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This is the Multimedia Impact Weather Briefing for Central Alabama from the National Weather
Service in Birmingham, AL. Today is Thursday, December 19, 2013. This briefing will focus
on the possibility of severe storms from late Saturday evening into Sunday.
A dynamic storm system will develop over the Great Plains to our west on Saturday. This
storm system will move northeastward and produce adverse weather for a large part of the eastern
United States through the weekend. South of the front depicted on this map severe storms
are possible, while north of the front winter weather will be possible. Here is a map focused
on the southeastern United States. A warm, very moist and unstable atmosphere will stream
over the Southeast United States on Saturday. This will prime the atmosphere over Central
Alabama for severe weather late Saturday into Sunday.
As we head through Saturday Night, an organized line of thunderstorms should develop ahead
of the cold front. A few supercell storms will be possible just ahead of the developing
line. Due to the moisture that will be in place, instability, lift and wind shear, some
storms may be severe with damaging winds and isolated tornadoes being the main threats.
At this time, it appears the window of severe storms will be from late Saturday evening
for far western Central Alabama until early Sunday afternoon for southeastern Central
Alabama. The red highlighted area will have the greatest chance of experiencing severe
storms from midnight to 6 am Sunday morning. The cold front will move eastward across Central
Alabama during the day Sunday and end the severe weather threat. The storms should decrease
in intensity moving west to east as the main upper level system lifts out northeastward.
Looking at the severe weather relative threat levels, 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 low.
In summary, confidence in the timing of the potential severe weather across Central Alabama
is increasing, with the best time frame being between midnight and 6 am Sunday morning for
locations west of a line from Linden, to Clanton, to Talladega, to Centre. Development of isolated
cells ahead of the main line is still uncertain, but possible. The main threats will be damaging
winds and tornadoes. It appears that the tornado threat will decrease slowly the further southeast
you get on Sunday. But damaging winds will still be possible. Travelers should continue
to pay close attention to this weather system as it will affect a large part of the country
this weekend. Also, if you live in Central Alabama, please make sure you have a way to
get severe weather warnings at night when you may be asleep.
Thank you for watching this presentation today. For rapidly changing weather situations, please
see our Graphicasts, advertised on the front of our website at www.srh.noaa.gov/bmx for
the latest information. If you have any additional questions, you can also give us a call at
205-664-3010. Have a good day.