511
FXUS64 KSHV 061753
AFDSHV

Area Forecast Discussion
National Weather Service Shreveport LA
1253 PM CDT Mon May 6 2024

...New AVIATION...

.UPDATE...
Issued at 1055 AM CDT Mon May 6 2024

The mid-morning satellite imagery indicates some cu towers
developing across portions of E TX/extreme SE OK into Wrn LA,
ahead of a weak mid level shortwave trough analyzed over ECntrl
TX. This coincides with some weak radar returns over these areas,
with a more definitive SHRA that continues to lift NNE from Ern
Shelby County TX into Srn Desoto Parish LA. Despite the extensive
stratus shield in place, warm advection and some insolation has
resulted in SBCapes climbing to 2000-2500 J/kg over much of the
region, with the combined forcing between the two yielding an
increase in convection especially as we move through the
afternoon. The latest RAP also suggests that lapse rates will
steepen enough this afternoon especially over E TX/SE OK in VC of
this trough, which would suggest that isolated strong to severe
storms would be possible. However, this threat would be brief
before diminishing during the evening once daytime heating is
lost and the parent shortwave trough shifts NE out of the area.

Since the convection is expected to remain scattered, have bumped
down likely pops to high chance, with mid and low chance pops
remaining over SCntrl AR/Ern sections of NCntrl LA. Did not make
any adjustments to max temps, as some insolation should result in
temps climbing into the mid/upper 80s this afternoon.

Have also removed the Dense Fog Adv headline for SE OK/Nrn
sections of SW AR as sfc observations and traffic cams indicate
that the morning fog has lifted.

Zone update already out...grids will be available shortly.

15

&&

.SHORT TERM...
(Monday through Tuesday)
Issued at 324 AM CDT Mon May 6 2024

Quiet start to Monday as temperatures through the morning hold in
the upper 60`s and low 70`s. Early morning RGB NT Microphysics
imagery showcases low clouds working across the FA with some
patchy to dense fog appearing on area ASOS. Given dense fog
development already in progress across the I-30 corridor, a Dense
Fog Advisory has been issued until 9 AM CDT. Elsewhere, patchy fog
should linger through sunrise before burning off by mid morning.
Low clouds will exist across the region through much of the day,
but should see enough breaks in the clouds to allow for sfcT`s to
climb into the mid to upper 80`s.

Aloft, weak upper ridging west of the CWA will work overhead through
the late morning, before sliding east by the afternoon. That being
said, shortwave troughing across Central TX and upper level energy
embedded within the shortwave is progged to move into the SW zones
of the FA by the afternoon. The mix of supportive GOM moisture in
association with deep surface southerlies, plus diurnal sfc
instability and embedded energy aloft within the progressive
shortwave should help to promote some thunderstorm activity this
afternoon across the Four State Region. While local severe probs
remain far lower when compared to areas NW of the CWA, model
soundings this morning, along with HREF UH profiles, showcase the
potential for stronger updrafts, with lapse rates of 7-8 deg
C/km, in a region of supportive SBCAPE values. All of this to say
that a few stronger thunderstorms, where hail production and
gusty winds, along with frequent lightning, can not be ruled out.

Latest Storm Prediction Center (SPC) outlook for the Day 1 period
continues to carry a Slight Risk (level 2 of 5) just northwest of
the I-30 corridor, with an extending Marginal Risk (level 1 of 5)
further south across SW Arkansas and NE Texas to cover the
forecasted decay of what is left on the southern side of the
severe threat across Central Oklahoma later today. General
consensus across the morning CAM suite is for the linear composite
to decay as it enters into McCurtain County early tomorrow AM.
For now, not ruling out some gusty winds as the line moves in. We
will need to closely monitor trends through the afternoon on the
fluid severe probs north of the I-30 corridor late this evening.

