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Area forecast discussion
National Weather Service Birmingham Alabama
652 am CDT Thu Sep 19 2019

Updated...
aviation discussion.

&&

Short term...
/updated at 0351 am CDT Thu Sep 19 2019/
today and tonight.

Upper level ridge axis extends northeastward from northern Mexico
into eastern Canada, between a trough along the West Coast and
Hurricane Humberto off the Atlantic coast. The only weakness in
the ridge, tropical depression Imelda, is rotating slowly
northwestward over southeast Texas. At the surface, high pressure
will amplify southward along the East Coast today, enhancing a
wedge pattern across Georgia and Alabama. A wedge front will push
westward across the area, bringing increased cloud cover this
morning and slightly cooler temperatures.

A stratus cloud deck will continue to spread into eastern areas,
reaching the I-65 corridor before sunrise. There is some
uncertainty on how quickly the cloud cover mixes out after
sunrise. If cloud cover persists longer than currently expected,
high temperatures will need to be adjusted downward by a few
degrees. For now, expect highs in the lower 80s to lower 90s,
with the coolest temps across the east. This is 10-12f cooler than
the past several days. Low level easterly flow will bring drier
air to the area, with dewpoints ranging from the mid 50s east to
upper 60s west this afternoon. This will keep heat indices below
100f.

An area of low level convergence is possible just to our southwest
today, as The Wedge front pushes westward and meets with low level
southerly flow associated with dew point Imelda. This convergent zone could
be close enough to the area for a few showers or storms across far
southwestern areas this afternoon.

Tonight, any convection diminishes with sunset. With continued
easterly surface flow, drier conditions remain across the area.
Lows will be in the upper 50s to upper 60s.

14



Long term...
/updated at 0351 am CDT Thu Sep 19 2019/

Friday through Wednesday.

The upper-level pattern will support a large area of high pressure
across the eastern Continental U.S. On Friday. With the surface high centered
in North Carolina, the airmass associated with easterly flow will
result in temperatures much closer to average for this time of year.
Afternoon highs in the mid to upper 80s are expected on Friday with
lows in the lower to mid 60 for Saturday morning. A slow warming
trend should take place over the weekend and into the upcoming week
as the high pressure retreats. 90s should become widespread for
Sunday and Monday.

An upper-level trough passing through the Great Lakes and Ohio
Valley will be associated with an approaching cold front for late
Monday into Tuesday. Rain chances are currently expected to diminish
as the front moves toward Alabama due to poor moisture quality and
weak low-level convergence. An airmass change also appears unlikely,
meaning above average temperatures should continue into Wednesday.

87/Grantham

&&

Aviation...
12z taf discussion.

A MVFR stratus deck is spreading across the area this morning, as a
wedge front pushes eastward. Expect reduced cigs at all terminals
for at least several hours this morning, before low level mixing
increases. Slowly scattered out cigs and increased heights by 15-
16z.

Winds will be from the east to southeast today, with occasional
gusts up to 18kts. Winds diminish this evening, to around 5kts.

14



&&

Fire weather...

A stratus deck with 2500-3500ft ceilings will slowly lift through
the morning, with winds remaining out of the east to southeast
through the day. A few showers or storms are possible across far
southwestern counties this afternoon. Otherwise, dry and warm
conditions will continue for the next several days. Afternoon
relative humidity values remain above 30 percent each afternoon
through the end of the week. Kbdi values will remain elevated as
drought conditions persist.

&&

Preliminary point temps/pops...
Gadsden 87 60 85 60 88 / 0 0 0 0 0
Anniston 86 61 86 61 88 / 0 0 0 0 0
Birmingham 89 65 87 64 89 / 0 0 0 0 0
Tuscaloosa 91 67 89 66 90 / 10 0 0 0 0
Calera 89 64 87 63 89 / 0 0 0 0 0
Auburn 85 62 84 64 86 / 10 0 0 0 0
Montgomery 89 64 88 65 91 / 10 0 0 0 0
Troy 88 63 87 64 89 / 10 0 0 0 0

&&

Bmx watches/warnings/advisories/...
none.

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