270
FXUS64 KLIX 021750
AFDLIX

Area Forecast Discussion
National Weather Service New Orleans LA
1250 PM CDT Sun Jun 2 2024

...New AVIATION...

.UPDATE...
Issued at 947 AM CDT Sun Jun 2 2024

Adjusted PoP, weather, and QPF forecasts to account for ongoing
convective trends based on the latest radar and satellite data.
A broad area of light to moderate stratiform rainfall with
occasional embedded thunderstorms will continue to impact the
I-10 corridor between Baton Rouge and New Orleans through the
morning hours, and have increased PoP to categorical or over 80
percent for this area.  Additional scattered shower and
thunderstorm activity will continue to develop through the morning
hours over parts of the Northshore. Around mid-day, this initial
round of stratiform rainfall should dissipate, but continued high
PWATS near 2 inches and daytime heating will support another
period of convective development from mid-afternoon through the
early evening hours. This development will occur along a boundary
draped in a northwest to southeast orientation across Southeast
Louisiana, and have PoP of 60 to 70 percent in place for the
Northshore, metro New Orleans, metro Baton Rouge, and the River
Parishes. Once again, the the primary threat will be heavy
rainfall that could lead to localized flooding issues and possibly
some hail and high winds if the core of the convective updrafts
are strong enough to punch above 40k feet. The convective activity
is still expected to dissipate in the mid to late evening hours,
generally between 8 and 10 PM, with the loss of daytime heating.
PG

&&

.SHORT TERM...
(Today through Monday)
Issued at 214 AM CDT Sun Jun 2 2024

The somewhat active pattern continues into Sunday with the region
remaining under a northwesterly flow aloft on the northeast side
of a rather strong H5 ridge centered over Mexico. Within this flow
(very reminiscent of summer) some rather robust impulses have
been sliding through the region and this should continue again
today and into the start of the new workweek. Initially, this
morning an impulse has helped develop some isolated but rather
strong T`storms just west of the Atchafalaya. These storms are
elevated in nature given the LCH and LIX 00z RAOBs depicting low
level inversions at the surface. Still, a strong wind gust, heavy
rain and hail (some could be large) will be possible with this
activity as it moves southeast. The best potential at the moment
early this morning seems to be along and west of the Mississippi
River or more specifically Terrebonne Parish and the near shore
gulf waters/Terrebonne Bay.

As this initial short wave continues downstream there may be a bit
of a break later this morning. This break will allow conditions to
destabilize and allow for additional showers and thunderstorms to
develop once again as yet another ripple within the flow moves
overhead. CAMs are NOT performing the greatest at the moment so
we did do a broad brush with POPs today and tried to get timing
down, but at this juncture POPs are based on timing of the
individual impulses as well as the diurnal cycle. With cloudiness
around, insolation looks to be limited, but a break in
showers/convection with the strong sun angle will still provide
enough surface heating to destabilize. Since CAMs are struggling,
followed the globals lead for both QPF/POPs generally across the
board through today. By Monday, we`ll need to watch a potential
MCS to our northwest, however, guidance isn`t very aggressive at
least not for our area. The synoptic pattern begins a very subtle
change allowing for the more intense mid level shortwave to become
negatively tilted and shifts the upper flow to a more zonal flow
keeping most of this activity to the north. Still, with very
subtle ripples within this flow and again diurnal processes, rain
chances are NOT zero, but should be quite a bit lower than today
with generally 20/30 POPs across the board. Consequently,
temperatures begin to rebound with MaxTs approaching the 90F mark
once again. (Frye)

&&

.LONG TERM...
(Monday night through Saturday)
Issued at 214 AM CDT Sun Jun 2 2024

A bit less active going into the long term as the zonal mid and
upper level flow continues across the region. Upper level ridging
will slide eastward across more of the central Gulf. With the
lower POPs and less cloudiness, temperatures will be increasing
into the 90s for most of the CWFA. By Wednesday, a surface front
and parent trough begin to slide southward from the Missouri
Ozarks and eventually winding up across the mid south. The zonal
flow quickly evolves by Wednesday and Thursday back to a northerly
flow. This will help bring the front southward toward the
northeast Gulf. With the upper trough moving south and eastward,
most of the best upper level support will miss our region to the
east, but the eastern third of the CWFA will have a shot of
showers/convection. As this first frontal boundary moves south and
east, surface high pressure develops/centers across the northern
Gulf. This will limit winds and overall will suppress rain
chances. Again, consequently, strong insolation will help max
temps climb into the 90s just about everywhere.

By Friday, a second front will be sliding southward from the
Ohio/TN River Valleys. Globals are a bit (or a lot) off with the
GFS being the slower of the solutions with the front draped across
our area a full 24 hours or more after the ECM. So, needless to
say confidence isn`t quite high in the timing. But, with the
broad- scale trough setting up across the east and the front
making it this far south, think rain chances will be there and
should gradually increase in time as confidence in when and
exactly where the better support will be aloft going into the
start of next weekend. (Frye)

&&

.AVIATION...
(18Z TAFS)
Issued at 1243 PM CDT Sun Jun 2 2024

A thunderstorm is currently in the vicinity of NEW and may impact
the terminal over the next hour. Given this threat, have included
a TEMPO group from 18z to 19z that includes a mention of gusty
winds, thunderstorms, and MVFR ceilings and visibilities. A
similar threat exists at all of the other terminals through around
00z as the atmosphere remain moist and unstable, but thunderstorm
probabilities are too low to include as a prevailing or TEMPO
group. Instead, have included periods generally ranging from 2 to
4 hours of prevailing rain shower activity with vicninity
thunderstorms between 19z and 00z at all of the terminals.
Ceilings will range from 2000 to 3000 feet over this period. If a
thunderstorm is expected to directly impact a terminal, an
amendment with TEMPO group will be added. After 00z, the
thunderstorm activity will wane with the loss of daytime heating.
Prevailing MVFR and VFR conditions are expected from 00z through
18z tomorrow at nearly all of the terminals. Only MCB could see a
brief period of IFR ceilings and MVFR visibilties develop beneath
a weak low level inversion between 10z and 13z tomorrow morning.
PG

&&

.AVIATION...
(12Z TAFS)
Issued at 625 AM CDT Sun Jun 2 2024

Unfortunately, short fused AMDs may be necessary through this
cycle, especially during the day today as timing of convection is
still a bit questionable. Made an attempt to use TEMPOs vs VCs to
try to hammer down timing with this mornings convection having the
best confidence. In the heaviest convection expect brief IFR
drops, otherwise VFR outside of convection will continue to be
possible. Overnight tonight, convection should decrease with a few
lingering -SHRAs around. Cannot rule out CIG/VIS drops, especially
for MCB by the end of this cycle. (Frye)

&&

.MARINE...
Issued at 214 AM CDT Sun Jun 2 2024

The main concerns going into the start of the new workweek and
beyond will be the potential for convection across the local
waters. In and around the local Gulf Waters and tidal lakes.
Surface winds eventually shift to a more southerly direction and
will generally range between light to moderate (some winds up to
15kts not out of the realm of possibility Tue/Wed), but high
pressure builds right back across the Gulf, which should help
relax surface winds and seas. Again, higher winds and seas can be
anticipated in convection. (Frye)

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  68  87  70  89 /  20  50  50  20
BTR  73  91  74  93 /  40  40  30  10
ASD  72  89  74  91 /  30  20  20  10
MSY  75  89  76  91 /  40  30  20  10
GPT  73  87  75  88 /  20  20  20  10
PQL  71  89  72  89 /  20  20  20  10

&&

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

$$

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