Valid 051630Z – 061200Z
…THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS OVER PORTIONS
OF MISSISSIPPI AND NORTHWEST ALABAMA…
Severe thunderstorms are expected today and tonight across portions
of the lower Mississippi Valley and Southeast, with damaging wind
gusts and a few tornadoes.
…Lower MS into TN Valley…
Morning water vapor imagery shows a strong upper trough digging
across the southern Plains. In the low-levels, a deepening surface
low currently over LA will track northeastward along the front into
parts of MS and northwest AL this afternoon and evening. The air
mass in the warm-sector has become quite moist with dewpoints in the
mid/upper 60s, with forecast soundings suggesting afternoon MLCAPE
values around 1500 J/kg. Given the increasing forcing mechanisms,
this should be sufficient for scattered thunderstorm development in
vicinity of the low and front.
12z CAM solutions suggest that convection will first form over
central LA as the large-scale forcing approaches. Low-level
vertical shear will promote some risk of discrete supercells, along
with more complex bowing structures. Forecast hodographs indicate
favorable parameters for a few tornadoes, including the risk of
strong tornadoes, as activity builds northeastward across the ENH
risk area. Damaging wind gusts and perhaps some hail are also
possible in the strongest cells.
Later tonight, another round of severe storms appears likely to form
along/ahead of the front across the remainder of the SLGT risk area.
Models are more diverse regarding timing/placement of this activity,
but sufficient vertical shear will pose a risk of a few supercells
capable of damaging winds and isolated tornadoes.