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fxus64 klch 271051 
afdlch

Area forecast discussion
National Weather Service Lake Charles la
551 am CDT Tue Jun 27 2017

Discussion...
for the 06/27/17 1200 UTC taf package.

&&

Aviation...
VFR has prevailed through the overnight period amid light surface
winds and underneath extensive mid/upper level cloud cover. Kbpt
has recently reported an MVFR ceiling. Believe this to be temporary,
but will continue to monitor observation. VFR is forecast to continue to
prevail through the forecast period, though once again convection
is expected to affect locations primarily along/S of I-10 as a
shortwave trof currently translating through central Texas digs into
the northwest Gulf. Light east to southeast surface winds are expected, though
direction/magnitude will vary near convection and associated
outflows.

13

&&

Previous discussion... /issued 437 am CDT Tue Jun 27 2017/

Synopsis...
klch 88d shows widespread showers over the coastal waters early
this morning, with just some isltd storms beyond 60 nm. This
activity was occurring along and south of a weak stationary sfc
boundary and aided by a shortwave trough aloft over the northwest
Gulf Coast. Laps precip water analysis shows deep tropical
moisture in place mainly along and south of I-10 with precipitable water in excess
of 2 inches, while lower values are north and east of the area.
This corresponds well to 00z sounding data as well with klch near
2 inches, klix at 1.6 inches, kshv at 1.4 inches and kjan around
an inch.

24

Discussion...
what's left of the weak frontal boundary will linger near the
coast today then dissipate tonight into Wednesday. Sfc high pres
settling just off the southeast US coast will ridge westward,
allowing a warm and moist southeasterly flow to become established
through early next week.

For today, the combination of the sfc boundary and the
disturbance aloft, along with additional interactions from outflow
boundaries, will allow for sctd showers and tstms again. The
highest chcs are expected over southeast TX, tapering to a slgt
chc acrs central la. Given the anomalously high moisture content
over the area, some storms will be capable of producing heavy
rainfall and intense rain rates, and with slow storm movement this
could result to localized flooding problems, especially in urban
areas and locations prone to poor drainage.

Abv normal rain chcs will continue Wednesday through Friday
aviation...04as lower pres in the mid and upper levels lingers
over the northwest Gulf Coast. Precip water values will remain
near or even abv 2 inches near the coast (from 2 to nearly 3 std
dev abv normal), and this deep moisture will gradually spread back
northward as the weakness aloft becomes sheared acrs the northern
Gulf Coast later this week. Heavy downpours and localized
flooding could again pose some potential problems in a few
locations.

Rain chcs will finally begin to subside by the weekend as the
subtropical ridge builds west and brings drier air aloft. While
some isltd showers will be possible with daytime heating, expect
convection will be minimal so kept pops "silent" at 14 percent or
lower late in the weekend through early next week.

Daytime temperatures will run slightly below normal (in the
middle to upper 80s) the next few days thanks to extensive cloud
cover and showers. Highs will trend warmer over the weekend into
early next week as the area begins to see fewer showers and a
little more sun. Overnight lows are expected to remain near
seasonal normals.

24

Marine...
easterly winds will shift more southeasterly by
tonight as the weak frontal boundary washes out and ridging builds
west along the Gulf Coast. A disturbance will meander over the
northwest Gulf region the next few days, interacting with the
abundant tropical moisture over the area to produce abv normal
shower and thunderstorm chances. Winds and seas will be locally
higher near tstms.

A generally moderate onshore flow will persist through the weekend
with periods of elevated winds and seas that could result in
possible exercise caution conditions at times.

24

&&

Preliminary point temps/pops...
aex 88 70 88 72 / 20 10 40 20
lch 87 74 87 75 / 40 20 50 50
lft 86 72 86 74 / 20 10 50 40
bpt 85 74 86 75 / 50 30 50 50

&&

Lch watches/warnings/advisories...
la...none.
Texas...none.

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