473
FXUS64 KSHV 081718
AFDSHV

Area Forecast Discussion
National Weather Service Shreveport LA
1118 AM CST Wed Jan 8 2025

...New AVIATION...

.UPDATE...
Issued at 1057 AM CST Wed Jan 8 2025

All eyes remain hyper-focused on the incoming winter storm across
portions of our area. As such, only minor changes were made to the
inherited forecast to account for very minor trends to
temperatures and dewpoint temperatures. Otherwise, no major
concerns for the rest of today. /33/

&&

.SHORT TERM...
(Today through Tonight)
Issued at 522 AM CST Wed Jan 8 2025

The early morning sfc analysis indicates arctic sfc ridging
anchored across the Plains and Lower MS Valley this morning, with
enough of a pressure gradient through to keep the air enough mixed
over our region. Meanwhile, the early morning satellite imagery
continues to depict extensive elevated cigs that has shifted E
across the Srn Plains and Lower MS Valley, as well as stubbornly
persistent stratocu cigs that have again backdoored SW into NE and
Cntrl LA. The combo of this pressure gradient and the cloud cover
has again kept min temps up this morning, with most locales
holding near or just below 30 degrees, with minimal change
expected through daybreak before a slow climb in temps begin.
Model guidance Tuesday suggested that the stratocu cigs over NE LA
would eventually thin/scatter out, but that didn`t happen while
this morning`s guidance hasn`t even initialized on these low cigs.
However, the cigs are wrapping around the periphery of the sfc
ridge, with the expectation of some erosion on their NE flank
later today per satellite trends, which should give way to
similar if not slightly milder temps than what was observed
Tuesday. Some thinning of the elevated cigs may occur at times as
well, but should eventually thicken up again from the W tonight as
the closed low over Nrn Baja continues to slowly dig farther SSE
along Baja and the Gulf of CA. The thickening of the elevated cigs
tonight should also help to slow the rate of the temp fall again,
with readings again falling into the mid/upper 20s across most
areas.

Then we await the deepening moisture profile and associated
forcing ahead of the closed low as it begins to open up/eject NE
across Nrn Old MX Thursday as it becomes absorbed into an upstream
trough digging through the Nrn and Cntrl Rockies.

15

&&

.LONG TERM...
(Thursday through Wednesday)
Issued at 522 AM CST Wed Jan 8 2025

Much of the focus of the long term discussion will be on our
pending winter storm, as cigs will quickly spread ENE and thicken
after daybreak Thursday. Overrunning will be delayed until later
in the afternoon and especially into the evening, with mainly
isentropic forcing expected by mid and late morning, resulting in
a mainly areas of IP/-SN in the morning which will gradually
saturate and evaporatively cool the column with time from W to E
through the afternoon. Thus, max temps will occur during the
morning across SE OK/E TX before slowly falling through the
afternoon, with the milder temps expected farther E across NE LA.
Have again undercut the NBM max temps Thursday to account for
this, with increased overrunning later in the afternoon N of the
developing sfc low along the Middle TX coast resulting in warmer
temps aloft migrating N allowing for more of a changeover to SHRA
over Deep E TX, and a mix of IP/-FZRA closer to the I-20 corridor.
Considerable discrepancies still remain through amongst the short
term progs as to the strength/depth of the warm lyr, with the
NAM/GFS both suggesting more of a changeover to -FZRA than IP,
especially where sfc temps can fall to/below freezing.

The GFS has trended colder and more in line with the consistent
NAM which continues to suggest that 2M temps falling to around
freezing by mid to late afternoon, where ice accumulations are
possible on exposed surfaces. Meanwhile, the various CAMs are a
bit colder and suggest more widespread icing accumulations via
FZRA farther S across Lower E TX/N LA for a longer duration until
temps can warm with the increased overrunning Thursday night.
Thermal profiles still depict mostly snow especially along and N
of the I-30 corridor of NE TX/SW AR, where the greatest snowfall
accumulations of 3-6+ inches are expected.

