235
FXUS64 KMEG 311201
AFDMEG

Area Forecast Discussion
National Weather Service Memphis TN
701 AM CDT Fri May 31 2024

...New AVIATION...

.SYNOPSIS...
Issued at 432 AM CDT Fri May 31 2024

Humid conditions will return to the Midsouth today and persist
through early next week. The increased atmospheric moisture will
support showers and thunderstorms each day. Rain chances will be
greatest tonight and Saturday, aided by an upper level low pressure
system lifting out of the southern plains. A few severe thunderstorms
will be possible this afternoon, primarily to the south and west
of a line from Jonesboro to Memphis to Oxford. Damaging winds and
localized flash flooding will be the primary severe weather
threats, with large hail a secondary threat.

&&

.DISCUSSION...
(Today through Thursday)
Issued at 432 AM CDT Fri May 31 2024

Tropical maritime air will return to the Midsouth today, in
advance of an upper level trough lifting out of the southern
Great Plains. Showers were already evident on KNQA radar at
discussion time, extending from central AR into north MS. Lightning
has been confined to central AR, but should expand eastward into
the Midsouth with midlevel height falls and a transition to
surface-based convection. 700-500mb lapse rates will range from
5.5-6.0 C/km, rather modest by last week`s standards. Surface-
based CAPE near 1200 J/kg will coincide with 0-6km bulk shear of
20-30KT to support a Slight Risk of severe storms over east
central AR and northwest MS during peak heating. The severe
threat should wane through the evening, given modest deep layer
shear and a stabilizing boundary layer. A 40KT low level jet will
nonetheless sustain convection through the overnight. A pre-dawn
flare up in thunderstorm coverage and intensity may occur ahead of
the midlevel trough axis passage. Midlevel lapses rates will
increase slightly to around 6 C/km during this period.

Saturday`s thunderstorm coverage and intensity appears more
nebulous in the wake of the midlevel trough. Storm coverage will
likely peak with daytime heating, though an MCV or two from
upstream convection over the plains may enter the mix.

Weak zonal flow / low amplitude ridging will prevail over the
Midsouth on Sunday. The southern Great Plains remain primed for
thunderstorms, given diffluent flow overspreading a weakly-
capped low level instability and moisture axis. Any convectively-
generated waves would likely propagate east through the Midsouth.
With surface dewpoints in the lower 70s, PWAT of 1.5-2.0 inches,
and daytime heating, it won`t take much to organize deep
convection over the Midsouth during the early part of next week.

Medium range global models remain consistent in depicting deep
upper low formation over the northern Great Lakes by the middle
of next week, with highly meridional (for early June) flow over
the eastern half the CONUS. For the Midsouth, northwest flow aloft
will facilitate a cold frontal passage on Wednesday. This front
will likely serve as focus for thunderstorms. A less humid
midcontinental airmass will likely follow, as we head into the
latter part of next week.

PWB

&&

.AVIATION...
(12Z TAFS)
Issued at 701 AM CDT Fri May 31 2024

Showers and perhaps an occasional rumble of thunder is possible
across the airspace this morning as a line of convection moves
through the Mid-South. Additional shower and thunderstorm
development is forecast to occur later this afternoon and last
into the overnight period. However, confidence in exact details of
TSRA timing and intensity remains low at this time. Greater
confidence exists in an extended period of IFR CIGS affecting most
of the airspace associated with persistent convective activity.

&&

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

$$

PUBLIC FORECAST...PWB
AVIATION...JPR