419
FXUS64 KMEG 240238
AFDMEG

Area Forecast Discussion
National Weather Service Memphis TN
938 PM CDT Thu May 23 2024

...New UPDATE...

.UPDATE...
Issued at 919 PM CDT Thu May 23 2024

A rather quiet night across the Mid-South at this hour. Flow aloft
remains largely zonal on the latest water vapor imagery from
GOES-East. Further to our west and southwest, a couple of MCS are
ongoing across southwest Oklahoma and northeast Texas
respectively. Hi-res model guidances shows both complexes
weakening after midnight and then redeveloping downstream near
the ArkLaTex in the predawn hours. This system may transition into
an MCV tomorrow and move through during the late morning and
early afternoon hours. With good instability and shear in place,
a hail and damaging wind threat would accompany this activity. As
such, the Marginal Risk has been trimmed back overnight tonight
and the Slight Risk has been expanded across the region for tomorrow.

Trimmed back POPs considerably through the overnight hours as
we remain well capped downstream of the MCSs. Additionally, low
temperatures were raised a couple of degrees as low stratus has
developed over the past hour. The rest of the forecast is in good
shape.

AC3

&&

.SYNOPSIS...
Issued at 245 PM CDT Thu May 23 2024

A series of upper-level disturbances will bring a potential for
showers and thunderstorms each day to the Mid-South through
Sunday. The greatest threat for severe thunderstorms will be
mainly Friday and Saturday evenings, and Sunday afternoon into
Sunday night. Large hail and damaging winds will be the primary
severe weather threats along with a potential for heavy rainfall.
A cold front will bring slightly cooler and drier air to the
region by next Tuesday.

&&

.DISCUSSION...
(This evening through next Wednesday)
Issued at 245 PM CDT Thu May 23 2024

GOES-16 satellite trends this afternoon show a decaying MCS
gradually evolving into an MCV over the Lower Mississippi and
Tennessee Valleys. Most of this morning`s showers and
thunderstorms have since pushed away from the Mid-South.
Temperatures as of 3 PM CDT are predominantly in the 70s to around
80 degrees due to earlier convection and cloud cover. Strong to
severe thunderstorm potential through Sunday night remains the
predominant concern in this afternoon`s forecast issuance.

An active pattern will remain in place across the Lower
Mississippi Valley as a series of shortwave troughs move through
the lower Mississippi Valley into Saturday night. An isolated
shower or thunderstorm or two may develop into early evening
across the area but confidence remains low at this time.
Otherwise, a minimum in convective activity is expected until a
nocturnal low-level jet develops later this evening over the
ArkLaTex and combines with a subtle mid-level shortwave trough to
produce additional showers and thunderstorms across the area
overnight into Friday morning. Short-term models including
Convective Allowing solutions have struggled with the weak mid-
level flow. Nonetheless, it appears daytime convection could be
in the form of an MCS gradually evolving into an MCV.

Strong surface-based instability combined with steep mid-level
lapse rates, and 0-6 km Bulk Shear between 30-40 kts indicate a
potential for some strong to severe thunderstorms Friday afternoon
and again Friday night as a weak front meanders into the Mid-
South. Additional strong to severe thunderstorms are possible
Saturday evening as the front retreats back north as a warm front.
High precipitable water values will pose a potential for heavy
rainfall and possible flooding due to saturated soils and
thunderstorms producing efficient rainfall rates.

Mid to long range model runs continue to indicate a potential for
organized convection across the Mid-South Sunday afternoon into
Sunday night across the Lower Mississippi Valley as a negatively-
tilted upper-level trough rotates from the Middle Mississippi
Valley into the Ohio Valley. The best upper-level forcing may be
displaced somewhat upstream. However, sufficient shear and
instability will be present to produce strong to severe
thunderstorms. Large hail and damaging winds continue to be the
primary severe weather threats. 0-1 km storm relative helicities
and clockwise curved hodographs suggest a potential tornadic
threat may exist especially over portions of West Tennessee. This
potential event will continue to be monitored in subsequent model
runs.

A cold front will bring a gradual end to showers and thunderstorms
by early next week as cooler and drier air filters into the
region.

CJC

&&

.AVIATION...
(00Z TAFS)
Issued at 610 PM CDT Thu May 23 2024

Scattered showers and thunderstorms will move across the Mid-South
starting overnight and continuing through much of the forecast
period. VFR conditions are expected for most of the forecast
period with MVFR ceilings possible in the vicinity of
thunderstorms. Winds will be mainly from the south at 5 to 10
knots.

&&

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

$$

PUBLIC FORECAST...CJC
AVIATION...ARS