679
FXUS64 KLIX 191048
AFDLIX

Area Forecast Discussion
National Weather Service New Orleans LA
548 AM CDT Sun Jul 19 2026

...New AVIATION...

.KEY MESSAGES...
Updated at 445 AM CDT Sun Jul 19 2026

- A mostly dry pattern is expected through this week. The primary
  concern will be increasing heat. Heat indices will be in
  advisory criteria through much of the week. Urban areas could
  approach heat warning criteria Mon-Wed.

- Isolated to widely scattered thunderstorms will begin to develop
  mainly along and east of I55 during the late afternoon hours
  through the first half of this week. Even though overall
  coverage of storms will remain low, those that do develop could
  be strong to severe.

&&

.SHORT TERM...
(Now through Wednesday)
Issued at 1057 PM CDT Sat Jul 18 2026

We will discuss the sfc low over the NE gulf, but the main issue
for our area is strong heating through much of this week. It is
possible that heat warnings will be placed for some areas over the
coming days. Most of the area sits on the outer envelope of the
convective blowups going on just to our east. The air from this
vertical circulation sinks over our area causing the air to
compress and heat up even more. The light winds produced between
the sfc low to the east and the sfc high to the west is northerly
bringing preheated air off the landmass as well. There will be
some chances for storms to develop giving some relief, but they
will not be widespread and best chances are to the east leaving
most of the area dry and hot. The storms that do develop will be
late in the day after the strongest heating has developed, so
eventhough relief could come for very few areas, it will only be
after the hottest part of the day has gone by.

The weak sfc low that was in the SE gulf last night is now over
the NE gulf where it will stall this morning through this evening.
Even when it does start meandering northward again by Monday, it
will be very slow. NHC decided to move upward with chances of
formation. This system has been a broad circulation for at least a
day. This does not mean it is a tropical cyclone, but it is a
broad circulation with no real organization. There are seveal
reasons we can look at this and say it is not a clear cut tropical
entity yet. One fact is that it is a vertically stacked low since
it is fighting a TUTT low and will continue to do so. There is a
roughly 48 hour window that winds aloft will weaken enough to
allow the sfc low to strengthen, which starts around noon today
through Tue morning. This is likely why the odds of this
developing increased. Even that time frame will exhibit some
complications for the system. A strong environment for tropical
development would have the mass of convective development and
pulsing over the sfc circulation and to its east through south.
This system has the most development on its west side. This does
eventually try to wrap around to its south then east, but it is
late in the game by that time. WV imagery shows some strong dry
air intrusion moving into the system from the NE as well, but that
also weakens with time. The troughing producing the storms on the
west side of the system arcs from GA to Mobile into the gulf and
bends back around to the south side of the sfc low. This is the
trough that eventually and slowly sneaks westward giving the
eastern portion of our area higher sh/ts chances. Weak sfc lows
can be dragged into areas of expolsive convective development
and/or a convective pulse(explosion) can and does create its own
mesovortex which can also become a sfc low. This is why the area
of tropical development odds are around and far west of the "X" on
NHC`s maps. Regarless of development odds, the low will likely
remain weak but some impacts from this will be strong/severe
storms over land and marine and heavy rainfall. This will hold
true for our area as the westward progression of this deeper
moisture field reaches us. Since these storms are developing in
some strong heating, they would have a higher potential to become
strong or severe. But they will be moving at a good pace, so other
than nuisance flooding is not expected. Most of this will take
place in coastal Miss. But areas east of I55 will have some odds
of getting a storm or two through mid week. By Tue into Wed, this
broad circulation is somewhere along the coast which could be from
the Pearl River to Pensacola as a cold front digs into the
SE CONUS picking up a good bit of its moisture.

&&

.LONG TERM...
(Wednesday night through Saturday)
Issued at 1057 PM CDT Sat Jul 18 2026

Medium range operational models generally agree on the larger
scale pattern Wednesday night with the upper ridge centered near the
Oklahoma-Texas border north of Dallas, and an upper trough across
the northeast quarter of the country.

Beyond that point, the question becomes how much northern stream
shortwaves moving down the east side of the ridge erode the
southeast extension of the ridge. A stronger shortwave could erode
the extension enough to allow a weak frontal boundary into the area
and increase rain chances (and lower temperatures a little). At
present, there doesn`t seem to be much change in the pattern until
at least next Saturday. There`s not enough difference in PoPs
between the operational models to make significant adjustments.
Would note that on the 18/12z ECMWF, the operational PoPs were
pretty close to the wettest member of their ensemble.

Rain chances will drive the high temperature forecast. Without rain,
it`s entirely possible that the current forecast isn`t high enough
late in the week. Heat Advisories and/or Extreme Heat Warnings can`t
be ruled out on any day through the end of the workweek.

&&

.AVIATION...
(12Z TAFS)
Issued at 445 AM CDT Sun Jul 19 2026

The only terminal that has any real chance of TSRA today will be
GPT. PROB30 group will be used to time this for today. Otherwise,
VFR through this taf cycle at all sites.

&&

.MARINE...
Issued at 1057 PM CDT Sat Jul 18 2026

A weak surface low over the northeast gulf and a surface high over
the northwest gulf will maintain a northerly flow over the north
central gulf through the first half of this week. As the low moves
north, winds will eventually become westerly by mid week. Wind
speeds will generally be 10 to 15 knots for most of the coastal
waters but well offshore winds could approach 15 to 20 knots for
short periods. Thunderstorm coverage will increase over the waters
east of the Miss River today with a steady westward penetration over
the next few days. Winds and seas will rapidly rise in and around
thunderstorm activity.

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...Heat Advisory from 10 AM this morning to 6 PM CDT this evening
     for LAZ034>037-039-046>048-056>058-064-070-071-076>087-
     089>100.

GM...None.
MS...Heat Advisory from 10 AM this morning to 6 PM CDT this evening
     for MSZ068>071-077-083>088.

GM...None.
&&

$$

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