816 
ACUS01 KWNS 270602
SWODY1
SPC AC 270600

Day 1 Convective Outlook  
NWS Storm Prediction Center Norman OK
0100 AM CDT Sat Jul 27 2024

Valid 271200Z - 281200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR
CENTRAL/EASTERN ND INTO NORTHWEST MN...

...SUMMARY...
Scattered severe thunderstorms are possible across portions of the
northern Plains vicinity, mainly this afternoon and evening.

...Synopsis...
An occluded deep-layer cyclone will move eastward across parts of
northern SK/AB today, as a larger scale upper-level trough will
remain in place across much of the western CONUS into the northern
Plains. Multiple embedded shortwaves within this trough will move
across parts of the Great Basin and northern Rockies/Plains through
the period. A surface trough will extend southward from the occluded
low into the northern High Plains, with secondary low development
possible across western SD. 

...Dakotas into northern MN...
Elevated convection will likely linger into this morning across
parts of northern MN, and also potentially across parts of the
Dakotas. A convectively enhanced shortwave trough related to the
Dakotas convection will move northeastward through the day. Some CAM
guidance depicts robust storm redevelopment across northern MN by
early/mid afternoon with a moist and increasingly unstable
environment, as this shortwave interacts with modifying outflow.
Should this development occur, deep-layer shear will be sufficient
for organized convection. While this scenario remains uncertain, a
couple of supercells and/or stronger clusters could develop, with a
threat of hail, damaging gusts, and perhaps a tornado. The Slight
Risk has been expanded eastward to cover this possible scenario, and
additional eastward expansion is possible if confidence increases. 

Farther west, there will be some potential for storm development
near the surface trough/weak cold front across west-central ND and
potentially into western SD during the late afternoon and evening,
though guidance continues to vary regarding storm coverage within
this regime. Steep low/midlevel lapse rates, moderate to strong
buoyancy, and sufficient deep-layer shear will support a threat of
hail and strong to severe gusts, which could spread into parts of
the eastern Dakotas during the evening. 

...Northern Great Basin into the central Rockies/High Plains
vicinity...
Scattered thunderstorms are expected this afternoon and evening from
the northern Great Basin into the central Rockies/High Plains, as
one embedded shortwave trough moves across WY into the
central/northern High Plains, and another shortwave moves from CA
into northern NV and southern ID. Multiple outflow-driven clusters
could evolve with time, posing a threat of at least isolated severe
gusts. Somewhat stronger instability across parts of northeast
CO/southeast WY into western NE could also support some hail
potential with the strongest storms.

..Dean/Halbert/Weinman.. 07/27/2024

$$