029
FXUS64 KMEG 201040
AFDMEG

Area Forecast Discussion
National Weather Service Memphis TN
540 AM CDT Thu Jun 20 2024

...New AVIATION...

.SYNOPSIS...
Issued at 355 AM CDT Thu Jun 20 2024

A ridge of high pressure will build across the region into the
upcoming weekend. This will result in mainly rain-free conditions
across a majority of the Mid-South. Highs this afternoon will be
in the lower 90s with temperatures rising into the middle to upper
90s by this weekend. Increasing low-level moisture combined with
the hot temperatures may produce heat index values around 105
degrees late this weekend into early next week. Shower and
thunderstorm chances will increase early next week as the upper-
level ridge retrogrades to the southwest U.S.

&&

.DISCUSSION...
(Today through Wednesday)
Issued at 355 AM CDT Thu Jun 20 2024

GOES-16 Water Vapor satellite trends and last evening`s 00Z upper
air analysis places an upper-level ridge over the Mid-Atlantic
states while an longwave upper-level trough axis extends over the
Western U.S. along the Pacific Coast. Mid to high level moisture
associated with Tropical Storm Alberto is producing some cloud
cover across the Lower Mississippi Valley early this morning. Warm
and humid conditions persist across the Mid-South with
temperatures as of 3 AM CDT in the upper 60s to middle 70s with
surface dewpoints in the upper 60s to lower 70s.

Short-term models continue to show the aforementioned upper-level
ridge retrograding west across the Lower Mississippi Valley into
the upcoming weekend. Model soundings indicate the potential for
perhaps an isolated thunderstorm or two across portions of West
Tennessee near the Tennessee River Friday afternoon into early Friday
evening during peak heating. However, confidence in coverage
remains low and kept rain chances near 10 percent. Otherwise,
mainly rain-free conditions should persist through the period with
temperatures rising into the middle to upper 90s Friday through
Sunday. NAEFS still indicate 850 mb temperatures rising to around
20C. (1-2 standard deviations above normal for late June)

Long-term operational and ensemble models indicate the
aforementioned upper-level ridge will retrograde further west to
the Southwest U.S. by next week placing the Lower Mississippi
Valley on the eastern periphery of the ridge axis. A combination
of weak northwest flow aloft with a nearby weak back door cold
front will result in isolated to scattered showers and
thunderstorms especially during peak heating beginning Sunday
night into next week. Heat headlines may become necessary by
Sunday afternoon or Monday as very hot temperatures combine with a
humid airmass to produce heat index values around 105 degrees at
some locations.

CJC

&&

.AVIATION...
(12Z TAFS)
Issued at 539 AM CDT Thu Jun 20 2024

VFR. Southeast wind 5-7 kt tonight will become light overnight as
high pressure settles over the region.

&&

.MEG WATCHES/WARNINGS/ADVISORIES...
AR...None.
MO...None.
MS...None.
TN...None.
&&

$$

PUBLIC FORECAST...CJC
AVIATION...JDS