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FXUS64 KBMX 162359
AFDBMX
Area Forecast Discussion
National Weather Service Birmingham AL
559 PM CST Thu Feb 16 2023
...New
MESOSCALE UPDATE...
.
MESOSCALE UPDATE FOR SEVERE WEATHER...
Issued at 553 PM CST THU FEB 16 2023
Convection this afternoon has struggled to organize over Central
Alabama despite favorable
shear profiles and
progged thermodynamics
supportive of sustained updrafts which haven`t truly materialized
up to this point due to several limiting factors. Nearby PERiLS
upper air soundings have indicated that
capping aloft did
eventually erode, but early onset of showers and thunderstorms and
associated convective
anvil blowoff from southern Mississippi
into southwest Alabama resulted in subdued surface heating and
weaker lapse rates than anticipated across west Central Alabama
which has limited the intensity despite favorable
shear profiles.
In fact, latest observed soundings and
forecast guidance confirms
that the low-level
jet is beginning to intensify as we
head into
the evening hours leading to even more favorable
shear profiles
and
hodograph curvature. While
shear profiles continue to support
thunderstorm organization, it appears that waning
instability as a
result of poor lapse rates from congealed thunderstorms and loss
of peak heating will further limit severe potential as the
activity gradually progresses eastward. Some cells continue to
show broad
rotation, so will continue to monitor for a
tornado or
two over the next several hours. Also monitoring for localized
flooding as there has been some evidence of training with heavier
downpours in
thunderstorm activity. Based on surface
obs, the cold
front has begun to reach the AL/MS state line. Despite lingering
post-frontal showers and a few elevated thunderstorms, the severe
threat will end abruptly once the
front passes by any given
location as surface winds veer sharply.