556
FXUS64 KMEG 061952
AFDMEG

Area Forecast Discussion
National Weather Service Memphis TN
252 PM CDT Mon May 6 2024

...New SYNOPSIS, DISCUSSION...

.SYNOPSIS...
Issued at 252 PM CDT Mon May 6 2024

An active weather pattern is underway for the Mid-South. Showers and
thunderstorms will start of as isolated today and continue to
increase in coverage and intensity by Tuesday and into Wednesday.
While there are severe weather chances each day, there is a growing
concern for severe weather development on Wednesday night. Lingering
showers and thunderstorms are possible on Thursday before a pleasant
weekend.

&&

.DISCUSSION...
(This evening through next Sunday)
Issued at 252 PM CDT Mon May 6 2024

A warm front lifting north has interacted with an outflow boundary
resulting in a few isolated showers and thunderstorms mainly across
West and Middle Tennessee as of 2 PM. Shortwave ridging is present
over Arkansas and will slowly push east and center over the Mid-
South. Shower chances will slowly decrease for most of the area as
the ridge assumes its position.

Ridging will be short lived as a low pressure system in the Central
Plains extends a deep trough across the Midwest and into the
Mississippi Valley. This trough will approach from the west/northwest
late tonight into early tomorrow morning. Convection assoicated
with this trough is likely to clip the northern portion of the Mid-
South. A Marginal and Slight Risk for severe weather are in place
across northeast Arkansas, the Missouri Bootheel and northwest
Tennessee. Deterministic soundings show decent MLCAPE ~1500 J/kg,
around 40kts of effective shear, and ample moisture with dew points
in the upper 60s and low 70s. Despite these parameters supportive of
severe weather, confidence remains low at this time due to diurnal
stability trends. As the surface stabilizes nocturnally, the NAM 3km
has been trending this line weakening as it approaches the region.
However, as the sun comes out and surface based instability creeps
up, a few storms could be severe with damaging winds and large hail.
Due to a linear storm mode, a quick, spin-up tornado cannot be ruled
out. Due to the timing of showers and thunderstorms, it is split
into two SPC outlooks, hence the two risk categories.

Confidence continues to increase severe weather potential on
Wednesday. A negatively tilted trough will interact with a surface
low under strong upper level divergence to allow convection to
commence. CIPS analogs are indicative of organized convection (70-
90%) generally along and north of Interstate 40. Our biggest concern
of this active pattern will be Wednesday night as deterministic
soundings continue to trend favorable for severe storms. GFS
soundings indicate MLCAPE values ~3500 J/kg, steep lapse rates, 40-
50 kts of effective shear, and a slight curvature to hodographs.
Another concerning aspect is as trends continue to paint this as a
nocturnal event, this means intensification of the LLJ. Nonetheless,
this potential severe weather event will be closely monitored over
the next couple of days. Stay tuned.

Some lingering showers and thunderstorms are possible on Thursday,
mainly along and south of Interstate 40. On the brighter side, the
weekend looks beautiful with seasonable temperatures in the 70s.

DNM

&&

.AVIATION...
(18Z TAFS)
Issued at 1245 PM CDT Mon May 6 2024

Residual convective boundary/effective warm front lifted north of
MEM late this morning. This feature may serve as a convective
focus for isolated TSRA around MKL this afternoon, in closer
proximity to a departing shortwave trough over middle TN.

South of this boundary, airmass is quite humid, with lower 70s
dewpoints. Several potential convergent zones were evident in the
cumulus field. Scattered -SHRA will be possible just about
anywhere, but forcing will need to be fairly strong for TSRA to
develop under ridging aloft.

Latest HRRR runs depict more solid TSRA coverage moving through AR
just prior to 12Z Tuesday. Will await additional 18Z guidance
before introducing TSRA to the MEM TAF for Tuesday morning/early
afternoon.

PWB

&&

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

$$

PUBLIC FORECAST...DNM
AVIATION...PWB