879
ACUS02 KWNS 161738
SWODY2
SPC AC 161737

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1237 PM CDT Sun Jun 16 2024

Valid 171200Z - 181200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF
NORTHERN PLAINS AND UPPER MISSISSIPPI VALLEY...

...SUMMARY...
Scattered strong to severe storms will be possible Monday over much
of the northern Plains toward the upper Mississippi Valley.

...Synopsis and Discussion...
Upper pattern early Monday morning is forecast to feature expansive
ridging centered over the Carolinas that covers much of the eastern
CONUS and a cyclone over the Pacific Northwest with associated
troughing over the much of the western CONUS. Southwesterly flow
aloft will persist across the northern and central Plains between
these two features, with some strengthening of this flow anticipated
as the western CONUS cyclone progresses eastward across the northern
Rockies and northern High Plains, and the ridging over the eastern
CONUS remains in place.

Scattered showers and thunderstorms will likely be ongoing from the
mid MO Valley into the Upper Midwest, to the north of a warm front
expected to extend from a surface low over the southwest
NE/northwest KS vicinity northeastward to another low near the WI/MI
border. These showers and thunderstorms are expected to gradually
shift northeastward throughout the day, remaining mostly north of
the warm front. There is some chance that this activity
restrengthens during the late afternoon/early evening over
east-central MN and central/northern WI, where the warm front is
expected to make gradual northward progress during the day. Ample
low-level moisture and strong buoyancy south of the warm front
suggests surface-based supercells capable of all severe hazards,
including tornadoes, are possible. However, the overall evolution of
this convective cluster still remains a bit uncertain, with some
guidance keeping it well north of the warm front. This uncertainty
precludes higher probabilities in this outlook.

Farther west, late afternoon thunderstorm development appears
possible along the lee trough arcing from southeast MT south into
far eastern CO/western KS. Highest probabilities for surface-based,
late afternoon/early evening storms appears to be across the central
High Plains. Any storms that do form could produce hail initially,
before quickly becoming more outflow dominant. There is some
potential storms develop close enough to one another for upscale
growth, with the resulting convective line progressing
east-northeastward across southern NE. Thunderstorm development also
appears probable across southeast MT amid moisture upslope flow and
strengthening large-scale ascent ahead of the approaching shortwave
trough. These storms will likely be elevated, with hail as the
primary hazard, but a few strong gusts could still reach the
surface. Isolated storms are possible farther south across the
southern High Plains, but warmer temperatures aloft and displacement
south of the better large-scale ascent should keep coverage
isolated. High-based character to any storms that do develop could
promote damaging gusts.

The low-level jet is expected to strengthen during the evening,
likely increasing to near 60 kt from the central Plains into the
Upper Midwest. Associated warm-air advection will likely result in
thunderstorm development north of the warm front across the northern
Plains and Upper Midwest. Enough vertical shear and elevated
buoyancy is in place for severe storms, with large hail as the
primary hazards. This activity is currently expected to stay north
of the warm front, but this front is forecast to move northward
through much of MN by early Tuesday. As a result, these is some
chance a storms may trend towards becoming surface-based early
Tuesday morning if they develop far enough south.

..Mosier.. 06/16/2024

$$