The threat for severe weather in South Mississippi continues to look meager. There is a chance that a few low-topped supercells may develop along the line, but these storms would pose only a marginal threat for severe wind and small hail. The tornado threat remains quite low.
From the Storm Prediction Center:
Mesoscale Discussion 0063
NWS Storm Prediction Center Norman OK
1243 PM CST Sat Jan 18 2020Probability of Watch Issuance…5 percent
SUMMARY…Isolated and transient low-topped marginal supercells possible the next few hours. Overall threat is expected to remain sub-severe.
DISCUSSION…Showers have periodically intensified in area of low level confluence ahead of the front across southern MS early this afternoon. This convection has been relatively low-topped, up to around 20 kft and is not producing lightning. However, forecast soundings and 18z mesoanalysis indicate effective shear values (25-40 kt) favorable for organized, marginal supercell structures. This is further supported by VWP data from the DGX 88-D, which shows a small, but favorably curved low-level hodograph.
Overall these features have been rather transient, developing in an area where stronger surface heating has occurred in thinner cloud cover. Temperatures across parts of far southern MS into adjacent southeast LA have warmed into the low 70s F, with dewpoints in the mid 60s F, resulting in MLCAPE values as high as 500 J/kg. This should support continued periodic intensification of showers and isolated thunderstorms through the afternoon ahead of the surface cold front. However, shear is expected to decrease throughout the remainder of the daytime hours and the overall environmental parameter space is probably at its most favorable now through the next 2-3 hours. Any severe threat is expected to remain limited in time and space and any stronger cells are expected to remain transient/sporadic.
Keep your eyes to the sky and keep an ear out for thunder. But rest easy. The atmosphere is not set up to produce widespread severe weather.
