Area Forecast Discussion
Issued by NWS Birmingham, AL

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FXUS64 KBMX 181658

Area Forecast Discussion
National Weather Service Birmingham AL
1158 AM CDT Sun Aug 18 2019

/Updated at 1135 AM CDT Sun Aug 18 2019/

The persistent hot and dry pattern continues to hold on across
Central Alabama late this morning. Areas that are currently under
a drought category certainly will worsen as temperatures approach
the century mark once again. Taking into account observation
trends the past couple of days and not a huge change in the
airmass across much of the area, I`ve decided to increase highs
this afternoon by a degree or two in some locations. 1000-850mb
thicknesses of 1435 to 1440 meters will certainly support
temperatures near 100 degrees for many spots across the northern
half of Central Alabama. Add the drought to the picture, and more
locations could hit 100 degrees as well.

Meanwhile, a weak area of low pressure is spinning across the
Florida Panhandle, and can be clearly noted on visible satellite.
As the low moves ever slowly eastward, we`ll be on the drier
northwest side of the system. A large moisture gradient exists on
the eastern side of the low as opposed to locations west and
northwest. PWATs this morning from the KBMX 12z sounding came in
at 1.25 inches, as opposed to the 2.12 measured at Tallahassee.
With the drier air continuing to dominate, I`ve reduced PoPs
across the southeast counties from our earlier forecast so that
only our far southeast may see some scattered activity, but
elsewhere should remain dry and hot for the remainder of the day.
We`ll keep an eye on heat indices this afternoon across the
southeast counties, as a few spots are expected to approach the
105 degree mark due to the higher low-level moisture. At this
time, we`re not anticipating any heat related products to be


/Updated at 0343 AM CDT Sun Aug 18 2019/
Monday through Saturday.

A weak low-level disturbance/trough will begin developing over the
Florida Panhandle and southern Georgia on Monday in between the
upstream ridge over the southern Plains and the Bermuda High over
the western Atlantic. This general weakness southeast of the
forecast area will usher in better moisture quality and support
scattered to numerous diurnal thunderstorms through at least
Thursday. Best chances will be south of I-20 where the column will
moisten a bit better and PWATs will be 1.8 to 2.0 inches closer to
the coast. We will see temperatures gradually return to seasonal
levels as 1000-850mb thicknesses decrease throughout the week with
highs in the low to mid 90s after Tuesday, but afternoon dewpoints
will remain near 70F as moisture works back in, and heat indices
near Heat Advisory criteria will need to be monitored during the
transition period early this week.

By the end of the week, a large-scale trough moves across Quebec and
deepens into the Ohio Valley. An associated cold front will extend
southwest from the far northeastern seaboard into the central
Mississippi Valley on Friday. We will continue to see 40 to 50
percent PoPs across Central Alabama on Friday and Saturday,
especially in the north as large-scale troughing and southwesterly
low-level winds become more prevalent over the area. These values
may be adjusted upwards in later updates as the overall
confidence increases with the front. At this time, confidence
remains low on whether the front will pass through the forecast
area, but it will likely be the driving factor for rain chances in
the northern half of the state beyond this forecast period.



12Z TAF Discussion.

A surface boundary that was south of all terminals yesterday has
drifted northward to north of the Interstate 85 corridor. As a
result, more moisture is available for low cigs and fog during
the early morning hours as evident from the swath of low cigs and
fog on satellite. I have an MVFR mention for MGM and below
airfield minimums for TOI. During the afternoon and very early
evening, some diurnally induced TSRA will be possible for these
two sites as well. Expect all other terminals to remain generally
VFR for the forecast.




High pressure will continue to provide hot and mostly dry weather
across the area today with drought conditions continuing for
portions of Central Alabama. Rain chances begin increasing on
Monday, especially in the south, with temperatures returning to
normal levels through the week.


Gadsden     99  71  98  70  95 /   0   0  20  20  40
Anniston    99  72  97  71  95 /   0  10  30  20  40
Birmingham 100  74  99  74  97 /   0   0  20  20  40
Tuscaloosa  99  74  98  74  96 /   0   0  30  20  40
Calera     100  72  98  71  95 /  10  10  30  20  40
Auburn      96  72  93  72  90 /  20  10  50  30  50
Montgomery  99  74  97  73  94 /  10  10  50  30  50
Troy        95  72  95  70  91 /  30  20  60  30  60




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