SPC Mesoscale Discussion: Severe Potential… Watch Unlikely

SUMMARY…Severe weather potential still appears generally marginal, but will probably maximize in the 2-6 PM CST time frame across parts of southeastern Louisiana into southern Mississippi. This may include the risk for a tornado; but, due to the isolated/marginal nature of the threat, a watch is not currently anticipated.

DISCUSSION…A gradual increase in convective development is ongoing aided by a plume of ascent driven by low-level warm advection now gradually spreading east of the lower Mississippi Valley. This is occurring coincident with daytime heating and a gradual influx of mid 60s to near 70F surface dew points across the north central Gulf coast, which may contribute to modest boundary layer destabilization (including CAPE exceeding 1000 J/kg) by 20-22Z. It appears that instability will become maximized inland of southeastern Louisiana coastal areas through the Lake Pontchartrain vicinity, where low-level hodographs may remain clockwise curved and sizable through late afternoon. The environment may become conducive to the development of a isolated supercell or two, accompanied by at least some risk for a tornado, and/or localized damaging wind gusts. This regime may attempt to spread east/northeastward into portions of adjacent southern Mississippi, before appreciable boundary layer instability likely becomes increasingly confined to the offshore waters after sunset. Otherwise, peak late afternoon instability may also be accompanied by an increasing risk for marginally severe hail, in stronger convection rooted both within and above the boundary layer.

Tags: MesoScaleDiscussion

Category: ALL POSTS, MescoScale Discussions