Area Forecast Discussion
Issued by NWS Lake Charles, LA

Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS64 KLCH 261610
AFDLCH

Area Forecast Discussion
National Weather Service Lake Charles LA
1110 AM CDT Wed Apr 26 2017

.DISCUSSION...
Morning KLCH RAOB revealed a robust capping inversion near 850MB,
which FCST soundings indicate will be slow to erode (and may not
do so completely) prior to the arrival of the frontal boundary to
the west. Model data points to the best prospects of this occurring
over parts of Central LA, with lower confidence extending farther
to the S/SW. Latest radar/satellite imagery depicts a pre-frontal
convergent/gravity wave induced band of light rain showers
currently heading through E TX, which high-res short term
guidance did a decent job of capturing, and indicate will tend to
fizzle out as they move farther to the SE.

South winds are already blowing at or near wind advisory criteria,
and while a general decrease from west to east is expected later
this afternoon, winds over Coastal SE TX and much of LA will
continue to be strong and gusty for the rest of the day. Thus,
hoisted a Wind Advisory through 7 pm for the aforementioned areas,
and also modified the Small Craft Advisories for frequent gusts
above 20KT for the coastal lakes and bays and nearshore waters.

13

&&

.PREV DISCUSSION... /issued 651 AM CDT Wed Apr 26 2017/

AVIATION...
Strong frontal system is expected to move down and through the
region today. Winds have already begun to pick up ahead of the
front with ceiling expected to remain VFR at least through the
noon hour. Ceilings dropping after the noon hour with shwrs and
thunderstorms on tap through the frontal passage. Looking at
MVFR/IFR wx. Frntl sys to move thru drg the eve hrs.

PREV DISCUSSION... /issued 417 AM CDT Wed Apr 26 2017/

DISCUSSION...
Biggest issue in the short term is the approaching cold front
which will move through the area late this afternoon into this
evening bringing scattered to numerous showers and thunderstorms.
While the most conducive severe weather parameters will remain
across northern Louisiana into southern Arkansas this afternoon,
forecast soundings across our area still show rather favorable
conditions for the development of severe weather this afternoon
into this evening. The NAM appears the most robust showing nearly
3200 J/KG CAPE and 0-1 KM shear values increasing to around 30
knots by 00Z amidst a very well curved hodograph. Other guidance
is not quite as favorable, but is still in the same ballpark.
This, combined with SPC`s enhanced risk area touching our northern
parishes and counties, encouraged me to add severe wording to the
zones across central LA and the piney woods counties of TX.
Waffled a bit as to whether or not to add severe wording further
south where sounding parameters are similar, but in the interest
of consistency I held off for the time being. That said, areas
further south along the I-10 corridor will still have the
potential to see at least isolated severe weather.

Flirted with the idea of a wind advisory for today, but just
about all guidance keep winds right at or just below the 20 MPH
criteria threshold. One may still be issued later this morning if
observations warrant but opted to forego for the time being.

Convection will clear the area from west to east and should be
completely out of the area by midnight tonight. Behind the front a
brief reprieve with slightly cooler and drier air filtering into
the region Thursday. High pressure quickly scoots off to the east
though veering winds back to the south and ushering in much
warmer temperatures and dewpoints. Some areas will be pushing 90
degrees for what I believe will be the first time this year on
Friday and if the current forecast verifies, we`ll be breaking
some record high minimums Saturday morning as lows will only be in
the mid 70`s. Rain chances also return Saturday into Sunday in
advance of our next frontal system which will, thankfully, bring
temperatures back down to more seasonal values for the early to
middle part of next week.

Jones

MARINE...
The approach of a cold front this evening will result in continued
breezy and gusty conditions through the day today. The resulting
elevated seas have necessitated the continuation of the small
craft advisory through 1 AM Thursday. A few isolated showers or
thunderstorms could develop over the coastal waters this evening
as the cold front moves through. Behind the front winds will
briefly turn offshore during the day Thursday before veering back
around to the south Thursday night.

&&

.PRELIMINARY POINT TEMPS/POPS...
AEX  83  53  80  64 /  70  50   0  10
LCH  83  57  82  68 /  40  30   0  10
LFT  86  61  85  71 /  30  40  10  10
BPT  84  56  82  70 /  40  20   0  10

&&

.LCH WATCHES/WARNINGS/ADVISORIES...
LA...Wind Advisory until 7 PM CDT this evening for LAZ027>033-041>045-
     052>055-073-074.

TX...Wind Advisory until 7 PM CDT this evening for TXZ215-216.

GM...Small Craft Advisory until 1 AM CDT Thursday for GMZ470-472-475.

     Small Craft Advisory until 7 PM CDT this evening for GMZ430-432-
     435-450-452-455.

     Small Craft Exercise Caution from 7 PM CDT this evening through
     late tonight for GMZ450-452-455.

&&

$$



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.