159
FXUS64 KLIX 021050
AFDLIX

Area Forecast Discussion
National Weather Service New Orleans LA
550 AM CDT Fri Oct 2 2026

...New AVIATION...

.KEY MESSAGES...
Updated at 546 AM CDT Fri Oct 2 2026

- Widespread rain and embedded thunderstorms will affect the area
  Today through Sunday. Rainfall totals of 4 to 6 inches with
  locally higher amounts and some localized flooding issues are
  expected, mainly along and south of I-10. Residents should
  continue to monitor the forecast for updates regarding this
  threat.

- Larger than normal tide ranges and onshore flow will produce
  minor coastal flooding on southeast facing shore lines during
  the high tide cycle the next several nights.

&&

.SHORT TERM...
(Now through Monday)
Issued at 1223 AM CDT Fri Oct 2 2026

The combination of deep tropical moisture, as noted by PWATS near
the daily max, a slow moving surface front, and an approaching jet
streak will all support categorical PoP of 80 to 100 percent
starting today and peaking on Saturday and Sunday. The surge of
deep tropical moisture will come from both the Pacific in the form
of the remains of Hurricane Polo and from a plume of Gulf
moisture feeding in from the southern Gulf. PWATS will rise to
between 2.3 and 2.5 inches starting today and persisting through
Sunday. The surge of moisture from the Gulf will be aided by the
development of a broad baroclinic low pressure system over the
western Gulf that will keep a persistent deep layer southeast flow
regime in place through the weekend. The peak timing for heavier
rainfall to occur will be Saturday and Sunday when the right
entrance region of a jet streak associated with the passage of
weak upper level trough axis slides into the Lower Mississippi
Valley. Increased forcing aloft will work in tandem with low level
convergence and forcing along a slow moving surface front that is
associated with the approaching trough axis. Enhanced moisture
pooling along the front will support the development of more
persistent bands of heavier rainfall along and just to the south
of the front from Saturday afternoon through Sunday afternoon
leading to rainfall totals of 4 to 6 inches for areas along and
south of I-10 including coastal Louisiana and Mississippi.
Localized amounts could approach 8 inches over the two days.
Rainfall rates are not expected to overly excessive as deep and
sustained convection is not supported, but several hours of 1 inch
per hour rainfall rates will lead to localized flooding issues
over time as the ground becomes saturated. For areas north of the
front, rainfall totals will be significantly lower in the 1 to 3
inch range over the weekend with most of the rainfall remaining
stratiform in nature due to a lack of instability. Temperatures
will be near average today, but will fall below average into the
low to mid 80s on Saturday and Sunday due to the extensive cloud
cover and rainfall expected. A persistent southeast flow of 10 to
15 mph, aided by the developing low in the western Gulf, will
allow for continued minor coastal flooding concerns during high
tide periods on south and east facing shores through Sunday.

Monday will be a day of transition for the region as the slow
moving cold front pushes offshore and the parent upper level
trough axis pulls well to the east. A more zonal flow pattern will
emerge and the region will still be beneath the right entrance
region of a jet streak. Drier air in the mid-levels will begin to
advect into the region, and a moisture gradient will emerge with
near average PWATS over the northern third of the CWA and above
normal values from I-10 southward. Temperatures will remain cool
in the low 80s as cold air advection on the back of an increasing
northeast wind takes hold, and this will limit instability
greatly. Upper level lift from the jet streak and some very weak
isentropic forcing over the surface based cold pool will support
continued mostly cloudy skies and scattered to numerous shower
development for areas south of I-10 on Monday. Further inland,
only isolated to widely scattered showers are expected, mainly in
the morning, before the drier air fully moves in. Cloud cover will
also begin to break up in the afternoon with partly cloudy skies
expected by late afternoon.