Attm, have the highest confidence for accumulating ice and snow
just N of the I-20 corridor of E TX into SW AR as temps should
fall/remain below freezing, where the Winter Storm Watch has been
upgraded to a Winter Storm Warning from 12Z Thursday through 18Z
Friday. Have maintained the Winter Storm Watch as is for the I-20
counties and parishes in E TX/N LA along the AR border, as snow
accumulations should quickly taper off although some icing
accumulations are still expected over these areas. Will allow the
Day shift to interrogate the various 12Z model data and decide
whether the current Watch area and/or areas to the south will need
a Warning or an Advisory. However, the latter will ultimately be
dictated as to how the freezing line evolves from late afternoon
through the overnight hours Thursday night as the precipitation
increases ahead of the opening/positive tilt upper trough and
intensifying regime N of the sfc low that will move along the SE
TX/SW LA coasts. Increasing warm air advection aloft, which should
translate into a slow warming of temps at the sfc with the
falling precip, should also gradually narrow the extent of mixed
precip Thursday night. In addition, even with temps at freezing,
the increasing intensity of the cold rains from the S will also
limit icing accumulations, and primarily confine this to elevated
surfaces such as bridges and overpasses.

The deeper wedge of colder air will eventually begin to slide SE
through Srn AR/N LA Friday morning on the backside of the sfc low,
as it ejects NE across SE LA/Srn MS. Thus, the mixed to liquid
precip should eventually change back over to -SN before
diminishing from W to E through the morning/early afternoon.
Wrap-around low stratus will linger though on the backside of the
departing system, with these cigs and the snow/ice pack and wet
grounds limiting any warmup. Should finally seen some clearing of
these cigs late Friday night, with slowly moderating temps
expected this weekend with increased insolation once the flow
aloft flattens out in wake of the departing upper trough. Near to
below normal temps and dry conditions should persist throughout
the remainder of the extended.

Thank you WFO`s FWD, TSA, and LZK for collaboration this morning.

15

&&

.AVIATION...
(18Z TAFS)
Issued at 1111 AM CST Wed Jan 8 2025

For the 08/18Z TAFs, VFR conditions will prevail for the majority
of this forecast period with SKC along the I-49 corridor and
building high clouds from the west this afternoon. CIGs look to
remain VFR through the evening and towards midnight, with
descending cloud decks towards daybreak ahead of our next
impactful weathermaker. East Texas terminals may begin to see
mixed precip impacts by or shortly after 09/12Z, but confidence
in timing and type of precip is not sufficient to prevail
conditions at this time. Northerly winds will continue at speeds
of 5 to 10 kts through the afternoon with gusts of up to 15 kts
possible, becoming light after sundown.

SP

&&

.SPOTTER INFORMATION STATEMENT...
Issued at 522 AM CST Wed Jan 8 2025

Spotter activation will not be needed through tonight.

&&

.PRELIMINARY POINT TEMPS/POPS...
SHV  29  38  33  38 /   0  80 100  80
MLU  25  42  33  39 /   0  30 100  90
DEQ  22  34  29  35 /   0  80 100  60
TXK  24  35  30  37 /   0  70 100  70
ELD  23  37  29  36 /   0  50 100  90
TYR  29  35  31  38 /   0  90 100  50
GGG  27  36  31  38 /   0  90 100  60
LFK  29  39  34  40 /   0  90 100  60

&&

.SHV WATCHES/WARNINGS/ADVISORIES...
AR...Winter Storm Warning from 6 AM Thursday to noon CST Friday for
     ARZ050-051-059>061-070>073.

LA...Winter Storm Watch from Thursday morning through Friday morning
     for LAZ001>004-006.

OK...Winter Storm Warning from 6 AM Thursday to noon CST Friday for
     OKZ077.

TX...Winter Storm Warning from 6 AM Thursday to noon CST Friday for
     TXZ096-097-108>112-124>126.

     Winter Storm Watch from Thursday morning through Friday morning
     for TXZ136>138.

&&

$$

SHORT TERM...15
LONG TERM....15
AVIATION...26