LIX issues Area Forecast Discussion (AFD) at Feb 13, 11:45 PM CST ...New AVIATION...967
FXUS64 KLIX 140545
AFDLIX
Area Forecast Discussion
National Weather Service New Orleans LA
1145 PM CST Thu Feb 13 2025
...New AVIATION...
.SHORT TERM...
(This evening through Friday night)
Issued at 222 PM CST Thu Feb 13 2025
Starting off with this afternoon, the front is way through here
with much cooler temperatures all across the area. Main concerns
from this morning update was the degree of multi-layer clouds
across the region and how they could effect highs. Looks like
we've trended more partly cloudy for most areas as most low-level
stratocumulus streets have dissipated across central/northern
areas. However, is still staying thicker over SE LA sandwiched at
the LCL and base of a strong subsidence inversion in the low-
levels. Holding on to the same morning updates which trends much
cooler mainly for northern, western and SE LA locations at the
25th NBM percentile blend. Otherwise, a quiet afternoon but breezy
with persistent CAA across the region.
Clouds will continue to trend thinner tonight, but may still see
a thin layer of mid-level altocumulus. CAA will dive temperatures
down into the upper 30's for northern areas, low to mid 40's for
the I-10/12 corridor. Not anticipating any freeze issues tonight
as winds remain elevated and we have just enough clouds in
combination with the winds to offset strong radiational cooling.
Going into Friday, the front that passed here and slowed down in
the central Gulf will return back as a warm front into the north-
central Gulf. Meanwhile, we'll see a (very) subtle mid-level
impulse dig out of northern Mexico into the central US along
progressive SW/NE flow aloft. This, in conjunction with increasing
low-level isentropic ascent associated ahead of the warm front
will increase clouds areawide going into the afternoon. While
it'll be warmer, was reluctant to warm us up too much for these
aforementioned reasons. There might be just enough isentropic
lift and attendant moisture aloft to squeeze out a few isolated
showers/drizzle for mainly central/western areas, but not
anticipating a lot with this (but did keep generally 20-30% PoPs
in). Once the actual warm front nears closer later Friday into
Friday night, we could see more light showers pop across coastal
SE LA closer to greatest low-level frontogenetic, but again, low
impact. PoPs are mainly in the 40's for coastal SE LA to the 30's
for northern coastal areas into the overnight hours.
Did want to also mention the potential for patchy areas of
coastal/marine advection fog with the warm front drifting north
going into early Saturday morning. Not entirely confident on the
degree/magnitude of fog at this time, but am confident for the
location across coastal/marine areas of SE LA. Will watch
guidance closely and made adjustments in subsequent updates. KLG
&&
.LONG TERM...
(Saturday through Wednesday night)
Issued at 222 PM CST Thu Feb 13 2025
Continuing into the day on Saturday, focus shifts to the west at
our next storm system taking shape. Just about all guidance is in
good agreement (per recent cluster analysis) that a deep west
coast trough will eject quickly into the southern Rockies,
progressively increase in amplitude and transition positive to
eventual neutral tilt into the central Plains. Surface reflection
will include eventual downstream low genesis over the central US,
setting the stage for rapid low strengthening (sub 1000mb) along
a prominent baroclinic zone stretching from central Texas into the
Ohio Valley region. We'll see storms erupt quickly during peak
diurnal destabilization over the ArkLaTex, coupled with an
increasing 850LLJ with the trough rounding out/pressing east with
time allowing in eventual supercellular structures to transition
more linear going into the evening hours. For us locally during
the day on Saturday, it'll be warm! Some areas may average 15-18
degrees warmer than what we'll see on Friday climbing into the
upper 70's to low to mid 80's for most. Currently have a high of
84 for Baton Rouge, which is one degree away from the record high
of 85 set in 1989, same for New Orleans with a forecast high of 82
and a record daily high of 83 set in 2018 so clear to say,
temperatures will be nearing close to records (possibly surpassing
for some, depending on trends).
