-- Discussion containing changed information from previous version are highlighted. --
665
FXUS64 KMEG 231613
AFDMEG

Area Forecast Discussion
National Weather Service Memphis TN
1113 AM CDT Thu May 23 2024

...New UPDATE...

.UPDATE...
-- Changed Discussion --
Issued at 1110 AM CDT Thu May 23 2024

GOES-16 Water Vapor satellite trends indicate an MCS propagating
east-southeast across the Lower Mississippi Valley. Latest
regional WSR-88D radar trends show showers and thunderstorms
generally along the Mississippi River with the better reflectivity
occurring towards central Mississippi. Latest mesoanalysis shows
mainly elevated instability present with MLCAPE values generally
below 500 J/kg at this moment with effective shear in excess of 40
kts.

Short-term models indicate the potential for these elevated
showers and thunderstorms to become surface-based into this
afternoon across portions of West Tennessee mainly near the
Tennessee River and northeast Mississippi. Damaging winds and
perhaps large hail will be the main threats if any thunderstorms
become severe. Though, not anticipating severe thunderstorm
coverage to be as widespread as yesterday`s event. Heavy rainfall
will continue to remain a concern with high precipitable water
values approaching 2 inches and the potential for thunderstorms to
produce efficient rainfall rates in a short period over already
saturated soils.

Overall forecast in good shape for the remainder of today and no
significant changes needed at this moment.

CJC
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&&

.SYNOPSIS...
Issued at 304 AM CDT Thu May 23 2024

Active weather will continue today through much of the forecast.
Showers and thunderstorms are possible each day with some
thunderstorms being strong to severe. Dry conditions do not look to
return until next Tuesday.

&&

.DISCUSSION...
(Today through Wednesday)
Issued at 304 AM CDT Thu May 23 2024

Mostly quiet weather can be found across the Mid-South at this hour,
but showers and thunderstorm chances will increase as the sun rises.
CAMs are struggling this active MCS/MCV weather pattern. A stalled
frontal boundary near the AR/MO border will pull ample moisture when
lifting back north by this evening. Convection is likely to fire up
across west Tennessee late this morning into the early afternoon.
Confidence is medium for the afternoon convection period.

The uncertainty lies in a potential round for morning convection as
well as a late evening round as two MCS`s and their decaying
vortices aim for the Mid-South. The NAMNest and ARW paint a MCS
to decay as it moves northeast across the Mid-South around 7 AM
this morning. Severe weather potential would be limited until late
morning and afternoon insolation. The HRRR depicts an MCV (from
the current ongoing convection in Oklahoma) to take a southward
dive across north Mississippi late this afternoon into the
evening.

Deterministic soundings are indicative of a damaging wind and large
hail as the primary threats for any storms that can develop a strong
updraft. Deterministic soundings are showing around 2000 J/kg of
MLCAPE, 0-6 km Bulk Shear values between 30-40 kts, and 0-1 SRH
values ~50 m^2/s^2. PWs are in the 90th percentile today, but soils
are very saturated across the Mid-South from recent rainfall. If
storms do begin to train (or heavy downpours) flooding chances are
higher today with a Marginal Risk for severe weather and A Slight
Risk for Excessive Rainfall in place.

Another Slight Risk for severe weather is in place for Friday as
another MCS takes aim. Guidance is hinting at this arrival to be
early Friday morning, but guidance has struggled with this pattern.
SPC has highlighted at least a 30% chance of severe weather on
Sunday as a deepening low pressure system will cross the Plains. Dry
conditions finally look to return on Tuesday under high pressure.

DNM

&&

.AVIATION...
(12Z TAFS)
Issued at 648 AM CDT Thu May 23 2024

TSRA is on track to enter the Midsouth at discussion time. Latest
HRRR runs appear reasonable in depicting this activity lifting
into middle TN by early afternoon. Scattered TSRA will be possible
by late afternoon, after the atmosphere has had time to recover.
Coverage should be more limited and focused along residual outflow
boundaries. Given the weak shear an increasing convective inhibition
post-sunset, a relatively quiet evening is expected for the MEM
inbound push.

TSRA chances will edge back up toward 12Z Friday, as activity
again moves in from the west.

PWB

&&

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

$$

PUBLIC FORECAST...DNM
AVIATION...PWB