Quick Mesoscale Update From NWS Birmingham

A QLCS currently extends from Randolph County southwestward to Lowndes County to southeast Mississippi. This is associated with a potent low-amplitude shortwave trough and associated speed max moving through. A 1006mb surface low is centered northwest of Montgomery with a warm front extending southeastward to near Eufaula, and a cold front extending southwestward behind the QLCS. A northern line segment moving through our east-central counties is elevated but damaging wind gusts have still been able to reach the surface. Note that there is no tornado threat that far north as it is north of the front, but was included in a tornado watch to avoid having two different watches out.

Further south, activity is weaker until you reach a bowing segment/comma head structure approaching southern Lowndes County. This will be the main feature of interest as it moves eastward across our southeast counties. Instability is surging ahead of this feature as the warm front lifts northward, with 6-7F dewpoint increases at Montgomery and Troy in the past hour. This suggests that SBCAPE (surface-based instability) is likely higher ahead of the line than indicated by SPC mesoanalysis. 45-50kts of 0-3km (low-level) shear oriented perpendicular to the line and 0-1km SRH of 300-400 m2/s2 will support threats of both damaging winds and embedded tornadoes as the QLCS moves eastward across our southeast counties through midday. Also will need to watch the potential for low confidence semi-discrete supercell ahead of the line as cells are developing west of Dothan.

Category: Alabama's Weather, ALL POSTS, Severe Weather