Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Lake Charles la
857 PM CST Friday Dec 6 2013
cold air advection continues this evening on gusty northerly winds as front has
now cleared the entire forecast area. Temperatures this evening
range from the middle 30s to middle 40s. With impressive inversion
depcited on the 00z radiosonde observation. Rain currently across southeastern
zones this evening with some lingering drizzle at times elsewhere.
Have been evaluating the data for the potential for freezing
rain/drizzle late tonight and tomorrow morning. Agree with the
previous shift that for the most part the timing of ending the
precipitation will outpace the time temperatures fall below
freezing. However there is some small potential of freezing rain/fzdz across
Avoyelles Parish late tonight.
It does appear that temperatures will be slow to rise tomorrow
during the morning. Precipitation will begin to re-develop late
morning as upglide increases in response to the next disturbance.
At this time it appears the areas where temperatures do reach or go
below freezing tomorrow morning will warm above freezing about the
time precipitation begins again.
Therefore have retained only rain wording at this time and should
there be a brief period of freeing precipitation the duration would
Rainfall amounts will also be very light as well during the
overnight and tomorrow morning.
Main update to the forecast is to increase wind speeds a bit and
refresh the hourly grids a bit based on current analysis.
Previous discussion... /issued 722 PM CST Friday Dec 6 2013/
Very cold air...originating over the snow covered fields of
Arkansas/Oklahoma...continue to ride into southeast
Texas/southwest Louisiana on northerly winds.
Southwesterly winds across the western Gulf of Mexico are
transporting modified Gulf air (post-frontal stratus) northward into
the western Gulf Coast states.
The modified Gulf air upslides the Arkansas/Oklahoma air
.Bringing about IFR-MVFR ceilings.
Previous discussion... /issued 423 PM CST Friday Dec 6 2013/
cold front has continued to slowly ooze to the east this
afternoon...and has now cleared all but the southeast part of the far southeast
marine zone. Cloudy and cold conditions have prevailed in the Post
frontal airmass...with patches of mainly light to moderate
rainfall. Trends in guidance today continued to point toward an
accelerated ending of rainfall across northern/western parts of
the area tonight...those that looked to be vulnerable to light
freezing rain. That may still occur for a brief period late
tonight if freezing temperatures and rain overlap...but it is
looking less likely that will occur...especially for any
significant duration of time.
Cold and cloudy weather is expected to persist through the weekend
as the region remains east of a longwave trough axis over the western
Continental U.S.. the active southwesterly flow aloft will yield periods of
enhanced rain chances...while also maintaining a healthy degree
of cloud cover and inhibiting any significant changes in
temperatures. There are a couple of nights...tomorrow night and
Monday night to be specific...where similar borderline freezing
rain/drizzle events are possible...though again none look
significant at this time. Will continue to monitor trends.
Drier air and warming temperatures are prognosticated to finally arrive by
middle to late week...but the reprieve looks short lived as a Pacific
storm system takes aim at the region for the weekend.
strong north to north winds will continue in the wake of a cold
front moving east across the northwest Gulf of Mexico. Winds and
seas are expected to start subsiding tomorrow...but are expected
to increase again on Monday as a secondary surge of cold air moves
into the region. The modifications to the marine hazards made
earlier today still look on target...though the duration into
Saturday evening may be a little pessimistic.
Preliminary point temps/pops...
klch 34 42 37 49 44 / 20 30 40 50 40
kbpt 34 43 37 48 44 / 10 30 40 50 30
kaex 30 41 34 44 39 / 20 30 50 50 50
klft 34 43 39 51 46 / 20 30 40 70 50
GM...Small Craft Advisory until 6 PM CST Saturday for the following
zones: coastal waters from Cameron la to High Island Texas out
20 nm...coastal waters from Intracoastal City to Cameron la
out 20 nm...coastal waters from lower Atchafalaya River to
Intracoastal City la out 20 nm...waters from Intracoastal
City to Cameron la from 20 to 60 nm...waters from Cameron
la to High Island Texas from 20 to 60 nm...waters from lower
Atchafalaya River to Intracoastal City la from 20 to 60 nm.
Small craft exercise caution through Saturday afternoon for the
following zones: Calcasieu Lake...Sabine Lake...Vermilion