789
FXUS64 KSHV 211117
AFDSHV

Area Forecast Discussion
National Weather Service Shreveport LA
617 AM CDT Fri Aug 21 2026

...New AVIATION...

.KEY MESSAGES...
Issued at 115 AM CDT Fri Aug 21 2026

 - Oppressive heat will continue again today, with widespread
   triple digit temperatures and even higher heat indices
   expected near and south of a stalling surface boundary over
   portions of Northeast Texas, Southern Arkansas, and North
   Louisiana. Thus, an Extreme Heat Warning is in effect for much
   of these areas today.

 - This boundary and a weakness aloft may again yield isolated to
   widely scattered showers and thunderstorms this afternoon and
   evening, some of which may produce damaging downburst winds.

 - The oppressive heat will continue this weekend through much of
   next week, although limited relief from the heat in the form of
   afternoon showers and thunderstorms will again be possible
   Saturday and again next week.

&&

.DISCUSSION...
Issued at 115 AM CDT Fri Aug 21 2026

The early morning sfc analysis indicates a stalled sfc bndry just
N of the region, over Ern OK, Wrn and Cntrl AR. This bndry was the
focus for more pronounced scattered convection Thursday afternoon
and evening, much of which has finally diminished as the air mass
has finally stabilized. However, remnant convective bndrys from
the earlier convection have spread SW through much of Srn AR into
Ern McCurtain County OK and Bowie/Cass Counties in NE TX, where
greater heat and instability still resides, and have sparked
additional isolated convection development. This should be short-
lived though as the air mass continues to stabilize overnight,
although additional isolated convection over Ern OK may spill SE
along elevated theta-e forcing, possibly affecting the NW zones
prior to daybreak before diminishing.

The aforementioned sfc bndry remains progged to drift S later
today, setting up somewhere over extreme NE TX/Srn AR/N LA in a NW
to SE oriented position, and could again play a role in
compressional warming this afternoon as well as some limited bndry
lyr moisture pooling. Even adjusting the higher NBM dewpoints down
2-3 degrees to reflect some mixing that should take place given
the very dry grounds in place with the ongoing flash drought, max
temps in the triple digits should yield heat indices at or above
110 degrees this afternoon over much of N LA/extreme SCntrl
AR/much of E TX along/S of I-20. Thus, have upgraded the existing
Heat Advisory to an Extreme Heat Warning for these areas through
02Z this evening, although will again allow the day shift to
re-evaluate and extend the appropriate heat products forward into
Saturday as the oppressive heat will continue. What`s left of our
sfc bndry tonight will either wash out or be nudged S of the area
Saturday, which may allow for slightly better mixing of dewpoints
and thus, slightly lower heat indices.

This bndry should also serve as focus for isolated to widely
scattered elevated convection by mid and late afternoon,
especially along/S of the I-20 corridor. Have maintained low
chance pops for this area, although isolated convection will be
possible farther N by late afternoon through the evening as
another weakness aloft should slide SSE around the Ern periphery
of the expanding upper ridge in place over the Four Corners Region E
into the Srn Plains. As was the case Thursday afternoon, isolated
strong to severe storms capable of producing damaging downburst
winds will be possible, and while this threat should diminish by
mid to late evening, additional scattered convection may
develop/spill SE overnight across SE OK/NE TX/SW AR ahead of
another weakness aloft set to spill SE. While the jury is still
out amongst the various models as to how much convection coverage
will linger into Saturday, reinforcing outflow bndrys may yield
slightly lower dewpoints Saturday, and elevated cigs may help to
taper back temps slightly as well. Confidence is not high enough
though to increase pops much above low chance over E TX, but there
is the potential for some relief to the heat in the form of at
least isolated afternoon convection.

The upper ridge center out W remains progged to begin expanding E
into the Srn Plains Sunday, with increased subsidence resulting in
mostly dry conditions areawide, with widespread triple digit temps
again expected. Another weakness aloft in the form of weak
shortwave energy is progged to traverse Cntrl/Ern AR into NCntrl
MS Sunday night/Monday morning, which may focus more organized
convection over these areas, mostly bypassing our region once
again aside from the far Ern zones. Very hot and dry conditions
look to persist through midweek, before the ridging begins to
slowly retrograde back W into the Desert SW for mid and late week,
which should allow for weaknesses in the NW flow regime to focus
more in the way of isolated to scattered convection over the
region through late week. This should also help to slightly lower
max temps below the century mark, providing at least some glimmer
of hope to the oppressive heat with perhaps, some wetting rains
for some, mainly across portions of Srn AR and N LA where
influence from the retreating ridge will be weakest.

15

&&

.AVIATION...
(12Z TAFS)
Issued at 614 AM CDT Fri Aug 21 2026

VFR conditions expected through the period ending 22/12Z. VCTS
conditions possible across most terminals this afternoon into the
evening hours with conditions improving by 22/04Z. Light south
winds to prevail this morning. However, a weak frontal boundary
expected to bring a windshift to the northwest for TXK/ELD/MLU/SHV
after 21/18Z with winds becoming light and variable areawide
after 22/00Z. /05/

&&

.SPOTTER INFORMATION STATEMENT...
Issued at 115 AM CDT Fri Aug 21 2026

Spotter activation may be need this afternoon and evening over
portions of East Texas and North Louisiana for thunderstorms that
may produce damaging downburst winds. /15/

&&

.PRELIMINARY POINT TEMPS/POPS...
SHV 103  78 101  76 /  20  20  20  10
MLU 103  75 102  75 /  20  20  20  10
DEQ 104  73 100  72 /  20  40  20  20
TXK 104  76 100  74 /  20  40  20  20
ELD 104  73 101  73 /  20  20  20  20
TYR 104  77 104  78 /  20  20  20  10
GGG 104  77 104  76 /  20  20  30  10
LFK 103  76 102  76 /  30  30  20  10

&&

.SHV WATCHES/WARNINGS/ADVISORIES...
AR...Heat Advisory until 9 PM CDT this evening for ARZ050-051-059>061-
     070-071.

     Extreme Heat Warning from 10 AM this morning to 9 PM CDT this
     evening for ARZ072-073.

LA...Extreme Heat Warning from 10 AM this morning to 9 PM CDT this
     evening for LAZ001>006-010>014-017>022.

OK...Heat Advisory until 9 PM CDT this evening for OKZ077.

TX...Heat Advisory until 9 PM CDT this evening for TXZ096-097-108>112.

     Extreme Heat Warning from 10 AM this morning to 9 PM CDT this
     evening for TXZ124>126-136>138-149>153-165>167.

&&


$$

DISCUSSION...15
AVIATION...05