Valid 041200Z – 051200Z
…NO SEVERE THUNDERSTORM AREAS FORECAST…
Isolated thunderstorms may occur later today across portions of the
southeastern US and the Big Bend of Texas.
Large-scale pattern is not expected to change appreciably over the
next few days as a broad upper trough will dominate the Great
Lakes/OH Valley region. Old synoptic front that settled into central
FL is gradually losing its identity and weak low-level convergence
is expected to focus a bit farther north late day1 as a weak surface
wave evolves off the GA Coast. This boundary should focus any deep
convective threat through the period. A secondary north-south zone
of low-level confluence is forecast to extend from the FL Panhandle
into the eastern Gulf Basin; this too could aid isolated
thunderstorm development, especially just off the coast over more
buoyant air mass.
…TX Big Bend…
Weak short-wave ridging is forecast to extend across northern Mexico
by late afternoon and large-scale forcing for ascent should remain
minimal across this region. Even so, strong diurnal heating and
orographic influences should aid isolated thunderstorms, mostly
south of the international border. A few weak thunderstorms could
approach the Big Bend but overall thunder threat should remain on
the marginal side.