Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

000 
FXUS64 KLCH 280224
AFDLCH

Area Forecast Discussion
National Weather Service Lake Charles LA
924 PM CDT Mon Mar 27 2017

.UPDATE...
Convective activity from earlier this evening has diminished and
moved away from the northern border of the CWA. Latest guidance
suggests only a very slight chance for the redevelopment of
showers during the overnight hour and the PoPs have been lowered
based on this and latest satellite imagery. Surface obs also show
that areas of patchy fog have developed over the coastal waters
and along the immediate coastline. Additional patchy fog could
develop inland after midnight tonight and fog has been added in
this forecast package. Rest of the grids look good and will not be
adjusted at this time.

&&

.PREV DISCUSSION... /issued 655 PM CDT Mon Mar 27 2017/ 

AVIATION...
Storm activity remains north and northeast of the CWA this eve as
the tail end of the shortwave drags just north of the region.
Activity is expected to end this evening with winds tapering off 
and clouds falling apart. Expecting to see clouds redevelop w/ 
some fog development after midnight. VFR wx thru midnight becmg 
MVFR/IFR thru sr. Conds improving rapidly aftr sr.

PREV DISCUSSION... /issued 412 PM CDT Mon Mar 27 2017/ 

DISCUSSION...
A very progressive weather week is already underway this 
afternoon as the tail end of a well defined shortwave swings
across the area sparking isolated showers and thunderstorms from
central Louisiana northeastward. This activity will continue for a
few more hours and with decent instability values, its possible
that a few of these storms could be on the stronger side. Any
activity that does develop is expected to wane after sunset. The
trough slides quickly to the east this evening replaced briefly by
upper level ridging Tuesday. 

By Wednesday a stronger upper level low and associated cold front
approaches the area. Conditions continue to appear favorable for
the development of severe thunderstorms Wednesday evening through
Thursday morning with forecast CAPE values in the 2k to 3k J/KG
range. Directional shear appears a bit limited attm but there will
be plenty of speed shear. Thus, I maintained the severe weather
wording in the forecast for Wednesday evening and expanded it to
Thursday morning. All modes of severe weather will be possible.

Once the front pushes through Thursday morning, we'll have another
brief respite from the precip before yet another system approaches
for the weekend. This system still has plenty of question marks. The
latest guidance now slows the system down with most of the 
activity holding off until at least Sunday. The faster Euro 
pushes the precipitation clear of the area by early Monday with 
the consistently slower and much wetter GFS keeping rain falling 
across the area through Monday night. The GFS seems to be over 
doing the QPF values (48 hour QPF totals over 10 inches compared 
to the ECMWF's 1.5 - 2.5). I would almost blame this on some kind 
of feedback issue, but the Canadian falls between the Euro and GFS
giving at least some credence to some higher rainfall values. 
Will continue to monitor, but for now simply went with a blend of 
the two.

Jones

MARINE...
Winds will relax tonight before increasing again on Tuesday in
advance of a cold front that will push through the area Wednesday
night into Thursday. The front will bring scattered showers and
thunderstorms some of which could be severe. Behind the front,
winds will turn offshore Thursday before veering back onshore
Friday in advance of another weather system expected to impact the
area late this weekend.

&&

.PRELIMINARY POINT TEMPS/POPS...
AEX  67  83  67  82 /  20  20  10  20 
LCH  66  81  68  81 /  10  10  10  40 
LFT  70  84  71  84 /  10  10  10  10 
BPT  69  83  71  82 /  10  10  10  60 

&&

.LCH WATCHES/WARNINGS/ADVISORIES...
LA...None.
TX...None.
GM...None.

National Weather Service Glossary of Abbreviations