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000
FXUS64 KLIX 060807
AFDLIX

Area Forecast Discussion
National Weather Service New Orleans LA
307 AM CDT Thu May 6 2021

.SHORT TERM (Today through Saturday Night)...

After a very wet and active weather pattern, we will jump right
into a drier pattern through the rest of the week and upcoming
weekend. Beginning with early this morning, a recent cold front
has delivered slightly cooler/less humid air into the region, with
the cold front currently slowing down a bit across far southern
marine zones, or roughly around 50-60nm south of the MS Delta.
Short-range CAM`s are in somewhat of an agreement of developing
convection along the front early this morning through around mid-
morning, as we see a bit more of a "push" of CAA in the surface to
mid-levels (evident by a deepening frontal zone in the vertical
increasing from 2500ft AGL 12Z to 6500ft AGL at 18Z) which will
locally enhance convergence/surface vorticity at the frontal
boundary (including weak deformation at 925mb) leading to some
spotty showers/storms. Good news is all of this activity will
remain well offshore, with only low-level clouds early this
morning right above the shallow front aloft, but will break up
throughout the AM hours revealing ample sunshine for all areas
today. Went with a warmer bias in the NBM ensemble spread, going a
few degrees above deterministic suggested highs today bringing
many areas into the lower to almost mid 80`s. Model soundings
indicate plenty of PBL mixing, which with this re-enforcing push
of drier air underway early this morning will help to keep
dewpoints down into the 50`s to even a few upper 40`s (NBM
constantly struggles with mixing processes, and have manually
dropped Td`s by peak mixing this afternoon to account for this
more realistic scenario).

Taking a peek aloft, the northern Gulf coast resides on the
upstream portion of a deep east-coast trough, with high amplitude
ridging parked over the Rockies helping to promote surface high
pressure across the central Plains, drifting south and east with
time. This surface high will settle in across the lower MS valley
tonight, lowering winds and amplifying radiative cooling processes
come daybreak Friday. For here, went the other direction with NBM
suggested low temperatures with a cooler bias, especially for the
northshore including typical drainage locations with lows making
it into the mid to even a few lower 50`s. Going into Friday during
the day, same story different day with another quick warm up to
perhaps a degree or two warmer than Thursday`s highs. Some upper-
level moisture will introduce some cirrus at 35,000ft AGL with
enough moisture to draw some nice contrails aloft, but will be
mostly sunny and a beautiful day.

Going into Saturday, the aforementioned surface high pulls east
of the area, allowing for a slow but steady moistening trend at
the surface to lower-levels. Td`s crank back up into the 50`s to a
few lower 60`s making it feel a bit more humid than previous
days. The increase of moisture will help moisten up the PBL enough
for some puffy cumulus development in the afternoon, perhaps some
cloud streets near marine areas with another day of warm
temperatures. Low clouds build in overnight Saturday night through
daybreak Sunday as the return flow deepens to around H7. Next
focus becomes a developing surface cyclogenesis across the
central Plains, but overall expect dry weather to persist through
the upcoming weekend. KLG

.LONG TERM (Sunday through Wednesday)...

Sunday, zonal flow will dominate the upper level pattern.
Southerly surface winds will help to enhance the warm air
advection and moisture advection into the area. An upper level
shortwave impulse is expected to move through the area late Sunday
night into Monday, which will contribute to enhanced rain
chances. As this shortwave moves through the area Monday early
morning, it will help set up a boundary over our area. The models
are very uncertain on where this boundary will set up. Currently,
the best consensus is for the boundary to set up north of us and
then slowly progress/build southward throughout the day Monday and
linger into Tuesday. Upper level divergence during the daytime
hours on Monday and Tuesday will help to enhance the instability
and rainfall efficiency for these storms.

Wednesday, another shortwave system is expected to move through
the area. Southerly surface winds will continue to enhance the
moisture advection and warm air advection into the area. Upper
level divergence will help to contribute to lifting in the
environment and produce more efficient rainfall. As the system
moves through, rainfall chances will be enhanced. The main risks
with these storms would be frequent lightning, gusty winds, and
heavy rainfall. MSW

&&

.AVIATION...
.06Z TAF Package...

VFR conditions prevail at most area airports and will persist
through the forecast period. KHUM and KNEW have MVFR conditions
due to lingering ceilings that are improving quickly. These
airports will reach VFR conditions by the daybreak hours Thursday,
and these conditions will persist through the forecast period.
MSW


&&

.MARINE...

A slow moving frontal boundary across outer 20-60nm zones will be
the focus for an increase in shower/storm coverage this morning,
but will dissipate as the front continues to drift south into the
central GOMEX later today. Expect dry/tranquil conditions to
persist into the upcoming weekend, with a steady transition into
easterly to southerly winds as surface high pressure presses east
of the area. Next rain chances arrive late Sunday and into Monday
with the arrival of the next storm system, with active weather
persisting into next week with several intervals of shower/storm
chances. Waves/seas remain generally low at this times, but if any
shower or storm activity becomes better organized, expect locally
enhanced waves as well as gusty, erratic winds within thunderstorm
development at any point through mid/late week. KLG

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  80  53  80  53 /   0   0   0   0
BTR  82  56  83  56 /   0   0   0   0
ASD  84  54  84  55 /   0   0   0   0
MSY  83  64  84  65 /   0   0   0   0
GPT  83  56  82  56 /   0   0   0   0
PQL  83  53  81  54 /   0   0   0   0

&&

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

$$