McComb, Mississippi 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

912
FXUS64 KLIX 111126
AFDLIX

Area Forecast Discussion
National Weather Service New Orleans LA
626 AM CDT Fri Jul 11 2025

...New AVIATION...

.SHORT TERM...
(Tonight through Sunday night)
Issued at 1112 PM CDT Thu Jul 10 2025

Little change in thinking from the previous forecast package in
terms of the overall pattern across the central Gulf coast through
the weekend. A weak upper level trough axis that has been over the
region the last several days has started to slowly dissipate
tonight and will continue to do so through the day on Friday. As
this occurs, a broad upper level ridge centered over Florida and
eastern Gulf will expand westward and eventually become directly
centered over the region on Sunday. Increasing upper level
subsidence will both warm and dry the mid to upper levels of the
atmosphere, and this will effectively induce a decent mid- level
capping inversion around 700mb. This inversion will help to limit
updraft growth, except where low level forcing mechanisms like
the seabreeze boundary and any outflow boundaries from previous
thunderstorm activity are in place. As a result, cloud development
and overall convective coverage will be lower than observed the
past few days. This is reflected in the PoP forecast which drops
from 50 to 60 percent on Friday down to 30 to 50 percent for
Saturday and Sunday. The highest PoP is in coastal areas where
seabreeze interactions will allow for more convective development
as noted previously. Model sounding analysis continues to show
favorable conditions for some wet microbursts to occur on Saturday
and Sunday with the deepest updrafts that develop. DCAPE is
forecast to be around 1200 J/KG and dry air entrainment into these
stronger updrafts is highly probable each day. The end result is
that a few strong to severe wind events could occur both Saturday
and Sunday afternoon.

Temperatures will also warm due to the combination of subsidence
aloft, greater solar insolation, and slightly lower humidity as
the dry air aloft mixes into the boundary layer. Highs will climb
from the upper 80s and lower 90s today into the lower to middle
90s for Saturday and Sunday. Heat index values values will also
increase as temperatures warm, but should remain below heat
advisory limits both on Friday and Saturday. By Sunday, heat
indices will begin to exceed advisory levels with values generally
between 108 and 110 degrees. A heat advisory will most likely be
needed for Sunday over non-coastal portions of the forecast area.

&&

.LONG TERM...
(Monday through Thursday night)
Issued at 1112 PM CDT Thu Jul 10 2025

The upper level ridge and resultant deep layer subsidence will
remain the dominant feature across the area through Wednesday.
This will keep warmer than average temperatures, dangerous heat
index values of 108 to 112, and lower rain chances in place
through the middle of next week. Heat advisories will likely be
needed each day through Wednesday as temperatures climb into the
middle to upper 90s beneath the dome of high pressure. The strong
mid-level capping inversion still in placed will limit most
convection to coastal locations where the seabreeze will continue
to serve as a low level forcing mechanism. Additionally, the wet
microburst potential will also remain elevated each afternoon as
DCAPE values remain above 1000 J/KG. This will keep the low end
severe risk of some isolated damaging wind gust events in place
each day through Wednesday.

All of the model guidance is in good agreement that the upper
level ridge will begin to shift further to the west by Thursday.
At the same time, a broad inverted trough will approach from the
east. This approaching trough will do two things, increase our
moisture aloft and provide increased lift. The combination of
PWATS returning back to more seasonal averages for this time of
year and greater deep layer forcing will support more convective
activity during peak heating hours on Thursday. PoP values reflect
this by increasing back into the 40 to 50 percent range, or pretty
much the normal PoP for mid-July. The greatest convective activity
will still be confined to the coast as the influence of the ridge
will not be completely gone on Thursday, but this convective
activity will help to lower temperatures back to near average in
the upper 80s and lower 90s for coastal locations. Further inland,
temperatures should warm back into the mid 90s before any
thunderstorm activity forms in the mid to late afternoon hours on
outflow boundaries from the coastal convection. As a result, heat
index values should be supportive of one more day of heat
advisories for our inland locations.

&&

.AVIATION...
(12Z TAFS)
Issued at 624 AM CDT Fri Jul 11 2025

VFR conditions will be prevailing but with high enough storm
chances again today have introduced TEMPO groups to time storms
with mainly IFR conditions for short durations. There is the
possibility of LIFR if heavy rain can reduce vis that low.

&&

.MARINE...
Issued at 1112 PM CDT Thu Jul 10 2025

Marine conditions will be benign through the period outside of any
localized impacts from convection. In response to a broad ridge
over the Gulf, winds will generally be out of the south/southwest
at 10 kts or less aside from areas near the immediate coastline
where sea/lake/land breeze cycles will have an influence on both
direction and speed. Otherwise, a fairly typical summertime
convective pattern will persist with showers and storms developing
during the late night, peaking during the morning hours, and
diminishing through the afternoon and evening.

&&

.PRELIMINARY POINT TEMPS/POPS...
MCB  91  72  93  72 /  60  10  40  20
BTR  92  74  94  75 /  50  10  50  30
ASD  92  74  93  73 /  50  10  40  20
MSY  93  78  94  78 /  50  10  40  30
GPT  91  76  91  76 /  50  20  40  20
PQL  91  74  92  73 /  50  20  40  20

&&

.LIX WATCHES/WARNINGS/ADVISORIES...
LA...None.
GM...None.
MS...None.
GM...None.
&&

$$

SHORT TERM...PG
LONG TERM....PG
AVIATION...TE
MARINE...PG