219
FXUS64 KMEG 122343
AFDMEG

Area Forecast Discussion
National Weather Service Memphis TN
643 PM CDT Sat Sep 12 2026

...New AVIATION...

.KEY MESSAGES...
Issued at 643 PM CDT Sat Sep 12 2026

- Midsummer-like heat will return to the Mid-South on Sunday and
  will persist into at least the middle of next week.

- Temperatures will likely moderate by next weekend, returning
  closer to seasonal normals with highs near 90 degrees.

&&

.DISCUSSION...
(This evening through next Friday)
Issued at 130 PM CDT Sat Sep 12 2026

Midday GOES water vapor imagery showed a compact deep upper
trough moving through the Midsouth. A shortwave trough was
evident over the western Ozarks, moving southeast behind the
upper trough axis. Attendant thunderstorms will likely continue
southeast across AR today, possibly following current convection
over the delta, southwest of Memphis. 12Z CAMs have struggled
with convective initiation and placement thus far.

Sunday should be clear of storms, as the upper ridge amplifies
behind the exited upper trough. Daytime temperatures will warm
into the mid 90s over the MS River delta, with 90s possible over
portions of the delta to the south of I-40. Dewpoints will likely
mix out to the upper 60s by midafternoon Sunday, but not before
heat indices reach 105. A Heat Advisory has been issued for areas
along the MS River for Sunday.

Medium range guidance consensus expands the upper ridge over the
Midsouth on Monday, amplifying 500mb heights to 595dam. The ridge
further amplifies to 599dam Tuesday and Wednesday. This is
impressively strong for mid-September. High temperatures Monday
through Wednesday will reach or exceed 100 degrees in places.
Unlike last week, the NBM appears to be handling dewpoints
better, with daytime mixing dropping dewpoints into the upper 60s
after Sunday. These moderate dewpoints should keep most of the
Midsouth out of Extreme Heat Warning criteria, but Heat
Advisories will be needed through at least midweek.

GEFS and ECMWF ensemble mean 500mb heights continue to depict the
upper ridge retrograding to the desert southwest by next weekend,
resulting in west/northwest flow aloft over the Midsouth. The
respective deterministic runs of these models depict an easterly
wave over the northern Gulf late next week, which comes ashore
over the weekend. Concurrently, a northern branch upper trough
drops into the mid-MS River Valley, entraining tropical moisture
from the remnant tropical wave. It is too early to place
confidence in this scenario, but should it verify, the net result
for the Midsouth would be temperatures moderating to near normal
by late next weekend or early the following week.

&&

.AVIATION...
(00Z TAFS)
Issued at 643 PM CDT Sat Sep 12 2026

Convection has largely dissipated across the CWA, but there is a
possibility of a few more showers/thunderstorms over the Delta
this evening. Anything that develops is unlikely to impact any of
the forecast terminals. Patchy fog will develop overnight, with
temporary IFR visibility expected at both MKL/TUP. Otherwise,
expect VFR conditions to prevail under light winds. Generally dry
conditions are anticipated Sunday, with a diurnal Cu field and
winds becoming more westerly throughout the day.

&&

.FIRE WEATHER...
Issued at 130 PM CDT Sat Sep 12 2026

There will be a potential for fog tonight, particularly over
northern Mississippi and West Tennessee. Hot and dry conditions
will return to the Midsouth from Sunday, with temperatures
reaching the 100 degrees in places Monday through Wednesday. The
heat will be accompanied by light 20 foot winds and minimum
relative humidity falling below 40 percent. Temperatures and
daytime relative humidity will moderate by next weekend.

&&


.MEG WATCHES/WARNINGS/ADVISORIES...
AR...Heat Advisory from 11 AM to 7 PM CDT Sunday for ARZ009-018-
     026>028-035-036-048-049-058.

MO...Heat Advisory from 11 AM to 7 PM CDT Sunday for MOZ113.

MS...Heat Advisory from 11 AM to 7 PM CDT Sunday for MSZ001-007-008-
     010>012-020.

TN...Heat Advisory from 11 AM to 7 PM CDT Sunday for TNZ048-049-088.

&&

$$

PUBLIC FORECAST...PWB
AVIATION...MJ