287
FXUS64 KLIX 010910
AFDLIX

Area Forecast Discussion
National Weather Service New Orleans LA
410 AM CDT Mon Jul 1 2024

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

.SHORT TERM...
(Today through Tuesday)
Issued at 406 AM CDT Mon Jul 1 2024

It has been another rough night across the region with temperatures
still in the upper 70s to mid 80s at 7z. Likely see temps drop
another degree or two but with most of the area starting the day
out around 80 once again it will take no time to heat up with heat
index values quickly climbing into the 100s later this morning.
In awful news at in the area Lakefront Airport (NEW) at 8z had a
heat index of 108 and was sitting at 88/82.

In other news TD3 become Tropical Storm Chris yesterday evening and
has already made landfall over Mexico. No impacts from this system
for our area.

Hurricane Beryl continues to the WNW and due to an Eyewall
Replacement cycle has seen some fluctuations overnight. Forecast
still brings it through the Caribbean and towards the Yucatan
Thursday night/Friday morning. Still looks like any direct impacts
from Beryl are unlikely however there remains a lot of uncertainty
regarding the forecast after Friday. With that it is important to
stay up-to-date with the forecast throughout the week.

Now to focus on the more immediate problem "THE HEAT". It is hot out
there; it is hot right now and the sun isn`t up yet. Today could be
the worst day of this current heat wave as the heat index could
approach 120 in a few locations. But why will today be worse than
yesterday and tomorrow? First the mid lvl ridge will continue to
build east with the center of the ridge possibly over the ARKLATEX
region by afternoon. This will increase the subsidence over the area
along with being accompanied by warming LL temps. H925 temps look to
be around 27-29C while h85 temps will be around 20-22C. This would
easily equate to highs in the 94 to 99 range. Typically there would
be another 1-2 degree F for the superadiabatic skin layer but given
just how humid the region is this probably won`t be the case.
However, there is another possibility that could lead to warmer
temps and that will be northerly winds which can provide weak down
sloping effects mainly over coastal MS. These northerly winds come
behind a weak sfc trough/backdoor "cold" front which has already
moved through but the drier air lags far back to the north and may
finally infiltrate the area tonight. So with no drop in the LL
moisture, warmer LL temps, and even possible downslope impacts the
last possible silver bullet to help keep the heat in check somewhat
would be convection. Yeah that isn`t looking great either today, at
least for the northern half of the CWA. Again this is partially due
to the boundary moving through providing northerly winds. during the
day today the LL winds will be out of the north with h85 winds
possibly as high as 15kts. This will drastically hinder any
northward progress of the seabreeze however it would enhance the
lake breeze headings south across the NO metro. It is that area
around I-10 and to the south that has the best potential for
afternoon storms. The other negative for convection besides the
subsidence and warm mid lvl temps, above the LL we actually dry out
some with PWs possibly dropping below 2" for the
northern/northeastern third of the CWA. With this we continued the
heat advisories and warnings for today and expanded the warning to
include the rest of the FL parishes and Pearl River County. Still
may need to update later this morning if it looks like there is a
good chance that southwest MS getting into the dangerous heat
conditions.

Tomorrow overall would be a carbon copy or worse depending on how
you looks at things. The center of the ridge is even closer to being
directly overhead, LL temps are possibly 1-2 degrees warmer, and mid
lvl temps are warmer with h5 temps around -2 again. This all suggest
HOT and mostly rain free there is just one other aspect that is
needed for heat and that is the humidity. Not lets not kid ourselves
it will still be humid, it is southern LA and MS in the Summer
humidity is baked in but with respect to what we will see today and
the past few days it looks like we could be a little drier. The
drier LL air finally trickles down into the area overnight tonight
and PWs continue to fall with some indication that PWs could be
under 1.75" across the northern half/third. Actual air temps still
look to range from the mid 90s to near 100 and many places could be
a degree or two higher tomorrow with respect to the max temp but the
heat index values are a little more in question. Convection should
be harder to come by but still can`t rule out some storms late in
the afternoon. As for heat don`t get optimistic thinking it will be
a dry heat it will still be oppressive but depending on how much dry
air can working into the area in the LL will dictate whether we see
heat index values in the 105-112 range for most of the area or if we
see the dangerous heat conditions in place with heat  index readings
at and above 113. Because of the uncertainty we issued an Excessive
Heat Watch for all the areas that are currently under the warning
and a heat advisory for all areas that currently have the advisory
in place. This will allow us to downgrade some or all of the watch
area to an advisory if it looks like the humidity will be
significantly lower. /CAB/

