SPC Mesoscale Discussion: Severe Potential… Tornado Watch Likely

SUMMARY…The initial signs of discrete convective development are occurring late this morning in the warm sector. Rapid environmental changes are forecast to occur between 10am CST/11am EST and the mid afternoon.

DISCUSSION…Visible satellite imagery shows widespread cloud cover across the destabilizing warm sector to the south of the primary frontal zone where the surface low is forecast to develop eastward across central AL into north-central GA later today. Surface dewpoints over the FL Panhandle and far southern AL have risen around 3 degrees F in the past hour and are indicative of strong poleward moisture advection occurring as the surface cyclone develops. The warming/moistening are contributing to MLCAPE increasing from near 0 J/kg to upwards of 1000-1500 J/kg by early-mid afternoon. Late morning VAD data show around 35-45 kt southwesterly 700mb flow from KMOB/KBMX/KMXX/KEOX in central and southern AL but stronger flow (50-55 kt) is now being observed farther west in Jackson, MS (KDGX) and Slidell, LA (KLIX). Models show the flow intensifying further over AL and GA this afternoon (55-60 kt 700mb). The end result is a hodograph exhibiting little weakness (no veer-back-veer tendency or a weak layer of winds). In summary, as moderate buoyancy and strong/veering flow through the profile combine with moist low levels, the threat for strong low-level mesocyclones associated with the discrete storms will increase, along with a corresponding risk for tornadoes of which a few may be strong.

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