Meanwhile, it'll be breezy as gradient winds get cracking ahead
of the system. Model soundings illustrate a well-mixed adiabatic
PBL thermal profile with 35-45kt winds at the top of the mixed
layer. Diurnal flux transport will have no problem bringing gusty
winds down to the surface with this setup. Did decide to increase
surface winds/wind gusts primarily late morning through the
evening closing in on the 90th percentile, averaging gusts in the
25-30 knots but may likely be higher than that for coastal areas
closer to 35 knots. As this is going on and severe weather is
taking shape back west, we could see a few streamer showers during
the day from confluence banding, but not expected to become too
much of an issue displaced from greatest LLJ dynamics and
attendant synoptic lift. As for lightning risk, will confidently
say the risk for lightning will be lower earlier in the day
(before 12PM) but the risk grows going beyond this into the
afternoon, primarily evening and even higher into the overnight
hours. At this time, it appears both the LLJ position
displacement to the north, providing mainly parallel flow to the
eastward advancing front would suggest a messy set up this far
south. This signals what could be many SW/NE lead confluence bands
becoming heaver through the evening/overnight hours providing
more widespread scattered shower/storm line segments head of the
main line, basically very similar to what we saw later in the
evening with this last system. Closer to the LLJ dynamics
(northern areas, primarily SW MS) some of these could be locally
strong to severe, with damaging winds and an isolated weak tornado
possible but farther south into the SLGT to MRGL, really seeing
more cons than pros in regards to a widespread severe weather risk
for the same aforementioned reasons of dynamic lift displacement
in a generalized low cape/ modest shear environment. Still bears
close watching however, and once within the HREF time frame, will
gain greater confidence.
This system is out of here in a hurry early Sunday, not expecting
this front to linger up which will usher in much cooler air in a
strengthening CAA regime. We quickly clear out with highs
generally reaching the low 60's. Next focus will be on the return
of some cold air early Monday morning. Model soundings illustrate
a strongly subsident vertical profile with radiational cooling
likely maximized. Only caveat may be the winds as we could remain
slightly breezy at around 04-06kts at the surface. This could be
overdone given any higher bias in the blend this far out in
advance, but regardless did edge colder with lows towards the 25th
percentile bringing low 30's for the northern Florida Parishes
and SW MS. Mid 30's generally for the I-10/12 corridor.
Starting the new work week cool and quiet going into the day
Monday through Tuesday as we enter a quasi-zonal flow aloft. Next
system knocking on the door on Wednesday will be watched towards
the end of the forecast period. Looking like an all-rain event for
the area with some thunderstorms possible. The bigger story will
be the upper- air pattern supporting a very strong 1050mb+ arctic
high into the northern US, undercutting the precip of this next
impulse causing snow for a good portion of central US/mid MS
valley region. Not expecting winter weather with this system here
locally, but as this system passes and the arctic air builds in
behind it, it's looking cold yet again for later parts of next
week so be sure to check back for more details. KLG
&&
.AVIATION...
(06Z TAFS)
Issued at 1135 PM CST Thu Feb 13 2025
VFR conditions continue for nearly all of the forecast period.
Northerly/northeasterly winds continue to be a bit elevated with
gusts up to 20 kts possible. Ceilings will begin to lower tomorrow
afternoon with terminals in the MVFR to IFR range for ceilings by
the end of the forecast period. -BL
&&
.MARINE...
Issued at 222 PM CST Thu Feb 13 2025
Gusty offshore winds have developed following a recent frontal
passage, with small craft advisories in effect through tonight
into the day on Friday. Winds will mainly remain north to north-
northeasterly, transitioning into northeasterly overnight. In
response, waves/seas will continue to increase reaching around 3
to 5 feet for protected waters to 5 to 9 feet for offshore gulf
waters. We will likely see another period of strong winds again
during the day on Saturday as winds switch from the south to
onshore flow, then a cold front sweeps across Gulf waters Saturday
night into early Sunday. Winds will become strong behind this
front, likely reaching small craft advisory criteria yet again but
with time, become more calm going into early next week. KLG
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 38 63 54 79 / 0 30 30 60
BTR 43 66 58 84 / 0 40 10 60
ASD 42 68 59 81 / 0 20 30 40
MSY 48 69 61 81 / 0 20 20 40
GPT 41 67 57 75 / 0 10 30 30
PQL 42 69 59 79 / 0 10 30 20
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...None.
GM...Small Craft Advisory until 6 PM CST Friday for GMZ530-532-534-
536-538-550-552-555-557-570-572-575-577.
MS...None.
GM...Small Craft Advisory until 6 PM CST Friday for GMZ532-534-536-
538-550-552-555-557-570-572-575-577.
&&
$$
SHORT TERM...KLG
LONG TERM....KLG
AVIATION...BL
MARINE...KLG
Source:
LIX issues Area Forecast Discussion (AFD) at Feb 13, 11:45 PM CST ...New AVIATION...---------------
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