Day 2 Convective Outlook  
NWS Storm Prediction Center Norman OK
1234 PM CDT Sat May 16 2026

Valid 171200Z - 181200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS FAR
NORTHEAST COLORADO...PORTIONS OF NEBRASKA...SOUTHEAST SOUTH
DAKOTA...FAR SOUTHWEST MINNESOTA...AND NORTHWEST IA...

...SUMMARY...
Severe storms are expected Sunday afternoon into Sunday night from
portions of the central Plains into the Upper Midwest. Supercells
with very large hail and strong tornadoes are possible, before one
or more linear bands of storms leads to an increase in the wind
damage risk.

...Synopsis...

A strong upper trough will dig across the western U.S. and pivot
east toward the Rockies/Four Corners vicinity on Sunday into early
Monday. Meanwhile, an early day upper shortwave impulse is expected
to be located over MN/IA. This feature will lift northeast across
the Upper Midwest/Great Lakes through Saturday evening. Enhanced
southwesterly deep layer flow will overspread the central High
Plains to the Upper Midwest while mid to upper 60s F dewpoints
spread north across portions of the southern/central Plains to the
Mid-MO/MS Valley and as far north as southern MN/WI.

At the surface, a lee low will deepen across southeast CO into
western KS. A sharp dryline is expected to extend southward across
west-central KS into far western OK/TX. Meanwhile, a cold front will
extend from eastern SD/central NE into northeast CO by afternoon,
while a warm front extends west to east across southern MN/WI and
into Lower MI. These boundaries will be focus for severe
thunderstorm development during the afternoon/evening.

...Northeast CO into NE/SD/MN/IA...

A volatile environment is expected to develop Sunday afternoon,
particularly across parts of NE/SD/MN/IA. Initial thunderstorm
development is expected across northeast CO into southwest NE within
an upslope flow regime ahead of the approaching synoptic cold front.
Low-level capping and weaker boundary layer moisture is expected
across this area. However, even elevated convection atop the
cooler/drier boundary layer will pose a risk for large to very large
hail given very steep lapse rates, strong vertical shear and
elongated/straight hodographs.

With time, additional convection is expected to develop further east
within the warm sector across parts of eastern NE and southeast SD
near the triple point and on the nose of the dry slot as a subtle
lead shortwave impulse overspreads the region. While some morning
cloudiness and showers could be ongoing across parts of the area
this activity is expected to quickly shift northeast and allow for
clearing. As a result,stronger heating of the moistening airmass
will result in a narrow corridor of strong destabilization (MLCAPE
2500-3500 J/kg). Forecast soundings indicate supercell wind
profiles, with effective shear greater than 40 kt across the region.
Backed low-level winds within the warm sector, veering with height,
will contribute to increasing low-level SRH and favorably curved
low-level hodographs. While the corridor for discrete supercells
will be narrow, partly due to capping and modest large-scale ascent
and partly due to the advancing cold front resulting in upscale
growth, the expectation is for a few supercells capable of producing
strong tornadoes and large to very large hail across northeast
NE/far southeast SD/southwest MN and northwest IA.

With time, one or more linear/bowing segments is expected to develop
near the east/southeast-advancing cold front and as the low-level
jet increases during the evening. An attendant risk of severe wind
gusts will accompany this activity. The severe risk will diminish
with time and eastward extent during the nighttime hours as
instability weakens and capping increases.

...KS/OK vicinity...

A more conditional risk is expected across KS into the southern
Plains vicinity. Capping and weak large-scale ascent will likely
inhibit convection. Nevertheless, a favorable thermodynamic and
kinematic environment will reside along the surface dryline from
west-central KS into western OK and eastern parts of the TX
Panhandle toward western north TX. Hot conditions behind the dryline
and moderate low-level convergence, particularly across the
northwest OK vicinity, may support sufficient mixing/deeper dryline
circulations such that a few storms develop. If these storms
develop, they will likely be higher based. Given very steep low to
midlevel lapse rates, moderate instability, and supercell wind
profiles, large to very large hail and strong/severe wind gusts will
be possible. Any storms that develop may struggle to move off the
dryline, and the corridor for severe potential will likely remain
confined.

...Lower MI...

Isolated thunderstorm are possible Sunday afternoon as a warm front
lifts northward and a weak upper shortwave impulse overspreads the
region. Weak to moderate destabilization is forecast as low-level
moisture increases beneath modest midlevel lapse rates. While
low-level winds will be light, vertically veering wind profiles and
increasing southwesterly mid/upper level flow will support organized
updrafts. Isolated gusty winds or small hail could occur with any
surface-based storms that occur into the evening hours.

..Leitman.. 05/16/2026