Area Forecast Discussion
Issued by NWS New Orleans/Baton Rouge, LA

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FXUS64 KLIX 142119
AFDLIX

Area Forecast Discussion
National Weather Service New Orleans LA
319 PM CST Thu Dec 14 2017

.DISCUSSION...
Relatively quiet weather for the next couple days before a switch
to a more active pattern Sunday through the first part of next
week.

Cold front currently stretching across northern Louisiana will
make its way through the local area tonight, reinforcing the
colder air mass already in place. Won`t see much impact on
tonight`s temperatures, but highs tomorrow afternoon will struggle
to cross the 50 degree as daytime heating is further hindered by cloud
cover behind the front. Temperatures Saturday morning will range from
the mid 30s for northern areas to the mid 40s across the south
shore, and lower 50s near the immediate SE LA coast.

The cold air will be short-lived, however. The front is expected
to stall over the Gulf on Friday and will be moving northward
again Saturday and Saturday night in response to a surface low
developing on the tail end of the front over western Gulf and
moving northward into Southwest Louisiana. In fact, Saturday
night`s low temperature will likely occur before midnight,
with temperatures warming through much of the night.

On Sunday, the previously mentioned surface low will move past the
local area, bringing widespread showers and isolated to scattered
thunderstorms. Severe weather threat looks limited to southwest LA
where instability will be greater due to proximity to the surface
low. Even there, the threat looks marginal at this time.

Front remains stalled across the local area on Monday and Tuesday
with 40 to 60 percent PoPs depending on location. Right now, the
highest PoPs are forecast over the southeastern half of the area,
but if the front stalls in a slightly different location, the area
of highest rain chances will also shift. Rainfall totals are
generally in the 1 to 3 inch range through the period, though
local amounts could be higher if thunderstorms move over the same
area multiple times. Highest rainfall totals currently forecast
in a swath from Morgan City to Baton Rouge to McComb, but again,
this is dependent on where the front stalls. The good news is that
this pattern looks more like a steady on and off rain with a few
thunderstorms mixed in rather than training thunderstorms that
would lead to a significant heavy rain threat. Of course, if any
areas do happen to see multiple rounds of thunderstorms in a short
period, there could be localized flooding concerns in low lying
and poor drainage areas.

Upper level energy will finally force a clearing front through the
area late Tuesday, with a return to high pressure for the second
half of the work week.

&&

.AVIATION...
Thick cirrus deck streaming from the tropical Pacific Ocean will
maintain upper level cloudiness for the duration of valid TAF
period. VFR conditions to prevail all locations. Frontal passage
this evening will shift winds to north generally from 02Z at KMCB to
06Z at KHUM.

&&

.MARINE...
West winds will be shifting to north and increasing to moderate
levels overnight tonight before leveling off Friday evening. A
cold front will stall over the central gulf late Friday with
a surface low forming in the west gulf on the frontal zone by
Saturday morning. This feature will lift quickly northward,
becoming a more mature system as it reaches the upper Texas coast
Saturday evening. In response to the tightening pressure gradient,
expect moderate east to southeast flow into Sunday. Once the
system lifts well north of the area, a stationary front will
remain over the Gulf States with pronounced onshore flow across
the coastal waters Sunday and Monday. A second cold front will
finally flush out the stationary front late Tuesday with colder
high pressure building into the north gulf for the middle of next
week.

&&

.DECISION SUPPORT...
DSS code: Green.
Deployed: None.
Activation: None.
Activities: None.

Decision Support Services (DSS) Code Legend
Green  = No weather impacts that require action.
Blue   = Long-fused watch, warning, or advisory in effect or
         high visibility event.
Yellow = Heightened impacts with short-fused watch, warning or
         advisory issuances; radar support.
Orange = High Impacts; Slight to Moderate risk severe; nearby tropical
         events; HazMat or other large episodes.
Red    = Full engagement for Moderate risk of severe and/or
         direct tropical threats; Events of National Significance.

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  40  49  34  57 /   0  10  10  10
BTR  42  51  36  58 /  10  10  10  10
ASD  44  52  38  58 /  10  20  10  10
MSY  48  51  43  59 /  20  30  10  10
GPT  45  51  39  58 /  10  10  10  10
PQL  44  52  37  59 /  10  10  10  10

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...None.
GM...None.
MS...None.
GM...None.
&&

$$

Aviation/Marine...24/RR
Rest of Discussion...95/DM


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