Area Forecast Discussion
Issued by NWS Lake Charles, LA

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564
FXUS64 KLCH 271720
AFDLCH

Area Forecast Discussion
National Weather Service Lake Charles LA
1220 PM CDT WED JUL 27 2016

.DISCUSSION...
For the 18Z TAF Issuance.

&&

.AVIATION...
Due to thunderstorm activity offshore...inland convective
coverage this morning has been limited. Numerous outflows along
with some insolation will allow for increasing coverage of showers
and storms this afternoon. For now...will have occasional
thunderstorms at all TAF sites. HRRR has been consistent in
decreasing activity late this afternoon. Although not
climatologically favorable...may need to monitor for some late
night fog especially if skies clear. For now...will not include in
TAFs but later shifts can monitor.


&&

.PREV DISCUSSION... /issued 1122 AM CDT WED JUL 27 2016/

UPDATE...
Large cluster of storms continues along and south of I-10 and over
the coastal waters. Large outflow boundary spreading south over
the coastal waters from earlier convection is resulting in a
southward propagation of showers and storms. Meanwhile, decent
coverage of convection acrs se TX with more isltd activity
further north and east into wrn and cntl LA. All of this continues
beneath a nearly stationary upper low cntrd over wrn LA.

Visible stlt shows widespread cloud cover spreading acrs the area.
The combination of clouds and morning showers has kept temps
cooler than fcst with middle 70s acrs the srn half of the area.
Further north, partly sunny skies have allowed for a more typical
warmup with temps in the lower to middle 80s.

An ensemble of morning HRRR runs along with 00Z ARW and 12Z NSSL
WRF appear to capture this morning`s convective pattern and all
indicate a general decreasing trend over the coastal waters with
activity bcmg a little more sctd inland through early aftn. Adjusted
POP distribution for today, but concerned that cloud cover may
limit heating, and ultimately convective coverage. Very
high precip water values in excess of 2 inches remain over the
region, so some storms will be capable of very high rain rates
that could result in localized flooding.

Also modified hourly temps and dewpoints to reflect recent obs,
and adjusted aftn highs especially acrs the srn zones where
temperatures are about 5-10 degrees cooler than this time
yesterday.

24

PREV DISCUSSION... /issued 730 AM CDT WED JUL 27 2016/

Discussion...
For the 12Z TAF Issuance.

Aviation...
This morning expect VFR conditions across the north with MVFR clouds
and visibility across the south as rain coverage increases. The
atmosphere is primed for large area of rain to develop during the
afternoon all areas perhaps a bit less over the extreme AEX
vicinity. Cloud heights will be jumping around as well as visibility
depending on stronger convective cells. Conditions are expected to
improve after 00Z with loss of daytime heating. 06

DISCUSSION...
Weather map shows moderate pressure gradient over the NW Gulf as
high pressure builds eastward across the eastern Gulf. Low
pressure trof axis aloft over SE Texas/Louisiana coast this
morning. The trof axis is providing focus for numerous showers &
isolated thunderstorms (not a lot of lightning strikes so far with
this activity) over the coastal waters, gradually moving inland
across S Louisiana.

The best chances for showers and thunderstorms will remain over
the coastal waters into lower Acadiana thru sunrise, and spread
inland later this morning into the afternoon hours. HRRR guidance
mostly in agreement but lagging a couple of hours behind. Like
the last few days, chances will diminish by evening with the loss
of daytime heating.

For Thursday, expecting less coverage over the coastal waters,
with the focus further inland and later in the late morning/early
afternoon hours as the upper level trof fills and drifts northward
with the sea breeze the primary focus for convection.

For the remainder of the forecast period, mainly sea-breeze late
morning and afternoon showers and thunderstorms, with possibly
better chances for the weekend. Temperatures near normal.

DML

MARINE...
SW winds ~15 kts early this morning will diminish to 10-15 kts
later today and become more south to southeast for the remainder
of the period as high pressure becomes re-established over the
northern Gulf of Mexico. Scattered to numerous showers and
thunderstorms will continue today as low pressure aloft remains
over the northwest Gulf of Mexico. Shower and thunderstorm chances
expected to gradually diminish later this week into the weekend.

DML

&&

.PRELIMINARY POINT TEMPS/POPS...
AEX  88  74  91  74 /  60  30  50  20
LCH  85  77  91  77 /  70  30  50  20
LFT  87  76  92  76 /  70  30  50  20
BPT  86  78  92  78 /  80  30  50  20

&&

.LCH Watches/Warnings/Advisories...
LA...None.
TX...None.
GM...None.
&&

$$


AVIATION...04



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