288
FXUS64 KSHV 201140
AFDSHV

Area Forecast Discussion
National Weather Service Shreveport LA
640 AM CDT Sun Apr 20 2025

...New AVIATION...

.SHORT TERM...
(Sunday through Monday)
Issued at 1254 AM CDT Sun Apr 20 2025

Much like 24 hours ago at this time, shields are holding so to
speak with again, strong to severe thunderstorms and flash
flooding going on upstream of the Piney Woods of NE TX and
just upstream of our portion of the Ouachitas across SE OK.

That will be changing as we go through today into tonight with the
arrival of a strong cold front that will finally begin edging our
way later today. The cold front will find its legs due in part to
the stubborn longwave trough across the Intermountain West that will
finally eject out into the Southern Plains today, filling as it
does so. Large scale ascent and frontal forcing will be the key
players in what should be a noticeable uptick in storm coverage as
we go through the day into the evening hours. The likelihood of
severe thunderstorms across our region today/this evening is more
difficult to nail down and will be more conditional depending on
just how unstable our warm sector will be today in advance of the
cold front. As we approach sunrise this morning, we should begin
seeing warm air advection showers/isolated thunderstorms
developing first across our northwest half with this uptick in
storm coverage spreading eastward, encompassing portions of SW AR
and N LA through late morning and that could postpone sufficient
instability from developing ahead of the cold front that will
begin pushing into our northwest zones somewhere between 18z-21z.
Progs, particularly the latest HRRR and a majority of CAM output
show convection exploding along the frontal boundary in the
21z-00z timeframe along a line from near LFK to SHV to just west
of ELD and this will be highly dependent again on just how much
instability the front will have to work with as we are beginning
to lose the upper level support of the ejecting trough to our
north by this time. Still think that large hail and damaging
thunderstorm wind gusts will be the primary threats with this
event late this afternoon into the evening hours but low level
directional shear is sufficient enough near and especially north
of the I-20 Corridor for the possibility of isolated tornadoes
through this evening as well. The severe weather threat should be
over north and west of this Lufkin to Shreveport to Texarkana line
by 00z this evening and have tried to adjust grids to support the
frontal positioning by this time.

The additional threat late this afternoon and especially this
evening is an excessive heavy rainfall and flash flooding threat
that will begin to materialize itself along the frontal boundary
across Deep East Texas into Northwest Louisiana and South Central
Arkansas. Progs are in pretty good agreement that the frontal
boundary will slow down dramatically as it gets east of the Piney
Woods and assuming we do see this rapid growth of convection along
the slowing frontal boundary, could easily see training of
thunderstorm cells which will result in a very narrow corridor of
excessive heavy rainfall so have added this wording to the weather
grids as well.

Thinking is the severe threat will end by mid to late evening
across our region with the flooding theat likely diminishing as
well by late evening into the overnight hours as the frontal
boundary continues to shift slowly south and east through our
parishes but the frontal boundary will likely still be located
somewhere near the lower end of Toledo Bend to south of MLU by
sunrise Monday Morning.

On Monday, kept a pretty tight gradient pop wise across our
southeast half due to the proximity of the frontal boundary still
hung out across our southeast parishes during the day but
instability and rainfall rates should not pose too much of a
severe and/or flooding threat once we transition from late
tonight into the day Monday.

13

&&

.LONG TERM...
(Monday Night through Sunday)
Issued at 1254 AM CDT Sun Apr 20 2025

The above mentioned front will begin returning back to the north
as a warm front Monday Night into Tuesday and this will result in
the returning of more showers/isolated thunderstorms during this
timeframe. As has been mentioned in previous long term
discussions, while we will be done with the effects of this
current trough to start the work week, broad southwest flow aloft
will continue across the Southwest Conus and into the Southern
Plains through the entire upcoming work week. The returning
frontal boundary will mean returning low level moisture and there
will be perturbations or spokes of forcing coming our way from
this progressive flow aloft that will generate periods of showers
and thunderstorms and some of this will be heavy at times through
the work week. Right now, those days of the best storm coverage
appear to be Wednesday and then maybe a brief break before
another round of rather widespread storm coverage sometime
Thursday into Friday. The likelihood of severe weather during this
timeframe is a little less certain given the absence of more
significant forcing with these perturbations but given the amount
of moisture that will be in place, periods of heavy rainfall can
certainly be expected with additional rises on area lakes and
river a pretty good bet as well. Expect to hear more on the
potential flooding theat, especially across the Middle Red River
Valley of NE TX, SE OK and SW AR throughout the upcoming week.

13

&&

.AVIATION...
(12Z TAFS)
Issued at 625 AM CDT Sun Apr 20 2025

Some spotty showers are beginning to develop in northeast TX ahead
of the slow moving surface boundary. These spotty showers will
still be possible in these areas through the morning, eventually
dissipating with minimal impacts. The main line is still expected
to move eastward into the Ark-La-Tx through the afternoon and into
tonight. Winds will shift from the southeast to the west and north
after the boundary moves through. Many sites will stay in the
range of VFR/MVFR ceilings and visibilities through the period,
but KLFK may drop to IFR ceilings at the end of the period due to
the front being slow to fully exit the region. /57/

&&

.SPOTTER INFORMATION STATEMENT...
Issued at 1254 AM CDT Sun Apr 20 2025

Spotter activation will likely become necessary today, especially
during the afternoon into the evening hours across portions of the
Four State Region for the onset of strong to severe thunderstorms
and the possibility of localized flooding.

13

&&

.PRELIMINARY POINT TEMPS/POPS...
SHV  84  62  82  65 /  80  80  20  20
MLU  86  65  77  65 /  30  70  70  30
DEQ  77  48  79  53 /  80  10   0   0
TXK  81  54  81  59 /  90  30   0  10
ELD  85  58  82  59 /  80  80  20  20
TYR  80  55  82  62 /  80  10   0  20
GGG  83  56  82  60 /  80  40  10  20
LFK  85  63  80  65 /  80  80  40  20

&&

.SHV WATCHES/WARNINGS/ADVISORIES...
AR...None.
LA...None.
OK...None.
TX...None.
&&

$$

SHORT TERM...13
LONG TERM....13
AVIATION...57