Terrytown, Louisianna 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

542
FXUS64 KLIX 100407
AFDLIX

Area Forecast Discussion
National Weather Service New Orleans LA
1107 PM CDT Wed Jul 9 2025

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

.SHORT TERM...
(Thursday through Saturday Night)
Issued at 1033 PM CDT Wed Jul 9 2025

A weak trough extending from the Northeastern CONUS into the Deep
South will continue to bring higher than average rain chances to
the forecast area through Friday. A pool of deeper moisture
associated with this weak trough axis will keep precipitable water
values between the 75th and 90th percentiles, or around 2 inches,
through Friday. This deep and plentiful moisture will combine with
ample instability as temperatures climb into the lower 90s to
produce scattered to numerous showers and thunderstorms each day.
Thunderstorm activity will generally form along the
seabreeze/lakebreeze initially and then spread outward on outflow
boundaries from decaying storms through the afternoon and early
evening hours. The increased omega aloft associated with the
trough will help the updrafts to maintain themselves longer than
in a typical Summer pulse thunderstorm situation, and this could
lead to some localized spots receiving higher rainfall totals than
typically seen on a July day. However, only isolated street
flooding in poorly drained and highly urbanized areas is the
primary concern with any storms that form both on Thursday and
Friday. Given the highly diurnal nature of the convection, largely
dry conditions are expected from mid to late evening into the
early overnight hours.

By Saturday, the weak trough is expected to fully dissipate and
stronger upper level ridging will begin to build in from the east.
As this ridge builds in, increasing deep layer subsidence will
lead to both warming and drying in the mid and upper levels. The
end result will be a reduction in overall instability as a weak
mid-level capping inversion forms. Precipitable water values will
also begin to drop with readings closer to average on Saturday, or
around 1.8 inches. Thunderstorm activity will tend to start later
in the day and be more scattered than observed on Thursday and
Friday. The drier air aloft could also more easily entrain into
the deeper updrafts, and this could lead to a few more wet
microburst events Saturday afternoon. This is supported by
downdraft CAPE values of around 1200 J/KG. These values are
significantly higher than those expected on Thursday and Friday.
The convection will also die off more quickly with largely dry
conditions expected by the early evening hours. Temperatures will
be slightly warmer due to the combination of less cloud
development and the subsidence aloft. Highs will warm more into
the low to mid 90s and heat index readings will be closer to 105
instead of 100.

&&

.LONG TERM...
(Sunday through Wednesday night)
Issued at 1033 PM CDT Wed Jul 9 2025

The upper level ridge will continue to build over the region on
Sunday and is expected to remain in place through Wednesday. The
increased subsidence aloft will keep precipitable water values
close to the median for this time of year, or between 1.7 and 1.8
inches, and this will result in lower convective coverage each
day. Shower and thunderstorm activity will be more scattered and
short-lived due to the lack of any deep layer forcing mechanisms
to support sustained updrafts. Unfortunately, the drier air aloft
will also continue to entrain into the deepest updrafts, and the
potential for wet microbursts will remain higher than average. The
thunderstorms will be diurnally induced with convection peaking
in the afternoon hours as the seabreeze/lakebreeze intensifies and
serves as a focusing mechanism for convective development.
Temperatures will also be above normal with most locations
climbing into the mid 90s each day. Although rain chances will be
lower and dry air will be in place aloft, surface dewpoints will
remain high in the mid to upper 70s through the period. As a
result, oppressive heat will be a concern starting on Sunday and
continuing through the end of next week. Heat index values are
highly probable to exceed heat advisory criteria of 108 degrees
each day. On average, maximum heat indices should range between
108 and 112 through the long term period.

&&

.AVIATION...
(00Z TAFS)
Issued at 1033 PM CDT Wed Jul 9 2025

Another round of convective activity will be the primary concern
at all of the terminals. This thunderstorm activity will be most
pronounced between 18z and 00z tomorrow, and TEMPO groups are in
place to reflect this risk. The thunderstorm conditions will not
last the entire afternoon, but brief periods of IFR visibilities
due to heavy rain, locally gusty winds of 25 to 30 knots, and
lightning could impact each terminal. A lower convective risk is
in place between 15z and 18z, and this is reflected by PROB30
groups at the terminals with some MVFR visibility and ceiling
impacts. Outside of the convective concerns, VFR conditions will
prevail at all of the terminals.

&&

.MARINE...
Issued at 1033 PM CDT Wed Jul 9 2025

Outside of the threat of thunderstorms capable of producing
waterspouts, gusty winds, higher waves, and lightning, conditions
across the coastal waters will remain relatively benign. A broad
ridge over the Gulf will keep winds from the south and southwest
at 10 knots or less through the period and seas will remain 2 feet
or less in the open Gulf waters. In the nearshore waters and
lakes, the seabreeze cycle will lead to more variable wind
directions with a light northerly flow of less than 10 knots in
the early morning hours shifting to a stronger southerly flow of
10 to 15 knots in the late morning and afternoon hours each day.
Thunderstorms will tend to form along the landbreeze boundaries in
the early morning hours and then linger into the late morning
before shifting inland.

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  91  71  90  71 /  50  30  70  20
BTR  93  74  90  75 /  60  20  70  20
ASD  93  73  91  74 /  50  20  70  20
MSY  93  77  92  77 /  60  20  60  20
GPT  93  75  91  75 /  50  20  60  40
PQL  93  73  92  74 /  40  30  50  40

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...None.
GM...None.
MS...None.
GM...None.
&&

$$

SHORT TERM...PG
LONG TERM....PG
AVIATION...PG
MARINE...PG