Forecast Discussion

370
FXUS64 KMEG 211724
AFDMEG

Area Forecast Discussion
National Weather Service Memphis TN
1224 PM CDT Sat Jun 21 2025

...New AVIATION...

.KEY MESSAGES...
Updated at 1221 PM CDT Sat Jun 21 2025

- Hot and humid conditions will persist into next week. Daily heat
  headlines are anticipated as heat index values exceed 105
  degrees.

- Isolated afternoon showers and thunderstorms will be limited to
  mainly north Mississippi through the weekend and then expand
  across the Mid-South next week.

&&

.DISCUSSION...
(Today through Friday)
Issued at 350 AM CDT Sat Jun 21 2025

A warm and muggy morning across the Mid-South at 3AM.
Temperatures are hovering in the mid to upper 70s with dewpoints
in the mid 70s. Persistent south winds continue to lock in low
level moisture. Today will likely by the hottest day of the next
several. A 594 dam ridge will build over the Mid-South and push
air temperatures into the mid 90s along with oppressive humidity.
Heat indices will peak in the range of 106 to 110 degrees this
afternoon across the entire Mid-South. The NBM continues to
underdo PoPs, so opted to stick close to the HREF. Convective
coverage will peak by late afternoon, mainly over north
Mississippi, but coverage could extend to pretty much anywhere
along and east of the Mississippi River. These pop-up showers and
thunderstorms will provide some much needed relief from the
oppressive heat.

Sunday will feature similar hot and humid conditions as the 594
dam ridge slowly expands and lifts NE. The ridge will weaken
slightly over northeast Mississippi and west Tennessee. This
weakness will allow a higher concentration of cu and thunderstorms
to occur, keeping temperatures a degree or two cooler. After
close collaboration with neighboring offices, opted to include the
majority of the Mid-South in another Heat Advisory for Sunday,
albeit the aforementioned portions of W TN and N Mississippi.

Hot and humid conditions look to persist throughout much of next
week. Both the ECMWF and NAEFS ESAT continue to support 30-year
return intervals for mean 500mb heights. The ridge will slowly
weaken and deamplify over the Lower Mississippi Valley and Gulf
Coast through late next week. As a result, the spatial extent of
additional Heat Advisories will be largely dependent on coverage
of shower and thunderstorms each day. This should become clearer
as we move into the hi-res model guidance window (generally 48
hours or less). Nonetheless, high temperatures will persist in the
low to mid 90s each day with oppressive humidity and diurnal
showers and thunderstorms. There is a high chance that heat
indices will remain over 100F all next week, with a medium to high
chance that the 105F threshold is eclipsed each day.

AC3

&&

.AVIATION...
(18Z TAFS)
Issued at 1221 PM CDT Sat Jun 21 2025

No major aviation concerns this period with VFR CIGs prevailing.
High pressure will continue to slide east this afternoon with a
few pop-up storms possible in the next few hours. While the
majority of the convective activity may be confined to the TN
River, opted to include TS mention at MEM, MKL, and TUP due to
uncertainties with the western extent of convective development
today.

ANS

&&

.FIRE WEATHER...
Issued at 350 AM CDT Sat Jun 21 2025

High heat and humidity will keep fire weather concerns at bay
through at least late next week. Light south and southwest winds
will occur each day.

AC3

&&

.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 11 AM to 8 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 11 AM to 8 PM CDT Sunday for MOZ113-115.

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

     Heat Advisory from 11 AM to 8 PM CDT Sunday for MSZ001>003-007-
     008-010>012-020.

TN...Heat Advisory until 8 PM CDT this evening for TNZ001>004-019>022-
     048>055-088>092.

     Heat Advisory from 11 AM to 8 PM CDT Sunday for TNZ001>004-
     019>022-048>055-088>090.

&&

$$

PUBLIC FORECAST...ANS
AVIATION...DNM