Probability of Watch Issuance...60 percent
SUMMARY...Isolated severe thunderstorms with primarily a strong to
damaging wind threat may develop this afternoon. Watch issuance is
possible.
DISCUSSION...Storms should continue to strengthen across middle into
eastern TN this afternoon along a trailing boundary extending
southward from a MCV in western/central KY. It appears that
large-scale forcing for ascent attendant to an upper trough over the
mid MD Valley and Upper Midwest may only glance this region. Even
so, low-level convergence along the trailing outflow boundary should
prove sufficient for additional convective development over the next
couple of hours as MLCAPE increases into the 1000-2000 J/kg range
downstream. An unseasonably strong belt of 40-50 kt southwesterly
winds is present around 700 mb from middle/eastern TN into AL and
much of GA this afternoon per VWP estimates from area radars and 17Z
mesoanalysis. As diurnal mixing of the boundary layer continues
across this region, low-level lapse rates will steepen further.
Strong to damaging winds may occur with storms as the enhanced flow
present at 700 mb reaches the surface through convective downdrafts.
Relatively greater storm coverage is anticipated across
middle/eastern TN this afternoon in closer proximity to the upper
trough, although isolated development may also occur farther south
into northeastern AL and northern/central GA. A Severe Thunderstorm
Watch may eventually be needed this afternoon for some part of this
region depending on radar trends.