Area Forecast Discussion
Issued by NWS Lake Charles, LA

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FXUS64 KLCH 240956

Area Forecast Discussion
National Weather Service Lake Charles LA
356 AM CST Mon Feb 24 2020


Short Term [Today through Wednesday]

The regional radar mosaic over the past several hours shows an
area of showers and rain developing across South-Central TX/the TX
Triangle region. This area of showers appears to be associated
with a subtle boundary at 850 hPa progressing eastward through a
broad region of isentropic ascent. This boundary and associated
area of showers will continue to move eastward over the next
several hours. As a result, scattered to numerous showers are
expected to be ongoing across Southeast Texas by daybreak.

A cold front extending from central OK southward into South-
Central TX will continue to progress southeastward through the
morning hours. This will provide additional forcing for ascent and
should result in a sold line of showers and rain developing along
the front as it moves eastward. Despite widespread cloud cover
that will inhibit insolation, surface dewpoints in the mid 60s and
lapse rates around 6.0 C/km could result in enough conditional
instability developing to support a few thunderstorms. HREF
guidance mean instability is generally 500 J/kg or less.
Therefore, while deep layer shear of 40-60 kts is expected today,
the limited instability should prevent any thunderstorms that
develop today from being severe.

The cold front will exit the CWA this evening and bring an end to
lingering showers. The next upper level trough is forecast to dig
into Southern Plains late Tuesday into Wednesday. At the surface,
a reinforcing cold front will surge southward and through the CWA
Wednesday afternoon. Given the richer deep layer moisture will be
advected out of the CWA with today`s frontal passage, little in
the way of precipitation is expected with Wednesday`s frontal

Long Term [Thursday through Monday]

The forecast area is progged to be dominated by cooler/drier
conditions and high pressure from the end of the week through the
end of next weekend after a cold front and associated long-wave
trough push through the region on Wednesday.

Thursday will be the coolest day of the forecast period, with lows
Thursday morning approaching freezing and highs topping out in the
mid 50s.

The longwave trough over the east will continue to slowly slide east
on Friday, but not before a vorticity max from The Plains/Midwest
jolts another surge of cooler air into the region on Friday. This
surge of cooler air will only slow down a warming trend as highs
climb into the 60s on Friday.

On Saturday, the forecast begins to get fuzzy, especially with
respect to the temperature forecast. Quite a bit of spread exists in
the models with respect to how quickly the surface high pressure
system moves eastward. The Euro has the high making its way east
quicker, resulting in return flow settling in sooner. This in turn
is resulting in warmer temperature forecasts from the Euro for

The Euro seems to be the outlier of the longterm models as the
GFS/CMC and ensemble guidance resolve a slower eastward progression
of the surface high pressure system resulting in a delayed return
flow and a cooler temperature forecast for Saturday-Monday.
Decided to take the temperatures down a little bit from the NBM
during this time period which was closer to the EURO forecast and
has also had a bit of warm bias the last 2 weeks.

By Sunday, return flow should be fully settled in across the region
resulting in a surge of warm moist Gulf air into the region. The
warm moist air will overrun cooler/drier air and result in
increasing cloudiness at low levels on Sunday, along with the
chance of scattered showers. This pattern will be persist into
Monday before our next frontal systems pushes through the region
mid- week.



Showers and a few thunderstorms are expected with a cold front
that will move through the coastal waters today. Showers and
storms should come to an end by late this evening as the front
exits the area. A second cold front is forecast to cross the
coastal waters late Tuesday evening and will result in elevated
winds and seas through Wednesday. If confidence increases that
winds will frequently reach gale force, a Gale Watch may be issued
later on today. Winds and seas are expected relax late on
Thursday as high pressure begins building over the region.


AEX  69  45  67  40 /  80  10   0  10
LCH  69  51  68  43 /  70  10   0  10
LFT  70  52  67  44 /  60  40   0  10
BPT  70  52  70  44 /  80   0   0  10


GM...Small Craft Exercise Caution from 9 AM CST this morning through
     this afternoon for GMZ450-452-470-472.



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