Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Lake Charles la
1141 PM CST Thursday Nov 26 2015
27/06z taf issuance.
ceilings have begun to lower to MVFR at aex/lft/Ara...and should
prevail through Friday morning. VFR ceilings continue at lch/bpt and
winds have been running a bit higher at these sites as well.
Winds should still diminish slightly overnight...with MVFR ceilings
developing through 08z. Ceilings will lift back to low VFR Friday morning
with isolated to widely scattered rain showers expected mainly near bpt/lch
during the day Friday. Southeast winds 10-15 knots will continue with gusts
to around 20 knots.
Previous discussion... /issued 943 PM CST Thursday Nov 26 2015/
radar indicated isolated showers moving out of the Gulf and
onshore across southeast Texas and southern Louisiana. Winds
remain up in the coastal waters as the pressure remains tight.
Current zones are fine.
Previous discussion... /issued 601 PM CST Thursday Nov 26 2015/
27/00z taf issuance.
strong gusty southeasterly winds will gradually diminish to between 5 and
12 knots by 06z. VFR ceilings to continue this evening with a few -shra
streaming over the area. MVFR ceilings expected to develop after 06z
as showers decrease. Ceilings will lift to VFR Friday morning as southeast winds
strengthen to 10-15 knots with gusts to around 20 knots at times.
Previous discussion... /issued 249 PM CST Thursday Nov 26 2015/
pressure gradient between strong high pressure over the northeast
U.S. And developing low pressure over Colorado has increased this
afternoon over the forecast area. The result has been very breezy
and gusty east to southeast winds. Sustained winds along the I-10
corridor down to the coast have been between 20 and 25 miles per hour with
frequent gusts over 35 miles per hour. Therefore...a Wind Advisory has been
issued for those areas until 6 PM...as winds will then decrease
after sunset and mixing from daytime heating also decreases.
Radar also shows spotty showers developing in the low level jet
and moving from the coastal waters onshore. Mainly light rain will
occur with these showers. Activity over land will likely briefly
decrease after sunset with the loss of daytime heating.
A cold front will move into the region on Friday...then down to
just northwest of the forecast area on Saturday. The cold front
will then basically become quasi-stationary through Sunday as an
upper level low southeast of Florida...will hold a middle level ridge
in place across the western and northern Gulf of Mexico...putting
the brakes on the front. The upper level low over the Bahamas will
move south early next week...with an upper level low over the
mountain west finally kicking off to the east. This will allow the
cold front to move slowly eastward across the forecast area on
Monday into early Tuesday.
Ahead of the front...warm and humid conditions will prevail into
the weekend. Occasional light spotty showers will also continue
during this time...with the possibility of fog development each
night as dew points in the middle to upper 60s moves over lower 60s
near shore water temperatures...and the surface gradient relaxes
as the front nears the forecast area.
With the slope of the front and southwest flow aloft...best chance
for rain will occur behind the front and thus during Monday into
Tuesday. Southwest flow aloft will advect deep tropical moisture
from east Pacific tropical cyclone into the frontal boundary.
However...this deep tropical moisture looks to stay west and
northwest of the forecast area through the weekend...and will lift
off to the northeast as the frontal system actually moves into the
forecast area. Therefore...rainfall with the frontal boundary in
the forecast area will be on the light to moderate side.
As the frontal boundary moves into the coastal waters on
Tuesday...clouds with chances for rain will continue through at-
least Wednesday as moist southwest flow aloft will prevail.
tight pressure gradient between strong high pressure over the
northeast U.S. And low pressure over Colorado will keep a
persistent moderate to strong east to southeast flow over the
coastal waters through the night into early Friday. This will also
keep seas at elevated levels. Therefore...Small Craft Advisory
will remain in effect for the eastern outer waters through Friday
morning with small craft exercise caution elsewhere.
The winds will begin to decrease later on Friday as the pressure
gradient relaxes as a cold front begins to approach the region.
Warm and moist air (dewpoints it the middle to upper 60s) will move
over relatively cooler near shore water temperatures (lower 60s.)
Therefore...some seas fog will be possible overnight for the near
shore waters and coastal lakes. This pattern for sea fog looks to
continue through the weekend.
Preliminary point temps/pops...
aex 64 77 64 75 / 10 20 20 20
lch 66 78 65 76 / 20 20 20 20
lft 65 78 64 77 / 10 10 10 10
bpt 68 77 66 76 / 20 20 20 20
GM...Small Craft Advisory until noon CST Friday for gmz472-475.
Small craft exercise caution through Friday morning for gmz430-