Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Lake Charles la
910 PM CDT Wednesday Sep 17 2014
with the loss of daytime heating...most of the shower activity has
dissipated...and will adjust probability of precipitation downward for the remainder of
the evening. Still pretty juicy airmass overhead with the 18/00z
upper air sounding from klch still showing high precipitable water values at
2.16 inches. Therefore...nocturnal shower activity will begin to
develop after midnight over the Gulf of Mexico and immediate
coastal areas. With storm motion expected to be toward the
southeast...this will keep most nocturnal activity over lower
southeast Texas...extreme lower southwest Louisiana...and the
coastal waters...and the pop distribution overnight will reflect
this. Still looks like an upper level disturbance will push into
the forecast area by tomorrow afternoon...with a decent chance for
showers and storms. With expected slow storm movement...and high
moisture content...some heavy rainfall may occur...especially over
portions of southeast Texas.
Previous discussion... /issued 518 PM CDT Wednesday Sep 17 2014/
00z taf issuance.
scattered/num rain showers/isolated thunderstorms and rain continues across southeast Texas/S la late this
afternoon. This will continue for the next hour or two...diminishing
by 00-01z this evening. Thus...thunderstorms in the vicinity continues through 01z for
terminals...excluding aex which has remained precipitation free today.
Next issue will be MVFR visibility/ceilings towards the 10-14z time
frame...with IFR possible for aex. Rain showers/thunderstorms and rain likely to begin a bit
earlier on Thursday for bpt/lch as main area of moisture/lift remains
focused across southeast Texas/SW la. Rain showers/thunderstorms and rain increases by late morning
into the afternoon for most terminals...with diminished chances
for aex once again.
Previous discussion... /issued 344 PM CDT Wednesday Sep 17 2014/
convection breaking out inland along the I-10 corridor from
southeast Texas extending east into southwest Louisiana to near
Crowley. Outflow boundaries appear significant enough to kick off
a few showers and thunderstorms well north of I-10 over the coming
couple of hours.
Main ingredients for this activity is an abundant amount of moisture
trapped in the atmospheric column in the southwest half of the
County Warning Area. The kicker appears to be a series of middle
level pieces of energy flowing across the region between the
backside of the eastern US trough and the northeast side of the
southern Texas high pressure ridge. This will continue through
Thursday so expect convection to die off tonight inland with loss
of daytime heating and reform over the Gulf waters later tonight.
Then...restart the process all over again on Thursday as disturbances
in the upper northerly flow kick off another round of convection
Thursday. Best chance of rain continues across southeast Texas and
southwest Louisiana...however...I do expect broader area of rain to
develop as significant pieces of energy flow into the area Thursday.
Friday should begin to see some drying out as the high to our
west builds eastward some and the eastern US trough pushes east.
Remaining activity should be pushed out into the Gulf of Mexico. Surface
high pressure will ridge southwest into the region Friday and Saturday
allowing for good drying.
The next cool front looks to be on track to move into our area late
Monday and early Tuesday giving US cooler temperatures at least
through the end of the forecast package or through Wednesday.
showers and thunderstorms will generally continue as deep
moisture prevails. A light variable wind regime is expected to
continue tonight and Thursday with a shift to higher easterly
flow Friday through the Monday as the frontal boundary approaches.
Preliminary point temps/pops...
klch 74 85 71 89 71 / 20 60 30 30 10
kbpt 74 86 72 88 72 / 40 60 30 30 20
kaex 72 88 69 91 68 / 20 30 20 20 10
klft 73 86 71 89 71 / 20 50 20 30 10