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

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FXUS64 KLIX 201005

Area Forecast Discussion
National Weather Service New Orleans LA
405 AM CST Tue Feb 20 2018

An upper level ridge is currently centered north of the Bahamas and
will remain there through most of this week. The west of this high
pressure extends into the western Gulf of Mexico. This extent of
coverage will change based upon intrusion of an upper trough to the
north. The main trough axis is still west of the Rockie Mountains. A
shortwave tracking through the trough will bring a cold front into
northern Louisiana Wednesday but likely stall it there do to the
weakness and northern track of the shortwave.

Rain chances will increase slightly today from yesterday as low
level moisture remains high with dewpoints in the upper 60s and
daytime heating increases buoyancy. Strong cap at the top of the
boundary layer will limit development to just showers but 20 to 40%
coverage appears likely across the CWA. Those rain chances will
increase quite a bit on Wednesday as the front mentioned above moves
into northern LA. There will will be a gradient in pops with higher
rain chances in northwestern zones of the CWA compared to
southeastern ones.

A slight retreat of the stalled front to north is likely on Thursday
as the shortwave races northeast and the ridge builds in from the
south. Rain chances should fall back into the 10-40% range as this
takes place. It will be a short reprieve from higher coverage as
another weak shortwave enhances shower and thunderstorm coverage
again on Friday. 80+ degree high temps will persist through this
part of the forecast period as 500mb heights remain `high`.

The main upper trough axis west of the Rockies will finally lift
northeast and race across the midsection of the country this
weekend. This will send a front through the forecast area early
Sunday morning. A line of showers and thunderstorms will likely
accompany this boundary as it moves through. As the trough exits the
east coast Sunday, it will shove the upper ridge near the Bahamas
into the southern Gulf of Mexico. This will lead to either an
extended wet period or dry period depending on how far south or
north the center ends up.


Ceilings will be mainly at BKN020-030 with some TEMPO ceilings at
BKN008 for those terminals down wind of cooler water bodies and the
Mississippi River. Vis restrictions should not be an issue this
morning provided that the wind does not ease. Any low ceilings will
break up by mid morning leaving all sites with BKN030-050. Same
conditions expected again tonight with a few terminals having
slightly reduced vis at locations with low wind speeds.


Winds will remain in the 15-20 kt range for most coastal waters and
this should keep fog from forming and instead promote a low stratus
deck from time to time along with a shower or two. The next cold
front will move toward the coast and stall well north of the coastal
waters Wednesday before moving back to the northwest, then stalling
once again over the central plains states. This will simply help
maintain the onshore flow through the week. The front will finally
push into the waters by Sunday.



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.

MCB  81  68  82  65 /  40  20  70  60
BTR  84  69  82  67 /  30  10  50  30
ASD  82  67  82  67 /  30  20  40  20
MSY  82  69  83  68 /  30  10  40  20
GPT  77  67  78  66 /  40  30  40  20
PQL  80  67  80  67 /  30  30  40  20



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