northern PA and NY have had
minimal surface convergence/focus to work with. However, such a
favorable environment for severe cells should continue to support
increasing storm severity, perhaps larger hail over time, and a
threat of a tornado or two where 0-1 SRH remains over 100 m2/s2.
…Please see www.spc.noaa.gov for graphic product…
LAT…LON 39918148 40168267 40638282 41008272 41048259 41208166
41648036 42057901 42507808 43057744 43457671 43667627
43787582 43637542 43237498 43007492 42257483 41537514
40977579 40677671 40407816 40117930 39918148