099
FXUS64 KSHV 062011
AFDSHV

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

...New SHORT TERM, LONG TERM...

.SHORT TERM...
(This evening through Tuesday Night)
Issued at 311 PM CDT Mon May 6 2024

Widely scattered convection is finally beginning to develop across
the region, in advance of a weak shortwave trough noted over E TX.
Some erosion/lifting of the morning stratus field has yielded
strong insolation and an unstable air mass areawide, characteristic
of SBCapes near or in excess of 3000 J/kg. Thus, additional
scattered convection development is expected to continue through
early evening, as this parent shortwave shifts NE through Srn AR/N
LA before exiting. Some additional convection may linger a little
longer though across SE OK/adjacent sections of SW AR, as a SWrly
LLJ intensifies to 40-50kts along a low level theta-e axis ahead
of the strongly negative tilt upper trough as it pivots through
Cntrl and Ern OK into the Ozarks. Very strong forcing/instability
along the Ewd advancing dryline will eventually lead to the
development of multiple supercells over Wrn and Cntrl OK later this
afternoon into the evening, which may consolidate into a linear
line as it quickly advances ENE through Ern OK into the Ozarks
overnight. Some of the latest CAMs continue to suggest that this
line may near Nrn McCurtain County OK and the adjacent Nrn SW AR
counties between 08-10Z, but will likely quickly weaken as the
best forcing aloft shunts NE away from the area with the ejecting
trough. Did place low to mid chance pops over this area for the
expected decaying convection, which may be sustained by the SWrly
LLJ and any residual instability remaining.

Hot, humid, and quiet conditions should return Tuesday, with
mostly dry conditions expected as what`s left of any mesoscale
bndrys from the decaying morning convection eventually washing
out with the onset of mixing. The sfc dry line is progged to mix E
into SE OK, NW AR into or just E of the Ozarks during the
afternoon, with some slightly drier air eventually mixing into SE
OK/adjacent SW AR. What`s left of this bndry should quickly begin
to lift back N/wash out by Tuesday night, although it could still
focus isolated convection overnight over SE OK/Nrn sections of SW
AR especially with the onset of the SWrly LLJ. Deep lyr moisture
is not expected to remain shallow, with no discernible
perturbations progged in the SW flow before eventually reloading S
of the closed low that is progged to spin over the Midwest.

15

&&

.LONG TERM...
(Wednesday through next Sunday)
Issued at 311 PM CDT Mon May 6 2024

The aforementioned closed low is progged to send a weak cold front
SE into the Srn Plains Wednesday, as it nears extreme NW AR into
SE OK/N TX by late afternoon. The GFS/ECMWF suggest that a
developing perturbation in the SW flow will help yield scattered
convection development by mid and late afternoon from NE TX into
SE OK/SW AR near and ahead of the front, coincident of very strong
instability that will develop as sfc temps near/exceed 90 degrees.
H700-500 lapse rates are progged to be steep, ranging from 7.5-8.0
C/km, thus promoting very strong updraft growth within a zone of
strong deep lyr shear. Thus, pending the strength of the
perturbation in the SW flow, severe thunderstorms appear likely
over these areas, where an Enhanced Risk has been outlined by SPC
in the Day 3 Outlook. This convection should persist into the
evening before shifting NE, with the attendant cold front
drifting S into E TX/N LA by daybreak Thursday. Depending on
whether the front temporarily stalls along/just S of the I-20
corridor Thursday or not, it appears that scattered convection
will redevelop near the bndry which could again flare up/become
severe, before finally shifting S of the area Thursday night.

Did highlight this area with mid/high chance pops Thursday
afternoon/evening, before cooler and slightly drier air begins to
spill S in wake of the cold fropa. The latest ensemble guidance
suggests that mostly dry conditions will prevail Friday through
most of the upcoming weekend, with near normal temps expected
through the period. Some of the deterministic guidance do suggest
that some weak perturbations may help enhance some convection
development this weekend, although refinements to the forecast are
likely in the coming days.

15

&&

.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  74  89  74  91 /  10   0   0  20
MLU  72  88  72  91 /  10  10   0  10
DEQ  69  86  65  86 /  40  20  20  50
TXK  73  88  72  90 /  20  10  10  50
ELD  71  87  70  90 /  10  10  10  20
TYR  73  88  73  90 /  10   0   0  30
GGG  73  88  72  90 /  10   0   0  30
LFK  73  89  72  91 /   0   0   0  10

&&

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

$$

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