SPC Mesoscale Discussion: Severe Potential… Watch Possible

SUMMARY…Severe potential, at least in an isolated sense, should gradually increase through mid/late morning, initially across southeast LA and far southern MS. While a Watch issuance is not imminent, observational/convective trends will continue to be monitored, and a Watch could become more probable later this morning.

DISCUSSION…Bands of increasing showers and some thunderstorms (mostly offshore at this time) exists across the region coincident with a warm/moist conveyor ahead of a cold front. The region will be increasingly influenced by an upstream upper-level trough, while richer moisture (some middle 60s F surface dewpoints) continues to develop northward/inland particularly across southeast LA. Although the 12Z observed sounding from LIX/New Orleans featured a cool stable near-surface layer, temperatures/dewpoints have already risen since, and sounding modifications/forecast soundings imply that convection could become more rooted in the boundary layer as temperatures climb through the upper 60s F and reach 70F in some cases. Accordingly, the aforementioned bands of showers should continue to deepen through the morning, with the possibility of increasing intensity and organization by late morning. Very strong low-level shear will support the possibility of a few supercells ahead of what should eventually be an organized line of convection. Overall, damaging winds along with the potential for a tornado or two will be the primary concerns, with hail magnitudes expected to be limited by convective mode and observed thin/weak overall buoyancy.

Tags: MesoScaleDiscussion

Category: ALL POSTS, MescoScale Discussions