Area Forecast Discussion
Issued by NWS Lake Charles, LA

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FXUS64 KLCH 201755
AFDLCH

Area Forecast Discussion
National Weather Service Lake Charles LA
1155 AM CST Mon Feb 20 2017

.DISCUSSION...
20/18Z TAF Issuance.

&&

.AVIATION...
A mix of MVFR/VFR cigs acrs the area this morning with an area of
rain spreading east into SE TX. The leading band of convection is
now approaching BPT where prevailing SHRA and isltd TS expected
through early evening. The area of rain will spread slowly east
today reaching LCH by 21Z, AEX by 22Z and further east toward
LFT/ARA by 00Z. Through the aftn, isltd TS will be possible with
the lead band as it moves east, with TS potential diminishing this
evening with decreasing instability/loss of heating. Prevailing
cigs will lower to MVFR as the rain shield moves east with
periodically lower cigs/vsbys in heavier SHRA. SEly winds around
10 kt will weaken and become VRB this evening through Tuesday
morning. SHRA will decrease from west to east late this evening
through Tuesday morning, with IFR conditions in low cigs/fog
lingering in its wake.

24

&&

.PREV DISCUSSION... /issued 1045 AM CST Mon Feb 20 2017/

DISCUSSION...
Regional 88Ds show the expected rainfall event playing out as
expected with a large area of precipitation beginning to make its
way into our far wrn zones. Convection had been on the wane the
previous couple of hours but is showing signs of recovery last
half-hour or so with multiple cells popping up along the leading
edge of the band. Previous forecast was in good shape with just
minor tweaks to POPs. Although rain looks to be heavy at times,
still not expecting flooding issues so not planning any flood
watch issuances at this time. Elsewhere, inherited grids/zones
look good as is based on latest obs/trends.

25

PREV DISCUSSION... /issued 524 AM CST Mon Feb 20 2017/

DISCUSSION...
12z taf issuance.

AVIATION...
MVFR to IFR ceilings this morning ahead of the area of TSRA over
SE TX. This area of TSRA will slowly spread/develop eastward over
SE TX later this morning, and into LA this afternoon and evening,
showing this progression in the terminals. SHRA/TSRA expected to
end from west to east between 06-12z TUE.

DML

PREV DISCUSSION... /issued 434 AM CST Mon Feb 20 2017/

DISCUSSION...Low level jet at 850 mb of 30-40 kts has now
overspread the area ahead of a vigorous and sharp mid/upper level
trof advancing east across west Texas. Feature will be the focus
of a very unsettled weather pattern over the next 24 hours.
Aforementioned jet among other things acting to mitigate any
inland fog development this morning. Have seen a continuation of
sea fog over the near shore waters and have a dense fog advisory
out until 9 AM. Rains will eventually end this issue as the day
progresses. Regional radar depicting a couple of lines of active
convection at this time over east Texas. More eastern line
appears focused along axis of strong warm advection in conjunction
with low level jet maxima. Line further to the west more in line
with surface trof and associated low level convergence.

East Texas rains will be spreading west to east across the
forecast area through today and tonight. Deep moisture on a
strong southerly flow through the column will be transported over
the region with precipitable water values maxing out near record
levels aided by the unusual mid-February warmth. Expecting much of
the area to see 1.5-2.5 inches. Have maintained locally heavy
rainfall possible wording in forecast. Weather prediction center
has the forecast area within a marginal risk of flooding rains.

Rain chances then diminish Tuesday as the mid/upper low advances
across south Louisiana then dips southeast into the north-
central gulf. A dry weather pattern then is ahead through the
remainder of the week. A dry frontal passage is on tap for late
Friday into early Saturday bringing somewhat cooler temperatures
for the weekend.

MARINE...Dense fog will remain into this morning as a long
fetch of relative warm and moist southeasterlies advance over the
cooler shelf waters of the northwest gulf. widespread shower and
thunderstorm activity is expected today, lessening Tuesday as low
pressure advances east through Texas and into the gulf waters. a
brief northerly flow will develop in the wake of the low for
Tuesday, returning to onshore Wednesday and holding until our next
frontal passage expected late Friday into early Saturday.

23

&&

.PRELIMINARY POINT TEMPS/POPS...
AEX  76  59  72  56 /  60  80  40  10
LCH  75  60  73  58 /  80  80  40  10
LFT  76  62  73  58 /  50  80  50  20
BPT  73  60  74  58 /  90  80  30  10

&&

.LCH WATCHES/WARNINGS/ADVISORIES...
LA...None.
TX...None.
GM...None.
&&

$$



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