Area Forecast Discussion
Issued by NWS Lake Charles, LA

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FXUS64 KLCH 271003
AFDLCH

Area Forecast Discussion
National Weather Service Lake Charles LA
503 AM CDT SAT AUG 27 2016

.SYNOPSIS...
Latest UA analysis and WV imagery shows a large ridge over the
ern CONUS with a trough over the Rockies and Intermountain West.
Closer to the area...a disturbance was noted traversing the swrn
periphery of the ridge, over the nw Gulf of Mexico.

At the sfc...weak high pres extends fm the NC coast west acrs the
lower MS valley while a broad inverted trough was located off the
LA coast. This was resulting in lt e to ne sfc winds acrs the
area. An abundance of tropical moisture continues to stream over
the area, with the latest GPS-met data showing precip water near 2
inches acrs se TX and srn LA with slightly lower values (less than
2 inches) to the north and northeast of these area.

KLCH radar shows sctd showers and a few tstms over the coastal
waters, and this activity has been increasing in coverage through
the night. Some of these showers were also spreading inland acrs
sw LA and into se TX, but staying generally lt to modt in
intensity.

Regarding the tropics, the disturbance between Cuba and the
Bahamas, Invest 99L, remains disorganized early this morning per
recent IR stlt imagery. Upper level wind shear continues to
interact with the system, which is limiting its development as it
moves slowly west.

&&

.DISCUSSION...
A rainy pattern will remain in place through the weekend as the
disturbance aloft and its weak sfc counterpart move slowly west.
East to se winds in the lower to mid levels will maintain an
influx of deep tropical moisture over the area, with precip water
fcst to remain abv 2 inches through early next week. The best chc
for showers and storms will be mainly along and south of I-10
today through Sunday. Given the high precip water values and mean
rh in excess of 80 percent, showers and storms will be capable of
producing very heavy rainfall at times. Rainfall amounts through
late Sunday are expected to range from one to two inches, but
locally higher amounts will be possible which could be a problem
for already water-logged areas. Water levels have been slowly
falling on area rivers, but flooding continues in many parts of sw
LA. However at this time, it looks like most of the higher
rainfall totals will stay closer to the coast and also further
west of the areas that took the brunt of the flooding a couple of
weeks ago.

Max temps today and Sunday are expected to stay below normal, with
highs in the middle to upper 80s as the combination of clouds and
showers limit heating. The only area that could reach the lower
90s looks to be cntl LA where less convective coverage is
anticipated.

Rain chcs will begin to decrease by Monday into Tuesday as the
upper ridge over the se CONUS begins to build back to the sw. At
the same time, attention will also turn to the se Gulf and
whatever has become of the tropical disturbance Invest 99L. As has
been the case for the past several days, there is quite a bit of
uncertainty regarding the development of this system, and because
of this, fcst confidence is below average. The recent Tropical
Weather Outlook fm NHC now has just a 40 percent chc of
development through the next 5 days. At this time, most of the
guidance indicates that the system will remain a weak low that
will begin to move northwest to north over the ern Gulf. With the
ongoing uncertainty, maintained continuity with the previous fcst
and followed the Superblend solution through the extended period,
with low chc PoPs and near climo temperatures.

&&

.MARINE...
Lt to modt ely winds will prevail through the weekend and into
early next week between high pres ridging acrs the se states and
a weak inverted trough over the nw Gulf of Mexico. The sfc trough
could develop into a closed low prior to moving inland along the
middle TX coast on Sunday, but the system should stay weak as it
moves slowly west in concert with low pres aloft. The primary
impact of the disturbance will be nmrs to wdsprd showers and
tstms over the coastal waters through Monday, with heavy rainfall,
brief gusty winds and locally higher seas expected with the
stronger storms.

Conditions from Monday into mid-week will depend on what
transpires with Invest 99L. The center of the system is progged
to cross the FL straits Sunday. The majority of guidance keeps the
system weak as it begins to turn northwest to north over the ern
Gulf Monday through Wednesday. At this time, the low is fcst to
remain east of the area, which will result in a continuation of e
to ne winds over the coastal waters.

&&

.PRELIMINARY POINT TEMPS/POPS...
AEX  90  73  91  73 /  30  20  40  20
LCH  86  74  87  74 /  70  40  60  30
LFT  88  73  88  73 /  50  30  50  20
BPT  86  74  87  74 /  80  40  70  30

&&

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

$$

PUBLIC...24


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