523
FXUS64 KMEG 071936
AFDMEG

Area Forecast Discussion
National Weather Service Memphis TN
236 PM CDT Tue May 7 2024

...New SYNOPSIS, DISCUSSION...

.SYNOPSIS...
Issued at 236 PM CDT Tue May 7 2024

Showers and thunderstorms will start out as isolated tonight and
continue to increase in coverage and intensity by Wednesday. While
there are severe weather chances today, there is highest
confidence and 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 Monday)
Issued at 236 PM CDT Tue May 7 2024

A few residual showers are depicted on KNQA as of 2 PM as a low
pressure system pulls away from the region. Elsewhere most of the
region will experience a brief lull in precipitation for the
afternoon. Later this evening, a warm front will begin its northern
ascent and may initiate convection. The 12z HRRR is very aggressive
with this development across West Tennessee. The other CAMs and
preceding HRRR runs are a bit less aggressive and have a quicker
storm motion. The other CAMs are also have the storm mode more
isolated and less organized so only Slight to Likely PoPs were
carried. Confidence is low in severe weather criteria being met due
to diurnal stabilization trends (storms may be elevated). Another
limiting factor is models are hinting at this front stalling just to
the northwest of the Mid-South resulting in a lack of forcing.

Confidence continues to increase for severe weather potential
tomorrow evening under a large Enhanced Risk for severe weather. A
strong trough will interact with a surface low under strong upper
level divergence to allow convection to commence. Despite this
primed atmosphere, the greatest height falls are slightly to the
north of the Mid-South. CIPS analogs have lesser probabilities
than this time tomorrow currently at 60-70% as opposed to
yesterday of 70-90%. These values are still indicative of
organized convection generally along and north of Interstate 40.
GFS soundings indicate MLCAPE values ~3000 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. It is not likely that any morning showers and storms squash
initiation as there is plenty of time to destabilize. Now is the
time to prepare for damaging winds of 70+mph, quick spin up
tornadoes that could be strong, and significant hail of 2" or
greater.

The line of storms should clear the area by 7 AM Thursday. Another
upper level disturbance from the Gulf Region may bring some showers
and thunderstorms Thursday afternoon and evening, mainly along and
south of Interstate 40. Some thunderstorms may be strong to severe.
On the brighter side, the weekend looks beautiful with dry and
seasonable temperatures in the 70s.

DNM

&&

.AVIATION...
(18Z TAFS)
Issued at 1251 PM CDT Tue May 7 2024

TSRA initiation potential, timing and coverage remain the primary
challenge in our modified tropical maritime airmass. HRRR remains
the outlier in initiating TSRA from near NQA to MKL and points
northward around 03Z this evening. NAM 3km depicts more limited
TSRA coverage, primarily after 06Z, over far NW TN. Remaining
CAMs remain largely dry tonight.

For the MKL TAF, some deference has been given to the HRRR and
latest TCF, resulting in retention of the PROB30 TSRA in the early
overnight.

Prefrontal ridging should cap TSRA develop Wednesday afternoon at
MEM. Should this cap break, rapid TSRA development and
intensification would be likely, given the considerable convective
instability. For the TAF sites, this would mostly likely to occur
at JBR, beyond the 24-hour TAF period.

TSRA chances will ramp up considerably at JBR and MEM after 00Z
Thursday / 7PM CDT Wednesday.

PWB

&&

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

$$

PUBLIC FORECAST...DNM
AVIATION...PWB