128 
FXUS64 KBMX 161803
AFDBMX

Area Forecast Discussion
National Weather Service Birmingham AL
103 PM CDT Sun Oct 16 2022

...New SHORT TERM, AVIATION...

.SHORT TERM...
(This afternoon through Monday) 
Issued at 1259 PM CDT SUN OCT 16 2022

The front remains stalled to our north across Tennessee where 
periods of light to moderate showers and storms have been ongoing
all day. High clouds are streaming across Central AL from the 
west, but the airmass is still very dry over the area with higher 
moisture confined to just along and ahead of the front. As the 
parent surface low begins to deepen and drift eastward over 
Ontario later today, the northeast-southwest oriented front will 
pick up speed again and pass across the area tonight through 
tomorrow morning. Scattered showers and storms will initially 
enter our northeast counties this evening, but weak forcing will 
limit areal coverage with only widely isolated showers expected as
the front moves from the I-20 to I-85 corridors overnight. Most 
areas stay dry or see very small accumulations with this frontal 
passage.

Clouds will gradually decrease in the north tomorrow afternoon with 
perhaps a few stray showers across the south/southeast as the 
low-level trough axis rotates over the area. With winds becoming 
northwesterly again behind the front, a cooler, dry airmass begins
to build back in throughout the day. Temperatures stay warm today
with highs in the lower to mid 80s then cooler tomorrow with 
upper 60s northwest to lower 80s southeast. 

86/Martin

&&

.LONG TERM...
(Monday night through Saturday)
Issued at 249 AM CDT SUN OCT 16 2022

A highly amplified/blocky pattern will remain in place for the
first half of the period. High-amplitude ridges will be over
Greenland and the western CONUS with an embedded anticyclone over
the northern Rockies. A deep trough will extend from the North 
Pole down through the eastern CONUS, with a 528 decameter low near
the eastern Great Lakes. Breezy northerly winds will be in place
at the surface between a 1034mb high centered over the Northern 
Plains and low pressure centered over Ontario and Quebec. This 
will result in strong cold air advection as 850mb temperatures 
fall into the 0.5 percentile for this time of year, or the 0 to 
-4C range. Winds should prevent frost formation Monday night, but 
the advection should be sufficient for a light freeze in some 
locations along the Highway 278 corridor by Tuesday morning. A 
freeze watch for Monday night will probably be needed for some of 
these locations in later updates. Daily record low maximum 
temperatures will be in jeopardy on Tuesday with the winds making 
it feel even cooler. Despite the cool temperatures, dew points in 
the teens associated with the modified Arctic air mass will cause 
RH values to fall below 25 percent for a few hours. Winds stay a 
couple mph below red flag warning criteria, but fire danger will 
still be elevated.

Winds remain up through the evening hours Tuesday night, but
should become light by Wednesday morning as high pressure
approaches. With a very dry air mass, a freeze is likely across
the northern half of the area, as well as further south in the
Black Belt region, with some 20s in the typically colder northern
locations. Frost will also be likely wherever winds become calm. 
Temperatures will be a few degrees warmer on Wednesday but still
well below normal. The ridge axis will be overhead Wednesday
night, with calm winds and ideal radiational cooling conditions.
Only possible fly in the ointment would be any high clouds from a
shortwave in northwest flow aloft, but at this time do not
expect this to have an impact on temperatures. A freeze and frost
are likely across much of the area, with lows in the 20s in the
north and other typically cooler locations. Record lows will be
very much in jeopardy. 

Temperatures begin to moderate on Thursday as winds take on a
westerly component due to a surface trough over the Ohio Valley, 
but still remain below normal. Lows will be milder Thursday night,
but with light winds some areas of frost will still be possible.
Lows could reach freezing again in some of the northeastern
cooler valleys, but the growing season will have ended up there by
then. A pattern change will be in progress by the end of the
period as a North Pacific jet eventually induces troughing over
the western and central CONUS, but there are some model
differences further east regarding if an upper low closes off
somewhere near the Southeast Atlantic coast. Either way,
temperatures trend warmer through the end of the period with
continued dry conditions.

32/Davis

&&

.AVIATION...
(18Z TAFS)
Issued at 1259 PM CDT SUN OCT 16 2022

A cold front will begin moving south into Central AL this evening. 
Not only will this produce increasing cloud cover, but also widely 
isolated showers near the northern terminals after 03Z. Weak forcing 
along the front will limit coverage, so for now only mentioned VCSH 
at BHM, ANB, and ASN. Ceilings should remain above 5kft then begin 
rising north to south late in this period as the front passes by. 
Sfc winds are generally westerly at 5 to 8 kts this afternoon, light 
to calm and variable overnight, then becoming northwesterly behind 
the front tomorrow morning.

86/Martin

&&

.FIRE WEATHER...

RH values will be in the 28 to 35 percent range this afternoon for
areas along and southeast of I-59, with southwesterly 20ft winds 
remaining under 10 mph. A cold front moves through tonight and 
tomorrow with a slight chance of showers most areas, except for 
the northeast counties where there will be a bit more coverage of 
showers and a couple thunderstorms. RH values fall into the 35 to 
40 percent range north of I-20 on Monday across the north. A cool 
and very dry air mass moves in by Tuesday with RH values less than
25 percent for a few hours areawide and northwesterly 20ft winds 
between 10 and 13 mph. 

&&

.CLIMATE...

Record "cool high" temperatures for October 18:

Birmingham: 55 (1955)
Tuscaloosa: 58 (1966)
Anniston: 54 (1955)
Montgomery: 60 (2009)

Record lows for October 19:

Birmingham: 29 (1948)
Tuscaloosa: 28 (1948) 
Anniston: 30 (1948) 
Montgomery: 34 (1948)

Record lows for October 20:

Birmingham: 32 (1964,1913)
Tuscaloosa: 32 (1989,1948) 
Anniston: 29 (1948) 
Montgomery: 32 (1989)

&&

.PRELIMINARY POINT TEMPS/POPS...
Gadsden     54  71  34  53 /  40  10   0   0 
Anniston    56  72  36  53 /  20  10   0   0 
Birmingham  58  71  38  52 /  20  10   0   0 
Tuscaloosa  59  73  40  54 /  10  10   0   0 
Calera      59  73  40  53 /  10  10   0   0 
Auburn      59  77  42  55 /  10  20   0   0 
Montgomery  59  78  43  57 /  10  20   0   0 
Troy        59  80  43  58 /   0  20  10   0 

&&

.BMX WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

SHORT TERM...86/Martin
LONG TERM....32
AVIATION...86/Martin