907
FXUS64 KSHV 171813
AFDSHV

Area Forecast Discussion
National Weather Service Shreveport LA
113 PM CDT Thu Jul 17 2025

...New DISCUSSION, SPOTTER INFORMATION STATEMENT...

.KEY MESSAGES...
Issued at 113 PM CDT Thu Jul 17 2025

 - Oppressive heat will continue this afternoon across North
   Louisiana, Southwest Arkansas, and portions of extreme
   Northeast Texas, with heat indices ranging from 105-109
   degrees.

 - An increase in cloud cover and scattered convection will result
   in slightly cooler conditions over much of the region Friday.

&&

.DISCUSSION...
Issued at 113 PM CDT Thu Jul 17 2025

The early afternoon satellite imagery indicates our tropical wave
continuing to spin as it drifts W into Upper Plaquemines Parish,
with scattered diurnal convection now beginning to develop to the
N and W of the center of circulation over portions of NE LA, Cntrl
and Srn MS. Closer to home, our region remains under the
influence of the Wrn branch of upper ridging from the SE CONUS,
with strong subsidence contributing to midday temps already in the
mid 90s across portions of Srn AR and much of N LA. In fact, in
areas where the scattered cu field has developed, mixing of
dewpoints has been limited, with heat indices already
reaching/surpassing 105 degrees across these areas as of 17Z. The
exception was over much of E TX (except the bordering counties
near TXK), where temps are several degrees cooler and better
mixing has been observed. Elevated cigs associated with the
approaching tropical wave have also begun to impact temps across
portions of Deep E TX and Sabine Parish LA, with this trend
expected to continue as these cigs spread farther WNW over these
areas through the afternoon. Thus, have cancelled the Heat
Advisory for portions of Lower E TX S of I-20 as well as Sabine
Parish, but have maintained the Advisory as is through 00Z this
evening for the remainder of N LA/SW AR/extreme NE TX.

The various hi-res and 12Z guidance suggests that the ongoing
scattered convection may continue through this evening across
Cntrl and NE LA before diminishing, with the more concentrated
areas of deeper convection persisting overnight near the 925-850
low which should drift W into Acadiana. Did maintain slight chance
pops overnight to account for isolated redevelopment over Lower
Toledo Bend Country into Cntrl LA on the N side of the low, with
the various guidance suggesting the low elongating into a SW to NE
oriented trough Friday morning from SE TX into WCntrl and NE LA.
This trough axis should focus scattered convection as the day
progresses once diurnal heating increases, with the convection
expected to become more numerous near and S of this trough. The
increase in cloud cover will also result in cooler max temps, with
heat indices expected to remain below criteria, thus not
necessitating the re-issuance of another Heat Advisory Friday.

The convection should again diminish during the evening with the
loss of heating, although some may linger overnight near the
residual trough axis from Deep E TX across N LA/far Srn AR.
Although the low level reflection of this trough should be lost by
Saturday, should again see an uptick in scattered convection
by afternoon from Deep E TX across N LA/SW AR before this trough
weakens further, and the SE CONUS upper ridge begins to expand
back W into the Lower MS Valley/Srn Plains Sunday. Thus, the
return to near to above normal heat and mostly dry conditions are
expected, with increasing heat to start the new work week likely
necessitating additional Heat Advisories for at least portions of
the region through much of the long term period.

15

&&

.AVIATION...
(18Z TAFS)
Issued at 1229 PM CDT Thu Jul 17 2025

Vicinity tropical airmass is responsible for an expanding CU
field across the airspace this afternoon, and even a marginal
chance for SHRA/TSRA during the peak of the daytime heating
period. As a result, aside from the SCT/BKN CU field below 5kft,
elected to add VCTS to MLU for a short period based on the hi-res
output targeting the eastern side of the airspace later in the
afternoon. Overnight, the aforementioned CU field will diminish
with a mix of SCT/BKN high level cirrus streaming north from the
coastal disturbance south of the region. Some uncertainty remains
when it comes to model advertised BR and low clouds overnight.
Whether this evolves is to be determined. By tomorrow afternoon,
another return of mostly BKN CU will be in place through the early
afternoon as the disturbance creeps further inland. VCTS should
hold off until after 18z, but elected to include some SHRA across
the southern zones of the airspace during the late AM and early
afternoon. VRB terminal winds should be the main theme through the
period, generally around 3-5kt.

KNAPP

&&

.SPOTTER INFORMATION STATEMENT...
Issued at 113 PM CDT Thu Jul 17 2025

Spotter activation is not expected through tonight. /15/

&&

.PRELIMINARY POINT TEMPS/POPS...
SHV  79  93  77  91 /  10  50  30  40
MLU  77  88  75  91 /  20  70  20  60
DEQ  73  95  73  92 /   0  10   0  20
TXK  77  93  76  92 /   0  20  10  30
ELD  75  92  74  90 /  10  40  20  40
TYR  74  93  75  90 /   0  20  10  20
GGG  76  94  74  90 /  10  40  20  30
LFK  75  90  74  90 /  10  60  30  40

&&

.SHV WATCHES/WARNINGS/ADVISORIES...
AR...Heat Advisory until 7 PM CDT this evening for ARZ050-051-059>061-
     070>073.

LA...Heat Advisory until 7 PM CDT this evening for LAZ001>006-010>014-
     018>022.

OK...None.
TX...Heat Advisory until 7 PM CDT this evening for TXZ097-112-126-138-
     151.

&&

$$

DISCUSSION...15
AVIATION...53