270
FXUS64 KMEG 211548
AFDMEG

Area Forecast Discussion
National Weather Service Memphis TN
1048 AM CDT Tue May 21 2024

...New UPDATE...

.UPDATE...
Issued at 1045 AM CDT Tue May 21 2024

Surface analysis late this morning places a surface low over
northeast Kansas with a cold front extending back into portions of
the Texas/Oklahoma Panhandle and a dry line located over West
Texas. Meanwhile, the Mid-South remains on the western periphery
of a surface and upper-level ridge axis. As of 10 AM CDT,
temperatures across the Mid-South are in the 80s at most
locations. A strong capping inversion present will result in a
continuation of rain free weather into this afternoon with
temperatures in the upper 80s to lower 90s. Forecast overall in
good shape and no updates anticipated at this time.

CJC

&&

.SYNOPSIS...
Issued at 302 AM CDT Tue May 21 2024

An unsettled weather pattern kicks off tonight as several systems
will cross the Mid-South. Wednesday night into Thursday is currently
the highest chance of severe weather. Temperatures will continue to
be near to above normal through the forecast period. Rain chances
are highest along and north of Interstate 40 with forecast
precipitation amounts of 4 to 6 inches over the next 7 days.

&&

.DISCUSSION...
(Today through Monday)
Issued at 302 AM CDT Tue May 21 2024

High pressure will continue to be pushed east by a complex of
thunderstorms as a low pressure system ejects from the four corners
region. An MCS is likely to decay as a very dry air is depicted
aloft on water vapor satellite imagery. A Marginal Risk is in effect
tonight for northeast Arkansas and a portion of the Missouri
Bootheel.  If a bowing segment is able to materialize, the forecast
environment may possess around 40kts of 0-6km bulk shear for a
damaging wind threat. As the cluster decays, it will be a race
against time due to diurnal stability trends. Confidence is low in
severe weather materializing, but a few storms could bring some
gusty winds and maybe small hail.

Tonight kicks off an unsettled weather pattern. NBM Thunderstorm
probabilities hang around the 30-60% range beginning Wednesday
afternoon through Monday. The attention does shift to Wednesday
afternoon into evening where an Enhanced Risk for severe weather has
been introduced. Southwesterly flow will surge a moisture plume and
bring dewpoints into the 70s ahead of a strong cold front.
Deterministic soundings are indicative of a damaging wind and large
hail as the primary threats. Inverted V soundings will provide
excellent mixing with around 50kts of effective shear. Unstable
lapse rates (~7 C/km) through the column with MLCAPE ~2500 J/kg may
bring large, to very large hail mainly to northeast Arkansas and the
Missouri Bootheel. On a positive note, 0-1km and 0-3km SRH values
are low which keeps the tornadic threat low compared to the wind
and hail threats. PWs are hanging in the 90th percentile or
higher, meaning locally heavy rainfall is possible. Particularly
with any strong updrafts could lead to localized flooding. Current
QPF values are highest along and north of I-40. A Flood Watch may
be needed if QPF continues to trend upward.

While it will not rain or thunderstorm the entire forecast period
(some areas may have breaks), another cluster of thunderstorms will
move through Thursday night into Friday. Several series of
systems continue to cross each night until dry conditions return
Tuesday evening. This active pattern is a result of the a heat
dome over Mexico making the Mid-South and adjacent areas
susceptible to an active weather pattern. QPF for the next 7 days
range from 4-6" along and north of I-40 and areas like Aberdeen,
MS may only see an inch. We will keep an eye on this active
weather pattern and monitor any severe potential in the coming
days.

DNM

&&

.AVIATION...
(12Z TAFS)
Issued at 650 AM CDT Tue May 21 2024

Wind will remain the primary concern today. KNQA VAD wind profiler
shows 25-30KT in the lowest 3 gates, will will likely be near the
peak surface gust potential through mid-afternoon.

Scattered TSRA will roll into northeast AR late this evening, then
into west TN overnight. 06Z HRRR depicts weaker mixed layer instability
east of the MS River, with perhaps lower lightning coverage
around MEM. For now, will maintain a PROB30 in the MEM TAF, in-line
with the Extended TCF.

Increased TSRA chances appear in store after 18Z Wednesday, beyond
the 30 hour MEM TAF. This TSRA will hold the potential for more
impactful winds, owing to greater daytime convective instability.

PWB

&&

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

$$

PUBLIC FORECAST...DNM
AVIATION...PWB