Perrytown, Mississippi Weather Forecast Discussion

467
FXUS64 KLIX 051216 AAA
AFDLIX
Area Forecast Discussion...UPDATED
National Weather Service New Orleans LA
716 AM CDT Sun Oct 5 2025
...NEW AVIATION...
.KEY MESSAGES...
Updated at 1213 AM CDT Sun Oct 5 2025
- Locally heavy rainfall and a marginal risk of flooding for
   areas south of I-10 on Sunday. Lighter rainfall north of I-10.
- Winds and seas will remain hazardous today and then gradually
   subside.
- Minor coastal flooding along east facing shores of southeast
   LA, including portions of the tidal lakes, and Hancock, MS
   county is expected through today`s high tide cycle.
.SHORT TERM...
(Today through Monday)
Issued at 1213 AM CDT Sun Oct 5 2025
Mid level upper low continues near the coast, even as there is an
upper ridge across most of the eastern half of the country. A strong
upper trough was moving across the northern Rockies. At the surface,
weak low pressure was noted off the coast of southeast Louisiana,
while high pressure was off the Virginia coast. Moisture levels
continued to increase during the day Saturday, at least over the
southeast half of the area. The LIX 00z sounding had precipitable
water values around 1.7 inches, near the 75th percentile
climatologically, with much drier air to the north and west. During
the day Saturday, any significant coverage of rain generally stayed
well to the south of Interstate 10, with most remaining offshore,
although there were a few patches of light rain reported. Lightning
also remained well offshore. Northwest portions of the area, where
there was more sunshine, saw high temperatures in the mid and upper
80s, but areas east of Interstate 55 struggled to get past 80
degrees.
Regarding coastal flooding, we expect one more high tide cycle with
flooding potential before winds and astronomical tide ranges both
decrease enough to lower the threat. No changes to current
configuration.
Not a great deal of change in the forecast scenario from previous
packages. The upper circulation is expected to get pulled northward
today and tonight as a shortwave moves through the base of the
trough in the Rockies. Moisture will start surging northward toward
sunrise into midday. Precipitable water values will increase to near
2 inches across most of the area by mid to late morning, thanks to
20 to 30 knot east-southeast winds at 925 and 850 mb. A precipitable
water value of 2 inches would be above the 90th percentile for early
October.
The precipitation shield should gradually begin spreading northward
toward sunrise. Scattered to numerous showers and perhaps a few
thunderstorms will overspread the entire area, probably by midday,
and could continue into the evening hours. The greatest threat of
heavy rain should be limited to areas generally near and east of
Interstate 55, on the east side of the trough axis, where 1 to 2
inches of rain looks fairly likely, but a few locations could see 2
to 4 inches of rain over the next 24 hours or so. Much of the area
has been rather dry since about August 29th, so most locations
should be able to tolerate a couple inches of rain unless it falls
in a very short time over an urban area.
The best forcing is expected to move north of the area later tonight
and Monday, but any drying of the airmass will be rather slow.
precipitable water values will only fall to about 1.8 inches by
Monday afternoon. So, if there`s any sunshine on Monday, it`s likely
to aid in the development of showers and perhaps a storm or two, but
the best heavy rain threat will have departed.
High temperatures will struggle to get very far beyond the 80 degree
mark today, but with high humidities, we probably won`t notice much
of a difference. Monday should see more breaks in the clouds, and
should allow temperatures to get into the middle 80s. Overnight lows
tonight aren`t likely to get much below 70, and along the south
shore of Lake Pontchartrain, more like mid 70s, as lake water
temperatures are still near 80 degrees.
&&
.LONG TERM...
(Monday night through Saturday)
Issued at 1213 AM CDT Sun Oct 5 2025
Upper ridging is expected to become established along the northern
Gulf Coast by Tuesday, with the center of the ridge eventually
becoming centered over Texas by Thursday into next weekend. The main
trough axis will eventually re-establish itself to the east of our
area by late week, returning to what has been the prevailing upper
air pattern for much of the last 6 weeks. Precipitable water values
will slowly decrease to between the 50th and 75th percentile by
Wednesday and Thursday, and to around the 25th percentile(approx 1
inch) by Saturday. This should be reflected in a gradual diminishing
trend in rain chances Tuesday and Wednesday, especially as one gets
further away from the coast. By Thursday and Friday, the only
mention of rain in the forecast is expected to be slight chances
over lower portions of the southeast Louisiana coastal parishes,
with the forecast for next Saturday completely dry.
As the airmass slowly dries out, we`ll start seeing a little more
sunshine each day. Much of the area should see highs 85-90F on
Tuesday, and everyone should be close to 90 Wednesday, and probably
through Friday. Saturday highs may be a little more in question, as
a shortwave moving toward the base of the trough to our east could
pull a dry cold front through the area. That may knock a few degrees
off of high temperatures for a day or two. As we get deeper into
October, with less daylight, average high and low temperatures
really start to show a downward trend. By the end of the week,
average highs are generally in the lower 80s and overnight lows
range from near 60 over southwest Mississippi to the mid 60s in
areas just south of Lake Pontchartrain. The numbers that are in the
current forecast for mid and late week are about 5-7F above normal.
All indications are that beyond the next few days...warmer and drier
than normal conditions are expected for a good portion of October,
certainly for the next week or two.
&&
.AVIATION...
(12Z TAFS)
Issued at 716 AM CDT Sun Oct 5 2025
Showers and storms will continued to increase this morning
especially for the coastal terminals. BTR and MCB will get a few
showers too, but the other terminals have a higher probability of
experiencing more coverage. MVFR or IFR conditions are expected
for most sites through the period. Even LIFR may be possible late
tonight as CIGs lower below 1Kft respectively. Winds will remain
moderate today and into the evening from an easterly direction
before they decrease late tonight. (Frye)
&&
.MARINE...
Issued at 1213 AM CDT Sun Oct 5 2025
Low pressure over the north-central Gulf and a high pressure
system over the eastern seaboard will keep a persistent easterly
flow of 15 to 25 knots in place across all of the waters today.
These winds will also have a pretty long fetch across the eastern
Gulf waters, and this will support higher seas of up to 10 feet in
the open Gulf waters due to a combination of wind waves and
swell. Small craft advisories are in effect through the afternoon
hours due to these hazardous conditions. The high will start to
become more dominant over the waters on Monday and Tuesday, and
this will allow the easterly winds to relax a bit to between 10
and 15 knots. Seas will also decrease to 2 to 4 feet as the winds
relax. This brief respite in rougher conditions will end on
Wednesday and Thursday as the pressure gradient tightens again
over the Gulf. Easterly winds will increase back to near advisory
levels in the offshore waters and seas will increase to 4 to 6
feet.
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB  80  70  84  70 /  60  40  50  20
BTR  83  71  87  71 /  60  50  50  10
ASD  79  69  85  69 /  80  70  50  20
MSY  83  74  88  75 /  80  60  50  10
GPT  80  71  83  71 /  90  70  50  20
PQL  80  70  84  70 /  90  70  60  20
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...Coastal Flood Advisory until 6 PM CDT this evening for LAZ069-
     070-076-078.
GM...Small Craft Advisory until 6 PM CDT this evening for GMZ532-534-
     536-538-555-557-575-577.
MS...Coastal Flood Advisory until 6 PM CDT this evening for MSZ086.
GM...Small Craft Advisory until 6 PM CDT this evening for GMZ534-536-
     538-555-557-575-577.
&&
$$
SHORT TERM...RW
LONG TERM....RW
AVIATION...RDF
MARINE...RW

NWS LIX Office Area Forecast Discussion