205
FXUS64 KMEG 131121
AFDMEG

Area Forecast Discussion
National Weather Service Memphis TN
621 AM CDT Sun Sep 13 2026

...New AVIATION...

.KEY MESSAGES...
Issued at 620 AM CDT Sun Sep 13 2026

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

- A Heat Advisory is in effect for areas along and to the west of
  the Mississippi River Sunday between 11 AM CDT through 7 PM CDT.
  Expect heat indices between 105 and 110 degrees.

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

&&

.DISCUSSION...
(Tonight through next Saturday)
Issued at 1116 PM CDT Sat Sep 12 2026

Storms have ceased as of around 23z, likely due to increasing
CINH from upper subsidence behind Friday`s trough and surface air
mass modification throughout the day. This will leave the region
dry through Sunday morning. Patchy fog is still possible tonight
with high clouds keeping a higher coverage of fog at bay.

Sunday will see the start of this pesky heat wave once again
regaining strength. NBM high temperatures have held steady with
peak temperatures in the upper 90s areawide with some locations
potentially reaching 100 degrees. Surface moisture is still
abundant enough too to bring heat indices across portions of the
region along and west of the Mississippi River above 105 degrees.
Therefore, we have issued a Heat Advisory from 11 AM through 7 PM
Sunday. For the vast majority of the area, PoPs are just about
non-existent, meaning that heat relief is not expected. However,
some short-term guidance hints that some outflow from potential
storms across Missouri could reach far northeastern Arkansas and
the Missouri Bootheel Sunday afternoon, but confidence is too
low. So, count on the heat sticking around through the day in
these areas.

Models are in good agreement that the upper ridge responsible for
the increase in temperatures will persist through at least the
middle of next week. The ridge will reach peak strength Tuesday
with forecast temperatures at or above 100 degrees for more than
half the Mid-South both Tuesday and Wednesday. Again,
precipitation chances are just about nil through next week
underneath the ridge. So, heat relief is unlikely, but what is
likely is the need for additional heat headlines through at least
Wednesday.

Ensembles have been hinting at a possible mechanism to remove the
heat through the last several forecast cycles, primarily through
a deflection of the polar jet south with the high retrograding
west. However, this solution must have lost rapport within the
ensembles, because now they seem to prefer a cutoff low
developing over the Atlantic, originating from a shortwave
currently over the Great Lakes. Members with this feature then
bring it south and west along the Atlantic Coastline through
midweek. At the same time, a tropical wave also propagates
through the Caribbean. The net effects of these features are a
growing consensus of ensemble members depicting some form of
troughing over the Gulf or southeastern CONUS by late next week.
Additionally, from a climatological perspective, we are well
overdue for some cooler temperatures, which should be on their
way any week now. So, confidence, albeit slowly, is beginning to
rise in a gradual weakening of the ridge late next week that
should hopefully yield lower temperatures. Lastly, although the
mean background synoptics may see a weakening in the upper ridge,
high forecast variability still exists in exact forcing
mechanisms and atmospheric moisture. So, precipitation chances
are uncertain for late next week and into next weekend for the
time being.

&&

.AVIATION...
(12Z TAFS)
Issued at 620 AM CDT Sun Sep 13 2026

Patchy fog may result in MVFR conditions for the next couple of
hours at MKL and TUP. Otherwise, VFR conditions are expected to
prevail at TAF sites through much of the period with light winds.
Short- term guidance indicates a low (< 10%) chance for a
thunderstorm during peak heating. However, probabilities remain
too low to mention at any sites for this TAF set.

&&

.FIRE WEATHER...
Issued at 1116 PM CDT Sat Sep 12 2026

There will be a potential for fog tonight, particularly over
north Mississippi and West Tennessee, but expectations are for
fog to remain patchy due to scattered cloud cover. A warming
trend will begin to decrease minimum relative humidity values
with most of the area expected to see values below 40%. This
trend will continue through much of next week while higher than
average to near-record heat remains throughout the region.
Fortunately, 20-foot winds are expected to be light and afternoon
10-hour fuels are expected to remain above 10%, which will keep
fire danger to a minimum through the period.

&&


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

MO...Heat Advisory from 11 AM this morning to 7 PM CDT this evening
     for MOZ113.

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

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

&&

$$

PUBLIC FORECAST...JAB
AVIATION...CJC