000
FXUS64 KLCH 061118
AFDLCH

Area Forecast Discussion
National Weather Service Lake Charles LA
618 AM CDT Sat Jun 6 2020

.AVIATION...VFR conditons are expected today and through the
evening, however patchy lower ceilings may begin to work into the
region tonight. Showers and a few storms will also begin to move
into the area tonight, but rain is not expected to be more
widespread until after the period. Winds will gradually increase
during the period and remain northeast.

&&

.PREV DISCUSSION... /issued 535 AM CDT Sat Jun 6 2020/

SHORT TERM.../Today through Monday/

Quiet night across the forecast area as convection that threatened
yesterday evening largely fell apart and/or continued to weaken as
it entered the area. An extensive outflow boundary did manage to
sweep through the area, but aside from a brief period of gusty
west winds across parts of Central LA, did so with little fanfare.
Region lies on the eastern flank of a mid/upper level ridge over
TX, which is progged to lift NE into MO over the next 24 HRS or
so. Model guidance depicts a subtle shortwave evident in moisture
channel imagery to drop SW underneath the ridge this afternoon,
which in concert with fringe outer bands of steadily approaching
TS Cristobal, will aid in kicking off isolated to scattered
showers and thunderstorms this afternoon and into this evening.
This is unlikely to have much impact on overall afternoon highs,
which are expected to top out in the lower 90s once again. The
exception to this may be the coastal Atchafalaya Basin area, which
will see increasing and more persistent cloud cover associated
with the tropical storm.

Cristobal remains a broad and asymmetric cyclone this morning,
void of deep convection near the presumed center with this
activity displaced well to the north and east. The latest
forecast track/intensity from NHC has changed little from the
previous advisory, and after coordination, it was decided to leave
the tropical storm watches and warnings as is for the time being.
On the forecast track, the storm will continue on a generally NWD
track, reaching the Louisiana coast near Cocodrie by SUN
afternoon. Bands of rain could begin affecting coastal South
Central LA as early as late tonight, but are more likely to begin
in earnest on Sunday as the storm draws closer to the coast. The
storm is anticipated to make a slight bend toward the NW as it
nears the coast, nudged in this direction by the aforementioned
ridge over MO, and will continue on this path SUN and MON. Latest
QPF progs from WPC paint a broad swath of 2-4 inches across parts
of Central and South Central LA over this 2 day period, with
locally higher amounts possible. Chose to hold off on a Flood
Watch as this time given the ambient dry conditions, steady
projected forward speed of the cyclone, and uncertainty
surrounding just how much convection will be present near and to
the west of the center. There are some signals in model guidance
that the storm may become a little more symmetrical in this regard
as it nears the coast and moves ashore, so it`s not out of the
question that a watch will be needed before all is said and done.

13

LONG TERM.../Tuesday through Saturday/

The remnants of Cristobal will continue northward toward MO by
Tuesday morning, leaving a long fetch of tropical moisture in its
wake acrs LA/MS. Precip water values will remain near 1.8-2.0 inches
(possibly a little abv 2 inches over the eastern zones), with
moderate to strong instability developing during the day.
This will allow for sctd showers and tstms to develop, especially
east of a Lake Charles to Leesville line. The deep tropical moisture
will support heavy rainfall in some of the storms, and as can be the
case as tropical systems move further inland, some training of
convection could develop potentially resulting in localized flash
flooding. This will be somewhat dependent on where Cristobal moves
inland as a slight offset to the east would decrease the threat acrs
our area.

By Tuesday night, a shortwave trough will be crossing the cntl and
southern plains, with a trailing cold front pushing through the area
late Tuesday night into Wednesday morning. Moisture pooling ahead of
the front along with low level frontal convergence will be
sufficient to produce a few showers and tstms on Wednesday. High
pres building behind the front, and northerly flow developing aloft
in the wake of the shortwave will begin to scour the deeper moisture
out of the area, resulting in dry conditions for Thursday. Dry
weather is expected to last through the end of the week as the
region remains between an amplifying ridge to the west and the
trough lingering over the eastern CONUS through the end of the week.

Daytime temperatures will be running abv normal Tuesday and
Wednesday, with highs ranging from the lower 90s east to middle 90s
acrs interior SE TX. Overnight lows will also be warmer than normal
Tuesday night amidst the moist airmass in place (lower to middle
70s). Drier air filtering into the region by Thursday and Friday
will allow for a greater diurnal variation in temperatures, with
highs still expected to top out in the lower 90s while overnight
lows possibly fall as low as the middle 60s acrs cntl LA with temps
in the upper 60s/around 70 elsewhere by Friday morning.

24

MARINE...
Winds and seas will increase through the day as Tropical Storm
Cristobal moves steadily north across the central Gulf of Mexico.
Conditions will continue to deteriorate tonight into Sunday as
the storm approaches the Louisiana coast. Small craft advisories
may be needed for parts of the coastal waters not under tropical
storm watches or warnings. The latest forecast track from the
National Hurricane Center brings the center of the storm ashore
near Cocodrie Sunday afternoon. With the storm forecast to remain
east of the area, a predominately offshore flow will prevail until
late Sunday night into Monday as the storm continues northward
and reaches farther inland. All marine interests should continue
to monitor the latest forecasts on this system through the
weekend.

13

&&

.PRELIMINARY POINT TEMPS/POPS...
AEX  92  71  88  71 /  30  20  50  70
LCH  92  74  87  74 /  20  20  50  60
LFT  91  74  85  74 /  30  20  60  70
BPT  92  74  89  75 /  30  20  40  50

&&

.LCH WATCHES/WARNINGS/ADVISORIES...
LA...Tropical Storm Watch for LAZ052>055.

TX...None.
GM...Tropical Storm Warning for GMZ455-475.

     Tropical Storm Watch for GMZ435.

&&

$$


AVIATION...05