115
FXUS64 KMEG 250308
AFDMEG

Area Forecast Discussion
National Weather Service Memphis TN
1008 PM CDT Fri May 24 2024

...New UPDATE...

.UPDATE...
Issued at 950 PM CDT Fri May 24 2024

Evening convection has finally weakened or moved out of the Mid-
South leaving a few quiet hours before the next round starts up.
Shower and thunderstorms are developing along the I-44 corridor as
a cold front presses into the MS River Valley this evening. While
that convection approaches from the NW another cluster of storms
over southern AR will approach from the west. These clusters of
storms will have an unstable and moist airmass to work with
across the Mid-South. MLCAPES range from 1500-3000 j/kg with
marginal 0-6km shear values of 30-35 kts. This environment could
support some severe storms overnight. PWs over 1.5 inches will
support locally heavy rain and isolated flash flooding. Latest
CAMS indicate that the most active time will be from midnight to 6
am with activity pushing into Middle TN and north AL thereafter.
Most of Saturday looks pretty good though redevelopment could
occur by late afternoon.

&&

.SYNOPSIS...
Issued at 323 PM CDT Fri May 24 2024

Unsettled weather will persist through Memorial Day weekend with
multiple rounds of heavy rain anticipated. In addition, severe
weather chances will return on Sunday. The main concern at this
time will be flooding as elevated rainfall rates accompany storms
through Monday morning. Fortunately, dry conditions should return
by Wednesday.

&&

.DISCUSSION...
(This evening through next Thursday)
Issued at 323 PM CDT Fri May 24 2024

3PM radar imagery depicts mostly dry conditions over the Mid-
South with a few pop-up thunderstorms forming over portions of
north Mississippi. Overall confidence for storm coverage this
afternoon and evening is low due to uncertainties regarding how
well the environment will recover from this morning`s convection.
However, satellite imagery depicts clearing skies over portions of
the Mid-South, which may further encourage storm development over
the next few hours. If storms do materialize, damaging winds and
large hail will be the main concerns.

Greater confidence exists overnight for a line of showers and
thunderstorms to dive southeast across Missouri, impacting the
Mid-South after midnight. The severe weather threat with this
line will be low due to the presence of a strong Elevated Mixed
Layer. Instead, the greatest concern will be heavy rainfall as
precipitable water values are forecast to be around the 99th
percentile. Prolific rainfall rates are anticipated overnight,
with a few areas forecast to see an additional 1 to 2 inches of
rain. Additional precipitation will further aggravate rivers and
streams, leading to rises above bankfull. We strongly suggest at
this time that you have a flood plan in place through the weekend.
A Flood Watch has been issued for the entire Mid-South through
Monday morning.

A lull in precipitation is possible by midmorning Saturday as the
aforementioned line pushes out of the area. There is a chance for
thunderstorms to redevelop in northeast Mississippi in the late
afternoon hours, but confidence for this remains low. If a storm
does develop, it will be capable of damaging winds.

Additional severe weather chances appear likely on Sunday as a
shortwave trough ejects across the Central Plains. Some model
discrepancies are evident for this forecast package, with the
ECMWF favoring a more progressive system tracking across southern
Missouri. If this solution materializes, severe weather impacts
will be more likely across the Mid-South, especially in areas of
northwest Tennessee. Timing of severe weather appears to be Sunday
evening into the overnight hours. At this time, midlevel lapse
rates are forecast to be around 7.5 C/km. In addition, MLCAPE
around 2500 J/kg and 0-3 km SRH of 250 m2/s2 are forecast.
Therefore, any storm that does develop will be capable of
producing all hazards of severe weather.

By midweek, upper level ridging should put an end to our unsettled
weather pattern with dry conditions returning Wednesday.

ANS

&&

.AVIATION...
(00Z TAFS)
Issued at 634 PM CDT Fri May 24 2024

Convection is sinking south of the TAF sites this evening and
it should be fairly quiet for the next few hours. The next round
of convection will push through the area after midnight and mainly
impact JBR, MKL and MEM. Looks like most of the activity will
push out of the Mid-South by mid-morning Saturday. Expect some
scattered low clouds in the morning improving to VFR as the day
progresses. Winds will generally be light outside of TSRAs.

&&

.MEG WATCHES/WARNINGS/ADVISORIES...
AR...Flood Watch through Monday morning for ARZ009-018-026>028-035-
     036-048-049-058.

MO...Flood Watch through Monday morning for MOZ113-115.

MS...Flood Watch through Monday morning for MSZ001>017-020>024.

TN...Flood Watch through Monday morning for TNZ001>004-019>022-
     048>055-088>092.

&&

$$

PUBLIC FORECAST...SJM
AVIATION...SJM