588
ACUS02 KWNS 230559
SWODY2
SPC AC 230557

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1257 AM CDT Thu May 23 2024

Valid 241200Z - 251200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PORTIONS OF
NORTHEAST TEXAS TO THE MIDDLE MISSISSIPPI AND LOWER OHIO VALLEYS...

...SUMMARY...
Severe thunderstorms capable of damaging gusts and large hail are
possible across the Middle Mississippi and Lower Ohio Valley
vicinity on Friday. Damaging gusts and large to very large hail also
will be possible across parts of southeast Oklahoma and the ArkLaTex
area.

...Synopsis...

Shortwave upper ridging is forecast over the upper Great Lakes and
Ohio Valley early on Friday. To the west, an upper shortwave trough
over the northern Plains will pivot northeast across the Upper
Midwest. This will result in height falls across the Midwest. At the
same time, a surface low over MN will lift north/northeast into
western Ontario. As this occurs, a cold front will develop east
through the period. The front is expected to be oriented from the
eastern Dakotas/lower MO Valley/eastern KS Friday morning, becoming
positioned from western Lower MI to southern IL/MO by Saturday
morning. The southern/western extent of this boundary will stall
over northwest TX into central OK as a weak low develops over
northwest TX. A dryline will extend southward from this low across
central TX.

Across the southern/southeast U.S., upper flow will generally be
westerly, but also around 50 kt at 500 mb. Some guidance suggest
convection may be ongoing across the Mid-South vicinity. A
convectively enhanced MCV associated with this remnant convection
from the Day 1/Thu period could focus thunderstorm potential across
parts of TN into northern portions of MS/AL/GA.

...Midwest...

A seasonally moist airmass (mid 60s to low 70s F dewpoints) will be
in place ahead of the eastward-advancing cold front. Steep midlevel
lapse rates will also overspread the region, aiding in strong
destabilization. Convection will likely be ongoing along the front
Friday morning across central IA into northeast KS/northwest MO. As
this convection spreads east into strong instability, storm
intensification is expected. Damaging gusts will be the primary
hazard given a likely more linear storm mode. With stronger cells
within the line, or any semi-discrete convection that can develop,
large hail will be possible. The timing and eastward extent of
severe potential is a bit uncertain into the evening and some
eastward adjustments to the Slight risk area is possible in
subsequent outlooks.

...Mid-South/TN Valley to GA/SC...

A weak shortwave impulse is forecast to move across the region on
Friday. Some guidance also suggest an MCV related to remnant
convection in the Day 1/Thu period of AR/MS will migrate across the
TN Valley. These features will enhance vertical shear amid a
seasonally moist and unstable airmass. A plume of steep midlevel
lapse rates will also be spread across TN/MS/AL/GA. Elongated
hodographs and marginal supercell wind profiles suggest hail will be
possible with the strongest cells. Damaging gusts also will be
possible given steep low-level lapse rates and a fairly dry EML. If
trends continue, higher severe probabilities may be needed in
subsequent outlooks.

...Southeast OK into the ArkLaTex Vicinity...

Forecast guidance is in good agreement that isolated to widely
scattered storms will develop near the dryline during the late
afternoon/early evening. A very moist airmass (surface dewpoints in
the low/mid 70s F) beneath midlevel lapse rates near 8 C/km will
result in strong instability (MLCAPE near 4000 J/kg). Furthermore,
forecast soundings indicate supercell wind profiles with
long/straight hodographs present. Large to very large hail will be
possible with this activity. With time, one or more cluster of
storms may develop and shift east/southeast during the evening/early
overnight hours, posing a risk of damaging gusts and hail.

..Leitman.. 05/23/2024

$$