FXUS64 KLCH 171816

Area Forecast Discussion
National Weather Service Lake Charles LA
1216 PM CST Sun Dec 17 2017

Final update for expiration of dense fog advisory and to make
another downward adjustment to forecast highs, which are
struggling to rise amid considerable cloud cover.



.PREV DISCUSSION... /issued 1157 AM CST Sun Dec 17 2017/


Visible satellite and radar indicate showers are continuing in the
vicinity of KLFT/KARA early this afternoon. Low stratus and
showers are expected to continue to produce LIFR/IFR through
around 20Z and then improve as the showers continue to move
eastward. Behind these showers, areas of low fog and stratus have
developed across SE Texas and SW Louisiana resulting in IFR/LIFR
conditions. The fog should rapidly dissipate over the next 1-2
hours and give way to VFR conditions that will prevail through the
rest of the day. SCT/BKN ceilings are forecast to range from
3.5-5 kft. Winds throughout the day are expected to be light and

Another period of showers and rain is forecast to develop late
tonight and continue throughout the day tomorrow. Ceilings will
drop to IFR after sunset with vicinity showers after midnight.
Vicinity showers will begin after 06Z increase to prevailing
SHRA/-RA after 12Z. In addition to the rain, IFR/LIFR fog will be
possible at KARA/KLFT early tomorrow morning.

PREV DISCUSSION... /issued 956 AM CST Sun Dec 17 2017/

Early public forecast update to issue a dense fog advisory for
most of E TX and Vernon Parish through noon, with obs and visible
satellite imagery showing a well established low cloud/fog bank
across roughly the NW 2/3 of the area. Latest HRRR/RAP guidance
as well as forecast soundings suggest visibility will improve over
the next couple of hours, though at least some degree of stratus
could remain amid a persistent frontal inversion. Forecast highs
were nudged a bit cooler based on ob trends, with further
adjustments possible pending tenacity of low clouds. Remaining
grids look on target.


PREV DISCUSSION... /issued 601 AM CST Sun Dec 17 2017/

Sfc low w/ weak front pushed thru KLCH and and KAEX this am.
The weak boundary appears to be located ovr south central La
and is expected to hang around thru the day and into the eve hrs
before lifting off to the northeast. The sfc reflection will lift
back to the north drg the day on Monday.

Redevelopment has been ongoing behind the bndry as shwrs have
formed ovr se Tx and swrn La. As a result ceilings and vsby have
been bouncing around as storms track ovr TAF lctns. This pattern
will hold thru the late mrng hrs w/ lctns switching fm LIFR/IFR to
VFR and back again. Aftn will see some improvement but this head
back down hill in the late eve hrs as the nxt impulse swings
thru the gulf cst rgn.

PREV DISCUSSION... /issued 527 AM CST Sun Dec 17 2017/

Quick update to raise POPs across southeast Texas and southwest
Louisiana for the 12Z to 18Z timeframe for the additional
development being observed on radar behind the initial line of
storms. New products are already out.


PREV DISCUSSION... /issued 358 AM CST Sun Dec 17 2017/

The well defined squall line that developed over southeast Texas
late last night has devolved somewhat into a more broad area of
light to moderate showers with a few embedded heavy rain producing
storms. The entire mass associated with an upper trough centered over
western Oklahoma will continue to push fairly quickly off to the
east with rain coming to an end across southeast Texas and
southwest Louisiana by mid to late morning and acadiana by early

The front is progged to stall perhaps a hundred miles or so
offshore later this afternoon and will quickly lift back to the
north as a warm front by early Monday providing another round of
widespread showers and likely a few more thunderstorms as
convection will have a little more energy to work with. However,
still not expecting anything in the way of significant severe
weather. The upper low steering the front back onshore, located
over northwestern Mexico will slowly progress eastward across
Texas Monday into Tuesday keeping rain chances elevated before
swinging another cold front through the area late Tuesday night
into early Wednesday morning. This front will provide a bit of a
reprieve from the rain much of Wednesday and Thursday before the
next upper trough and frontal system digs south Friday.

There has been much discussion in social media circles with
regards to the potential for winter weather with next weekend's
front and while it is still too early so say one way or the other
with any certainty (we are still talking day 7) the GFS does
presently keep enough moisture over the region to at least allow
us to keep the idea in the back of our heads...and for those
dreaming of a white Christmas, a reason to hope.


Breezy southerly winds in the vicinity of a broken squall line
will quickly weaken this morning as the front moves offshore. In
its wake, offshore flow may briefly develop near the coast before
winds turn back out of the southeast overnight as the front lifts
back to the north as a warm front. Some patchy marine fog has
already developed this morning south of Vermilion bay and this
fog is likely to expand and become more dense overnight tonight.
This fog layer could potentially persist through early Wednesday.
The nearly stalled frontal boundary will continue to provide a
focus for widespread showers and a few thunderstorms Monday into
Tuesday before the next cold front pushes through the area
Wednesday morning.


AEX 65 52 65 61 / 20 40 70 40
LCH 68 57 71 64 / 30 40 80 30
LFT 71 60 73 65 / 80 50 60 20
BPT 67 56 70 64 / 10 40 70 40



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