12AM Day 2 Convective Outlook for Saturday, February 21. THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FROM SOUTHEAST ALABAMA AND THE NORTHERN FLORIDA PANHANDLE EAST INTO SOUTHERN SOUTH CAROLINA
SUMMARY
Thunderstorms are possible across parts of the eastern Gulf and south Atlantic coast states Saturday, accompanied by at least some risk for damaging wind gusts.
Discussion
Strong west/southwest mid-level flow will be in place across the southern and eastern United States at the start of the forecast period. A subtle southern stream shortwave trough will amplify on Saturday as it interacts with this stronger mid-level flow and approaching northern stream trough.
A remnant frontal boundary will be stretched from southern North Carolina southwestward toward southeast Texas. A surface low will develop along this frontal boundary during the day on Saturday in response to the amplifying mid-level trough before quickly out to sea by Sunday morning.
Ongoing thunderstorms at the start of the forecast period should persist through the morning, as the mid-level wave amplifies and surface low develops. Along and south of the front, modest diurnal heating will result in an environment with up to 500 to perhaps 1000 J/kg of most unstable CAPE. Long, straight hodographs largely parallel to the frontal zone should favor small linear/bowing segments over supercells, despite the strong deep-layer shear present. A marginal threat for damaging wind gusts will accompany any sustained thunderstorm segment. A modest low-level jet during the morning hours may provide enough low-level streamwise vorticity to support a brief tornado or two. This threat should diminish during the afternoon as the low-level jet veers and weakens.