618
FXUS64 KLIX 132048
AFDLIX

Area Forecast Discussion
National Weather Service New Orleans LA
348 PM CDT Thu Jun 13 2024

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

.SHORT TERM...
(This evening through Friday night)
Issued at 149 PM CDT Thu Jun 13 2024

In a nutshell, hot.

In more detail....An upper level ridge of high pressure will build
eastward into the area becoming more centered over the lower
Mississippi Valley tomorrow and especially Saturday. With the
high centered near the region, subsidence aloft will suppress
convection and POPs are generally 10 percent or less through the
weekend. The lack of showers/storms and cloud cover will also
allow temperatures to rise into the mid to upper 90s and a couple
places may even touch the century mark on Saturday. While
dewpoints won`t be pleasant, slightly drier air mixing down from
aloft during the afternoon should help keep the heat index from
rising to oppressive levels. Current forecast calls for max heat
index readings in the 98 to 102 range on Friday and in the 100 to
105 degree range on Saturday.

&&

.LONG TERM...
(Saturday through Wednesday night)
Issued at 149 PM CDT Thu Jun 13 2024

Saturday evening, upper ridging will be centered over Alabama and
moving northeastward to West Virginia by Tuesday and over the Mid
Atlantic States by mid to late week next week. That will eventually
open up the local area to mid-level easterlies by Sunday or Monday.
By early next week, the Central American Gyre will likely aid in the
development of low pressure in the Bay of Campeche. The easterlies
should be sufficient to move any low pressure that does develop
westward into Mexico by mid to late week next week. The low will
strengthen the surface pressure gradient between it and the Bermuda
High. The low level onshore flow will allow moisture levels to
rapidly increase from about 1.4 inches Saturday evening to about 2
inches by Monday evening, and remaining in the 2.0 to 2.2 range near
and south of Interstate 10 through midweek next week. As shortwaves
move westward through the easterlies, they will produce rounds of
rain and thunderstorms. There have been differences between the GFS
and ECMWF families regarding the strength of the ridge to the
northeast and how quickly they move away, with the ECMWF based
solutions generally stronger with the ridging. These solutions tend
to keep the focus of heavier rain amounts generally over the Gulf of
Mexico and/or west of our CWA. Over the last couple of days, the
area of heaviest rainfall has gradually shifted westward in both the
NBM and WPC solutions. That`s certainly not to say we are looking at
a dry week by any means, but any heavy rain/flooding threat doesn`t
appear to be quite as high as it appeared a couple days ago. The
heaviest rain amounts at this point in our area look to be perhaps a
general 2-3 inches between Interstate 10 and the Louisiana coast,
with lighter amounts to the north, although there is still some
uncertainty involved in the forecast.

As moisture levels increase, this will likely have a significant
impact on low temperatures near south of Interstate 10 from Saturday
night onward until we get out of the wetter pattern, with overnight
lows 75 to 80 (and maybe a few lower 80s) common for much of that
area. We`ll likely have one more day of above normal high
temperatures on Sunday with highs in the mid 90s if precipitation
holds off long enough. Convective temperatures are forecast to fall
off to around 90 on Monday for most of the area, and into the mid to
upper 80s for the middle of next week. Any areas that are fortunate
enough to not get rained on during a particular midday period could
get a little warmer than those values, but not much. As guidance has
been drifting toward the previous ECMWF solutions, the slightly
warmer NBM readings vs GFS seem to be the way to go.

&&

.AVIATION...
(18Z TAFS)
Issued at 1239 PM CDT Thu Jun 13 2024

All terminals currently VFR. However, the higher moisture content
across the southeast half of the area has become apparent over the
last hour or so with a fairly widespread cumulus field southeast
of a KMCB-KBTR line, where most cloud bases are well above FL030.
We`ve even seen a few SHRA/TSRA south of Lake Pontchartrain that
will be close enough to KMSY and KHUM to justify at least VCTS for
the next few hours. It appears that light northwest winds may
provide enough of a lake shadow the next few hours to keep cells
far enough away from KNEW to leave them out of that terminal area.
Forecast soundings do show lower precipitable water values
progressing southeastward during the afternoon hours and
convective areal coverage should diminish prior to sunset. Should
see VFR conditions overnight, and little or no SHRA/TSRA
development tomorrow.

&&

.MARINE...
Issued at 149 PM CDT Thu Jun 13 2024

High pressure building into the area will keep conditions
generally benign through Saturday with light winds and seas 2 feet
or less, though a few showers/storms could produce locally higher
winds and seas, mainly across the outer waters. As the high shifts
eastward on Sunday in response to a broad low developing over the
Bay of Campeche, the pressure gradient will tighten somewhat and
cause winds to strengthen to 10 to 15 knots. Additionally, a
surge of deeper moisture will result in higher rain chances by
Sunday as well. Expect the moderate onshore flow to persist
through the early part of the week, with potential for
strengthening to advisory criteria in the Monday/Tuesday time
frame. Will need to keep an eye on the tides going into Monday and
especially Tuesday. If the moderate to strong southeast winds
persist as currently forecast, minor coastal flooding would be
possible.


&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  67  94  70  96 /   0   0   0  10
BTR  72  97  75  99 /   0   0   0  10
ASD  73  96  74  98 /   0   0   0  10
MSY  78  95  79  96 /  10   0   0  10
GPT  74  95  76  95 /   0   0   0  10
PQL  71  98  73  99 /   0   0   0  10

&&

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

$$

SHORT TERM...DM
LONG TERM....RW
AVIATION...RW
MARINE...DM