&&

.LONG TERM...
(Monday night through Thursday)
Issued at 1223 AM CDT Fri Oct 2 2026

Upper ridging will be over the Rockies Monday evening, with
shortwaves off the Atlantic Coast and moving through the central
Plains States. Ridging will remain over the Rockies for much of next
week, with troughing becoming established from west Tennessee to
east Texas on Thursday. The frontal boundary that will bring rain to
the area this weekend will be over the Gulf by Monday night and not
expected to return inland. High pressure centered over Michigan
Monday night will move off the Atlantic Coast at midweek.
Northeasterly flow early in the week will gradually become
easterly, but no real indications that surface flow will become
onshore to any great extent.

This pattern looks like it should keep most significant rainfall (>
0.5 inch) offshore for the midweek period, or at best, over the
lower portions of the Louisiana coastal parishes. We`ll still have
precipitable water values exceeding the 90th percentile
climatologically Monday night for much of the area (>1.9 inches) and
approaching the daily max across the southeast half. Drier air does
start working into northern portions of the area Tuesday morning,
but it may take until midday Wednesday to get most of the area close
to the 50th percentile. Low level moisture (near and below 850 mb)
looks to remain pretty high through Thursday. Certainly there is
disagreement between the 01/12z operational runs of the GFS and
ECMWF on sky cover, with the GFS the more pessimistic on cloud
cover for Tuesday through Thursday. Rain chances should gradually
lower from the 40-60 percent range on Tuesday to around 20
percent by Thursday, with areas north of the Interstate 10/12
corridors likely remaining dry Wednesday and Thursday.

Will let the NBM temperature forecast ride for now, which has most
high temperatures in the lower to middle 80s, but would note that if
the more pessimistic GFS (cloudy) trends verify, high temperatures
could struggle to get past 80 degrees in some areas Wednesday. The
current numbers appear to favor the ECMWF solutions somewhat better.

&&

.AVIATION...
(12Z TAFS)
Issued at 546 AM CDT Fri Oct 2 2026

Aperiod of more widespread shower and thunderstorm activity is
expected to impact the coastal terminals of HUM, MSY, NEW, ASD,
and GPT between 15z and 00z today. These terminals have
prevailing light to moderate rainfall with visibilities of 3 to 5
miles in place over this period, and PROB30 wording for scattered
storms that could produce gusty winds, lightning, and IFR
visibilities for brief periods of time. Further inland, the rain
threat will be lower at HDC, MCB, and BTR with prevailing VFR
conditions in place through the entire forecast period. However,
PROB30 wording is in place through the afternoon hours to reflect
the risk of some passing showers and storms at times that could
produce gusty winds, lightning, and MVFR visibilities of 3 to 5
miles. Toward the end of the period after 08z, stratus build down
will occur leading to all of the terminals experiencing a mix of
MVFR and IFR ceilings impacts. MCB will be most impacted with
ceilings falling to around 500 feet. Ceilings should remain
between 800 and 1500 feet at the remaining terminals.

&&

.MARINE...
Issued at 1223 AM CDT Fri Oct 2 2026

A tightening pressure gradient over the coastal waters that will
form in response to a developing low pressure system in the western
Gulf.  This will allow southeast winds to remain elevated near 15
knots with higher gusts through Saturday.  Very choppy seas of 4 to
6 feet will accompany these winds in the open Gulf waters.  The
lakes and sounds will see slightly lower winds closer to 10 knots
and choppy conditions through Saturday.  Winds will briefly relax to
10 knots or less on Sunday as a front stalls along the coast.  This
front is expected to then slowly push through the waters on Monday
and Tuesday.  Winds will turn northeasterly behind the front and
increase back to 15 to 20 knots as cooler and drier air advects over
the warm waters.  Another low will form along the front by
Wednesday, and this should increase winds in small craft advisory
range of 20 to 25 knots.  Seas will also increase to 5 to 7 feet by
Wednesday leading to rough conditions.  Thunderstorms will also be
around today through Monday, but the only main concerns will be from
lightning and heavy rainfall reducing visibilities.

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...Coastal Flood Advisory until 9 AM CDT this morning for LAZ070-
     076-078-091-093-095-097.

GM...None.
MS...Coastal Flood Advisory until 9 AM CDT this morning for
     MSZ086>088.

GM...None.
&&

$$

SHORT TERM...PG
LONG TERM....RW
AVIATION...PG
MARINE...PG