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FXUS64 KBMX 141724

Area Forecast Discussion
National Weather Service Birmingham AL
1124 AM CST Thu Nov 14 2019

For 18Z Aviation.


/Updated at 0342 AM CST Thu Nov 14 2019/

Today and Tonight.

Extensive high clouds covered Alabama this morning in advance 
of a storm system over south Texas. The air mass over central 
Alabama is extremely dry with PWAT's less than one-quarter of an
inch. Radars to the west of Alabama show light echoes associated 
with mid level clouds, but the rain is not likely reaching the 
ground due to the presence of dry air. It will take awhile for the
air mass to saturate enough to allow the rain to reach the 
surface, and any rain this morning will likely be too light to 
measure. As the upper low lifts into east Texas later today, 
better forcing aloft will allow for the air mass to become moist 
enough for rain to develop across areas south of I-20. A northern 
stream short wave trof will phase up with the southern stream 
upper low and form a closed upper low by sunrise Friday. The 
phasing of the two systems will pull the rain northward for areas 
east of I-65, with the higher rainfall amounts across the 
southeast portions of Alabama overnight. Measurable rain this 
period will be generally along and south of I-59. The air mass 
will remain too stable for any thunderstorm development. The cloud
cover and rain will keep temperatures on the cool side, with most
areas holding in the middle to upper 40s.


/Updated at 0342 AM CST Thu Nov 14 2019/

Saturday through Thursday.

The center of a 500 mb closed low is expected to track across 
Southeast Alabama on Friday. Clouds and light rain may continue to 
plague the southeastern quadrant of our area due to enhanced lift 
associated with strong vorticity near the center of the upper low.
Temperatures in this area are likely to hold in the mid to upper 
40s during the afternoon. Other areas to the north and west should
see 50s for afternoon highs. The upper low will finally move out 
of our forecast area on Friday night, leaving behind dry 
conditions and temperatures ranging from the mid 50s to mid 60s 
for afternoon highs on Saturday and Sunday.

A series of shortwaves will dig across the Deep South and Carolinas
on Monday and Tuesday with strong height falls extending well into
the Gulf of Mexico. Models currently suggest the strongest lift 
with this system will be aimed too far south to include rain 
chances at this time. A transient ridge will move across the 
region on Wednesday with dry conditions. 



18Z TAF Discussion.

The atmosphere has increasing moisture with rainfall expected to
reach the ground by the afternoon. Only included VCSH at each TAF
site for now due to uncertainty in coverage and timing of showers
through the afternoon. This evening...most rainfall will be
limited to KMGM and KTOI...where enough low level moisture will
allow MVFR visibilities tonight through Friday morning. With 
continued cloud cover and light winds...not anticipating fog 
development in the early morning...but will amend if needed. 




Rain chances will increase this afternoon and tonight generally 
along and south of Interstate 20. Some of this rain could linger 
into Friday across our eastern counties. Dry conditions will 
return for the weekend with afternoon relative humidity values 
remaining above critical levels.


Gadsden     48  37  52  31  58 /  20  30  10   0   0 
Anniston    48  37  51  33  60 /  20  50  20  10   0 
Birmingham  49  38  52  32  59 /  20  40  10   0   0 
Tuscaloosa  50  37  55  30  59 /  20  30   0   0   0 
Calera      49  38  52  32  59 /  30  50  10  10   0 
Auburn      47  40  48  37  59 /  40  80  50  20   0 
Montgomery  49  42  51  35  62 /  50  70  30  10   0 
Troy        48  42  50  36  61 /  60  80  40  20   0 



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