Harvey, Louisianna 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

124
FXUS64 KLIX 231904
AFDLIX

Area Forecast Discussion
National Weather Service New Orleans LA
204 PM CDT Mon Jun 23 2025

...New SHORT TERM, LONG TERM...

.SHORT TERM...
(This evening through Tuesday night)
Issued at 122 PM CDT Mon Jun 23 2025

A weak upper trough in the central Gulf is rounding the expansive
598dam ridge centered over the OH River Valley that is scorching
much of the eastern CONUS through midweek. This is providing a
subtle enhancement of mid-level moisture which will encourage
slightly more convective coverage than previous days. We`re
already beginning to see the lake and seabreezes initiate and the
easterly surface flow will promote pushing these storms westward
and farther inland through the afternoon up to more of the Florida
Parishes and southwest MS by sunset. Downdraft CAPE remains high
especially along the I-10 corridor and Atchafalaya Basin today
which will allow any taller, wider updraft to produce winds
upwards of 40 to 50 mph and potentially some small hail though
mid-level lapse rates are below 6 C/km and the freezing level is
over 15kft which would result in whatever hail that can grow in
the updraft melting before it hits the ground. And of course high
rain rates can occur with some of these cells though propagation
vectors do not support backbuilding nor training of storms that
would enhance a localized flash flood threat.

A more respectable surge of mid-level moisture can be tracked back
to showers and storms currently sitting offshore in the Gulf
waters which will gradually spread northwest through tonight and
into tomorrow morning. This should hold temperatures down as
convective blow off increases cloud coverage and scattered
showers and storms pass through especially the southern half of
the CWA through midday on Tuesday. Additional convection is likely
to initiate on the sea/lake breezes in the northshore and
southern MS if enough sunshine remains to heat the surface and
destabilize these boundaries. This surge of mid-level moisture
will depart by Tuesday evening ushering in drier air that will
assist in stabilizing the coastal regions before moving farther
inland after sunset.

&&

.LONG TERM...
(Wednesday through Sunday night)
Issued at 122 PM CDT Mon Jun 23 2025

Drier air in the mid-levels ushered in by the expansive, strong
ridge over the eastern CONUS will dry us out quickly on Wednesday.
This coupled with weak surface high pressure moving back overhead
will likely result in the hottest day of the year thus far as
latest guidance indicates temperatures will soar back into the mid
90s areawide to even upper 90s in a few places. Low-level moisture
will still plentiful with dew point temperatures in the mid to
upper 70s along the southshore especially. This will allow heat
indices to once again flirt with or exceed Heat Advisory criteria
of 108F even as dew point temperatures begin to mix out and
decrease during peak daytime heating. Afternoon storm coverage
will be much more isolated and updrafts will struggle even along
the lake and sea breezes only further increasing confidence that
it`s gonna be a hot and miserable day with little to no relief on
Wednesday.

This wave of drier air and convective suppression won`t last long
fortunately, as mid-level moisture gradually returns into the
latter half of the week in association with another upper trough
getting tucked under the southern periphery of the eastern CONUS
ridge which by this point is beginning to break down and weaken.
This upper trough will promote more scattered to widespread
convective coverage each day into the weekend. Recent indications
are pointing toward the potential of lingering troughing and/or
another trough split of some sort in the northeast Gulf into
early next week which could continue this wetter than normal regime
beyond Day 7.

&&

.AVIATION...
(18Z TAFS)
Issued at 1258 PM CDT Mon Jun 23 2025

Showers and storms are beginning to pop up along the lake and sea
breezes providing brief MVFR to IFR impacts to terminals this
afternoon. ASD is already seeing these impacts with TSRA, IFR
VIS, and 15-20kt gusts. Expect more of the same elsewhere,
especially inland terminals at HDC, BTR, and MCB as the afternoon
progresses. PROB30s have been updated to reflect the latest
forecast timing for storm development/propagation. Otherwise VFR
conditions will prevail with light easterly winds at night gusting
to 10-15 knots during the daytime. Another round of showers and
storms is likely to start earlier tomorrow starting over the
coastal waters and moving inland into the late morning and have
added PROB30s to MSY, NEW, and GPT to start at the end of the
forecast period.

&&

.MARINE...
Issued at 1258 PM CDT Mon Jun 23 2025

Easterly to southeasterly winds at less than 15 knots are
expected while we stay positioned on the southwest flank of the
Bermuda High over the southwest Atlantic through Tuesday. Higher
chances of storms are expected today and Tuesday as a weak
easterly wave passes by. A few of these storms could be strong
and cause significant wind shifts, high winds and seas, frequent
lightning, and waterspouts. Winds will become lighter and more
variable as high pressure moves overhead Wednesday through Friday.

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  72  92  72  95 /  30  30   0  20
BTR  74  93  74  96 /  30  60  10  30
ASD  73  92  73  95 /  30  40   0  20
MSY  80  92  79  95 /  20  60  10  20
GPT  75  91  75  94 /  30  30  10  20
PQL  73  94  73  97 /  30  30  10  20

&&

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

$$

SHORT TERM...TJS
LONG TERM....TJS
AVIATION...TJS
MARINE...TJS