Scientific Forecaster Discussion
fxus64 kbmx 060548
Area forecast discussion
National Weather Service Birmingham Alabama
1148 PM CST Thu Dec 5 2019
for 06z aviation.
/updated at 0236 PM CST Thu Dec 05 2019/
Surface ridge remains directly over central Alabama this
afternoon. Some mid and high level cloudiness was streaming over
the region also, and this will make skies on and off clouds and
sun the remainder of the afternoon especially west. Temperatures
have warmed up in spite of the clouds and all areas will move
into the 60s. Temperatures will not be nearly as cold overnight.
Boundary layer winds swing around to the south and there will
still be be on and off mid and high clouds. Most areas will
bottom out in the 40s.
The next storm system will affect the area toward sunrise and
throughout the day Friday. Overall instability is very limited and
did not even mention any thunderstorms. A rumble can not
completely be ruled out. Slightly slower progression of rain
overnight, but after sunrise, showers should make a steady west to
east movement with a large area receiving around a tenth to one-
half inch of rain.
/updated at 0325 am CST Thu Dec 05 2019/
Friday through Wednesday.
A shortwave trough and vorticity maximum moving into Alabama will
provide increasing upper-level lift and warm advection on Friday.
Rain showers should become widespread northwest of Interstate 85
by late morning and continue across the eastern counties into the
afternoon. Some showers could linger overnight in the southeastern
counties where low-level lift will be enhanced by an inverted
trough. Rain is not expected during the daytime on Saturday, but
low-level convergence and weak isentropic lift will support
overcast skies and temperatures close to raw model output.
A large area of high pressure to our northeast will be associated
with a wedge of cool air and easterly surface winds on Sunday as
southerly flow increases in the 925-850 mb layer. In addition to
persistent overcast skies, increasing isentropic lift and warm
advection may lead to drizzle and light showers. Some of this
could be measurable, and rain chances have been increased into
the 30-40 percent range for most of the area.
A stronger storm system will impact much of the eastern Continental U.S.
Early next week as a large upper-level trough takes shape. This
should bring a frontal passage and more substantial rainfall to
the area Monday afternoon through Tuesday night. Much colder
conditions will move in behind the front for Wednesday.
06z taf discussion.
VFR conditions are expected for tonight and into the morning.
Lower cigs will move in from the west with rain showers associated
with a low pressure system. During Friday afternoon MVFR cigs
will spread across the area. Cigs may go IFR at a few spots by
Friday evening as the system continues to the southeast. Rain
should begin to end from west to east during Friday evening.
A disturbance will bring rain to the area from west to east
through the day on Friday. Overcast conditions are expected on
Saturday with perhaps a few spotty light showers. Rain chances
increase on Sunday and into the upcoming week. There are no fire
weather concerns at this time.
Preliminary point temps/pops...
Gadsden 41 54 43 55 45 / 10 80 40 0 10
Anniston 43 56 45 56 46 / 10 80 40 10 10
Birmingham 45 57 47 57 49 / 10 80 40 0 10
Tuscaloosa 43 60 48 58 50 / 10 90 30 10 10
Calera 41 58 47 58 48 / 10 90 40 10 10
Auburn 43 62 48 57 46 / 0 50 50 10 20
Montgomery 42 65 50 61 50 / 0 80 40 10 20
Troy 41 67 51 60 50 / 0 70 40 10 20