923
FXUS64 KMEG 051454
AFDMEG

Area Forecast Discussion
National Weather Service Memphis TN
954 AM CDT Sun May 5 2024

...New UPDATE...

.UPDATE...
Issued at 954 AM CDT Sun May 5 2024

Currently dry conditions across the Mid-South won`t last much
longer with showers and thunderstorms increasing from southwest to
northeast throughout the day. A shortwave trough is moving across
the Southern Plains this morning with large scale forcing for
ascent overspreading the region. Lift may be further enhanced as
a mesoscale convective vortex (MCV) from overnight convection in
the Southern Plains moves across the Arklatex. Temperatures are
generally in the low/mid 70s across the CWA with dewpoints in the
mid/upper 60s. Ongoing convection over AR will lift northeast this
morning, reaching the Memphis area by 2-3 PM with occasional
showers and thunderstorms possible throughout the evening and into
the early morning hours.

Additional diurnal heating will destabilize the boundary layer
with MLCAPE of 1000-1500 J/kg this afternoon. Mid-level lapse
rates are rather weak at 6.5 C/km and really aren`t expected to
steepen this afternoon, generally limiting hail size to marginally
severe criteria (1" or less). Deep-layer shear is relatively weak
at this time, but will increase this afternoon as a mid-level jet
streak approaches the region. This will raise effective bulk
shear to 30-35 kts. The combination of these ingredients will
likely lead to largely multicellular convection with the potential
to produce damaging wind and marginally severe hail. Low-level
shear remains rather weak and will keep the tornado potential low.

MJ

&&

.SYNOPSIS...
Issued at 430 AM CDT Sun May 5 2024

An active pattern is expected across the Mid-South this week with
several rounds of showers and thunderstorms beginning mainly this
afternoon and continuing into Thursday. A few strong to severe
thunderstorms are possible this afternoon with damaging winds and
large hail as the threats. Additional severe weather is possible
Tuesday and Wednesday. Temperatures will remain above normal
through mid-week with highs mainly in the 80s with lows in the 60s
and 70s. Cooler temperatures and drier weather is anticipated for
next weekend.

&&

.DISCUSSION...
(Today through Saturday)
Issued at 430 AM CDT Sun May 5 2024

GOES-16 Water Vapor satellite shows a mature MCS located across
Texas early this morning. This convective activity is associated
with a mid-level shortwave trough moving through the Southern
Plains. Meanwhile, mostly clear skies and a nearly saturated
boundary layer is resulting in some patchy fog at times
mainly across portions of West Tennessee near the Tennessee River.
Temperatures as of 3 AM CDT are in the 60s. Strong to severe
thunderstorm potential through mid-week is the predominant concern
in this morning`s forecast issuance.

Short-term models indicate the aforementioned mid-level shortwave
will move through the Lower Mississippi Valley today. Shower and
thunderstorm chances will gradually increase throughout the day
with the best chances occurring this afternoon into tonight.
Surface-based CAPE values increasing to between 1500-2000 J/kg
and 0-6 km Bulk Shear values between 25 to 30 kts support the
potential for a few strong to severe thunderstorms this afternoon
with damaging winds as the primary severe weather threat. Poor
700-500 mb lapse rates may mitigate the severe weather threat to
an extent.

Mid-range models continue to advertise a greater potential for
severe thunderstorms Tuesday and especially Wednesday. Showers and
thunderstorms are expected to develop upstream across western
Missouri and Arkansas Monday night and weaken as they begin to
move into the Mid-South towards Tuesday morning. Moderate
surface-based instability combined with ample shear and
moderately-steep to steep mid-level lapse rates will support
strong to severe thunderstorms where redevelopment occurs.

Some model differences still remain with the placement of a
surface low over the Middle Mississippi Valley on Wednesday.
Nonetheless, moderate to strong instability combined with deep
layer shear should be more than sufficient for severe
thunderstorms on Wednesday as a cold front approaches the Mid-
South. Large hail, damaging winds, and tornadoes are possible.
Cooler and drier air will filter in to the region by the end of
the week with temperatures falling slightly below normal for early
May.

CJC

&&

.AVIATION...
(12Z TAFS)
Issued at 645 AM CDT Sun May 5 2024

Challenging convective forecast this afternoon and evening. An
upper level disturbance will lift into the region this afternoon
spawning SHRAs and TSRAs. Due to the scattered nature of
convection this afternoon, went with a tempo at MEM and JBR and
kept PROB30 at MKL and TUP. Hi-res models suggest another band of
SHRAs and TSRAs firing up after 06/00Z and mainly affecting MEM
and TUP. IFR CIGs are expected to develop areawide after 06/06Z.
Conditions may not improve until late Monday morning.

AC3

&&

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

$$

PUBLIC FORECAST...CJC
AVIATION...AC3