888
FXUS64 KLIX 132116
AFDLIX

Area Forecast Discussion
National Weather Service New Orleans LA
316 PM CST Sat Dec 13 2025

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

.KEY MESSAGES...
Updated at 1247 PM CST Sat Dec 13 2025

 - The coldest air of the year will bring dangerous wind chills
   and a widespread freeze to the area Sunday night into Monday
   morning. A Cold Weather Advisory is in effect over this time
   period.

 - Strong winds and dangerous seas are expected Sunday into Monday
   after a strong cold front moves through. Small Craft Advisories
   and Gale Warnings are now in effect for this time period.

&&

.SHORT TERM...
(This evening through Monday night)
Issued at 1247 PM CST Sat Dec 13 2025

No significant changes in the overall forecast from before as the
model guidance remains in very good agreement on the timing of a
strong cold front that will pass through the region late tonight
and tomorrow morning. A rapidly deepening northern stream trough
will quickly descend into the eastern third of the CONUS tonight
into tomorrow. As this trough deepens, the arctic airmass over the
northern Plains will begin to sweep southward along the
Mississippi Valley in the form of a fast moving frontal boundary.

Before the arctic airmass intrudes into the region, a very
unseasonably moist and warm airmass will be over the area this
evening into the late overnight hours with temperatures still
sitting in the 50s and even lower 60s through late evening. Some
moisture pooling will occur in advance of the front in the late
evening and early overnight hours, and this will allow PWATS to
climb to near the 90th percentile for this time of year. However,
the moisture will be shallow, residing below 700mb. The shallow
nature of the moisture and a lack of mid-level instability will
keep any pre-frontal convective activity at bay. However, this
warm and moist airmass will be easily lifted over the shallow cold
pool to produce a period of post-frontal stratiform light to
moderate rainfall late tonight into early Sunday morning. Rainfall
totals should remain below a quarter of an inch. The rain will
quickly come to an end by mid-morning tomorrow as the drier and
colder arctic airmass moves in from the north. In fact, skies
should be clear by the mid-afternoon hours based on the depth and
strength of the arctic airmass moving in.

Although the main brunt of the colder air will remain well
displaced to the north and east of the forecast area, we will
still experience the coldest air we have seen this season with
lows falling into the 20s and lower 30s Sunday night into Monday
and highs only warming into the mid to upper 40s on Monday. For
areas north of I-10/12, a hard freeze and a threat to pipes will
exist tomorrow night as temperatures will remain below 25 degrees
for several hours.  In addition to the cold air temperatures,
dangerous wind chills will take place tomorrow night across the
region as gusty north winds of 10 to 20 mph persist through the
night. Wind chill values will fall into the teens along and north
of the I-10/12 corridor and the low to mid 20s further south.
These wind chill values are low enough to prompt the issuance of a
cold weather advisory for the entire area.

The thermal trough axis associated with the deep layer cold pool
over the eastern third of the country will start to shift to the
east Monday night, but that will not mean a return to milder
conditions. After a chilly and sunny Monday with highs struggling
to reach the mid to upper 40s per the latest 925mb temperature
profiles, lows will easily fall back into the upper 20s and lower
30s for most of the region Monday night. Only the immediate coast
of Louisiana and areas along the southshore of Lake Pontchartrain
remaining in the mid to upper 30s.

&&

.LONG TERM...
(Tuesday through Friday night) Issued at 1247 PM CST Sat Dec 13
2025

A return to a much warmer and more humid airmass will quickly
happen as we move into Tuesday and Wednesday of next week. On
Tuesday, the trough over the eastern CONUS will fully depart and a
shortwave upper level ridge axis will slide in from the west. In
the low to mid-levels, a broad high will also slide to the east.
This will allow for a deep layer onshore flow pattern to develop,
and PWATS will gradually climb back to more average levels for
this time of year by Wednesday. A weak southern stream vort max
will slip through on Wednesday night and Thursday, but limited mid
and upper level moisture over the area will keep any shower
activity isolated to widely scattered even as PWATS rise to over
1.2 inches.  Once this system passes by, a zonal flow regime will
develop over the area for Friday. A weak front will slightly cool
temperatures, but only by a few degrees from the mid 70s on
Thursday into the upper 60s on Friday. These temperatures are
still well above average for mid-December.

&&

.AVIATION...
(18Z TAFS)
Issued at 1247 PM CST Sat Dec 13 2025

Fob probabilities are higher than average generally between 00z
and 09z at GPT, ASD, NEW, MSY, and HUM as warm and humid air
advects over the cooler nearshore waters this evening. The fog
will persist until increased forcing along a fast moving front
occurs after 09z. The forecast calls for an extended period of IFR
and LIFR visibility and ceiling restrictions at these terminals.
At the remainder of the terminals, post-frontal low stratus and
rain will lead to additional IFR conditions, generally between 06z
and 14z. These IFR conditions will also impact GPT, ASD, NEW,
MSY, and HUM, as the fog lifts into a stratiform cloud deck with
light to moderate rainfall from 09z to 16z. After 16z, fast
improvement into MVFR and VFR conditions will occur as a drier
airmass moves in from the north.

&&

.MARINE...
Issued at 1247 PM CST Sat Dec 13 2025

Light onshore flow and a warm and humid airmass moving across the
cooler waters of the sounds and tidal lakes could support some fog
development this evening into the early overnight hours. However,
this fog will quickly clear later tonight as a front moves through
all of the waters. A rapid change in conditions will take place
tomorrow morning as a very strong cold front moves through. Winds
will turn northerly and increase in speed to between 25 and 30
knots with higher gusts from mid to late morning tomorrow through
Monday morning. Small Craft Advisories and Gale Warnings are in
effect for the waters over this time period. Another high will
then quickly settle over the area on Tuesday, and this will allow
winds to turn more easterly and fall back to less than 10 knots.
Seas will also begin to subside as the winds decrease Monday night
into Tuesday. Wednesday and Thursday will see a slight increase in
the onshore flow to 10 to 15 knots as the pressure gradient over
the waters tightens in response to a passing shortwave feature,
but no impacts to mariners are expected once we get past Sunday
and Monday.

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  41  47  21  48 /  70  10   0   0
BTR  46  52  24  49 /  60  20   0   0
ASD  47  57  22  49 /  40  30   0   0
MSY  52  59  32  47 /  30  30   0   0
GPT  48  57  26  49 /  40  30   0   0
PQL  47  57  22  49 /  40  30   0   0

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...Cold Weather Advisory from 9 PM Sunday to 9 AM CST Monday for
     LAZ034>037-039-046>048-056>060-064>071-076>090.

GM...Small Craft Advisory from 6 AM Sunday to 9 AM CST Monday for
     GMZ530-532-534-536-538-550-552-555-557.

     Gale Warning from 6 AM Sunday to 9 AM CST Monday for GMZ570-572-
     575-577.

MS...Cold Weather Advisory from 9 PM Sunday to 9 AM CST Monday for
     MSZ068>071-077-083>088.

GM...Small Craft Advisory from 6 AM Sunday to 9 AM CST Monday for
     GMZ532-534-536-538-550-552-555-557.

     Gale Warning from 6 AM Sunday to 9 AM CST Monday for GMZ572-575-
     577.

&&

$$

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