Valid 111300Z – 121200Z
…THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS PARTS OF THE
Isolated damaging winds and a brief tornado are possible across
parts of the Southeast States this afternoon.
Overall severe risk appears rather limited. After expansion of the
Marginal Risk area in the prior outlook, only categorical change
this outlook is to trim risk area in central AL based on expected
midday frontal position.
A broad swath of stratiform rainfall is ongoing with a low-level
warm advection regime from the southern Appalachians to the Lower
Mid-Atlantic region. This regime will quickly translate east off the
coast through midday. Modest diabatic surface heating should occur
in its wake from the South Atlantic Coastal Plain southwest towards
the central Gulf Coast ahead of a southeast-moving cold front. In
the mid-levels, minimal height change amid southwest flow will allow
a continuation of weak lapse rates, yielding meager MLCAPE to around
500 J/kg. Modest low-level convergence along the front may support
isolated lower-topped convection during the afternoon. Sufficient
deep-layer shear will exist for a few organized updrafts, but the
limited buoyancy and lack of greater large-scale ascent will likely
temper overall convective intensity/coverage. It is plausible that
severe storms may fail to develop entirely or remain quite sparse.