Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

Area forecast discussion 
National Weather Service Lake Charles la
1153 PM CDT Thursday Jul 24 2014

25/06z taf issuance.


few changes to earlier thinking with VFR expected to prevail
through the period...although some brief periods of MVFR fog will
be possible overnight at lch and aex. Isolated afternoon rain showers/thunderstorms and rain will
be possible...but for now will carry vc mention only at lft/Ara
where influence of upper ridge will be less. 24


Previous discussion... /issued 1000 PM CDT Thursday Jul 24 2014/

a few storms continue over eastern Louisiana and southern
Mississippi this evening. Southeast Texas and SW la is closer to the
upper level ridge and any chance for precipitation is getting crushed
by the ridge. This pattern will hold into the weekend with the
best chance for a storm towards the middle of next week. Current
zones look fine. 19

Previous discussion... /issued 644 PM CDT Thursday Jul 24 2014/

25/00z taf issuance.

a weak outflow boundary is approaching klch...with winds expected
to become Ely for a brief period. An isolated shower or storm is
possible along the boundary as it crosses the area...but overall
likelihood is quite low. A few isolated rain showers/thunderstorms and rain are also occurring
over the Atchafalaya basin...well east of the Acadiana
terminals...but activity is moving slowly SW so kept thunderstorms in the vicinity at these
sites through 02z. Otherwise...expect prevailing VFR conditions
through the period with lt variable winds tonight gradually becoming
southwesterly Friday afternoon. Isolated rain showers or thunderstorms and rain will be possible again Friday
afternoon with best chances confined to the Acadiana region as an upper
ridge begins to build in from the west. 24

Previous discussion... /issued 314 PM CDT Thursday Jul 24 2014/

this afternoon...water vapor imagery shows the old elongated upper
level low extending from the northwest of Gulf of Mexico across
southeast Louisiana. Meanwhile...tail end of a short wave trough is
moving into the forecast area...with much drier air behind
upper level ridge centered over the southwest U.S. Tries to expand
to the east. So far...showers and storms have developed along the
shear axis of the old upper level low...roughly south of I-10 over
southwest and south central Louisiana...and near the sea breeze
boundary that is hugging the coast. This will be the area that
will most likely see any further development of storms before
sunset helps dissipate the activity. Main hazards with the storms
will be frequent cloud to ground lightning...brief heavy rainfall
and wind gusts over 35 miles per hour.

The short wave will continue to move to the southeast tonight and
will continue to shear and move the old upper level low out of the
forecast area. Upper level ridging will then build into the
forecast area from the west and prevail through the weekend. This
will help limit shower and thunderstorm activity to mainly just
along the sea breeze during the afternoon hours.

A short wave will move down from the northern plains early next
week and help dig a large upper level trough over the eastern U.S.
Farther to the south...while upper level ridge begins to retreat
back to the west. This will allow a surface front to push to near
the forecast area by Tuesday...then roughly stall somewhere over
the forecast area for the middle part of the week as best push
behind the trough will be east of the forecast area. The surface
front will help increase showers and storms...along with
decreasing daytime air temperatures somewhat. Still some
differences and questions on just how far south this front can
get...especially this time of year. Latest thinking is that some
drier less humid air may reach northeastern portions of the
forecast area by looks like right now that most
of the forecast area will remain with typical muggy Summer weather.


weak pressure gradient over the northwest Gulf of Mexico with
strength of winds and seas mainly driven by local thunderstorm
activity and associated mesoscale-scale boundaries. Away from the
storms...winds are mainly light with low seas.

Surface high pressure over the eastern Gulf of Mexico will ridge
across into the coastal waters on Friday. Mainly light onshore
winds will develop as a result. This pattern will prevail through
the weekend...with only isolated showers or storms as an upper
level high builds in.



Preliminary point temps/pops...
klch 73 93 74 93 / 10 20 10 10
kbpt 75 93 75 94 / 10 20 10 10
kaex 72 94 73 95 / 10 20 10 10
klft 74 92 75 93 / 10 30 10 20


Lch watches/warnings/advisories...



National Weather Service Glossary of Abbreviations