926
FXUS64 KLIX 140842
AFDLIX

Area Forecast Discussion
National Weather Service New Orleans LA
342 AM CDT Sun Jul 14 2024

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

.SHORT TERM...
(Today through Monday)
Issued at 339 AM CDT Sun Jul 14 2024

An upper level ridge is currently centered near the 4-Corners and
loosely extends across the southern CONUS. Its quite a bit flatter
east of Texas due to a shortwave tracking across the northern
quarter of the country. This pattern is relatively typical for
summer locally with diurnally driven convection what`s to be
expected. The biggest question is initiation timing and coverage.
Day after day, spatial coverage has been generally quite a bit lower
than NBM forecast. CAMs have done a decent job relatively speaking.
They generally show late morning to early afternoon before inland
storms develop along seabreeze boundaries and then propagating in
whatever direction the outflow boundaries dictate. Urban flash
flooding will be the greatest potential impact with storms. For
coverage/POP forecast, again went much less than the NBM which has
been way too high lately. At any given time, might not even be more
than isolated, though overall areal coverage at the end of the day
will be more in line with scattered.

Otherwise, the arguably more large scale weather impact today (and
well into next week) will be continued heat. Increased 500mb heights
from ridge to the west will continue to support mid/upper 90 degree
highs. That, combined with upper 70 to low 80 dewpoints, will again
bring heat indices in the 108 to 112 degree range for most of the
CWA. Did decide to add a targeted Excessive Heat Warning along areas
adjacent to Lake Pontchartrain. What drove this decision was looking
at KNEW observations yesterday. Seabreeze winds helped to maintain
upper 70 dewpoints even in the peak heating hours. This resulted in
a max daytime heat index of 115 degrees. So thinking is that
potential heat index will be possible again today at any location
around the Lake.

MEFFER
&&

.LONG TERM...
(Monday night through Saturday)
Issued at 339 AM CDT Sun Jul 14 2024

The remainder of the forecast period, which runs through Saturday,
really hasn`t changed much at all outside of relatively small
changes in day-to-day rain chances. Heat will still be the biggest
impact. The upper ridge centered west of the CWA will remain
expanded across the southern half of the country. That`ll keep highs
in the mid to upper 90s. Not going to see much nighttime relief from
heat and have increased forecast lows 1-3 degrees above the cool-
biased NBM.  Even through convective coverage will vary from
scattered to numerous each day, still probably will need a heat
advisory for 5 consecutive days, with the potential for a small
portion of the forecast area to need an Excessive Heat Warning
early/mid next week. It`s the end of this portion of the forecast
period that global models suggest that a fairly amplified upper
trough dives south across the eastern 1/3 of the US. That would
certainly break down the ridge aloft and lead to temps closer to
climo.

MEFFER
&&

.AVIATION...
(06Z TAFS)
Issued at 339 AM CDT Sun Jul 14 2024

VFR conditions will prevail through the period. Isolated to
scattered showers and thunderstorms are possible during the
afternoon hours. This could impact the terminals resulting in
temporary gusty winds and VIS restrictions due to brief heavy rain.
Probability at any given location/time is fairly low, so for the
time being have included only vicinity groups. However, as
confidence in timing and location increase, tempo groups may be
added.

&&

.MARINE...
Issued at 339 AM CDT Sun Jul 14 2024

The area will remain under surface ridge for the most part,
although the center will not always be aloft during the forecast
period. That means winds and seas wont` be much impact outside of
convection, with seas 2 feet or less throughout the period.
Otherwise, typical summertime nocturnal to early morning showers and
storms expected with brief gusty winds and waterspouts the main
threats.

MEFFER

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  93  73  93  73 /  50  30  60  10
BTR  96  79  97  80 /  30  20  60   0
ASD  95  80  94  81 /  40  20  70  10
MSY  95  81  93  82 /  30  20  70  10
GPT  93  79  92  80 /  30  30  60  10
PQL  96  77  95  79 /  40  30  50  20

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...Heat Advisory from 11 AM this morning to 7 PM CDT this evening
     for LAZ034>037-039-046>048-056-057-059-064-065-071-079-081-
     083-085-086-088>090.

     Heat Advisory from 11 AM to 7 PM CDT Monday for LAZ034>037-039-
     046>048-056>060-064-065-071-076>090.

     Excessive Heat Warning from 11 AM this morning to 7 PM CDT this
     evening for LAZ058-060-076>078-080-082-084-087.

GM...None.
MS...Heat Advisory from 11 AM this morning to 7 PM CDT this evening
     for MSZ068>071-077-083>088.

     Heat Advisory from 11 AM to 7 PM CDT Monday for MSZ068>071-077-
     083>088.

GM...None.
&&

$$

SHORT TERM...ME
LONG TERM....ME
AVIATION...DM
MARINE...ME