Gale Warning 1, NWS New Orleans, LA

Area Forecast Discussion
National Weather Service New Orleans LA
343 PM CST Thu Jan 9 2025

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

.SHORT TERM...
(This evening through Friday night)
Issued at 251 PM CST Thu Jan 9 2025

Surface low pressure developing over the western Gulf is forecast
to deepen as it moves east-northeastward toward the central Gulf
Coast. This will result in gusty conditions across the local area
as winds respond to the tightening gradient. The strongest winds
will generally be late tonight through midday tomorrow. Knowing
that the models tend to underforecast winds and especially wind
gusts associated with these deepening lows, have gone a little
above the NBM across roughly the southern half of the forecast
area.

The resulting forecast supports the issuance of a wind advisory
for areas generally along and south of a line from Morgan City to
Hammond to Pascagoula where the forecast calls for sustained winds
in the 20 to 25 mph range with wind gusts of 35 to 40 mph. Short
range ensembles suggest at least a low end chance that the wind
advisory may need to be extended northward by one more zone, but
the probability (10-20%) is low enough that it didn't seem
warranted at this time.

In addition to the windy/gusty conditions, the other threat this
system will bring to the area is potential for locally heavy
rain. The overall forecast and forecast reasoning haven't changed
much. Looking at the latest short range ensemble guidance the
area of greatest threat continues to be roughly along and north of
the I-10/12 corridor where the storm total forecast is 1-2 inches
and ensemble guidance indicates potential for 3+ inches.

While totals in this range usually wouldn't be much cause for
concern, any storms with higher rainfall rates will quickly result
in runoff given the dormant vegetation and harder ground as a
result of recent cold weather. While widespread flooding is not a
concern, the extra runoff could lead to street flooding and/or
localized ponding of water in low lying and poor drainage areas.
WPC continues to highlight most of the area in a marginal risk
area, which still seems warranted given the isolated threat.

Rain should be exiting the area by late afternoon, though clouds
will stick around overnight. Cold air advection will dominate the
cooling processes tomorrow night, and lows will drop into the 30s
area-wide. Any freezing temperatures should be limited to
southwestern Mississippi and adjacent Louisiana parishes, though
wind chills will hit the freezing mark across nearly the entire
forecast area late tomorrow night/Saturday morning.

&&

.LONG TERM...
(Saturday through Wednesday night)
Issued at 251 PM CST Thu Jan 9 2025

Going into the weekend, Saturday will be quite chilly. With
continued cold air advection and clouds not forecast to break up
until midday or later, afternoon temperatures will struggle to
reach 50 degrees most places. As high pressure settles over the
area Saturday night, light to calm winds, low dewpoints and clear
skies will allow for efficient radiative cooling. Overnight
temperatures will drop into the upper 20s and lower 30s for areas
along/north of the I-10/12 corridor and in the mid to upper 30s
for most places south of the interstate.

Another storm system is forecast to pass through the northern Gulf
Sunday night, with isolated to scattered showers spreading across
the local area beginning as early as Sunday morning. The best
rain chances will be across coastal areas, and the current
forecast POPs may prove too high if the track of the low trends
farther south as indicated in some of the model solutions.

Once this low passes by, expect dry high pressure to build in
again, with below normal temperatures persisting through at least
Thursday.

&&

.AVIATION...
(18Z TAFS)
Issued at 251 PM CST Thu Jan 9 2025

A deepening low will bring impacts to all terminals over the next
24-36 hours. Thus far most of the precipitation has been
evaporating before reaching the surface, but conditions will begin
deteriorating this evening as cigs lower and light showers spread
across the area. Moderate to heavy showers will spread eastward
across the area after 06z resulting in both cig and vsby
restrictions with most terminals experiencing at least period if
IFR conditions by daybreak. Additionally, winds will begin
strengthening after 3z at most terminals with llws affecting most
terminals at different times between 06z and 15z. While rain will
move out of the area after 18z, low cigs will

&&

.MARINE...
Issued at 251 PM CST Thu Jan 9 2025

Deepening low pressure will result in hazardous conditions across
the coastal waters through at least the next 36 hours. Have tried
to segment the headlines to give better timing for the more
hazardous conditions, which will spread from west to east across
the coastal waters this evening through tomorrow morning. The Gale
Watch has been upgraded to a Gale Warning for all waters except
Lakes Pontchartrain and Maurepas where a small craft advisory has
been issued. Winds and seas will begin to gradually ease late
tomorrow, but a advisory conditions will persist through at least
tomorrow night before high pressure settles in resulting in
benign conditions for the second half of the weekend.

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  37  46  31  47 /  90 100   0   0
BTR  43  55  35  52 / 100 100   0   0
ASD  43  60  35  50 /  70 100   0   0
MSY  48  66  38  49 /  80 100   0   0
GPT  43  63  35  49 /  50 100   0   0
PQL  41  64  35  52 /  30 100  10   0

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...Wind Advisory from 6 AM to 6 PM CST Friday for LAZ058>060-
     064>070-076>078-080-082-087>090.

GM...Small Craft Advisory from 6 PM this evening to 6 AM CST Saturday
     for GMZ530.

     Small Craft Advisory from 6 PM this evening to 6 AM CST Friday
     for GMZ532-534-536-538.

     Small Craft Advisory from noon Friday to 6 AM CST Saturday for
     GMZ532-534-536-538.

     Gale Warning from 6 AM to noon CST Friday for GMZ532-534-536-538.

     Small Craft Advisory until 6 PM CST this evening for GMZ550-552-
     570-572.

     Small Craft Advisory from 3 PM Friday to 6 AM CST Saturday for
     GMZ550-552-570-572.

     Gale Warning from 6 PM this evening to 3 PM CST Friday for
     GMZ550-552-570-572.

     Small Craft Advisory from 6 PM this evening to 3 AM CST Friday
     for GMZ555-557-575-577.

     Small Craft Advisory from 6 PM Friday to 6 AM CST Saturday for
     GMZ555-557-575-577.

     Gale Warning from 3 AM to 6 PM CST Friday for GMZ555-557-575-577.

MS...Wind Advisory from 6 AM to 6 PM CST Friday for MSZ086>088.

GM...     Small Craft Advisory from 6 PM this evening to 6 AM CST Friday
     for GMZ534-536-538.

     Small Craft Advisory from noon Friday to 6 AM CST Saturday for
     GMZ534-536-538.

     Gale Warning from 6 AM to noon CST Friday for GMZ534-536-538.

     Small Craft Advisory until 6 PM CST this evening for GMZ552-570-
     572.

     Small Craft Advisory from 3 PM Friday to 6 AM CST Saturday for
     GMZ552-570-572.

     Gale Warning from 6 PM this evening to 3 PM CST Friday for
     GMZ552-570-572.

     Small Craft Advisory from 6 PM this evening to 3 AM CST Friday
     for GMZ557-575-577.

     Small Craft Advisory from 6 PM Friday to 6 AM CST Saturday for
     GMZ557-575-577.

     Gale Warning from 3 AM to 6 PM CST Friday for GMZ557-575-577.

&&

SHORT TERM...DM
LONG TERM....DM
AVIATION...DM
MARINE...DM