827
FXUS64 KSHV 132009
AFDSHV

Area Forecast Discussion
National Weather Service Shreveport LA
309 PM CDT Mon May 13 2024

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

.SHORT TERM...
(This evening through Tuesday Night)
Issued at 309 PM CDT Mon May 13 2024

The mid-afternoon sfc analysis indicates that our warm front has
shifted N a bit more than progged, due to inverted sfc troughing
that has developed along the Middle and Upper Texas Coast. As a
result, this bndry has lifted N across SE TX into WCntrl LA, from
near a UTS, to LFK, to AQV, then SE to AQV to OPL line as of 19Z.
A couple of different small MCS`s have developed and quickly
spread into the TX Coastal Bend into SE TX this afternoon along
and just S of the front, with diurnal heating and moisture pooling
along the front contributing to SBCapes of 4000-5000 J/kg over SE
TX into SW LA. Some of the CAMs had suggested that some of this
convection may build a bit farther N into Deep E TX and NCntrl LA
late this afternoon through the evening, ahead of shortwave trough
that will traverse SE TX and Cntrl LA, and while an isolated svr
and heavy rainfall threat will remain possible through the
evening over the Srn counties of Deep E TX into NCntrl LA. Given
the widespread 3-5+ inches that has fallen over the last 36 hrs,
and any additional heavy rainfall could result in flash flooding,
have opted to keep the Flood Watch going for Deep East TX into
Cntrl LA. Fortunately, additional rainfall amounts should remain
below an inch, with the convection quickly diminishing from W to E
this evening as drier air begins to entrain ENE ahead of upper
troughing that will swing through overnight. Thus, the Flood Watch
will likely be cancelled early later this evening or early Tuesday
morning.

Narrow bands of convection have also developed along a weak cold
front over Cntrl and NE OK, with this persisting evening through
the evening as the front drifts SE into NE TX/SW AR this evening.
It`s likely that the front will not have enough push to drift
completely through the area overnight, and will eventually have to
mix E through midday Tuesday once deeper WNW winds are able to mix
this bndry E. Slightly cooler and drier air will gradually filter
E in wake of the fropa, with a couple of dry days expected. Near
normal temps are expected Tuesday, but did bump the NBM max temps
up a degree or so to account for stronger insolation and its
typical cool bias.

15

&&

.LONG TERM...
(Tuesday night through next Sunday)
Issued at 309 PM CDT Mon May 13 2024

Sfc ridging will build SE into the region Tuesday night, setting
the stage for good radiational cooling and resulting in cool
conditions areawide. However, temps will quickly rebound with
strong insolation Wednesday, and as ridging aloft builds E over
the region. The flow will quickly become SW by Thursday ahead of
troughing that will swing through the Nrn and Cntrl Rockies, which
will absorb a weak closed low over the Desert SW before swinging
through the Srn Plains Thursday night/Friday. Low level moisture
return is expected to commence Thursday, and while areas of -RA
will be possible during the morning with a lead shortwave, the
core upper low will begin to open up into a trough as it moves
over the area Thursday night/Friday. This second trough will tap
into a potentially strong LLJ, which could reinforce a heavy rain
threat over at least portions of the area. Both the GFS and ECMWF
suggest that the trough will shift E of the area by the start of
the new weekend, thus trending drier for next week. However, the
ensembles are slower in clearing the convection out, and while
slight chance/low chance pops were maintained through Saturday,
did drop mention of pops for the remainder of the weekend into the
remainder of the long term period. Thus, temps will trend back
hotter with the departure of the convection this weekend.

15

&&

.AVIATION...
(18Z TAFS)
Issued at 1231 PM CDT Mon May 13 2024

For the 13/18Z TAFs, IFR to MVFR CIGs persist at are area
terminals. Cloud decks look to show limited improvement through
the course of this forecast period, with the caveat of developing
showers and thunderstorms which look on course to impact our east
Texas and north Louisiana zones this evening, bringing impacts
most likely to KLFK, KTYR and KLFK, spreading north and east
later in the evening and diminishing towards morning. At
terminals where precip concludes a few hours before daybreak, fog
development will be possible. Variable winds look to become
southerly overnight before returning to westerly and northwesterly
by the end of this forecast period.

/26/

&&

.PRELIMINARY POINT TEMPS/POPS...
SHV  66  86  64  91 /  30   0   0   0
MLU  66  86  62  87 /  60   0   0   0
DEQ  58  82  57  87 /  30  10   0   0
TXK  63  84  60  89 /  30   0   0   0
ELD  63  84  58  88 /  40  10   0   0
TYR  64  85  63  89 /  20   0   0   0
GGG  64  85  61  89 /  20   0   0   0
LFK  64  87  62  90 /  40   0   0   0

&&

.SHV WATCHES/WARNINGS/ADVISORIES...
AR...None.
LA...Flood Watch through Tuesday morning for LAZ017-018-020-022.

OK...None.
TX...Flood Watch through Tuesday morning for TXZ149-152-153-165>167.

&&

$$

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