I missed the ENH upgrade.. guess that was predictable with 70F dews, strong forcing and high shear. If there's a little more Cape realized, look out
...Portions of the PA/NY vicinity southward/southwestward to the
southern Appalachians...
A zone of showers and thunderstorms should be ongoing at the start
of the period from the mid Ohio Valley/Mid South region
south-southwestward to the western Gulf of Mexico, in the vicinity
of an advancing surface cold front. A secondary area of showers --
perhaps with some embedded lightning -- will be shifting quickly
northeastward across the Carolinas/Virginia vicinity. Only minimal
severe risk -- mainly in the form of gusty winds or a brief tornado
-- is apparent at this time within either of these areas of
convection through the first several hours of the period.
With time, the advance of the cold front across the southern, and
then the central, Appalachians during the afternoon in conjunction
with the strengthening upper system will result in gradual
organization of a band of frontal convection. Very strong flow
aloft will aid in the convective organization, with upscale
evolution toward a semi-continuous band of storms expected. By late
afternoon/early evening, storms will likely have become fairly
well-organized, crossing south-central and southeastern PA, MD, VA,
and the Carolinas along with attendant risk for strong/damaging wind
gusts.
Low-level wind profiles will become supportive of supercells during
the afternoon across the pre-frontal warm sector. While suggestive
of some tornado potential, pre-frontal warm-sector storms are
largely not anticipated. Still, a few mainly QLCS-type tornadoes
will be possible, given the overall dynamic/kinematic set-up --
particularly from late afternoon through mid evening.
As storms near the coast overnight, gradual weakening of the
convection -- and associated diminishing of the severe risk -- is
expected, though limited wind risk will likely extend to near the
mid Atlantic/Carolina coasts overnight.