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000 
FXUS64 KLCH 290232
AFDLCH

Area Forecast Discussion
National Weather Service Lake Charles LA
932 PM CDT Fri Apr 28 2017

.UPDATE...Isolated showers have developed over the region through
the past few hours. These showers are rapidly moving north and are
generally producing light amounts of rainfall. The only update
this evening was to start precip a bit earlier to match with the
current trends, otherwise the forecast remains on target.

&&

.PREV DISCUSSION... /issued 629 PM CDT Fri Apr 28 2017/ 

DISCUSSION...
For the 29/00Z TAF Issuance.

AVIATION...
Gradient between high pressure over Southeast US and developing
storm system east of the Rockies, will allow for windy conditions
during the period with south winds between 15 and 20 knots, with
gusts near 30 knots during the day on Saturday. The south winds
will continue to bring in Gulf moisture with overcast ceilings
mainly at MVFR levels around 1500 feet, although some periods of
ceilings at IFR levels will be possible during the late overnight
and early morning period. Most of the shower activity is expected
to hold off until Saturday afternoon, with more widespread
activity beyond the TAF period.

Rua

PREV DISCUSSION... /issued 507 PM CDT Fri Apr 28 2017/ 

DISCUSSION...
Brisk and gusty south winds are expected to subside this evening,
though will remain elevated along the coast, but are expected to
begin intensifying again after midnight as a 40-50kt LLJ at H925
develops over the region downstream of an upper trof digging into
the Four Corners and its associated SFC low over the Southern
Plains. Have issued a wind advisory for coastal SE TX/SW LA
beginning later tonight, with the advisory expanding east and then
north on Saturday in tandem with the expected strong and gusty 
winds. Speeds of 20 to 30 mph with gusts to near 40 mph are
expected. Winds will subside a bit over inland areas Saturday 
evening, but are expected to remain above advisory criteria along
and south of I-10 into Sunday, ending from west to east with the
passage of a cold front. This persistent and strong southerly
fetch will result in above normal tides (around 1.5 to 2 feet
above the astronomical tides), resulting in minor coastal flooding
at the time of high tide SAT morning. 

From a convective standpoint, potential for isolated to scattered
convection Saturday afternoon and evening continues as it appears
one or more subtle impulses will translate through the SW flow
aloft downstream of the main upper trof. Both shear and
thermodynamic profiles will tend to become increasingly favorable
for a severe risk through the day, so any late day activity will
have some potential. Bulk of convection still appears like it 
will be tied more closely with the front itself, with this 
activity posing an attendant severe and locally heavy rainfall 
risk. 

There is generally good consensus on the timing of the front, 
with activity entering E TX after midnight SAT and exiting east of
the Atchafalaya by early/mid afternoon SUN. Looks like an average
of 1 to 2 inches of rain is expected areawide, with locally higher
amounts possible. Progged PWATs suggest efficient rain producing 
convection, with most of this rain likely falling within a 
relatively short period of time. This could pose a risk of rate- 
driven low lying/urban type flooding, so will maintain the locally
heavy rainfall wording.

Drier and cooler air to push in behind the front SUN through MON,
with temperatures starting to recover MON night as south winds
return. Rain chances return TUE night and continue through THU as
another upper trof impacts the region.

13

MARINE...
Strong and gusty southerly winds will increase further tonight
into SAT as a CDFNT approaches the area. Seas of 10-12 FT are 
expected over the outer coastal waters with 7-9 FT over the 
nearshore waters. Winds of 20 to 30 knots with gusts in excess of 
gale force are expected. In addition to the strong winds and rough
seas, numerous showers and thunderstorms will move through the 
coastal waters late SAT night into SUN afternoon. as the front 
pushes through the area. Behind the front, winds will turn 
offshore and subside. 

13

&&

.PRELIMINARY POINT TEMPS/POPS...
AEX  75  86  70  74 /  20  40  90  90 
LCH  78  84  68  75 /  20  40  90  90 
LFT  78  87  75  81 /  10  30  40 100 
BPT  78  85  66  78 /  20  30  90  60 

&&

.LCH WATCHES/WARNINGS/ADVISORIES...
LA...Coastal Flood Warning from 5 AM to noon CDT Saturday for LAZ073-
     074.

     Wind Advisory from 1 AM Saturday to 7 AM CDT Sunday for LAZ073-
     074.

     Wind Advisory from 9 AM to 9 PM CDT Saturday for LAZ027>033-
     043>045.

     Wind Advisory from 7 AM Saturday to 7 AM CDT Sunday for LAZ041-
     042.

     Coastal Flood Advisory from 5 AM to noon CDT Saturday for LAZ041-
     052.

     Wind Advisory from 7 AM Saturday to 11 AM CDT Sunday for 
     LAZ052>055.

TX...Wind Advisory from 1 AM Saturday to 7 AM CDT Sunday for TXZ215.

     Wind Advisory from 7 AM Saturday to 7 AM CDT Sunday for TXZ216.

     Coastal Flood Advisory from 5 AM to noon CDT Saturday for TXZ215.

GM...Small Craft Advisory until 7 AM CDT Sunday for GMZ450-452-455-
     470-472-475.

     Small Craft Advisory from 1 AM Saturday to 7 AM CDT Sunday for 
     GMZ430-432-435.

     Small Craft Exercise Caution until 1 AM CDT Saturday for GMZ430-
     432-435.

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