Valid 151630Z – 161200Z
…NO THUNDERSTORM AREAS FORECAST…
The risk for thunderstorms appears negligible across the contiguous
U.S. through tonight.
Isolated to scattered showers are expected to continue in the
offshore waters and adjacent coastal area through tonight. Weak
mid-level lapse rates as sampled by the 12Z Miami observed sounding
and a lack of greater large-scale ascent is likely to preclude the
development of deeper convection and thunderstorms.
…Central/southern Louisiana vicinity…
A few lightning flashes cannot be entirely ruled near coastal
Louisiana around the end of the period, but overall thunderstorm
potential is still currently expected to remain low (sub-10
percent). Strengthening warm advection will result in an increase in
convective showers overnight. Sufficient moistening may
occur for scant elevated buoyancy towards the end of the period.
However, the presence of a rather dry 600-500 mb layer beneath
relatively warm 400-mb temperatures /near the -20 C level/ suggests
that convection may remain too shallow to yield charge separation
for lightning prior to 12Z Sunday.