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

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023
FXUS64 KLIX 152004
AFDLIX

Area Forecast Discussion
National Weather Service New Orleans LA
304 PM CDT Sun Sep 15 2024

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

.SHORT TERM...
(This evening through Tuesday night)
Issued at 237 PM CDT Sun Sep 15 2024

A broad upper level low pressure system that has dominated the
Southeastern CONUS for the past few days will continue to bring a
risk of showers and thunderstorms to the forecast area through
Tuesday evening. This increased convective activity will be
driven by a combination of near average PWATS around 1.75 inches,
upper level forcing, and diurnal instability as SBCAPE peaks
between 1000 and 1500 J/KG each afternoon. Convective activity
will tend to peak in the afternoon hours and wane in the overnight
hours each day. There will also be a gradient to the POP values as
the deeper moisture and strongest forcing will be located across
the northern and eastern portions of the forecast area including
southern Mississippi and the Northshore both Monday and Tuesday.
This area will see POP peak between 40 and 60 percent tomorrow and
30 to 40 percent on Tuesday. Temperature spread between the 25th
and 75th percentiles in the NBM is small, so have stuck with NBM
deterministic output for both highs and lows in the short term
period. This keeps temperatures near average both Monday and
Tuesday.

&&

.LONG TERM...
(Wednesday through Saturday night)
Issued at 237 PM CDT Sun Sep 15 2024

By Wednesday, the upper level low is expected to pull well east of
the region, and a strong upper level ridge with increasing deep
layer subsidence and drier air will build over the forecast area.
The end result will be an extended period of limited cloud
development, lower humidity, no rain chances, and near to slightly
warmer than average high temperatures from Wednesday through
Saturday. Overnight lows will easily cool into the upper 60s and
lower 70s due to the dry airmass in place. Once again, there is
not a large degree of spread in the model solutions, so the
temperature forecast follows the NBM deterministic output closely.

&&

.AVIATION...
(18Z TAFS)
Issued at 237 PM CDT Sun Sep 15 2024

A few showers may develop in the vicinity of MSY, HUM, NEW, and
GPT through the forecast period as a weak frontal boundary remains
stalled over the area. However, prevailing VFR conditions with
ceilings of 3500 to 4500 feet are expected at all of the terminals
through around 10z. After 10z, light boundary layer winds over
portions of the region will allow for another round of low stratus
and fog development to occur. Probabilities of fog development
are highest at MCB, and have included a period of IFR stratus and
MVFR visibilities at that terminal from 10z to 14z. Fog and low
stratus development cannot be ruled out at BTR, HDC, and ASD, but
the probabilities for development are too low to include in the
forecast package. PG

&&

.MARINE...
Issued at 237 PM CDT Sun Sep 15 2024

Very weak gradient flow over the coastal waters will remain in
place through the end of the week, and this will keep winds below
10 knots and seas below 2 feet. These benign conditions will
occasionally be interrupted by scattered convective activity
producing locally gusty winds and waterspouts, but overall no
significant impacts to maritime activities are forecast through
the end of the week.

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  68  84  68  83 /  10  70  30  30
BTR  70  87  71  86 /   0  40  20  30
ASD  70  86  70  84 /  10  40  30  40
MSY  73  85  74  84 /  10  30  20  30
GPT  72  83  71  83 /  10  40  30  40
PQL  72  83  70  84 /  30  50  40  40

&&

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

$$

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