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Area forecast discussion
National Weather Service New Orleans la
409 PM CDT Fri Aug 23 2019

Short term...
more rain is expected across the region this weekend. A broad
low over northwest Gulf of Mexico will continue to move north
bringing deep tropical moisture over the area. That is moving
north. This has already brought a surge of deep tropical moisture
into southeast Louisiana and south Mississippi with precipitable
water (pw) values running in the 2 to 2.3 inch range. This
moisture will remain in place through the weekend and into Monday.
The weather prediction center maintains a marginal risk of
excessive rainfall along the coast this evening. For Saturday, a
small portion of the coast will be in a slight risk of excessive
rainfall and other areas in a marginal risk. Heavy rainfall will
be possible with any convection over the next few days. The
potential for banded storms and training storms over areas that
have saturated soils pose a greater risk for flash flooding. A
shortwave will be moving southeast from the central and Southern
Plains into the lower Mississippi Valley Sunday and this should
help pull this disturbance over the immediate forecast area. This
will maintain deep tropical moisture and a favorable environment
for fairly widespread rainfall and a threat of locally heavy
rainfall. The entire forecast area is in a marginal risk of
excessive rainfall on Sunday and Sunday night. We will have to
watch to see if the risk areas are updated or expanded for Sunday,
and also will have to watch to see if they could be extended into
Monday especially across the eastern portions of the area.



Long term...
a wet pattern continues into next week. Afternoon convection will
continue each day. A frontal boundary will start to approach the
region from the north. This should serve to trigger more
convection during this time period. Guidance suggests that the
boundary will get through the area. We will have to monitor the
forecast for changes. Just expect temperatures to not be as hot
with increased rain chances.



&&

Aviation...
expect showers to diminish over the next few hours across the
area. Expect mostly MVFR to VFR conditions to prevail overnight
into Saturday. Afternoon convection will once again play a role in
the forecast as more widespread coverage for Saturday is
expected.

&&

Marine...
no significant changes to the forecast this afternoon which is
basically light onshore winds and low seas outside of convection.
The air mass will become increasingly more conducive for tropical
funnel and waterspout formation in the near shore waters, near
shore marshes and tidal lakes/bays through the weekend. Expect
nocturnal convection each night over the waters through next week.

&&

Decision support...
dss code: yellow.
Deployed: none.
Activation: none.
Activities: marginal risk excessive rainfall Sunday.
Marginal to slight risk Saturday.

Decision support services (dss) code legend
green = no weather impacts that require action.
Blue = long-fused watch, warning, or advisory in effect or high
visibility event; marginal risk severe or excessive rain.
Yellow = heightened impacts with short-fused watch, warning or
advisory issuances; radar support for slight risk severe
or excessive rain.
Orange = high impacts; enhanced risk severe; nearby tropical events;
hazmat or other large episodes.
Red = full engagement for moderate to high risk of severe and/or
excessive rainfall, or direct tropical threats; events of
National significance.

&&

Preliminary point temps/pops...
mcb 72 88 72 88 / 20 70 40 80
btr 74 88 74 88 / 20 70 40 80
asd 73 90 73 89 / 20 70 40 80
msy 77 89 77 89 / 20 70 40 80
gpt 74 89 74 88 / 20 70 40 80
pql 73 92 74 91 / 20 70 40 80

&&

Lix watches/warnings/advisories...
la...none.
GM...none.

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