Mesoscale Discussion 1997
NWS Storm Prediction Center Norman OK
0924 PM CDT Mon Aug 14 2023
Areas affected…parts of the North Carolina into southern Virginia
Concerning…Severe potential…Watch possible
Valid 150224Z – 150500Z
Probability of Watch Issuance…60 percent
SUMMARY…Isolated to widely scattered strong thunderstorm
development appears increasingly possible to the east of the Blue
Ridge through midnight-2 AM EDT, posing a risk for damaging wind
gusts and at least some potential for a tornado or two.
DISCUSSION…Due to initially more stable conditions to the lee of
the Blue Ridge, it is not clear that ongoing thunderstorm
development spreading across and east of the Cumberland Plateau will
maintain intensity while crossing the mountains. However, the
latest NAM, in particular, suggests that substantive destabilization
is possible during the next few hours, aided by northward low-level
moisture advection along lee surface troughing. This is forecast as
the leading edge of mid-level height falls, downstream of the
significant short wave trough turning eastward into the lower Ohio
Valley, begins to spread east of the higher terrain. Coinciding
with strengthening of lower/mid-tropospheric flow (30-40 kt in the
850-700 mb layer), including enlarging clockwise-curved low-level
hodographs, the environment may become conducive to at least
isolated to widely scattered supercell development.
Thermodynamic profiles near/east of the Blue Ridge remain the
primary uncertainty concerning severe weather potential.
Lower/mid-level lapse rates, including near the surface, may remain
weak. However, seasonably high surface dew points in the 70s F may
compensate and support some potential for a tornado or two, in
addition to the the risk for potentially damaging wind gusts.
…Please see www.spc.noaa.gov for graphic product…
LAT…LON 36078169 37767877 36707863 35228073 35288176 36078169