Area Forecast Discussion
Issued by NWS New Orleans/Baton Rouge, LA

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992
FXUS64 KLIX 020950
AFDLIX

Area Forecast Discussion
National Weather Service New Orleans LA
450 AM CDT Tue Jul 2 2024

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

.SHORT TERM...
(Today through Independence Day)
Issued at 322 AM CDT Tue Jul 2 2024

The beat on the street is the heat and unless you have been
sitting inside an air conditioned room (pretty smart more by the
way) you have probably noticed. This is not going to get better
today but should be slightly better the next few days. Better will
be relative as it will still be hot but rain chances go up for
Wednesday and the 4th of July and that should help keep the
afternoon highs down some. But until we get to tomorrow we will
have to get through today which may be every bit as rough as
yesterday.

As for today, the biggest change will be the moisture and that is
more so the mid and upper levels. The ridge has continued to slide
to the east and will be centered directly north of the area this
afternoon while drier air will slowly continue to work in from the
north and northeast. The 00Z sndg last night had a PW just below 2"
and GOES16 TPW showed drier air just off to the north and northeast
drifting to the area. This along with very warm mid lvl temps and an
increase in subsidence should drastically hinder convective
development over the northern half of the area. PWs will still be at
or just abv 2" along the coast and this may allow for greater
potential for storms to develop this afternoon along the seabreeze
and or lake breeze. The biggest issue for the seabreeze is the
northerly winds in the LL which will keep it from moving to the
north much thus why the best rain chances will likely be across the
southern and southwestern portions of the CWA. The lake breeze
heading south and southwest out of Lakes Pontchartrain and Maurepas
may actually provide the best chance for rain in portions of the
river parishes as it pushes southwest of I-10.

So what does this mean for the heat today. The biggest problem is
the lack of rain and cloud cover meaning that most of the area will
have little difficulty warming up today. LL moisture is still very
high with maybe the one exception being across portions of southwest
MS where slightly drier air may mix in enough to get the dewpoints to
fall to near 70. Elsewhere it doesn`t look like there will be any
relief in humidity values. High yesterday got even hotter than
expected in many locations with MSY and ASD topping out around 98.
The only real change from yesterday with respect to temps is that
the LL may be a degree or two warmer. With that highs should be
every bit as high as they were yesterday if not a degree or two
hotter. The one exception could be coastal MS where the we should
not have the light to moderate northerly flow which typically leads
to some local compressional heating. Winds from the sfc to h925 will
begin very light and slowly veer around to the east by midday and
possibly ESE this afternoon. This would help keep coastal Ms from
torching out but it could be a double edged sword as if the
seabreeze can develop and try to penetrate inland some the humidity
will increase or as the seabreeze approaches microscale
compressional heating in front of that boundary and moisture pooling
could make things even more miserable. With highs once again
expected to be in the mid 90s to near 100 across the entire area
and the very humid airmass in place heat index values should have no
problem getting into the 110s again for a large chunk of the area
and could once again approach 120 in isolated areas. An Excessive
Heat Warning and Heat Advisory has already been issued and no
changes were made to it.

As for tomorrow and Independence Day it looks like we could see
some relief in the form of much higher rain chances along with early
initiation. The ridge remains over the southeastern CONUS but does
begin to flatten out more while the drier air that could move in
today looks to be replaced by a very moist airmass. Almost a weak
easterly wave as it moves under the ridge. But possibly the biggest
change and positive aspect for convection will be LL winds as the
h85 winds come already back around and should be out of the
southeast by late morning/midday Wednesday. This should allow for
the seabreeze to develop much earlier say around late
morning/midday. That along with increasing cloud cover will help
contain the afternoon highs some but make no mistake highs will
still be in the lower to mid 90s. Of course the humidity will be
high and could be even greater now and that will likely lead to the
oppressive conditions continuing but should be nothing like what
should be seen today and what has already occurred the last few days.
Thursday could be a carbon copy of tomorrow but the concern is that
we may actually be between weak waves rotating around the ridge and
thus depending on timing Thursday could be a good bit drier rain
wise and likely a degree or two warm. At this time we have held off
on any heat headlines for Wednesday and Thursday due to the
uncertainty of rain coverage, timing, and impacts on the temps. That
said it is highly likely that some locations will be under a heat
advisory both days. /CAB/


