536
ACUS02 KWNS 190552
SWODY2
SPC AC 190551

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1251 AM CDT Sun May 19 2024

Valid 201200Z - 211200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS
CENTRAL/EASTERN NEBRASKA...NORTHERN KANSAS...SOUTHWEST IOWA AND
NORTHWEST MISSOURI...

...SUMMARY...
Severe thunderstorms are possible across parts of the central Plains
Monday evening into the overnight hours. Additional more isolated
strong to severe storms are possible from the Middle Mississippi
Valley to Lower Michigan through Monday afternoon.

...Synopsis...

A somewhat complex pattern is expected across the Plains to the
upper Great Lakes on Monday. During the morning, an upper shortwave
trough is forecast over the IA vicinity. Convection will likely be
ongoing across parts of the upper MS Valley in association with this
feature as it lifts northeast across WI. Further south, some
guidance is hinting at a possible MCV or outflow over central MO
related to the convective remnants of an intense MCS forecast in the
Day 1/Sun period over KS. Across the central Plains, an area of
broad, enhanced southwesterly mid/upper flow will persist over
NE/KS, though large-scale ascent will remain weak through peak
heating. Capping will likely suppress convection during the
afternoon, and airmass recovery from convection in the Day 1 period
will occur through the daytime hours. A potent lead upper shortwave
trough, emanating from the larger-scale western U.S. upper trough,
will eject into the central High Plains overnight.

At the surface, a broad warm sector with dewpoints in the 60s to
near 70 F will extend east/northeast from the central/southern
Plains to the Mid/Upper MS Valley vicinity. A warm front will lift
north through the day into northern WI/Lower MI. A dryline will
extend south/southwest from northwest OK to southwest TX. Overnight,
surface cyclogenesis will ensue across KS/NE as the upper shortwave
trough approaches the region. A cold front will sharpen and begin to
shift east across central NE/KS late in the period.

...Central Plains to Lower MO Valley...

Severe potential will increase by early Monday evening as the upper
shortwave trough moves into the central Rockies and large-scale
ascent increases. Initial storm development over northeast CO into
southwest NE/northwest KS will pose a risk for damaging gusts and
hail. As a surface low develops east across KS/NE convection will
increase in coverage, particularly over NE. Given timing of
convection (mainly during the nighttime hours) and potential for
linear development as a cold front sharpens and shifts east
overnight, damaging gusts and hail will be the main hazards as
storms approach the MO River by Tuesday morning. The southward
extent of severe potential into KS is a bit uncertain. Strong
capping will likely persist over the southern half of the state.

...Eastern IA into Lower MI...

Convection will likely be ongoing Monday morning. Severe potential
is uncertain during the morning, but any organized storms could pose
a risk of marginally severe hail and locally strong gusts. Guidance
suggests severe potential may increase with eastward extent, and
into the afternoon, from northeast IL into Lower MI as stronger
destabilization will occur ahead of morning activity. Effective
shear magnitudes are forecast to be around 25-30 kt. Meanwhile,
steepening low-level lapse rates, with a mixed boundary layer to
near 850 mb is noted in forecast soundings. Marginal supercells
capable of hail and strong gusts will be possible. If confidence
increases, portions of this area may need higher probabilities in
subsequent outlooks.

...Central MO vicinity...

A somewhat conditional risk is possible across parts of the central
MO vicinity. It is possible that an MCV migrating across the area or
any remnant outflow related to Day 1/Mon activity could focus
thunderstorm development during the late morning into afternoon.
Large-scale ascent will be weak over the area, and deep-layer flow
modest. However, thermodynamic profiles will support marginal hail
and strong gusts if storms develop.

..Leitman.. 05/19/2024

$$