266
FXUS64 KMEG 182337
AFDMEG

Area Forecast Discussion
National Weather Service Memphis TN
637 PM CDT Sat Jul 18 2026

...New AVIATION...

.KEY MESSAGES...
Issued at 637 PM CDT Sat Jul 18 2026

- A Heat Advisory has been issued for both today and tomorrow.
  Heat indices will peak between 105 and 108 F. Those without
  access to adequate cooling or air conditioning will be the most
  vulnerable.

- High heat will continue to ramp up into early next week with
  highs reaching into the mid to upper 90s. Heat advisories and
  potential Extreme Heat Warnings are anticipated both Monday and
  Tuesday.

- Many areas will see dry conditions next week; however, isolated
  afternoon showers and storms can not be ruled out each day as
  peak daytime heating occurs.

&&

.DISCUSSION...
(This evening through next Friday)
Issued at 104 PM CDT Sat Jul 18 2026

Rinse and repeat forecast as a subtropical ridge continues to
broaden over the southern Gulf and the Texas and Louisiana
coastline while a tropical disturbance continues to churn near
the Florida peninsula. These two systems have placed us, here in
the Mid-South, under upper-level quasi northwest flow. The
airmass remains very moist with current PWATs in the 1.8-2.0"
range with dewpoints in the mid to upper 70s. Afternoon highs
will also increase into the mid 90s across much of the area. As
such heat indices in areas west of the Mississippi River and into
the Delta region are most likely to reach values of 105+ F and
remain under a Heat Advisory. With residual moisture and peak
heating this afternoon, a few pop-up showers and storms, mainly
along the Tennessee River are anticipated. Effective shear
remains next to nothing with SB and MLCAPE in excess of
2500 J/kg, low-level lapse rates around 7.3 C/km, and DCAPE
around 600, in these areas. Gusty winds and small hail cannot be
ruled out this afternoon, though the parameter space will likely
not be able to sustain much upscale growth.

By this evening, upper-level northwest flow will become more
defined as the aforementioned ridge and upper-low continue to
build and move. A few embedded shortwaves could promote enough
lift for a few pop up showers and storms this evening over
northeast Arkansas and the Missouri Bootheel. Tomorrow will be a
near persistence forecast, just warmer. A Heat Advisory will go
into effect for areas along and west of the Mississippi River at
10AM through 9PM tomorrow. One thing to note about tomorrow: NBM
is painting heat indices 105+ F across nearly the entire Mid-
South, however, as northwest flow becomes more defined and PWATs
remain slightly above the 75th percentile for this time of the
year, 1.8-2.2", many areas will likely fall just short of 105+ F.
Either way, our entire area will be hot and humid tomorrow and
time outdoors should be limited. Tomorrow afternoon will also see
pop-up showers and storms with peak heating and a few embedded
shortwave perturbations. Very similar to today, gusty winds and
small hail may be found in stronger thunderstorms.

Monday and Tuesday will be more of a slam dunk for heat indices
in excess of 105F as the aforementioned subtropical ridge
broadens over the central High Plains and slightly east, closer
to our area. Some counties, especially in the Delta region could
see heat indices in excess of 109 F, potentially warranting an
Extreme Heat Warning come Monday, though NBM might be once again
overdoing dewpoints as HeatRisk is only pinging on around 20-25%
of extreme heat levels. Tuesday will be our warmest of the next
7 days as the ridge continues to build further east into the
Mississippi Valley and a decent swath of warm air advection moves
over the Mid-South. Areas west of the Mississippi River and in
the Delta regions may warrant an Extreme Heat Warning as highs
soar into the upper 90s across nearly the entire Mid-South.
Moisture and afternoon pop-up showers and storms will likely
inhibit areas east from reaching indices in excess of 109F.

Come mid-week, ensembles continue to hint that an upper-low will
begin pushing south from Ontario over the northeast with a dry
cold front pushing southeast across the Mid-South. Though, the
ENS still wants to keep the aforementioned ridge slightly east
into the Mississippi Valley and the aforementioned low pressure
further north, keeping temperatures in the mid 90s for Wednesday
and into the weekend. Confidence is higher in the cooler
evolution decreasing highs into the lower 90s and potential upper
80s with heat indices closer to 100F. Forecast PWATs remain
slightly above the 75th percentile over the next 7 days,
therefore, isolated afternoon showers and storms, mainly confined
to areas along the Tennessee River, will remain.

AEH

&&

.AVIATION...
(00Z TAFS)
Issued at 637 PM CDT Sat Jul 18 2026

VFR expected at all terminals through tonight with west-
southwesterly winds between 5 - 10 knots diminishing quickly
after sunset. Winds will pick back up to a similar level Sunday
morning with afternoon thunderstorm chances increasing through
the afternoon, particularly at MKL/TUP. Some thunderstorms are
still possible at JBR/MEM, but current guidance does not give
enough confidence to mention in this set of TAFs.

&&

.FIRE WEATHER...
Issued at 104 PM CDT Sat Jul 18 2026

Fire weather concerns are not anticipated as ample moisture
remains over the Mid-South and 20ft winds stay below 10 mph.

&&


.MEG WATCHES/WARNINGS/ADVISORIES...
AR...Heat Advisory until 8 PM CDT this evening for ARZ009-018-026>028-
     035-036-048-049-058.

     Heat Advisory from 10 AM to 9 PM CDT Sunday for ARZ009-018-
     026>028-035-036-048-049-058.

MO...Heat Advisory until 8 PM CDT this evening for MOZ113-115.

     Heat Advisory from 10 AM to 9 PM CDT Sunday for MOZ113-115.

MS...Heat Advisory until 8 PM CDT this evening for MSZ007-010-011-020.

     Heat Advisory from 10 AM to 9 PM CDT Sunday for MSZ001-007-008-
     010>012-020.

TN...Heat Advisory from 10 AM to 9 PM CDT Sunday for TNZ001>003-019-
     020-048>051-088-089.

&&

$$

PUBLIC FORECAST...AEH
AVIATION...JAB