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Office: LIX

FXUS64 KLIX 140951
AFDLIX

AREA FORECAST DISCUSSION
National Weather Service New Orleans LA
351 AM CST Thu Dec 14 2017

.SHORT TERM...
Zonal flow has developed over the local area. This will promote
temperatures to moderate today as 500mb heights increase from
yesterday. Therefore, expecting highs to rise into the mid 60s this
afternoon.

A cold front will be moving through the CWA tonight into Friday
morning as a somewhat weak upper trough swings across the
Mississippi Valley. The sub-tropical jet will be carrying Pacific
moisture across Mexico to the northern Gulf coast as this front
moves into the Gulf. It appears the timing of this moisture will be
such that showers don't develop along the front until it reaches the
coast. So, have kept pops mainly restricted to areas from New
Orleans southward.

.LONG TERM...
Models still show a cutoff stuck over the Baja of California late
this week, getting pickup and racing northeast this weekend as
another trough drops into the Rockies. Numerous showers and a few
thunderstorms are likely to develop as frontogenesis takes place
along the Gulf Coast region. Exact timing of when rainfall will
begin is still not certain, but moisture moving up from the SW will
begin a top down saturation Saturday evening. Model soundings
indicate quite a saturated column but with ample winds aloft. This
would suggest minimal instability for severe storms but a few may be
strong with downbursts possible.

The boundary will likely stall along the northern Gulf Coast as
troughing is maintained west of the CWA. This will lead to bouts of
rain moving across the area. Storm intensity may increase Monday and
Tuesday and the stalled front lifts north and puts the CWA in the
warm sector. Otherwise, its not until the middle of next week that
the base of the trough finally shifts east and flushes the moisture
out.

MEFFER
&&

.AVIATION...No real issues overall. VFR conditions will be
prevalent through today and tonight while upper level and eventually
mid level clouds will build in through the night. Cold front will
finally get a push overnight and all terminals should have a
wind out of the north before 12z Friday. /CAB/

&&

.MARINE...Winds remain on the lighter side out of the west today and
then should really begin to ramp up early Friday morning out of the
north as a cold front surges south. Likely to need at the least
exercise caution headlines Friday and possibly an SCY for a few of
the zones, best candidates would be the open waters west and south
of the delta. Winds will relax somewhat Saturday but we should still
see moderate winds as they winds veer around to the east and then
look for moderate to strong onshore flow Sunday as a weak sfc wave
develops along the middle TX coast and the extreme southeastern
CONUS. /CAB/

&&

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  62  39  50  34 /   0  10  10  10
BTR  64  43  52  37 /   0  10  10  10
ASD  65  45  53  38 /   0  10  10  10
MSY  65  48  53  42 /   0  10  20  10
GPT  64  46  53  40 /   0  10  10  10
PQL  65  45  54  38 /   0  10  10  10

