688
ACUS03 KWNS 280743
SWODY3
SPC AC 280742

Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0242 AM CDT Sun Apr 28 2024

Valid 301200Z - 011200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR EASTERN
NE...WESTERN IA...NORTHWEST MO...NORTHEAST KS...

...SUMMARY...
Severe thunderstorms will be possible on Tuesday from parts of the
mid/upper Mississippi Valley into the central/southern Plains.

...Synopsis...
An amplified mid/upper-level shortwave trough is forecast to move
eastward from the northern Rockies into parts of the
northern/central Plains on Tuesday, accompanied by a strong
mid/upper-level jet. A surface wave is forecast to move from the
central Plains toward the upper MS Valley, with a separate low
expected to largely remain in place across the southern High Plains.

...Upper MS Valley into the southern Plains...
Low-level moisture will stream northward through the day from the
southern Plains into the central Plains and upper MS Valley, in
response to the approaching shortwave trough. While the richest
moisture will likely remain displaced southward of the shortwave
track, 50s to near 60F dewpoints could spread as far north as
eastern NE/western IA and southern MN by Tuesday afternoon. This
moistening beneath relatively steep midlevel lapse rates will
support diurnal destabilization, with peak MLCAPE ranging from
around 500 J/kg across southern MN to greater than 1500 J/kg across
the southern Plains.

Thunderstorm development is expected along a weak cold front Tuesday
afternoon, as diurnal heating weakens MLCINH. The greatest coverage
of storms and strongest deep-layer shear are expected from southern
MN into parts of eastern NE and western IA, in closer proximity to
stronger ascent attendant to the shortwave. A few stronger
cells/clusters will be possible, capable of producing large hail,
damaging winds, and possibly a tornado or two. Storm coverage and
deep-layer shear will likely decrease with southward extent, though
stronger instability into parts of KS/OK could support at least an
isolated severe thunderstorm threat during the afternoon and
evening.

A Slight Risk has been added where confidence is greatest in overlap
of greater storm coverage and shear with more favorable instability.

..Dean.. 04/28/2024

$$