070
ACUS02 KWNS 230602
SWODY2
SPC AC 230600

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
0100 AM CDT Sun Jun 23 2024

Valid 241200Z - 251200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF MN
AND FAR NORTHEAST ND INTO NORTHWEST WI AND WESTERN UPPER MI...

...SUMMARY...
Severe thunderstorms are possible on Monday across parts of the
northern and central Great Plains into the upper Mississippi Valley
and Great Lakes. Isolated severe storms are also possible across the
coastal Carolinas.

...Northern Great Plains into the upper MS Valley and Great Lakes...

A rather conditional Slight Risk has been maintained across parts of
MN into northern WI and western upper MI, where confidence in storm
development within a favorable environment is currently highest.

A mid/upper-level shortwave trough and related surface low are
forecast to move eastward across parts of SK/MB during the day on
Monday. A weak secondary surface low may develop along a trailing
cold front across the eastern Dakotas, while a warm front will move
northeastward across MN through the day.

The environment will become conditionally favorable for severe
thunderstorms through the day, with increasing low-level moisture
beneath a stout EML supporting strong buoyancy across the warm
sector, in the presence of moderate deep-layer shear. Storm coverage
and evolution remain uncertain across the region, due to EML-related
capping concerns and generally modest large-scale ascent. There is
some potential for early-day convection across ND to spread
southeastward through the day with some severe threat. Isolated
storm development will also be possible near the cold front from the
far eastern Dakotas into west-central/northwest MN. Some increase in
elevated convection will be possible Monday night across a larger
portion of MN into northern WI, in response to an intensifying
low-level jet.

Any surface-based storms that develop within this regime could
become supercells, with an attendant threat of very large hail,
localized severe gusts, and possibly a tornado. There will also be
some potential for upscale growth into a southeastward-moving MCS by
Monday night, depending on the evolution of convection earlier in
the day. A southeastward expansion of greater severe-wind
probabilities may eventually be needed if confidence in the MCS
scenario increases.

...Black Hills vicinity into parts of NE and western IA...
The southern portion of the surface trough/weak cold front moving
across the Dakotas is forecast to reach parts of NE by afternoon.
Strong heating in the vicinity of the boundary will support isolated
to widely scattered high-based thunderstorm development. With
generally weak midlevel flow across the region, storms may quickly
become outflow dominant, but steep tropospheric lapse rates will
support at least isolated severe gusts. The strongest updrafts may
also be capable of producing some hail.

Farther west, high-based convection may also develop from eastern WY
into the Black Hills vicinity, which may spread eastward into the
early evening with a threat of isolated severe gusts.

...Coastal Carolinas...
A cold front is forecast to move across the coastal Carolinas
vicinity, with scattered thunderstorm development expected during
the afternoon. Moderate to locally strong prefrontal buoyancy (with
MLCAPE of near/above 2000 J/kg) and effective shear generally around
25-30 kt will support potential for a few stronger multicells and
perhaps a marginal supercell or two, with an attendant threat of
locally damaging winds and hail.

..Dean.. 06/23/2024

$$