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

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FXUS64 KLIX 240910

Area Forecast Discussion
National Weather Service New Orleans LA
410 AM CDT Mon Apr 24 2017

Latest surface analysis showed a 1006mb low over South Carolina with
a cold front extending south through Florida and east Gulf of
Mexico. A 1017mb high pressure was located over south Texas. Light
north to northwest flow was noted over the forecast land area
this morning. Latest upper air analysis and infrared satellite
imagery revealed a low/tight cyclonic circulation over northern


Upper level low will continue to push east across Georgia today.
Cold air advection will become nil as an upper level ridge axis
starts to build in across the Lower Mississippi Valley today and
tonight. Surface high and dry air will settle over region tonight.

Surface high will shift east Tuesday. Another upper level trough
is expected to move across the Central Plains. This will yield a
lee side trough over Central and Southern Plains. GFS and ECMWF
are showing a stronger disturbance associated at the base of the
trough on Wednesday. Moisture return will occur over east Texas
Tuesday night. The main upper level trough will deepen from
Minnesota to north central Texas by Wednesday. The base of trough
becomes slightly negatively tilted from east Oklahoma to northeast
Texas. Surface front will push east across the forecast area
Wednesday night. Precipitable water values up to 1.9 inches will
pool along and ahead of front. The associated dynamics will sweep
Mid and parts of Lower Mississippi Valley. Surface base cape
values increase up to 1800 to 2800 j/kg north to south across the
forecast area and helicity around 230 to 180 m/s north to south
across the forecast area Wednesday night according to GFS. Have
increased chance of convection for Wednesday night into early
Thursday. In addition, will use stronger wording for strong storms
and possibly severe storms Wednesday night in the outlook.


Not much of a passage with the mid week system as instability and
moisture should return by Thursday night. As a result, lower
levels will remain humid on Friday and a slight chance of some
convection possible on Saturday. GFS show a deep upper level
closed low over the Southern Plains Saturday night while ECMWF
show a long wave developing from Minnesota to Texas. Both
scenarios create a strong wind field across the Lower Mississippi
Valley Saturday through Sunday. Aside from scattered to numerous
convection anticipated on Sunday and Sunday night, winds will be
very strong and may hamper outdoor activities Saturday and Sunday.
As a result, wind advisories and/or possibly high wind warnings
could be issued later this week for part or all of the area this
weekend. Moisture and instability will be in play and synoptic
pattern may yield around of strong to severe convection across
part or all of the forecast area Sunday afternoon through Monday


11-3.9u satellite and surface observations indicate that low level
clouds have exited the area. Other than patchy light fog at sunrise
that may temporarily drop VIS to MVFR, VFR conditions will prevail
at all terminals today.


Post frontal offshore winds will persist today as upper level trough
swings through the southeastern United States. Surface ridge quickly
moving in behind this trough is already beginning to relax the wind
field in the tidal lakes and nearshore waters. CAA will maintain
exercise caution conditions offshore today but likely not much
longer than midday.  Winds will switch back to southerly  Tuesday as
the ridge shifts east of the area. Wind speeds will increase back
into the mid/upper teens by Wednesday as a weak upper trough and
developing surface trough move east across the lower Mississippi
Valley. The local coastal waters will be on the southern end of this
weak front and thus not expecting much more than a brief west wind
behind the boundary. The bigger concern for coastal waters will be
this weekend when models show a very amplified upper trough and deep
surface low moving across the country. Strong small craft to
possibly gale conditions Saturday into Sunday.


DSS CODE...Green.

Decision Support Service (DSS) Code Legend:
GREEN  = No weather impacts that require action
BLUE   = Long fused Watch/Warning/Advisory in effect or high
         visibility event
YELLOW = Heightened impacts with short fused
         Watch/Warning/Advisory issuances; Radar support
ORANGE = High Impacts - Slight to Moderate risk of severe weather;
         Nearby tropical events, HAZMAT or other large episodes
RED    = Full engagement for moderate risk of severe weather; Direct
         tropical threats; events of national significance.


MCB  76  51  81  60 /   0   0   0   0
BTR  77  55  81  63 /   0   0   0   0
ASD  78  56  81  64 /   0   0   0   0
MSY  77  60  80  66 /   0   0   0   0
GPT  78  60  79  68 /   0   0   0   0
PQL  78  57  80  64 /   0   0   0   0



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