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Welcome to the Multimedia Impact Weather Briefing for Central Alabama. Today is Friday, December
20, 2013. I am Meteorologist Mark Linhares and I will guide you through the presentation
today. This briefing will focus severe thunderstorm development Saturday Night into Sunday. Due
to the holidays and numerous travel plans that are starting this weekend, please stay
abreast of the latest developments as this storm system will affect travel across a large
part of the eastern Untied States. The well-advertised, dynamic storm system
looks right on track and confidence is increasing that severe thunderstorms will develop across
Central Alabama. Here is a look at the weather setup over the Lower Mississippi Valley into
the Southeast. Unseasonably warm, moist and unstable air will stream northward out ahead
of the developing storm system. There will be several lifting mechanisms that will produce
ongoing showers and thunderstorms along and ahead of this developing storm.
As we head into Saturday evening from 8 pm to midnight, an organized line of thunderstorms
should develop just ahead of a pre-frontal trough in Mississippi. This activity will
approach west central Alabama. A few storms are even possible just ahead of the developing
line. Due to the moisture, instability, lift and shear, some storms may become severe with
damaging winds and tornadoes. The red highlighted area will have the greatest chance of experiencing
severe storms as the threat area move west to east and crosses into Central Alabama.
The midnight to 4 am time frame will be fairly active. The organized line of storms will
move into west Central Alabama. Once again, a few storms are even possible just ahead
of the developing line. Severe storms accompanied by damaging winds and tornadoes are possible,
especially in the red highlighted area. During the 4 am to 8 am time frame, the line
will slow down right across central Alabama. As the main storm system lifts out to the
northeast, some of the severe ingredients will weaken slightly. But we still think there
will be a risk of severe weather including tornadoes in the red highlighted area. Beyond
8 am, confidence suffers somewhat. There will be remaining instability while some of the
other ingredients continue to weaken. Therefore, a few strong to severe storms may persist
beyond 8 am bu this time frame will need further evaluation as the event approaches.
The main threat associated with this system will be damaging straight line winds. But
there will be a chance of tornadoes, especially if isolated cells develop ahead of the main
line or if breaks develop in the convective line. The large hail and flooding threats
appear smaller but have slightly increased from previous forecast.
Here are some safety rules and definitions to remember. I'll give you a few seconds to
read these notes. Please start reviewing your safety plans now and make any appropriate
changes before the weather starts. There is a good possibility of a watch being issued
Saturday night. If a warning becomes necessary, enact your safety plan and take shelter immediately.
In Summary, Confidence in the severe threat and timing is increasing. Development of supercells
ahead of the main convective line is still somewhat uncertain, but certainly possible
and possible within the line. At this time, the greatest severe weather threat appears
to be northwest of a line from near Selma, to Clanton, to Talladega, to near Centre.
The main threats will be damaging winds and tornadoes. It appears that the tornado threat
will decrease early Sunday. But damaging winds may still be possible.
Travelers should pay close attention to this weather system as it will affect a large part
of the country this weekend. Please check back for later updates as we get closer to
this event.
Thank you for watching this presentation today. For rapidly changing situations, please see
the our graphicast, advertised on the front our website for the latest pertinent information.
If you have any additional questions, please give us a call at 205-664-3010. Have a great
day.