Area Forecast Discussion
Issued by NWS Lake Charles, LA

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FXUS64 KLCH 302330

Area Forecast Discussion
National Weather Service Lake Charles LA
530 PM CST Mon Jan 30 2023

...New AVIATION...

(Tonight through Wednesday night)
Issued at 345 PM CST Mon Jan 30 2023

Mid-afternoon sfc analysis shows a stalling cool front situated over
the sern zones while high pressure is noted over the cntl Plains.
Water vapor imagery shows a wswrly flow aloft between ridging over
the Gulf and troffing over the nrn Plains/Rockies with an embedded
cutoff low moving ashore over srn CA. Within this flow, a series of
disturbances were noted. The combo of these features was yielding an
overrunning pattern which was keeping all but the extreme sern zones
in quite the overcast stratus regime. CAA behind the front was
holding temps across primarily sern TX in the upper 40s or 50s.
Local 88Ds continued to show a few light returns this afternoon,
although these were likely resulting in just light spits of rain as
opposed to any true shower activity, which was far more common
across nern TX and the ArkLaTex where lift from a departing
disturbance was a little greater.

Quite the forecast this afternoon with multiple issues to deal with.
The old frontal boundary is progged to simply meander across mainly
the sern zones or coastal waters throughout the short term while
multiple disturbances sweep past the region in the wswrly flow
aloft. Ahead of the boundary, areas of dense fog, likely of a hybrid
variety, will linger, especially over the near shore waters through
tonight and on into tomorrow morning. Some of this fog will quite
possibly spill over into lower Acadiana after sunset tonight, with
visibilities likely lowering to below a mile after midnight. For
now, with some uncertainty remaining, have elected to no issue any
advisory for this area for tonight. As far as the remainder of the
forecast area goes, patchy fog will be likely, although dense fog is
not expected...although it certainly can`t be ruled out either given
how moist our boundary layer is and is forecast to remain.

As far as precip goes, given the very moist antecedent conditions
within the overrunning regime and the periodic weak disturbances
passing nearby, along with the stationary sfc boundary, widely
scattered showers look possible through tonight, with best bets
remaining across the nwrn zones where lift is progged to be best
with proximity to the weak vorts. This also appears to be the
pattern at least into Wednesday, although slim POPs over the sern
zones gradually diminish as the weak boundary finally slips out
the area while the troffing aloft digs deeper into nrn Mexico,
carrying the best lift a little farther nwd.

Beginning late Wednesday and especially moving into Wednesday night,
the swrn CONUS storm system is progged to fill/eject enewd toward
the wrn Gulf region. As it does, a sfc low is expected to develop
over the nwrn Gulf/adjacent TX coast which will then sweep newd
across the ern portions of the forecast area. With forecast
soundings indicating moisture increasing (PWAT values progged to
climb to as much as 1.7 inches - well above the 90th percentile per
SPC sounding climo), showers are expected to become widespread
across all but maybe the sern 1/4 of the forecast area by 12z

With the boundary situated across the forecast area, temp forecasts
are really interesting through the short term, with quite the
gradient likely, beginning tonight and tomorrow where 20 (or more)
degrees could separate the far nwrn zones from locations closer to
the s-cntl LA coast.



(Thursday through next Sunday)
Issued at 345 PM CST Mon Jan 30 2023

A surface low will lift up the Texas gulf coast Thursday morning
into the the very moist environment across the region (forecast
PWAT 1.4-1.7) serving as an additional focus for the development
of widespread showers and thunderstorms. Meanwhile, a shortwave
sliding quickly east across Texas will finally push the long
meandering frontal boundary through the area late Thursday night
into Friday morning. With soils still largely saturated and many
area waterways already in flood, the expected heavy rainfall
within some of these storms will have the potential to result in
street flooding as well as the exacerbation of already ongoing
river flooding.

The widespread precipitation should come to an end following fropa
Thursday evening.Some ensemble members do show some trailing
moisture behind the front that could allow for a few, lighter
showers early Friday Friday morning with skies clearing by
afternoon. Ridging aloft and high pressure at the surface will
maintain clear skies and benign conditions through the weekend with
temperatures running slightly below normal Friday and Saturday and
then near normal Sunday.



(00Z TAFS)
Issued at 524 PM CST Mon Jan 30 2023

Old frontal surface boundary extending from off the southeast
Texas coast to onshore in between KARA and KPTN will move little
during the period. Southwest flow above the surface is helping to
provide a frontal inversion. This will keep low level moisture
trapped with very low ceilings and stratus build down type patchy
fog. Therefore, IFR/LIFR conditions are likely to persist during
the period at all terminals.



Issued at 345 PM CST Mon Jan 30 2023

Issued another Dense Fog Advisory for the near shore waters beginning
now and going through 16z/10L tomorrow morning (and it wouldn`t
surprise me if it needs to wind up being extended). Fog guidance
seems to be in relative agreement that the waters generally east
of the sfc boundary where warmer/moister air persists over the
cooler shelf waters, will maintain much lower visibilities through
tonight. Patchy fog is likely over the remainder of the coastal
waters, and although dense fog looks a little more patchier over
the wrn-most waters, elected to expand the advisory to cover these
waters as well.



AEX  41  49  35  45 /  30  40  50  40
LCH  51  57  43  52 /  30  30  30  30
LFT  54  60  47  57 /  20  20  20  10
BPT  49  57  45  52 /  30  30  30  30


GM...Dense Fog Advisory until 10 AM CST Tuesday for GMZ435-450-452-



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