&&

.LONG TERM...
(Friday through Monday)
Issued at 322 AM CDT Tue Jul 2 2024

Heat is the first concern with the forecast for Friday and into
the weekend but obviously many are interested in the forecast for
Beryl. Medium range models are in decent agreement and the more
trust worthy ones show a similar setup as Beryl moves across the
Yucatan and into the southwestern GOM. Given the high uncertainty
with rain potential and where Beryl eventually ends up we have
stuck pretty close to the NBM guidance.

The ridge that has brought us our heat wave and will dominate the
region through the week will start to slowly slide east on Friday
and the decreasing subsidence and lower hghts may allow for a decent
shot of rain again but LL temps remain quite high and this should
still lead to widespread lower to mid 90s Friday and into the
weekend with a few upper 90s not out of the question Friday. With
that we could easily see heat headlines continue.

As for Beryl, it continues to hold its own as it begins to move into
the central Caribbean today. At 8Z Beryl was still a category 5
hurricane and even though it is moving into a more hostile
environment, has not weakened yet but this is expected to begin
today. The latest forecast brings Beryl over the Yucatan early
Friday and into the southwestern GOM overnight Friday night. Key
things to watch over the next few days. Track as it approaches
Jamaica. If it moves south or over Jamaica there is a good chance
that Beryl will continue moving more west especially if it weakens
significantly. Second, how strong is Beryl as it approaches the
Yucatan. A stronger system will feel the steering currents more
and that could play a big role into where Beryl eventually goes.
Third will be our ridge. As long as it remains over the
southeastern CONUS and Gulf coast it should help to continue to
steer Beryl to the west-northwest and northwest. That said the
western periphery of the ridge will begin to erode this weekend as
a disturbance drops southeast out of the northern Plains and
Upper MS Valley. The steering currents could break down rather
quickly over the western Gulf and that is why you may be seeing
that larger spread in the media/social media. At this time it
still looks unlikely we will see any direct impacts from Beryl. If
Beryl weakens significantly over the next 24-36 hours as it moves
into a hostile environment and/or hits Jamaica which would
significantly disrupt it, Beryl would likely take more a almost
due west and could very well just continue west. If Beryl remains
organized it should continue to follow a WNW to NW motion into the
southwest Gulf and then slow down some. It could then take a NW
to NNW turn or if far enough south slowly to the W and WNW. So the
main take away is for our area relax and just continue to follow
the latest forecast. Latest forecast from NHC has Beryl as
tropical storm just off the Mexican coast Sunday morning. If you
have family along the coast in Mexico and southern to central TX
coast remind them to closely pay attention. /CAB/

&&

.AVIATION...
(12Z TAFS)
Issued at 322 AM CDT Tue Jul 2 2024

VFR conditions will likely persist through the forecast for most
if not all but HUM today. HUM has the best chance of seeing
convection but there could be a few storms near MSY, NEW and GPT
late this afternoon. Obviously any passing TSRA will lead to
reduced vsbys and lowered CIGs. Gusty winds are also possible but
outside of that VFR condtions will be the rule. /CAB/

&&

.MARINE...
Issued at 322 AM CDT Tue Jul 2 2024

Weather across the coastal waters will remain generally benign
outside of convection and convection may be a tad harder to get
today but still possible each morning. 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  98  76  92  74 /  10  10  70  10
BTR 101  80  95  79 /  20  10  80   0
ASD  98  79  92  78 /  20  20  80  10
MSY  98  81  92  80 /  20  20  80  10
GPT  96  79  90  78 /  30  40  70  10
PQL  97  78  94  77 /  30  40  70  10

&&

.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.

     Heat Advisory from 10 AM this morning to 7 PM CDT this evening
     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.

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

GM...None.
&&

$$

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