Valid 241630Z – 251200Z
…THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS EASTERN
A tornado or two and isolated damaging winds are possible this
evening through tonight across the eastern Carolinas.
No changes have been made to inherited Marginal Risk.
A closed mid-level low and attendant surface cyclone over the Mid-MS
Valley will gradually move northeast and occlude towards southern
Lake MI. Secondary weak cyclogenesis will occur across the Piedmont
of NC/VA tonight in advance of an embedded mid-level speed max
progressing eastward from the Gulf Coast States to the Carolinas.
Some increase in low-level moisture is expected across the South
Atlantic Coastal Plain in response to southerly low-level flow from
the FL East Coast and gradual erosion of a currently cool air mass
inland. Surface dew points should only reach around 60 F with mean
mixing ratios approaching 11 g/kg, yielding a plume of weak MLCAPE
from 250-750 J/kg across the Savannah Valley to southeast NC
Convergence along/just ahead of the cold front trailing from the
slowly deepening surface cyclone will increase this evening and
persist as a zone of focused ascent through tonight. A band of
generally elevated convection is expected to form across central NC
with trailing portion towards coastal SC becoming surface-based,
shifting east through the night. Deep-layer vertical shear will
favor the potential for a couple embedded supercells, but the
limited buoyancy will likely preclude greater sustainable coverage.
Low-level hodographs will be adequate for a tornado or two, along
with isolated damaging winds, mainly across eastern SC into