Area Forecast Discussion Issued by NWS Birmingham, AL
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FXUS64 KBMX 042336
AFDBMX
Area Forecast Discussion
National Weather Service Birmingham AL
536 PM CST Thu Mar 4 2021
.UPDATE...
For 00Z Aviation.
&&
.SHORT TERM...
/Updated at 1048 AM CST Thu Mar 04 2021/
Through Friday.
The presence of stable high pressure is clearly evident on visible
satellite imagery by the expansive lack of clouds across the Deep
South. With a very dry airmass and abundant sunshine, it will feel
like Spring outside. At this hour, some areas have already
reached or exceeded yesterday`s high, so continued to trend a bit
on the warm side of guidance with highs in the lower 70s expected,
and I also slightly lowered dewpoints based on the latest trends.
After midnight, mid & high-level clouds will increase from the west
ahead of a shortwave cutoff low which will be moving east-
southeastward through the Southern Plains at that time. The
increased cloud cover should keep our overnight lows several degrees
warmer than last night. During the day tomorrow, we remain under the
influence of high pressure with any forcing still to our west, so we
stay dry with highs in the 60s north to lower 70s south beneath a
layer of mid-level clouds.
86
.LONG TERM...
/Updated at 0118 PM CST Thu Mar 04 2021/
Only minor changes to the previous long term forecast. Lack of
low-level moisture will greatly limit chances for measurable
precipitation Friday night. However, given stout mid-level lift
from the shortwave and some mid-level moisture, added in a mention
of isolated sprinkles areawide Friday night. Otherwise, went
with the cooler guidance especially on lows over the weekend with
a backdoor cold front and low dew points. Areas across the
north/east will see a freeze Saturday and Sunday nights so any
sensitive plants should be protected, but our official growing
season and frost/freeze products do not begin until March 15. For
next week, went on the warm side of guidance with stout ridging
aloft and fairly dry ground conditions.
32/Davis
Previous long-term discussion:
/Updated at 0330 AM CST Thu Mar 04 2021/
Friday night.
A cutoff low, currently near the Four Corners, will meander toward
the Lower Mississippi River Valley Friday night. As a result,
increasing cloudiness is expected, with a stray light shower
across the south. Lack of sufficient moisture really has dampened
overall rain chances as this system passes over the area. Synoptic
forcing will exit Central AL by Saturday morning nonetheless.
Saturday through Wednesday.
The overall upper-level pattern through around Monday will feature
some fashion of northwesterly flow aloft and generally stable, dry
conditions. I currently don`t have any mentionable rainfall and
expect that high pressure remains in control across the eastern
CONUS for several days. It will likely be Tuesday before any
reasonable changes to flow aloft take place as medium-range guidance
suggests ridging across the Plains breaks down and moves eastward.
This will promote a warming trend with high pressure moving into the
western Atlantic with a subsequent transition to southerly low-level
flow here. Sub-tropical ridging is currently progged to build across
the Gulf thereafter. Thus, warm weather is expected across the Deep
South next week with the primary stream of southwesterly flow aloft
to our northwest. Until a Rossby wave can win against this progged
deep-layer ridge near the Gulf Coast States, we may remain dry and
warm well into next week.
40/Sizemore
&&
.AVIATION...
00Z TAF Discussion.
Surface high pressure and dry air remain the dominant weather
features across the Southeast, leading to VFR conditions for area
terminals this forecast period.
Mid-level clouds increase from the west through tomorrow with
ceilings at or above 20kft. Winds will be light out of the north
overnight, and become northeasterly to easterly Friday morning, at
6-7kts.
14
&&
.FIRE WEATHER...
A prolonged period of relatively low afternoon relative humidity
values is expected over the next few days, but 20ft winds and KBDI
values remain below critical values. Only small/light rain chances
are expected Friday night. Relative humidity values fall below 30
percent in most areas Friday afternoon, with a few areas in the
east falling below 25 percent for a couple hours. Relative
humidity values fall into the 25 to 35 percent range Saturday and
Sunday with slightly cooler conditions, and may fall below 25
percent Monday afternoon as temperatures begin to warm.
&&
.PRELIMINARY POINT TEMPS/POPS...
Gadsden 36 65 37 59 30 / 0 10 10 0 0
Anniston 39 66 39 59 31 / 0 0 10 0 0
Birmingham 41 67 41 60 33 / 0 10 10 0 0
Tuscaloosa 42 70 43 62 34 / 0 10 10 0 0
Calera 41 67 41 60 33 / 0 10 10 0 0
Auburn 43 67 43 58 35 / 0 0 10 10 0
Montgomery 42 71 44 62 36 / 0 10 20 10 0
Troy 43 72 46 61 36 / 0 0 20 10 0
&&
.BMX WATCHES/WARNINGS/ADVISORIES/...
None.
&&
$$