011
FXUS64 KMEG 171140
AFDMEG

Area Forecast Discussion
National Weather Service Memphis TN
640 AM CDT Mon Aug 17 2026

...New UPDATE, AVIATION, FIRE WEATHER...

.KEY MESSAGES...
Issued at 639 AM CDT Mon Aug 17 2026

- The Extreme Heat Warning has been extended across north
  Mississippi, much of eastern Arkansas, and southwest Tennessee.
  A Heat Advisory remains in effect for the rest of the Mid-South.

- Isolated shower and thunderstorm chances exist along a weak
  frontal Monday. Temperatures will moderate slightly behind this
  front on Tuesday, but will still likely reach Heat Advisory
  criteria across at least portions of the Mid-South.

- More widespread relief from the dangerous heat is expected late
  this week, with temperatures returning to near normal.

&&

.UPDATE...
Issued at 639 AM CDT Mon Aug 17 2026

UPDATE... Scattered showers and thunderstorms have begun to
develop along a weak frontal boundary this morning. Accordingly,
PoPs have been increased to approximately 20 percent for
locations along and south of the I-40 corridor through mid-
morning. Additional isolated convective development remains
possible this afternoon, primarily concentrated south of I-40.

AC3

&&

.DISCUSSION...
(Tonight through next Sunday)
Issued at 1041 PM CDT Sun Aug 16 2026

The latest 500mb analysis indicates a broad 596 dam ridge
centered over the ArkLaTex region with us here in the Mid-South
situated along its northeastern quadrant. This is good news as
over the past several days, this ridge has been centered over us
with heights around 597-599 dam. However, dangerous heat will
still be witnessed across the entire Mid-South tomorrow with
areas mainly west of Jackson Tennessee and south of the Tennessee
and Mississippi state line seeing heat indices 110+F. These areas
remain under an Extreme Heat Warning through Monday with the rest
of the Mid-South now under a Heat Advisory for heat indices
105+F. Please take heat safety precautions seriously as we are
several days into this heatwave.

Overnight Monday, a weak cold frontal boundary, currently
extending across the southern Ohio River Valley and into
southeastern Missouri, will begin to dip down into our area.
Ahead of it, moisture pooling is anticipated. CAMs continue to
hint at isolated shower and thunderstorm development Monday
afternoon as dewpoints in the low to mid 70s could have the
potential to filter in. However, increased dewpoints may very
well mix out by the mid afternoon hours, potentially cutting off
overall shower and thunderstorm activity. Any areas that do see
convective development will also see brief relief from oppressive
heat Monday afternoon.

The persistent ridge will continue to retrograde allowing 500mb
heights to gradually fall, heading into Tuesday as quasi-zonal
flow begins to filter in aloft. Many areas, especially over
northern Mississippi and in eastern Arkansas will likely continue
to see heat indices 105+F Tuesday with continued influence from
upper-level ridging. By Wednesday, as pretty strong return flow
moves over the region, we could see yet another triple digit air
temperature day with the entire Mid-South likely warranting heat
headlines. Luckily, by Thursday, ensembles are hinting at lowered
heights beginning to filter in from the Midwest as a secondary
weak frontal boundary also begins to dip down. Confidence in
temperatures trending closer to normal by Friday and into the
weekend continues to increase. Though subsequent Heat Advisories
may be warranted past Wednesday, oppressive heat is not expected.
As far as rain chances go, a cold frontal boundary and weak
troughing from the Midwest is expected to give lift to scattered
shower and thunderstorm development both Thursday and Friday. If
shower and thunderstorm chances pan out, we could be looking at a
relatively nice weekend with highs in the upper 80s to lower 90s.

AEH

&&

.AVIATION...
(12Z TAFS)
Issued at 639 AM CDT Mon Aug 17 2026

VFR conditions will prevail as a weak front pushes across the
region. A northwest wind shift has already cleared JBR and is
progressing through MKL and MEM; confidence in the timing of this
frontal passage is high based on recent observations. Isolated
SHRAs and TSRAs will linger near MEM before shifting south toward
TUP this evening.

High-resolution guidance (HRRR) indicates limited convective
coverage, supporting the inclusion of a PROB30 for the TUP
forecast. Winds will veer NE overnight and remain light (less
than 5 kts), posing no concerns for current operational tailwind
limitations.

&&

.FIRE WEATHER...
Issued at 639 AM CDT Mon Aug 17 2026

Fire weather danger is expected to remain at a minimum as minimum
relative humidity values teeter around 40-50% through late week.
Due to dry and warm soils, nighttime fog formation is not
expected. Our next shot at wetting rain returns Thursday aided by
a cold frontal passage.

&&


.MEG WATCHES/WARNINGS/ADVISORIES...
AR...Heat Advisory until 8 PM CDT this evening for ARZ009-018.

     Extreme Heat Warning until 8 PM CDT this evening for ARZ026>028-
     035-036-048-049-058.

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

MS...Extreme Heat Warning until 8 PM CDT this evening for MSZ001>017-
     020>024.

TN...Heat Advisory until 8 PM CDT this evening for TNZ001>004-019>022-
     050>055-090>092.

     Extreme Heat Warning until 8 PM CDT this evening for TNZ048-049-
     088-089.

&&

$$

PUBLIC FORECAST...AEH
AVIATION...AC3