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Area forecast discussion
National Weather Service Birmingham Alabama
527 am CST Wed Nov 13 2019

for 12z aviation.


Short term...
/updated at 0356 am CST Wed Nov 13 2019/

Today and tonight.

A frigid morning across central Alabama with temperatures in the
upper teens across the northwest counties and 20s elsewhere. Since
this is considered a significant freeze, no more freeze warnings
will be issued this fall/winter season. The core of the Arctic air
mass will shift eastward to the Atlantic Seaboard this afternoon
and surface winds will become east to southeast at 5 to 10 mph.
The change in wind direction will help usher in a warmer air mass
and highs today will reach the upper 40s to lower 50s. High clouds
will spread quickly over the area tonight in advance of a
southern stream storm system. Temperatures tonight will be much
warmer than this morning with lows in the upper 20s to lower 30s.


Long term...
/updated at 0356 am CST Wed Nov 13 2019/

Thursday through Tuesday.

Models continue to converge toward the European model (ecmwf) solution for Thursday
through Saturday, indicating phasing of shortwaves in the northern
and southern streams to our west. As the two shortwaves merge,
lift may increase enough to produce a shield of light rain over
the southern two-thirds of the area on Thursday afternoon with
temperatures holding in the 40s under overcast skies. Strong
height falls over Mississippi will correspond with strengthening
isentropic lift and large-scale ascent across Alabama Thursday
night, resulting in a high chance of widespread light rain along
and south of I-20. Rain chances have been increased into the 60 to
90 percent range for this portion of our forecast area.

The forward speed of the developing upper low has decreased in
recent model runs, increasing the possibility of clouds and rain
lingering across our eastern half on Friday. A shear axis or
deformation zone may form just north of the closed upper low
Friday night and early Saturday morning, further delaying the
exit of the rain. Rain chances have been increased but will need
to be raised much higher if model trends continue.

The upper low should finally move out of our forecast area on
Saturday afternoon, leaving behind dry conditions and 50s to 60s
for afternoon highs on Saturday and Sunday. Another strong
shortwave is expected to dig across the deep south on Monday and
Tuesday with strong height falls extending well into the Gulf of
Mexico. Models currently show the strongest lift with this system
will be aimed too far south to include rain chances at this time.



12z taf discussion.

VFR conds thru the period with no cig or vsby issues. A cold and
dry Arctic high will settle over the area today. Light northeast
sfc winds this morning will become east this afternoon. Cirrus
clouds will thicken across the area tonight.



Fire weather...

Cold and dry conditions will continue today values falling into
the 30s. Widespread light rain appears likely generally along and
south of I-20 for Thursday afternoon and Thursday night. Some of
this rain could linger into Friday across our eastern counties.



Record lows for this morning.

Location record
------------- --------
Birmingham 22 (1911)
Montgomery 24 (1968)
Tuscaloosa 22 (1968)
Anniston 24 (1968)


Preliminary point temps/pops...
Gadsden 49 27 46 39 49 / 0 0 10 40 20
Anniston 50 30 47 40 49 / 0 0 10 60 30
Birmingham 50 32 48 39 49 / 0 0 20 50 20
Tuscaloosa 51 33 48 39 52 / 0 0 30 40 10
Calera 50 31 47 40 49 / 0 0 30 60 20
Auburn 50 32 47 41 48 / 0 0 40 80 50
Montgomery 53 34 49 42 51 / 0 0 50 80 30
Troy 53 34 49 43 49 / 0 0 50 80 40


Bmx watches/warnings/advisories/...
freeze warning until 10 am CST this morning for the following
counties: Autauga...Barbour...Bibb...Blount...Bullock...
Shelby...St. Clair...Sumter...Talladega...Tallapoosa...

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