Harvey, Louisianna 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

642
FXUS64 KLIX 282334
AFDLIX

Area Forecast Discussion
National Weather Service New Orleans LA
634 PM CDT Sat Jun 28 2025

...New AVIATION...

.SHORT TERM...
(This afternoon through Sunday)
Issued at 1137 AM CDT Sat Jun 28 2025

Quick synopsis/overview: The southern US remains underneath a
general weakness in the H5 pattern aloft, anomalously high PW
across a large portion of the southern, central and eastern US as
well as a very weak shortwave impulse weakening across AL/GA will
all support an increase in summertime shower/storm activity
activity through this weekend.

Starting off with around the lunch hour, recent KHDC radar and
GOES-16 satellite trends continue to illustrate shallow/scattered
convection developing mainly across coastal SE LA and MS
locations. We`re looking at most of this convection beginning a
tad early than typical, and by looking closer at the 12Z KLIX
sounding from earlier this morning, reveals a lot of answers.
Will safely say, it`s a summertime sounding given anomalously high
total column moisture (PW ~1.98", approaching the 90th percentile
according to SPC sounding climatology) with a thermal profile
strongly moist adiabatic. Tc is low in the 85-87F range thanks to
the anomalously moist airmass, which all supports earlier in the
day convection that we are seeing. Additionally, the wind profile
is extremely weak, given near zero low-level SRH and bulk winds
providing very little movement in convection today. Overall,
storms will be forced by a combination of thermodynamic driven
surface heating to begin today, then expand in coverage by
boundary interactions/collisions. The lack of low-level wind speed
will result in some boundary interactions to cause updrafts to
become rooted/slow to a crawl and with very proficient rain rates
from high PW`s, flash flooding may be a concern in a few areas.

Additional threats with storms today include gusty
downdraft/downburst wind gusts in excess of 30-40mph. Not seeing a
strong indication of dry air in the mid-levels causing entrainment
and downward wind transport potential, with relatively low DCAPE
in the 500-700J/kg range. But ofcourse, will be monitored. Also
will watch for any updrafts rooted to boundaries/collisions of
boundaries for waterspouts later this evening, and again each
morning for the next few days.

No major adjustments to temperatures. Will continue to keep an eye
on convective coverage, as that could cause MaxT`s to bust in a
few spots depending on how much rain falls in one particular area.
But generally overall, should top out in the low 90`s similar to
what we saw yesterday. Then it`s rinse/repeat tomorrow as we say
in the same pattern/weakness aloft with the same threats with
afternoon storms.

&&

.LONG TERM...
(Sunday night through Friday)
Issued at 1137 AM CDT Sat Jun 28 2025

Going into next week, not much changing as we remain in a large
region of weakness aloft. A shortwave trough/impulse will swing
across the MidWest/Great lakes region, providing a front and
associated PVA into the mid MS valley region. This de-amplifies
with time providing only remnant energy into the general area
mid- week. Basically, it`ll be more of the same through about
Wednesday. But thereafter, ridging begins to take over across the
southern Plains into the northern Gulf, gaining greater
confidence that we`ll see less in the way of typical afternoon
summertime storms and more in the way of heat. For now, maximum
heat indicies may likely approach/surpass advisory criteria later
in the week and next weekend, that`s important to know due to
July 4th activities and should serve as a heads up for those
planning outdoor events. Please protect yourself from the heat and
stay tuned for any future potential advisories as we near closer.

&&

.AVIATION...
(00Z TAFS)
Issued at 628 PM CDT Sat Jun 28 2025

Areal coverage of TSRA/SHRA at forecast issuance time was very low
and will only carry VCTS at KMCB for initialization of forecast.
Most of what`s left of TSRA should dissipate in the next couple of
hours. Main question for Sunday will be how extensive areal
coverage of TSRA will be. For now, will operate under the idea
that instantaneous coverage will remain less than 50 percent, and
will primarily use PROB30 to cover afternoon storms. If a more
obvious focus becomes apparent, later forecasts may be able to use
TEMPO or prevailing for a few of the terminals.

&&

.MARINE...
Issued at 1137 AM CDT Sat Jun 28 2025

Expecting much in the same daily overnight and morning chances for
scattered to numerous showers and storms through this weekend
into next week. Daily risks for morning waterspouts, gusty erratic
winds and lightning can be expected in any one storm. Otherwise
outside of mainly morning activity, conditions will remain mainly
calm with winds light and waves/seas under 2-3ft.

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  71  90  72  90 /  20  60  10  60
BTR  75  91  75  93 /  20  80  10  60
ASD  73  91  73  91 /  20  80  20  70
MSY  78  92  78  92 /  30  80  20  70
GPT  75  89  75  89 /  40  70  40  70
PQL  73  90  73  90 /  40  80  60  80

&&

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

$$

SHORT TERM...KLG
LONG TERM....KLG
AVIATION...RW
MARINE...KLG