Severe Storm Outlook Narrative (AC)
Issued by NWS

Home |  Current Version |  Previous Version |  Graphics & Text |  Print | Product List |  Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38
365
ACUS01 KWNS 121251
SWODY1
SPC AC 121250

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0750 AM CDT Sat Jul 12 2025

Valid 121300Z - 131200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE GREAT
LAKES AND MIDWEST...

...SUMMARY...
Scattered severe storms capable of damaging winds are expected
across eastern Lower Michigan to the Lower Ohio Valley, mainly from
mid-afternoon through sunset.

...Great Lakes/Midwest...
An eastward-moving shortwave trough near the Manitoba/Ontario and
Minnesota international border vicinity will overspread Lake
Superior through late today into this evening while gradually taking
on more negative tilt, with a convectively influenced perturbation
ahead of it. Associated moderately strong westerlies will be
relegated to portions of Wisconsin/Michigan, with sub-25 kt
mid-level westerlies generally prevalent southward into the
lower/middle Ohio River vicinity.

Influenced by the lead shortwave trough, storm redevelopment may
occur relatively early today across northern/eastern Lower Michigan,
which could include some supercells. Primary storm development along
an initial composite cold front/outflow is anticipated by mid to
late afternoon from parts of eastern Lower Michigan towards the
Wabash/Lower Ohio Valleys. Ample buoyancy (2000+ J/kg MLCAPE) will
be prevalent ahead of this boundary despite warm mid-level
temperatures. Unidirectional southwesterlies and nearly uniform wind
speeds through the lower/middle troposphere will limit deep-layer
shear and the degree of organized clustering. Still, the  setup will
be adequate for mainly a scattered damaging wind threat that will
subside after sunset with storms lingering across Kentucky/Ohio.

Isolated severe hail/damaging winds may also develop along the
secondary cold front advancing eastward across northern/eastern
Wisconsin and upper Michigan. Cooling mid-level temperatures will
aid in weak MLCAPE of 500-1000 J/kg this afternoon. Westerly
low-level wind profiles will modulate the degree of deep-layer shear
and help to marginalize the overall threat.

...Southern Plains including Oklahoma and North Texas...
Today`s severe risk will be influenced by multiple
slow-east/southeast-moving MCVs that persist this morning across
southwest Kansas and the Texas Panhandle. Storms will likely
diurnally increase and intensify this afternoon across much of
Oklahoma and a large part of north Texas. A modest MCV-related
enhancement to the lower/middle tropospheric wind field may persist
today, which could lead to some brief supercell structures and
quasi-organized linear structures as mergers become more prevalent.
Damaging winds and some hail may occur, and portions of the region
will be reevaluated for a possible Slight Risk upgrade should
confidence increase in a semi-focused corridor of severe potential
this afternoon through early evening.

...Colorado/New Mexico...
Modestly enhanced mid/upper-level north-northwesterlies over the
higher terrain should aid in weak/transient updraft rotation as
numerous cells develop during the afternoon. Isolated severe hail
will be possible regionwide, with isolated severe gusts mainly
across interior to southern New Mexico.

...Mid-South/Tennessee Valley to the Carolinas/Virgina...
A pulse storm environment characterized by weak effective bulk shear
but moderate buoyancy will support a threat for isolated wet
microbursts from mid-afternoon to early evening, with tree damage
possible.

..Guyer/Bentley.. 07/12/2025

$$