Area Forecast Discussion
Issued by NWS Lake Charles, LA

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FXUS64 KLCH 211143
AFDLCH

Area Forecast Discussion
National Weather Service Lake Charles LA
643 AM CDT Mon Oct 21 2019

.DISCUSSION...
12Z TAFS

&&

.AVIATION...
A squall line preceding an advancing cold front will push through
area terminals over the next six to eight hours...considerably
faster than indicated in previous TAFs. Strong, gusty winds,
torrential rainfall and frequent lightning will accompany the
squall line. The best estimate for timing of the line is outlined
in TAFS, but will be subject to amendment based on the line`s
observed forward speed. Ahead of the line ongoing scattered
showers and thunderstorms will produce intermittent periods of
MVFR to IFR conditions.

Winds behind the frontal boundary will turn moderate out of the
northwest through the afternoon and overnight. Ceilings will
improve to VFR behind the front with skies clearing from west to
east through the evening.

Jones

&&

.PREV DISCUSSION... /issued 407 AM CDT Mon Oct 21 2019/

DISCUSSION...
Early morning sfc analysis shows our cold front currently
stretching from an area of low pressure nearing the Ozarks back
swwd through nern TX. With a tight pressure gradient in place
between the low and high pressure over the sern CONUS, a bit of a
breezy night is ongoing per recent sfc obs with srly winds running
5-10 knots with occasionally higher winds. Water vapor imagery
shows a deepening storm system crossing the nrn Plains this
morning, with a trof axis extending swd past the Rio Grande
Valley. Strong lift in a divergent flow aloft along with the
presence of a sfc pre-frontal trof has led to the development of a
significant squall line currently moving into the ArkLaTex with
various warnings strewn along it from cntl TX newd. Closer to
home, another area of showers/few storms has developed along a
convergence line over the nern Gulf, extending newd into lower
Acadiana.

Fairly straightforward forecast this morning. Convection
along/ahead of the front will continue to move sewd, moving into
the far nwrn zones prior to sunrise. Expect widespread showers
and thunderstorms through at least early afternoon before precip
begins tapering off from nw to se with FROPA. Forecast soundings
indicate decent CAPEs along with good
moisture/instability/helicity plus shear/lapse rates prior to
frontal passage. SPC has the area highlighted in a slight risk for
today which given the severe parameters is certainly
reasonable...will highlight this risk in the morning HWO. Showers
will finally clear the far sern zones this evening as a drier wrly
flow around the departing storm system takes over aloft. With the
approach of cooler Canadian high pressure, we`ll see a return of
more seasonal temperatures today with temps mostly in the 70s
before we see lows fall to the 50s tonight. Dry cooler weather
will then persist through mid-week as high pressure dominates.

Another short-term issue is the minor coastal flooding we`ve seen
the past day or so. Surge data continues to indicate one more high
tide cycle later this morning with projected levels running
1.5-2.0 feet above normal tide...thus no changes to the inherited
Coastal Flood Advisory at this time.

As the high moves off to the east by Thursday and the Gulf opens a
bit aloft, will see a quick increase in moisture through the
column for the end of the work week. The next significant
shortwave crossing the center of the country will help push the
next cold front/associated sfc wave through the area late Thursday
into Friday. Even cooler temps are progged behind this system with
highs for Friday/Saturday expected to stay in the 60s across most
of the forecast area.

MARINE...
Issued a short-term SCA for the wrn/cntl coastal waters through
this morning as obs/progs indicate winds running 20 knots or
greater over these waters thanks to the tight pressure
gradient/nocturnal low-level jetting over the region. Expecting a
shot of elevated, but sub-SCA offshore flow post-frontal passage
tonight and Tuesday. Another round of SCEC winds are then expected
behind the late week front.

&&

.PRELIMINARY POINT TEMPS/POPS...
AEX  77  50  74  47 / 100  10   0   0
LCH  79  55  76  50 /  90  10   0   0
LFT  80  55  75  50 /  90  60   0   0
BPT  79  56  77  53 / 100  10   0   0

&&

.LCH WATCHES/WARNINGS/ADVISORIES...
LA...Coastal Flood Advisory until 11 AM CDT this morning for LAZ041-
     052>054-073-074.

TX...Coastal Flood Advisory until 11 AM CDT this morning for TXZ215-
     216.

GM...Small Craft Exercise Caution until 1 PM CDT this afternoon for
     GMZ432-435-455-475.

     Small Craft Advisory until 1 PM CDT this afternoon for GMZ450-
     452-470-472.

&&

$$


AVIATION...66


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