By 12Z Saturday, most guidance is in agreement that the 500mbshortwave takes on a more neutral tilt (oriented N-S) over the TNValley and becomes a closed low over GA. PVA becomes maximizedover the Southeast while a surface low spawns along a coastalfront east of the Carolinas. As the 850mb low deepens over northernGA and heads east into SC, easterly 850mb theta-e advection willdirect low-level moisture around the 850mb low and support a bandof moderate-to-heavy snow from northern GA to central SC. Farthernorth, the same tongue of 850mb theta-e is funneling along the850mb front to the north of the 850mb low track from northern SCon east through the heart of NC. This is where the deformation zoneis likely to form, pivoting over central NC and northern SC with1-2"/hr snowfall rates likely. This band of heavy snow is likely toensue farther east into southeast VA, where 700mb FGEN is moreideally placed to support strong vertical velocities within a fullysaturated DGZ. Similar to NC, look for intense bands of heavy snowover southeast VA to form late Saturday afternoon and persist intoSaturday night. These bands of heavy snow in eastern NC andsoutheast VA depict 700-500mb lapse rates >6.5C/km Saturdayafternoon and evening. It is here where not only are 2"/hr snowfallrates achievable, but so is the likelihood for thundersnow. Theintense vertical velocities in eastern NC and southeast VA mayresult in some subsidence in north-central NC and south-central VA.Snowfall is still likely to reach warning criteria, but theseregions are potentially susceptible to lesser snowfall amounts asthey are caught between the influence of the strong upper-low tothe south, and the strengthening coastal low.
WPC
