734
FXUS64 KMEG 292028
AFDMEG

Area Forecast Discussion
National Weather Service Memphis TN
328 PM CDT Sun Jun 29 2025

...New DISCUSSION, FIRE WEATHER...

.KEY MESSAGES...
Updated at 325 PM CDT Sun Jun 29 2025

- High humidity and heat will build across the Mid-South Monday
  afternoon ahead of a cold front. A Heat Advisory is in effect
  for portions of eastern Arkansas, southwest Tennessee, and
  northwest Mississippi Monday afternoon.

- There is a low chance (<30%) of a few strong to severe
  thunderstorms tomorrow afternoon ahead of a cold front. Damaging
  winds are the main threat with any severe thunderstorms.

- The Mid-South will see a few days of heat relief through midweek
  before heat builds back in for the Fourth of July weekend.

&&

.DISCUSSION...
(This evening through next Saturday)
Issued at 325 PM CDT Sun Jun 29 2025

A warm and humid day across the Mid-South this afternoon with
temperatures in the upper 80s to 90 degrees with heat indices in
the upper 90s to lower 100s. Isolated to scattered thunderstorms
are ongoing across the region as seen on the latest radar scan.
The latest GOES East satellite imagery shows the cu field
destabilizing across the region with an outflow boundary over SE
MO. The instability field varies greatly from east to west, with
1500 J/kg of MLCAPE over much of west TN and to up 3000 J/kg of
MLCAPE across eastern AR and north MS. Wind shear remains weak
once again (less than 10 knots) across the region, so wet
microbursts and single cell convection is favored. The area
favored for the strongest storms this afternoon is over eastern
AR, southwest TN, and northwest MS, or where the highest
instability and DCAPE exist. There is some concern for flooding
(~30% chance) over extreme northeast AR and the Missouri
Bootheel, or near a slow-moving outflow boundary in the short
term. Most of the convective activity will diminish within an hour
or so after sundown with mainly benign weather overnight.

The forecast has changed considerably for Monday. A Northern
Plains trough will swing southeast into the Middle Mississippi
Valley during the day on Monday. Ahead of that trough, moisture
will pool with PWATs climbing above 2 inches areawide, or above
the 97th percentile. Low level moisture will be especially
enhanced, as dewpoints climb into the mid to upper 70s along and
west of the MS River. Most of the region will remain dry with
mostly sunny skies through mid afternoon. Heat indices will swell
into the triple digits areawide by early afternoon, with 105F or
greater across our southwestern counties. A heat advisory was
collaborated with surrounding offices for portions of northwest
MS, eastern AR, and southwest TN for heat indices between 105 and
108F.

The largest change for Monday is the expansion of a Marginal Risk
(1/5) for severe thunderstorms. Highly unstable air will build
across the region by tomorrow afternoon, characterized by
3000-4000 J/kg of MUCAPE. The remnants of an MCS or weak shortwave
will translate southeast into the region in the afternoon hours
and early evening hours. Uncertainty remains quite high as hi-res
guidance continues to struggle on the timing an evolution of
convective initiation tomorrow. If any organized convection can
develop during peak heating, plenty of fuel will be available on
hand for robust storm development. Another slightly more
predictable round of showers and thunderstorms will occur late
Monday night into Tuesday morning just ahead of a cold front. The
strength of the second area of thunderstorms will be highly
dependent on the evolution of the potential first round.
Kinematics will be slightly better than the past week or so, with
up to 25 knots of bulk shear on hand compared to the weak 10 knots
the past few days.

Storms will continue into Tuesday morning and afternoon as the
front slowly pushes southeast through the Mid-South. Weak surface
high pressure will build into the region for Wednesday and
Thursday along with lower humidity. Heat indices will remain below
100 degrees through this period along with dry conditions.

Heat will quickly build back into the region on the 4th of July,
as a 591 dam ridge builds in to the Lower Mississippi Valley. NBM
guidance calls for areawide triple digit heat indices this
upcoming weekend and potentially into the following week.

AC3

&&

.AVIATION...
(18Z TAFS)
Issued at 1228 PM CDT Sun Jun 29 2025

A few storms linger across West TN with some new development over
north MS near TUP. Additional storms will fire this afternoon as
the surface destabilizes with daytime heating. Coverage is
questionable given the early day convection, but there is enough
support to warrant PROB30 for TSRA at all terminals through early
evening. Isolated showers and thunderstorms are possible tonight,
but confidence is too low to mention in TAF. Otherwise, expect
similar conditions on Monday with daytime convection firing by
early afternoon. The NBM/HREF probabilities (20-35%) are hinting
at the potential for MVFR ceilings Monday morning.

&&

.FIRE WEATHER...
Issued at 325 PM CDT Sun Jun 29 2025

No fire weather concerns for the next several days. Moderate to
high chances of wetting rain will continue into Tuesday. Slightly
lower humidity will arrive midweek behind a weak cold front. Heat
and high humidity will build back into the region for the 4th of
July weekend.

AC3

&&

.MEG WATCHES/WARNINGS/ADVISORIES...
AR...Heat Advisory from noon to 9 PM CDT Monday for ARZ026>028-035-
     036-048-049-058.

MO...None.
MS...Heat Advisory from noon to 9 PM CDT Monday for MSZ001-007-008-
     010>012-020.

TN...Heat Advisory from noon to 9 PM CDT Monday for TNZ048-049-088.

&&

$$

PUBLIC FORECAST...AC3
AVIATION...MJ