Latest from the Storm Prediction Center…
Mesoscale Discussion 1741
NWS Storm Prediction Center Norman OK
0315 AM CST Fri Dec 28 2018
Areas affected…southwest AL…far southern MS
Concerning…Severe potential…Watch unlikely
Valid 280915Z – 281015Z
Probability of Watch Issuance…20 percent
SUMMARY…The potential for mesocyclones may maximize with quasi-discrete storms as they merge with the squall line. A modest
conditional risk for a brief/weak tornado and/or wind damage would likely focus with rotating convective structures.DISCUSSION…Recent surface analysis places a warm front over southwest AL extending east but arcing to the southeast towards Dothan. South of the boundary, surface-based buoyancy (750-1000 J/kg SBCAPE) will support updraft vigor in combination with low-level shear aiding in storm organization. It seems a condition of a stronger/deeper and more persistent updraft (characterized by echo tops exceeding 30,000 ft) is needed to potentially acquire low-level rotation. Yet, based on radar analysis during the past several hours, storm intensification may also need a favorable cold-pool-merging interaction between a quasi-discrete storm and the squall line. Given the conditional environment is favorable for storm rotation but only one storm has realized this potential, will continue to monitor activity over the central Gulf Coast.
