063
ACUS02 KWNS 100540
SWODY2
SPC AC 100538

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1238 AM CDT Thu Sep 10 2026

Valid 111200Z - 121200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM CENTRAL
NEBRASKA INTO THE UPPER MIDWEST...

...SUMMARY...
Severe thunderstorms are possible across portions of Nebraska to the
Upper Midwest late Friday afternoon into Friday night.

...Nebraska/eastern Dakotas/Minnesota/Wisconsin...

An upper shortwave trough will move across the northern Plains and
Upper Midwest on Friday. As this occurs, a belt of enhanced
southwesterly flow will overspread the region, particularly from the
Dakotas into MN/WI. Cooling aloft will also support steepening
midlevel lapse rates atop a moistening boundary layer in which
increasing southerly low-level flow will transport 60s dewpoints
northward across the region. A surface low is forecast to develop
and shift east across SD, with a surface cold front shifting
southeast through period. This front will be oriented from northeast
to southwest from northwest MN/eastern ND into central SD near the
surface low by mid to late afternoon. A dryline will extend
southward from the surface low over central SD through central NE.
Corridors of moderate instability are forecast along/ahead of the
front, and thunderstorm development is expected by late
afternoon/early evening across northern MN.

Vertically veering wind profiles will support initial supercell
storms capable of all hazards, including damaging wind, large hail,
and a couple of tornadoes. Some hail greater than 2 inch diameter is
possible if supercell mode can be maintained. Given strong linear
ascent along the surface boundary, and an increasing southwesterly
low-level jet during the evening, initial supercells are likely to
cluster and/or grow upscale into line of convection spreading
east/northeast through the nighttime hours.

Convective coverage is a bit more uncertain, and overall severe
potential more conditional, with southward extent into eastern SD/IA
and central NE. Large-scale ascent will be weaker further south, and
this could be problematic for overcoming inhibition from warmer
850-700 mb temperatures, especially through early evening. As the
surface cold front overtakes the dryline in NE overnight, elevated
convection could develop within a low-level warm advection regime.
Whether storms develop during the early evening or overnight, some
severe risk from damaging gusts and hail will be possible.

..Leitman.. 09/10/2026

$$