Area Forecast Discussion
Issued by NWS New Orleans/Baton Rouge, LA

Home |  Current Version |  Previous Version |  Text Only |  Print | Product List |  Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
415
FXUS64 KLIX 181107
AFDLIX

Area Forecast Discussion
National Weather Service New Orleans LA
607 AM CDT Tue Aug 18 2026

...New AVIATION...

.KEY MESSAGES...
Updated at 605 AM CDT Tue Aug 18 2026

- Dangerous heat continues with afternoon heat indices commonly
  reaching 110115F through the week. Warm overnight
  temperatures will offer limited 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 Friday)
Issued at 1027 PM CDT Mon Aug 17 2026

We are pretty close to where we should be for this time of year.
Hot, humid and oppressive sums it up for mid August. The heating
is quite intense and storms that do develop during this heat will
not have many others around to compete with for that energy which
means any particular storm can go rogue causing damaging winds and
all other attributes of severe thunderstorms. This is typical for
our summers though. There is always a silver lining somewhere,
and with any of these storms, there will be some cooling shade
and rain. The big picture is still playing out like it should as
the large high over the EastPac is now starting to show some
leveraging into the SW CONUS. The H3 level will show how these
synoptic systems play out the best. As the large high gets into
place over the SW, this will amplify the polar jet along the west
coast causing a deep upper trough to set up down stream to the
east sending the large upper low, taking up a very large amount
of Canadian real estate, toward the southeast. The west side of
this trough will begin to tap much stronger winds on its west side
as the large high squeezes the upper trough. The much stronger
winds on the west side of the upper trough will cause it to start
digging into the central part of the country by late week, and by
Friday we should see a very strong upper trough moving toward the
southern CONUS. This synoptic weakness will also help more storms
get going as well. We will see the scattered version of storms
until the end of this week when the attending frontal system
starts to help plenty of storms fire up along and ahead of it as
it moves toward the area by Fri.

&&

.LONG TERM...
(Friday night through Monday)
Issued at 1027 PM CDT Mon Aug 17 2026

As we move into the long term portion of the forecast, the global
models agree on the large scale pattern with ridging centered near
the Four Corners area, and near Bermuda, with troughing over the
Great Lakes and Appalachians, extending southward into Florida. Some
of the differences we had seen in last night`s solutions have for
the most part resolved themselves. The upper weakness we had been
seeing depicted in the eastern Gulf now is depicted by both families
of medium range modeling to be picked up by the northern stream
trough and carried northeastward along the Atlantic Coast. That`s
similar to the ECMWF based solutions we looked at last night.

This solution with northwesterly upper flow will bring a surge of
drier air into the area, with precipitable water values near 2
inches on Friday down to around 1.5 inches Saturday afternoon.
That`s pretty close to the 25th percentile climatologically. As we
saw last week, that doesn`t preclude convective development, but is
likely to keep any development rather isolated and limited to max
heating hours. That drying trend looks to continue through Sunday
before moisture starts returning on Monday. I`d expect we`ll
probably see a bit of a downward trend in precipitation chances for
Saturday in the next day or so, but don`t anticipate any completely
dry days. And as always with northwest mid-level flow, we can`t rule
out convective complexes approaching from that direction.

Don`t really see high temperatures changing much through the
weekend, with highs in the mid and upper 90s every day, and isolated
locations perhaps touching 100. We may have a couple days of lower
humidities and slightly cooler low temperatures over the weekend,
but not counting on that quite yet.

&&

.AVIATION...
(12Z TAFS)
Issued at 605 AM CDT Tue Aug 18 2026

Outside TSRA developing late in the day, VFR will be the rule for
this taf cycle. Those sites with the highest chances of getting
sh/ts will be shown with timing.

&&

.MARINE...
Issued at 1027 PM CDT Mon Aug 17 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 at 10
to 15 knots during the night and morning hours then generally
lighter wind speeds during the daylight 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 this morning to 8 PM CDT this evening
     for LAZ034>037-039-046>048-056-070-071-090-091-093>097.

     Extreme Heat Warning from 11 AM this morning to 8 PM CDT this
     evening for LAZ057-058-064-076>087-089-092-098>100.

GM...None.
MS...Heat Advisory from 11 AM this morning to 8 PM CDT this evening
     for MSZ068>071-077.

     Extreme Heat Warning from 11 AM this morning to 8 PM CDT this
     evening for MSZ083>088.

GM...None.
&&

$$

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