Area Forecast Discussion
Issued by NWS Birmingham, AL

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FXUS64 KBMX 212059
AFDBMX

Area Forecast Discussion
National Weather Service Birmingham AL
359 PM CDT Mon Oct 21 2019


.SHORT TERM...
/Updated at 0339 PM CDT Mon Oct 21 2019/
Through Tonight

A widespread area of light to moderate rainfall is slowly pushing
eastward across Central Alabama this afternoon, with scattered to
numerous heavier rain showers moving northeastward near and south
of the I-85 corridor. This activity is ahead of an approaching
cold front that has nearly stalled this afternoon near the
Mississippi River. Low and mid level winds became parallel to the
front this morning, causing the deceleration of the front. A
shortwave will round the base of an upper level trough this
evening, and push the front eastward and through Central Alabama
overnight.

Southern and southeastern counties remain the primary area of
concern for strong to severe storms through this evening. This
is the most likely area where surface instability, wind shear,
and dynamics from the approaching short wave will come together.
However, the ongoing shower activity is helping to stabilize the
airmass. Will continue to assess conditions and radar trends, but
for now will maintain the ongoing marginal and slight risk areas.

14


.LONG TERM...
/Updated at 0344 AM CDT Mon Oct 21 2019/
Tuesday through Sunday.

High pressure will move into the region on Tuesday behind a cold
front. Although the airmass behind the front will be quite dry,
mild afternoon temperatures are expected. A strong pressure
gradient should lead to breezy conditions Tuesday afternoon with
highs in the upper 60s to lower 70s. The center of the high
pressure will move close to us on Wednesday morning, allowing for
light winds and strong radiational cooling. Some locations in the
north could drop into the upper 30s with 40s elsewhere. Dry and
tranquil conditions will continue through Thursday afternoon as
the high pressure shifts toward the Carolinas.

There is significant model disagreement regarding the evolution of
the upper air pattern Thursday night through Sunday. The GFS is
much more progressive with the ejection of the shortwave and also
more aggressive with onset of southerly flow Thursday night. This
would result in rain becoming widespread after midnight. The
ECMWF shows a significant portion of the trough becoming cut off
over Texas, with much less coverage of rainfall through Friday.
This solution seems a little too slow while the GFS may be too
fast. High rain chances will be maintained for Thursday night
through Friday night with a potential for widespread beneficial
rainfall. The timeline for a frontal passage and arrival of drier
conditions remains unclear for Saturday and Sunday.

87/Grantham

&&

.AVIATION...
18Z TAF Discussion.

A widespread area of rain with embedded thunderstorms is moving into
west Central Alabama at mid day, ahead of a cold front still west of
the Mississippi River. Ahead of the rainfall, scattered to broken
MVFR cigs will spread to all terminals as low level moisture
increases. Gradient wind gusts are possible at most terminals, from
the south, up to 20kts.

As rainfall spreads eastward, cigs and vis could fall to IFR,
especially within areas of heavier rainfall. Cannot rule out thunder
or a stronger storm, with a few strong wind gusts. Rainfall will end
from west to east overnight, with IFR cigs and southwesterly winds
persisting through sunrise. The front will move through early
Tuesday morning, with winds increasing from the northwest.

14


&&

.FIRE WEATHER...

Widespread rainfall is expected through tonight ahead of an
approaching cold front. Additionally, thunderstorms are possible,
primarily across southeastern areas through this evening.
Rainfall will end from west to east overnight. Cooler and drier
conditions will follow for Tuesday through Thursday. Minimum
afternoon RH values for Tuesday and Wednesday are expected to
range from 30 to 35 percent. Moisture and rain chances return for
the end of the week.

The Alabama Forestry Commission continues to have a fire alert in
effect that includes all of Central Alabama. For more information
about restrictions, visit their web site at forestry.alabama.gov.

&&

.PRELIMINARY POINT TEMPS/POPS...
Gadsden     52  70  40  69  42 /  80   0   0   0   0
Anniston    55  70  42  69  45 /  80   0   0   0   0
Birmingham  55  70  45  71  47 /  80   0   0   0   0
Tuscaloosa  52  70  44  73  47 /  70   0   0   0   0
Calera      53  70  43  70  46 /  80   0   0   0   0
Auburn      60  71  45  69  47 /  80  10   0   0   0
Montgomery  59  73  45  72  47 /  80   0   0   0   0
Troy        60  73  45  71  46 /  80  10   0   0   0

&&

.BMX WATCHES/WARNINGS/ADVISORIES/...
None.

&&

$$


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