Drought in Alabama, March 1 to 19, 2024

Area Forecast Discussion
National Weather Service Huntsville AL
1052 PM CST Thu Feb 29 2024

...New AVIATION...

.NEAR TERM...
(Tonight)
Issued at 851 PM CST Thu Feb 29 2024

Low chances (20-30%) for light rain showers will continue late
this evening ahead of an upper trough shifting into the lower
Mississippi Valley and Mid South region. Precipitation chances
will increase markedly to between 60-90% late tonight into early
Friday morning as deeper lift begins to take place. The greatest
window for moderate to heavy rainfall will likely hold off until
later into the daytime hours on Friday (more on this in the
section below), but breezy SE winds will begin to pick up
overnight into the 15-20 MPH range as dense low cloud cover
settles in. Collectively, this will prevent temperatures from
dropping off much overnight, with lows in the low to mid 40s being
common. Only minor tweaks made to the forecast based on the
latest obs/trends as everything remains on track.

&&

.SHORT TERM...
(Friday through Sunday)
Issued at 324 PM CST Thu Feb 29 2024

Expect the bulk of the rainfall to become widespread and moderate
at times during the day on Friday though, as low level forcing
strengthens rain to increase in coverage and become more
widespread during the day on Friday, as upper low moves NNE and
the a surface low along the front to our south moves into
Mississippi. Models have been trending slightly heavier and more
widespread with the rainfall on Friday. This makes sense given
that the upper level trough axis with the upper low is driving the
eastward progression of the surface front with these two
interacting pieces of energy in the atmosphere. Thus keeping
closer to the slower progression eastward of other model guidance
and a longer duration of rainfall with this surface front through
Friday night. Evaporative cooling given the very dry air between
the surface and 950 mb Friday morning should help to keep
temperatures from climbing much above the 45 to 50 degree range
during the day. So a raw and rainy day expected. This will not be
a washout and don't expect many thunderstorms with it, but a solid
0.50 to 1.0 inch of rainfall looks possible through Friday night.

The longwave trough axis and surface front finally get a more
serious eastward push late Friday night. This should begin to
diminish rainfall chances mainly after midnight. Locations near
and east of the I-65 corridor will likely seen persistent light to
moderate rainfall through the evening hours. Don't expect more
than isolated to scattered rain showers after midnight through 6
AM on Saturday.

Thankfully, expect clearing Saturday morning from west to east,
in the afternoon, so it will be nice to see the sun again. With
zonal flow continuing aloft and southerly flow near the surface
continuing behind the front, temperatures will actually get
warmer. Sunshine in the afternoon should help temperatures climb
into the lower to mid 60s in most locations.

By Saturday night, a stronger storm system moves out of the
Pacific northwest into the Upper Midwest region. Southerly flow is
expected to continue ahead of it over the southeastern CONUS and
southwesterly flow aloft develops. This will keep lows warmer,
only dropping into the upper 40s to lower 50s. This may be too
cool.

During the day on Sunday, this surface low quickly moves
northeast into southern Canada. With the same synoptic setup in
place over the southeast highs should climb into the upper 60s to
lower 70s. Cloud cover right now is keeping these temperatures a
bit cooler than they could be given 925 mb temperatures. If less
cloud cover occurs temperatures could be higher on Sunday.

&&

.LONG TERM...
(Sunday night through Thursday)
Issued at 324 PM CST Thu Feb 29 2024

Beginning Sunday night, low chances of showers move into the
Tennessee Valley as ensemble data hints at an upper level trough
forming through the Central-Southern Plains and continuing
eastward. As a result of this, a sfc low is forecast to form in
the northern Rockies and a cold front may extend southward,
possibly moving into our area by Tuesday-Wednesday. There
continues to be uncertainty on the track of the aforementioned low
as well as the amplitude of the trough. Therefore, stuck with
blended guidance for rain chances which resulted in medium chances
of rain Monday through Wednesday with a low chance of producing
lightning.

&&

.AVIATION...
(06Z TAFS)
Issued at 1052 PM CST Thu Feb 29 2024

Ceilings will gradually lower over the remainder of the night as
dense cloud cover and -SHRA pushes into the area ahead of an
approaching trough from the west. MVFR conditions will develop due
to reduced ceilings/visibilities by early Friday morning and SHRA
increase in coverage. Winds will also become gusty at times out of
the SE between 15-20 kts at times. Late in the day into the
evening hours, low stratus will build in as -RA tapers off and
ceilings will drop to IFR to low-end MVFR conditions through the
end of the period.

&&

.HUN WATCHES/WARNINGS/ADVISORIES...
AL...None.
TN...None.
&&

NEAR TERM...AMP.24
SHORT TERM....KTW
LONG TERM....KTW
AVIATION...AMP.24