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

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FXUS64 KLIX 220959

National Weather Service New Orleans LA
359 AM CST Thu Feb 22 2018

An upper level ridge is currently centered north of the Bahamas and
extends into the Bay of Campeche. It will remain there through the
end of this week. The ridge will expand northwestward slightly today
as a weak shortwave north of the area lifts. This will bring more
subsidence over the area, thus limiting rainfall today. Have trimmed
pops in value and areal coverage to just areas in the northwest
portion of the CWA. From a temp standpoint, no real changes which
means near record highs expected. Blended models remain too cold
while MAV/MEX performing best right now.

The lack of rain today will be a short lived as another weak
shortwave draws moisture north Friday, enhancing shower and
thunderstorm coverage. Increased pops into the 50 to 70% range to
account for this.

The main upper trough axis currently 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. It still appears that the boundary will stall as it
moves it. Exactly where could range from SW Mississippi to just
offshore of the LA coast. A line of showers and thunderstorms will
likely accompany this boundary as it moves in. Higher rain chances
persist into Sunday night. Monday`s rain chances will depend on if
the front gets nudged offshore or stays put.

The ridge that was north of the Bahamas will then shift west towards
the southern Gulf of Mexico. This may or may not put the CWA in
conducive area for persistent shower and thunderstorm development
early next week. It will be dependent on how close the center is in
proximity to the CWA. The ECMWF suggests close enough to keep most
of the area drier while the GFS is on the wetter side. Additional
differences include timing and latitude of the next trough that
will be moving across the country. Such large difference in model
solutions decreases extended forecast confidence which led to making
few changes.


Ceilings will be mainly at BKN030-040 with some SCT as well. TEMPO
ceilings this morning at BKN003-006 for those terminals down wind of
cooler water bodies and the Mississippi River. Vis restrictions
could be as low as 1sm for these terminals as well. Any low ceilings
will break up by mid morning. Tonight may have a bit more FG for
those near the cooler water bodies as ceilings may fall to OVC001
and IFR or worse vis at times since wind speeds may be a little
lower tonight.


.AVIATION...Occasional MVFR to IFR conditions due to ceilings and/or
fog restricted vsbys can be expected overnight and through the
early/mid morning hours Thursday...with locally LIFR category
conditions possible at times at the more coastal terminals.
Conditions will improve to VFR Thursday afternoon before lowering
back into the MVFR category Thursday evening. /11/


.MARINE...Onshore flow will continue into the weekend and then the
front will try to slide to the coast Sunday night but will likely
stall until it gets another surge south Monday evening. Winds will
finally become offshore late Monday but this will be short lived as
onshore flow will return by midday Tuesday. /CAB/

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  83  65  79  66 /  20  20  60  30
BTR  84  67  81  66 /  20  20  70  20
ASD  82  65  80  67 /  10  20  50  40
MSY  82  67  81  68 /  10  20  60  40
GPT  78  63  77  66 /  10  10  50  30
PQL  81  62  78  66 /  10  10  40  30



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