Area forecast discussion
National Weather Service Birmingham Alabama
1052 PM CDT Friday may 17 2013
Update...
mesoscale update and late evening update.
&&
Discussion...
Showers and storms have finally decreased in intensity due to the
loss of daytime heating this evening...but several storms were
able to achieve severe limits with large hail being the primary
Mode of severe weather. Looking at the current mesoanalysis
setup...a weak surface trough remains draped across northern
portions of central Alabama...which helped to trigger the severe
storms earlier this evening due to over 2000 j/kg of cape with
lifted indice's over -6 based on rap analysis. A sharp moisture gradient
exists across the state...with near 70 dewpoints across all of
central and western Alabama...but lower 60s to upper 50s dewpoints
along the state line. Based on the reduced instabilities and the
lack of any upward vertical motion ongoing...we should finally
begin to see any organized convection dissipate. However...with
some instability and lift still present...pop-up showers and
storms will continue to be likely during the overnight hours due
to the slow moving surface trough continuing to push through.
Periods of heavy rainfall will be possible as precipitable waters on the 00z
kbmx sounding are indicating well over 1.50 inches. A few areas
that observed heavy rainfall earlier this evening could encounter
ponding of water on roadways in a few poor drainage areas. Updates
are already out.
56/gdg
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Aviation...
00z taf discussion.
Widespread showers and storms have spread over much of central
Alabama late this afternoon ahead of a large outflow boundary.
Thunderstorms and rain was added to the short term for keet and kbhm as the boundary
moves through with a temporary wind shift to the northwest
following the passage of the boundary. The boundary has gone
through ktcl...and the majority of the thunderstorms and rain has moved through.
However...a few showers will remain possible through the evening.
For kanb...generally rain will be expected with a few embedded
thunderstorms and have opted to go with thunderstorms in the vicinity for that location
through 03z. The southern locations of kmgm and ktoi will have
less of a chance of thunderstorms and rain development with the loss of daytime
heating...but have gone with thunderstorms in the vicinity for the early evening hours at
kmgm and no mention of thunderstorms in the vicinity or thunderstorms and rain for ktoi at this time.
For the remainder of the overnight hours...MVFR ceilings will remain
possible with most showers and storms expected to dissipate.
56/gdg
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Bmx watches/warnings/advisories...
none.
&&
$$