&&

.LONG TERM...
(Tuesday night through Sunday)
Issued at 406 AM CDT Mon Jul 1 2024

Overall wish we had better news but models continue to be in
rather decent agreement advertising the heat will continue through
the 4th of July but at least we may get out of the very
oppressive conditions Wednesday through Friday. The other thing to
keep an eye on was mentioned earlier and that is Hurricane Beryl.
NBM looked good for the most part and not major deviations were
made from it.

Wednesday and through the rest of the week and into the weekend the
ridge will continue to build over the area and to the east
dominating the region through the work week. The ridge appears to
flatten out some but is still centered over or near the area. This
would likely allow for weak to possibly modest easterly flow that
could bring a big increase in rain chances but that is still highly
uncertain. The ridge does weaken some and this would likely lead to
minimal drops in the temps both in the mid lvls and the LL and that
along with slightly better rain chances should keep highs in the
lower to mid 90s. There is still the risk of heat headlines through
the week but at this point it would only be heat advisory conditions
and over the more typical humid locations.

As for Beryl, again the NHC official forecast brings Beryl over the
Yucatan overnight Thursday and into the Bay of Campeche/southwest
GOM Friday. After that a lot will depend on how strong or how much
is left of Beryl and how strong the ridge is over the area and
whether there is some erosion on the western periphery of the ridge.
Right there is still too much uncertainty whether Beryl would just
continue chugging along to the WNW into Mexico or start to take a
turn to the NW/NNW. /CAB/

&&

.AVIATION...
(12Z TAFS)
Issued at 406 AM CDT Mon Jul 1 2024

VFR conditions persist across the area and unless convection
impacts any this afternoon there should be no other impacts
through the day and evening. Greatest potential for impacts from
convection should be HUM/MSY/NEW. Obviously with any storm reduced
vsbys and lower cigs should be expected. If convection fires
today it would likely hold off till after 20z. /CAB/

&&

.MARINE...
Issued at 406 AM CDT Mon Jul 1 2024

Weather across the coastal waters will remain generally benign
outside of convection. However, the chance of showers and storms
will be fairly high through at least mid week and mainly over the
overnight hours. While higher winds and seas will accompany any
storms, winds otherwise should generally be no higher than 10-15
knots with seas/waves mostly 2 ft or less. /CAB/

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  95  73  97  76 /  20  10  30   0
BTR  99  79 100  80 /  50  20  40  10
ASD  97  78  97  78 /  40  10  50  20
MSY  96  81  95  81 /  60  20  60  20
GPT  96  78  93  79 /  30  10  50  30
PQL  99  77  96  78 /  30  20  50  30

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...Excessive Heat Warning from 10 AM this morning to 7 PM CDT this
     evening for LAZ034>037-039-046>048-056>060-064-065-071-
     076>090.

     Excessive Heat Watch from Tuesday morning through Tuesday
     evening for LAZ034>037-039-046>048-056>060-064-065-071-
     076>090.

     Heat Advisory from 10 AM this morning to 7 PM CDT this evening
     for LAZ066>070.

     Heat Advisory from 10 AM to 7 PM CDT Tuesday for LAZ066>070.

GM...None.
MS...Excessive Heat Warning from 10 AM this morning to 7 PM CDT this
     evening for MSZ068-077-083>088.

     Excessive Heat Watch from Tuesday morning through Tuesday
     evening for MSZ068-077-083>088.

     Heat Advisory from 10 AM this morning to 7 PM CDT this evening
     for MSZ069>071.

     Heat Advisory from 10 AM to 7 PM CDT Tuesday for MSZ069>071.

GM...None.
&&

$$

SHORT TERM...CAB
LONG TERM....CAB
AVIATION...CAB
MARINE...CAB