512
FXUS64 KLIX 190504
AFDLIX

Area Forecast Discussion
National Weather Service New Orleans LA
1204 AM CDT Wed Aug 19 2026

...New SHORT TERM, LONG TERM, AVIATION, MARINE...

.KEY MESSAGES...
Updated at 1019 PM CDT Tue Aug 18 2026

- Dangerous heat continues with afternoon heat indices in the
  105-113 degree range through the week. Warm overnight
  temperatures will offer limited to no relief.

- Only isolated to scattered afternoon storms are expected the
  next couple days. Coverage should be somewhat greater toward
  the Mississippi coast and eastern portions of the forecast area.

&&

.SHORT TERM...
(Now through Saturday)
Issued at 1019 PM CDT Tue Aug 18 2026

No big changes in the ongoing fcast. The old quasistationary 850mb
trough that has been plagueing the SE CONUS will remain. At this
writing, it is located from near Vicksburg to Pensacola where it
bends and runs along the gulf coast to the Atlantic. Storms will
once again fire along and south of this boundary but will not get
too far south as they will run into stacked stability and
suppression. Any one storm or two of those that develop will
continue to have the potential to become severe. There may be even
less in number of storms today than there have been. For most of
the area, that will still be zero, but the most eastern portion
of the area that has seen activity, could see less today. The
heat headlines will remain as well, and cumulative effects can
begin to have impacts as this continues. This same story should
play out over the next few days. Some changes will occur by late
Fri as a front moves toward the area causing a bit more storm
activity that should help give the area some rain and cloud cover,
not for most of Fri since the trough will be moving in late in
the day, but Sat could have cloud cover long enough to retard
heating. Residual cloud cover, if it can hold, may actually take
the heat headlines down for a day or two by the end of the week.

&&

.LONG TERM...
(Saturday night through Tuesday)
Issued at 1019 PM CDT Tue Aug 18 2026

As we move into the long term portion of the forecast on Saturday
night, the global models agree on the large scale pattern with upper
ridging centered near the Texas/Oklahoma Panhandles with an
extension southeastward into about the western half of the Gulf. The
upper trough will extend from the western Great Lakes to the Florida
Peninsula. By Tuesday evening, the ridge won`t have moved very much,
being centered near the Texas-New Mexico border and still
controlling the western Gulf, while strengthening slightly, with the
upper trough off the Atlantic Coast.

The frontal boundary between Interstates 20 and 40 Saturday night
won`t make much southward progress by Tuesday, either, perhaps
approaching Interstate 10. Precipitable water values that will
generally be between the 25th and 50th percentile on Sunday (1.6
inches) will increase to about the 75th percentile (2 inches) on
Monday before dropping off again on Tuesday.

Shortwaves moving southeastward into the base of the upper trough
appear to be displaced far enough away from the local area that they
may keep any organized MCS activity away from the area during the
Sunday-Tuesday period. Any isolated thunderstorm development is
likely to continue recent trends of developing on lake and sea
breeze boundaries early in the afternoon and propagating away from
those boundaries. They also tend to dissipate prior to sunset. If
there`s going to be a day that favors a little greater threat of
damaging winds, it would be Sunday, when forecast soundings show
DCAPE values of 1100-1500. But that`s also the day that looks to
have the least (and possibly no) convective development.

The hot weather isn`t going anywhere either. NBM numbers continue to
show highs between 95-100 Sunday through Tuesday. Even if we assume
that these values are a couple degrees on the high side of reality,
it still keeps a significant portion of the area 5-7 degrees above
normal. The GFS solutions do appear to be a little aggressive in
bringing drier dew points into the area during this period, although
the 18/18z wasn`t quite as aggressive as earlier operational runs.
ECMWF solutions tended to keep dew points in the 70s. This would
primarily impact overnight lows Monday and Tuesday mornings. The NBM
solution favors a forecast along the lines of the ECMWF solutions.
We`ll see how this works out over the next day or two.

&&

.AVIATION...
(06Z TAFS)
Issued at 1019 PM CDT Tue Aug 18 2026

VFR for most terminals today. TSRA will develop late in
the day again with the highest chances within the same areas that we
have seen for the last few days. Outside TSRA, VFR will be the rule
for all terminals.

&&

.MARINE...
Issued at 1019 PM CDT Tue Aug 18 2026

Surface high pressure centered over the central Gulf will maintain a
generally weak pressure gradient through much of the period. A
predominantly westerly flow will continue, with higher winds during
the early morning and late night hours. Isolated thunderstorms will
remain possible with winds and waves higher in and near this
activity, particularly during the overnight and early morning
hours.

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...Heat Advisory from 11 AM to 8 PM CDT Wednesday for LAZ034>037-
     039-046>048-056>058-064-070-071-076>087-089>100.

GM...None.
MS...Heat Advisory from 11 AM to 8 PM CDT Wednesday for MSZ068>071-
     077-083>088.

GM...None.
&&

$$

SHORT TERM...TE
LONG TERM....RW
AVIATION...TE
MARINE...TE