Forecast Discussion

FXUS64 KMEG 231124

Area Forecast Discussion
National Weather Service Memphis TN
624 AM CDT Tue Apr 23 2024

...New AVIATION...

Issued at 338 AM CDT Tue Apr 23 2024

Breezy south-southwesterly winds will return to the Midsouth
today. Under mostly sunny skies, today`s highs will warm to
within a few degrees of normal. The warming trend will continue on
Wednesday, despite the passage of a weak cold front tonight.
Scattered light showers will accompany the front north of
Interstate 40 tonight, and over north Mississippi on Wednesday.
Additional showers and a few thunderstorms will spread into the
Midsouth on Thursday, aided by returning humidity.


(Today through Monday)
Issued at 338 AM CDT Tue Apr 23 2024

West-northwest flow aloft will prevail over the lower MS River
Valley today, around the southern perimeter of a progressive upper
low lifting through the upper Midwest. A weak surface cold front
will pass through most of the Midsouth tonight. Scattered post-
frontal showers and isolated thunderstorms will develop north of
I-40, aided by positive 850mb theta-e advection. Early morning VAD
wind profilers from around the region showed warm advection was
already underway, with a southwesterly 35-40 knot low level jet
and veering vertical wind profiles.

The front will stall over north MS on Wednesday, under northwest
flow aloft. The 850-500mb thickness gradient will be similarly
oriented, serving as a corridor for upstream convection over the
central plains to propagate into the Midsouth late Wednesday night
and Thursday. By this time, precipitable water values will
increase to around 1.6 inches, roughly 80th percentile of late
April climatology. As we go through the day Thursday, upper level
heights will build, as a progressive upper ridge axis lifts east
through the lower MS River Valley. This will effectively shift the
convective corridor north into northeast AR, the MO bootheel and
northwest TN by Thursday evening.

A deep upper low will lift from the central plains through the
upper Midwest on Friday. Models are consistent in ejecting a
shortwave from the southern plains through the Ozarks and mid-MS
River Valley Friday afternoon. Most of the Midsouth will remain
convectively capped, but a few storms may move into northeast AR,
the MO bootheel and northwest TN.

A similar setup is expected for Saturday, but a slight eastward
shift of the pattern and rain chances. Model spread begins to
widen thereafter, but it appears that a longwave trough passage
will support more widespread thunderstorm chances across the
Midsouth late Sunday through Monday.



(12Z TAFS)
Issued at 620 AM CDT Tue Apr 23 2024

Gusty southwest winds up to 23 kts are expected today ahead of a
cold front passage later tonight. As this boundary moves through
the Mid-South, scattered showers will develop and impact JBR, MKL,
and MEM. By the end of the period, expect light north winds to be
in place.