Area Forecast Discussion
Issued by NWS Birmingham, AL

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FXUS64 KBMX 170604

Area Forecast Discussion
National Weather Service Birmingham AL
1204 AM CST Mon Feb 17 2020

For 06Z Aviation.


/Updated at 320 PM CST Sun Feb 16 2020/
Through Monday.

A weak upper level wave brought light rain to much of the area
today. An area of showers continues to move eastward across
southeast Central Alabama this afternoon. Elsewhere, a mix of
cloud decks are keeping temperatures in the mid 50s. The upper
level wave will move east of the area early this evening, pushing
the rain showers south and east of the area. A weak surface
reflection associated with this wave, a weak surface trough, will
remain near far southeastern portions of the area. Tonight, low
level moisture remains elevated, especially near this feature, as
mid levels dry out. A mix of low clouds and fog is expected
overnight, near and south of the I-20 corridor. Where cloud
heights are the lowest, across the south, patchy drizzle is also

Monday, temperatures rebound into the 60s and lower 70s, as we
wait for the next rain maker. Skies will remain partly to mostly
cloudy, but dry conditions through the daytime hours, with showers
returning Monday evening.


/Updated at 336 AM CST Sun Feb 16 2020/
Tuesday through Sunday.

A low pressure system is expected to lift into the Great Lakes
region early Tuesday, stretching a cold front southwards through
the Mid-MS Valley and into the ArkLaTex. This cold front will
slowly make a push southeastward toward Central AL, but likely
won`t make it here until late Tuesday night into the overnight
hours. Ahead of this front, an upper level shortwave trough lifts
out of Southern TX, and move across our area in the early morning
hours of Tuesday. This will lead to widespread showers with some
embedded thunderstorms for much of the day. PWATs are forecast to
be 1.5- 1.6", so expect periods of locally heavy rainfall. This
should be a more progressive system, so aside from localized
flooding in low- lying or poor drainage areas, we shouldn`t see a
widespread flooding threat like we saw last week.

The cold front will push through Central AL Tuesday evening and into
the overnight hours. There`s not much in the way of instability by
this point due to the widespread rain during the day, so any severe
potential is very low. The front is expected to push south and east
of our area by early Wednesday morning, though the NAM slows the
progression and hints at more of a post-frontal precip pattern that
isn`t shown in the other guidance. I`ll keep some chance of rain in
the forecast for Wednesday, but I think we should see a brief break
in the rain.

Moving into Thursday, the frontal boundary is along the Gulf Coast
and we have a cooler northerly flow move in. A weak upper level
shortwave impulse ejects eastward into our area along with an upper
level jet in a generally zonal pattern aloft. This will lead to
another round of rain showers along and behind the frontal boundary,
which will essentially include the southern half of Central AL. Rain
chances remain around 20-30% for locations north of I-20. Right now,
guidance suggests temperatures will be above freezing for locations
that see precip, so I will hold off including any winter mix precip
in the forecast right now. However, this will be a cold rain with
temperatures in the upper 30s to mid 40s.

High pressure builds in early Friday morning, clearing out any rain
chances for Central AL. We should finally be able to see some mostly
clear skies again Friday and Saturday as the ridging slides across
our area. Guidance has another system moving through the Plains
toward the end of the weekend which could bring our next shot of
rain. I`ll trend PoPs up for Sunday, but details remain uncertain as
models vary substantially on timing and evolution of the trough as
it moves through the Rockies.



06Z TAF Discussion.

Low stratus clouds are pushing northward as evident on satellite.
They are near the Interstate 20 corridor. So, have some short
tempo groups for near some in the north that cigs have not arrived
yet. All should go prevailing before too long along with some
patchy fog. Some drizzle is possible across the south (MGM/TOI)
tonight into the early morning. After 15z or so we should have a
break from precip until Monday night as a warm front moves
northeast across Central Alabama bringing showers in its wake. Low
cigs should lift to MVFR during the afternoon but clouds overall
should remain through the forecast.




Lingering rain showers will exit to the south and east this
afternoon, with a mix of low clouds and fog expected for most
areas overnight. Where cloud decks are lowest, drizzle will also
be possible. After a brief period of dry conditions tomorrow,
another round of widespread rain is expected Monday night through
Wednesday. Highest amounts of rainfall through this period will
be south of I-20. A cold front slides through Tuesday night into
Wednesday, shifting the winds more northerly. A second round of
rain moves in Thursday behind the front. Rain chances finally end
Friday through Saturday as high pressure builds in.


Gadsden     42  63  54  69  48 /  10  10  80 100  80
Anniston    45  64  55  69  51 /  10  10  80 100  80
Birmingham  45  65  58  70  50 /  10  10  90 100  80
Tuscaloosa  46  67  58  71  50 /  10  10  90 100  80
Calera      45  65  57  69  51 /  10  10  90 100  80
Auburn      47  63  56  68  57 /  20  10  70 100  90
Montgomery  50  69  59  73  57 /  20  10  80 100  90
Troy        50  70  59  72  60 /  60  10  80  90  90




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