&&

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

$$



Office: LCH FXUS64 KLCH 141209 AFDLCH Area Forecast Discussion National Weather Service Lake Charles LA 609 AM CST Thu Dec 14 2017 .DISCUSSION... For 12z TAF issuance. && .AVIATION... Early morning obs show patchy fog across the area, especially over Acadiana where visibilities were down below a mile at times... expect this trend to continue through sunrise before improving. Otherwise just a continuation of VFR with cirrus with light mainly wrly winds through the expected FROPA late tonight when a slightly elevated nrly flow should commence. 25 && .PREV DISCUSSION... /issued 354 AM CST Thu Dec 14 2017/ DISCUSSION... One more rather pleasant day in store today before a much wetter pattern develops for the weekend into next week. Increasing moisture on southerly low level winds will allow temperatures to rise into the mid to upper 60's areawide this afternoon despite the broken high clouds streaming across the region out of the Pacific. By late tonight an upper trough will approach the area pushing a frontal boundary through. While guidance is still consistent in keeping the best rain chances offshore, isolated to scattered showers will still be possible Friday morning with the highest coverage expected near the coast. Behind the front, afternoon highs will be running about 15 degrees cooler Friday with overnight lows Friday night once again dipping into the 30s except along the immediate coastline. The cooler air will be short lived, however, as the front, which will stall just offshore lifts back to the north as the next in a series of troughs develops of the Baja peninsula and swings across the region Saturday into Sunday bringing numerous showers and a few thunderstorms. SPC has placed the area in a marginal risk for severe weather Sunday. Forecast soundings are indicating plenty of low level shear as the trough ejects northeast, but very little in the way of instability. So while a stronger storm or two cannot be ruled out, at least for now the overall severe weather threat is very low. Beyond Sunday, guidance begins to diverge considerably and confidence in the forecast beyond this point is very low. What seems apparent is that one or more troughs will ride the subtropical jet across the southern US. The uncertainty comes with how much moisture is present for these systems to work with. The wetter GFS leaves a plume of moisture across the region in the wake of the ejecting trough Sunday night and thus continues high rain chances Monday into Tuesday while the operational Euro keeps the moisture offshore Monday before moving it back into the area by midweek. The Canadian being my tiebreaker for this forecast sides more heavily with the GFS and thus I went on the higher side with rain chances through midweek, but the forecast is a blend of the available guidance (and a few of my own tweaks) so as not to lean too heavily on any individual solution. Finally, it is still too early to provide any reliable forecast for the Christmas weekend or Christmas day (still 11 days away) and any attempts to do so at this point are futile. Jones MARINE... Light and variable winds will prevail through the day ahead of our next frontal passage. Showers are expected to accompany this boundary, followed by a strengthening offshore flow Friday morning. Rain chances increase once again by late Saturday and into Sunday as an upper level low moves out of Mexico across the area. && .PRELIMINARY POINT TEMPS/POPS... AEX 63 39 54 33 / 0 10 10 0 LCH 68 44 53 38 / 0 20 20 0 LFT 66 43 52 38 / 0 20 30 0 BPT 69 45 54 39 / 0 30 20 0 && .LCH WATCHES/WARNINGS/ADVISORIES... LA...None. TX...None. GM...None. && $$ AVIATION...04
Office: SHV FXUS64 KSHV 141149 AFDSHV Area Forecast Discussion National Weather Service Shreveport LA 549 AM CST Thu Dec 14 2017 .AVIATION... For the 14/12Z terminal forecast will prevail VFR flight categories through the end of the forecast period. Clouds spreading over the terminals especially to the South of a KELD- KSHV-KGGG-KTYR line will have sct and bkn 15-27 KFT clouds and ceilings. Surface winds will be light and variable early this morning then becoming Northerly 5-10 knots with the passage of a cold front moving to the South. /06/ && .PREV DISCUSSION... /issued 437 AM CST Thu Dec 14 2017/ DISCUSSION... A weak cold front just north of the Red River Valley will move into the region, but with little effect on daytime conditions. Further south, a broken cloud cover in the mid and upper lvls, persistently covering much of areas south of I-20, will finally begin to shift east as stg upper lvl zonal flow becomes more confluent. Temps to remain mostly seasonal thru Friday night. A deepening upper trough to the west will begin to pull deep moisture into east TX Saturday aftn, with deep saturation spreading across the area Saturday night into Sunday. The surface boundary will then begin to shift eastward, although models not quite in as good agreement with the eastward shift and possible stalling out over portions of LA into early next week as they are with the initial surge of moisture into the area. Some elevated instability, along with stg wind shears, may create some embedded thunder, mainly across the southern portions of the area, mainly Saturday night. After this precip moves out of the area, a slowly building upper ridge will bring mostly seasonal and persistent temps back into the area. /07/ && .PRELIMINARY POINT TEMPS/POPS... SHV 63 37 55 34 / 0 0 0 0 MLU 60 36 52 33 / 0 0 0 0 DEQ 58 30 55 30 / 0 0 0 0 TXK 58 33 54 33 / 0 0 0 0 ELD 58 32 54 32 / 0 0 0 0 TYR 63 36 55 36 / 0 0 0 0 GGG 63 36 56 34 / 0 0 0 0 LFK 65 40 55 36 / 0 0 0 0 && .SHV WATCHES/WARNINGS/ADVISORIES... AR...None. LA...None. OK...None. TX...None. && $$ 06/07