By Tuesday, mostly dry conditions will prevail locally, though
there remains some low end probs for thunderstorm development as
highlighted in the Day 2 SPC outlook. Similar to yesterday`s
afternoon package, guidance still promotes little to no
thunderstorm development, with local rain chances still near 10
percent. Heat will start to become a headline as we return to the
upper 80`s, nearing 90 deg F Tuesday afternoon. Muggy afternoon
conditions will support heat indices returning to the mid to even
upper 90`s in some spots, as Td`s hover in the low to mid 70`s.

RK

&&

.LONG TERM...
(Tuesday Night through Monday)
Issued at 324 AM CDT Mon May 6 2024

By Wednesday, troughing near the Four Corners will lead to ascent
across the Southern Plains, supporting the return of increased
severe probs locally for the Four State Region. Modest
instability, steep lapse rates and ample bulk shear values will
aid in the chance for mature thunderstorm development as lift
associated with an advancing cold front meets an unstable airmass
ahead of the boundary. Based on the latest NWP solutions,
convective initiation would be sometime in the late afternoon,
evolving through the early evening, possibly carrying over into
the overnight period as the front advances south through early
Thursday AM.

As a result of the advertised setup, the latest Day 3 outlook from
the Storm Prediction Center advertises an expansive Enhanced (level
3 out of 5) severe threat across SW Arkansas, through SE Oklahoma,
into NE Texas. This just barely enters NW Louisiana. A Slight Risk
(level 2 of 5) exists for much of the remaining sfc area of the CWA.
The aforementioned boundary will slowly work across the southern
zones through Thursday/Thursday afternoon. Not ruling out additional
thunderstorms across the southern zones early Thursday afternoon,
but this remains somewhat uncertain at this time as it will depend
on the forward speed of the front, and it`s timing with diurnally
driven instability across SE TX and south-central Louisiana.

By Friday AM, the front will have cleared the FA with sfc high
pressure following behind. As a result, a gradual return to some
below or near normal temperatures will be in order following
warmer temperatures both Tuesday and Wednesday. This far out,
guidance still suggests the chance for additional showers and
thunderstorms by the end of the upcoming weekend, and into early
next week. That being said, given the uncertainty this far out,
trends in the guidance will need to be closely monitored through
the week.

RK

&&

.AVIATION...
(18Z TAFS)
Issued at 1239 PM CDT Mon May 6 2024

Patches of MVFR broken ceilings continue at midday, especially
across E TX and along and northwest of the I-30 corridor, but
trends are towards most areas (maybe aside from TYR) becoming VFR
within a few hours. Isolated showers and thunderstorms have
started to initiate recently across central and eastern portions
of the Four State region over the last couple of hours and expect
isolated to scattered activity of this sort to expand across the
entire region through the afternoon. For this reason, VCTS
included at most TAF sites, starting roughly around 20 UTC. Still
don`t high confidence in impact at any particular TAF site at
present and amendments will come when there is confidence to the
latter. Any direct storm impact this afternoon could bring brief
gusty winds, frequent lightning, small hail, and heavy downpours.
Away from storms, expect south to southeast winds of 10 to 15 mph
this afternoon and gusts up to 25 mph are possible, especially
across E TX. Most of the convection should diminish this evening
and significant severe thunderstorm activity is likely to remain
to the NW and N of a large majority of our region tonight.
Otherwise, low clouds of MVFR to IFR levels should build back in
from the south later tonight and not improve until later tomorrow
morning. Visibility reductions will be rather isolated. Some
isolated light showers or sprinkles will be possible later
tonight through tomorrow morning, but any impact should be low.
Finally, expect winds to remain somewhat elevated through the
night with a veering to more SW wind tomorrow morning. /50/

&&

.PRELIMINARY POINT TEMPS/POPS...
SHV  86  73  89  72 /  50  10   0   0
MLU  88  71  88  71 /  30  10  10   0
DEQ  83  66  85  66 /  50  40   0  10
TXK  85  71  87  70 /  50  30   0  10
ELD  85  69  87  68 /  40  20   0  10
TYR  84  72  87  71 /  50  20   0   0
GGG  84  72  87  71 /  50  10   0   0
LFK  85  72  90  71 /  40   0   0   0

&&

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

$$

SHORT TERM...15
LONG TERM....53
AVIATION...50