Gretna, Louisianna 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

541
FXUS64 KLIX 300538
AFDLIX

Area Forecast Discussion
National Weather Service New Orleans LA
1138 PM CST Wed Jan 29 2025

...New AVIATION...

.UPDATE...
Issued at 830 PM CST Wed Jan 29 2025

A dense fog advisory has been issued for areas along and east of
the I-55 corridor in southeast LA and coastal MS. Probabilities
of dense fog (<1 mile visibility) have increased especially for
adjacent coastal areas to the tidal lakes and sounds. While mid to
upper-level clouds will slow radiational cooling, light
southeasterly winds will continue to advect moist air over the
colder than normal shelf waters near the coast. Confidence is
highest in low ceilings of less than 1000 feet across the area,
but areas near the coastline could see continued stratus build
down into dense fog after midnight. Confidence is lower for areas
of downtown New Orleans and areas west of the I-55 corridor where
925mb winds will be increasing overnight ahead of the approaching
system. 925mb winds exceed 15-25 knots after 0900 UTC across the
western half of the CWA which should lift any dense fog into
stratus and limit the extent/period of dense fog conditions.
Confidence is highest for dense fog impacts along the Northshore
and coastal MS where winds will remain weaker through daybreak.

Morning commuters are encouraged to use caution commuting on
bridges around Lake Pontchartrain and I-10 in coastal MS. Use
low-beam head lights, increase distance between you and the car
ahead of you, and reduce your speed. Patchy dense fog can cause
rapid changes to visibility, especially during first light near
sunrise.

&&

.SHORT TERM...
(This evening through Thursday)
Issued at 151 PM CST Wed Jan 29 2025

Surface high pressure continues to exit stage east this afternoon
switching the low level winds to a more onshore/return flow. This
flow will be light at first, however, a fairly rich low level
moisture surge is on the way. With the somewhat light to low end
moderate winds, sea fog may advect inland. Didn`t issue a dense
fog advisory for landbased zones as there is still a few
questions about inland extent and density. However, already
looking a bit fuzzy on the Twin Span cameras. SREF has also been
very bullish with potential fog overnight over the local waters
and adjacent coast. Unlike the last couple of days where stat
guidance was overplaying VIS reductions, SREF was very persistent
and is verifying the best at this juncture...so will follow the
SREF lead through midday Thursday.

Outside of the fog the only story left is warmth, especially away
from the local waters. As the H5 cutoff low moves east, our
heights over the region will increase during the day on Thursday.
This with a warm return flow will help warm us again into the
70s...with BTR perhaps approaching 80F Thursday afternoon. (Frye)

&&

.LONG TERM...
(Thursday Night through Tuesday night)
Issued at 151 PM CST Wed Jan 29 2025

Eyes shift upstream as a broad scale trough begins to spiral
eastward from the high plains and eventually north and eastward
toward the Great Lakes by early Friday. Ahead of the upper level
low, the surface low will develop over the TX Hill Country and
move ahead of the upper level feature. As it moves over the Ohio
River Valley, a surface front will swing through out region.
However, behind the front only minor drops in temp but a fairly
dry airmass will settle into the region, which will limit any fog
issues.

As for the frontal passage or the potential for rainfall/storms,
overall largely unchanged. Best dynamic forcing looks to be over
Arkansas and the midsouth removed from our region. Furthermore,
timing isn`t the best for destabilization. This time of the year
you`re going to need one of the other..cape or strong upper level
support in order to get much of an appreciable threat. In this
case, both seem to be lacking. What isn`t lacking here is the low
level wind shear where a 45-55kt LLJ develops. With that 0-1km SRH
values are very supportive for severe and may actually be too much
of a good thing. With little in the way to give updrafts much
strength, wind shear will likely roll any weak narrow updraft that
tries to initiate limiting vertical stretching overall. That said,
if a rogue updraft does grow wider/stronger a conditional severe
weather threat will exist. This is why SPC has delineated
(respectively) a marginal to slight risk with the best potential
closer to the best upper support and timing across southwest
Mississippi. In addition, WPC did highlight a marginal ERO for
heavy rainfall during the same time. Overall, this will be
extremely limited given the transient nature of the band of
convection. Although, NBM90 shows a reasonable worst case of
around 2 inches of so across the northwestern tier before QPF
signal really decreases with the eastern advancement of the band
of showers and storms.

Going into the weekend, the upper level pattern doesn`t really
change much and continues a more progressive/zonal flow aloft,
which suggests not much in terms of a cool down, although drier
low level air should push into the region. With a continuation of
above average temperatures into the start of the new workweek,
globals show the low level flow increasing again as an onshore
flow takes shape. Models show a surface front stall to our
north within the mean zonal flow and perhaps our next chance of
rain by Tuesday with an H5 trough trying to maneuver toward our
general vicinity. (Frye)

&&

.AVIATION...
(06Z TAFS)
Issued at 1134 PM CST Wed Jan 29 2025

IFR to LIFR CIGs expected tonight, especially for coastal
terminals with visibilities intermittently reaching below 3SM.
Probabilities have increased for dense fog for GPT which has
prompted inclusion of LIFR VIS and TEMPO for 1/4SM FG. Have
decreased confidence for IFR to LIFR fog for BTR, MSY, HDC, and
NEW since wind obs continue to be elevated. South- southeast
winds will increase out of the south after 12 UTC Thursday morning
ahead of the next system with winds gusts in excess of 25 to 30
knots. Timing has slowed slightly for SHRA/TSRA in association
with a line of storms so have kept predominantly VC and -SHRA
mentioned for now in terminals along/west of I-55.

&&

.MARINE...
Issued at 151 PM CST Wed Jan 29 2025

Light onshore flow has become established over the local waters
this afternoon. This flow will gradually increase as pressure
gradient increases ahead of the next system due into the region
late Thursday and early Friday. Very rich low level moisture will
surge northward over a very cool sea surface leading to sea fog
overnight tonight through around midday or so Thursday across the
nearshore waters. Additionally, low level flow will increase
leading to the need for cautionary headlines nearshore and SCA for
the outer waters of the Gulf. As the front pushes through some
improvement is anticipated going into the upcoming weekend.
(Frye)

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  57  74  59  71 /  10  30 100  20
BTR  61  80  61  73 /  10  20  90  10
ASD  57  74  61  73 /  10  10  60  30
MSY  59  74  62  73 /  10  10  60  20
GPT  54  69  59  71 /   0  10  40  50
PQL  54  73  62  76 /   0  10  30  60

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...Dense Fog Advisory until 9 AM CST Thursday for LAZ039-064-
     068>071-076>082-087>090.

GM...Dense Fog Advisory until noon CST Thursday for GMZ530-532-534-
     536-538-550-552-555-557.

     Small Craft Advisory from 3 AM to 6 PM CST Thursday for GMZ570-
     572-575-577.

MS...Dense Fog Advisory until 9 AM CST Thursday for MSZ077-083>088.

GM...Dense Fog Advisory until noon CST Thursday for GMZ532-534-536-
     538-550-552-555-557.

     Small Craft Advisory from 3 AM to 6 PM CST Thursday for GMZ572-
     575-577.

&&

$$

SHORT TERM...RDF
LONG TERM....RDF
AVIATION...TJS
MARINE...RDF