085
ACUS02 KWNS 271705
SWODY2
SPC AC 271703

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1203 PM CDT Thu Jun 27 2024

Valid 281200Z - 291200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL
PLAINS INTO MISSOURI...IOWA AND SOUTHERN MINNESOTA...

...SUMMARY...
Severe thunderstorms may develop from parts of the central Plains
into parts of the Middle and Upper Mississippi Valley on Friday.
Large hail, damaging wind, and a couple tornadoes will be possible.

...Northern/Central Plains to the Mid/Upper MS Valley...

An upper trough over the northern Rockies will develop east to the
Upper Midwest/upper Great Lakes vicinity. A convectively enhanced
vorticity maxima also is forecast to be located over the
lower/mid-MO Valley Friday morning. This feature will drift east
toward Lake Michigan through evening. At the surface, an area of
elongated low pressure will located near the international border in
the vicinity of ND and southern Saskatchewan/Manitoba. This feature
will shift east into northern MN and eventually the U.P. of MI and
Lake Superior. At this occurs, a cold front will shift southeast
across the northern Plains and Upper Midwest through the period.
Isolated strong thunderstorms are possible ahead of the cold front
during the afternoon/evening across parts of the Dakotas into MN.
Locally strong gusts and a few instances of hail will be possible
with this activity.

Further south, a secondary surface low may develop in the vicinity
of western/central KS on the nose of very strong heating over the
southern Plains. Rich low-level moisture will be in place across the
central Plains to the Mid-MS Valley. Morning convection will likely
be ongoing in a strong low-level theta-e advection regime from
northwest MO into IA/southeast MN/WI and northern IL. This activity
poses some uncertainty in convective evolution into the afternoon as
it may stunt destabilization, especially across parts of MO/IA/IL.
If airmass recovery can occur, supercell wind profiles would support
an all hazards risk, especially in the vicinity of any modified
outflow from morning convection. Given uncertainty, only minor
adjustments to the ongoing outlook have been made across the
MO-Valley vicinity.

Confidence is higher that strong destabilization will occur across
parts of KS/NE. Convection will likely develop over southeast
WY/northeast CO in a post-frontal upslope flow regime during the
late afternoon. As this activity spreads east/southeast into NE/KS,
isolated supercells and clusters will pose a risk for severe gusts.
Steep low and midlevel lapse rates will be present, with a
deeply-mixed boundary-layer evident in forecast soundings.
Furthermore, dry air around 700 mb will further aid in strong
downdraft potential. Isolated gusts to 80 mph will be possible. With
any more discrete supercell activity, straight/elongated hodographs
and large elevated instability and steep midlevel lapse rates will
support isolated significant hail to around 2.5 inches in diameter.

..Leitman.. 06/27/2024

$$