387
ACUS01 KWNS 120547
SWODY1
SPC AC 120545

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1245 AM CDT Sat Jul 12 2025

Valid 121200Z - 131200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS IN THE CENTRAL
GREAT LAKES TO THE LOWER OH VALLEY...

...SUMMARY...
Scattered damaging winds are most probable across eastern Lower
Michigan to the Lower Ohio Valley, mainly from mid-afternoon through
dusk.

...Great Lakes...
A shortwave trough centered on the MB/ON to Dakotas/MN borders will
take on an increasingly negative tilt as it ejects across northwest
ON and the Upper Great Lakes. Ahead of this feature, a convectively
aided shortwave impulse should dampen as it accelerates
north-northeast through the central Great Lakes into northeast ON by
early afternoon. Belts of enhanced mid-level southwesterlies will be
confined to WI/MI.

Ongoing convection from Lake MI to MO is expected to largely decay
this morning. Some guidance suggests reinvigoration may occur in the
late morning across northern Lower into eastern Upper MI as the lead
shortwave impulse passes. Primary storm development along an initial
composite cold front/outflow is anticipated by mid to late afternoon
from parts of eastern Lower MI towards the Wabash/Lower OH Valleys.
Ample buoyancy will be prevalent ahead of this boundary despite warm
mid-level temperatures. Unidirectional southwesterlies and nearly
uniform wind speeds through much of the kinematic profile 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 dusk in parts of OH/KY.

Isolated severe hail/damaging winds may also develop along the
secondary cold front pushing east across northern/eastern WI and
upper MI. 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.

...OK/TX/NM/CO...
Multiple areas of ongoing thunderstorms from southern NE to the TX
Panhandle are expected to persist and shift south-southeastward this
morning. Differential diabatic heating in vicinity of remnant
MCVs/outflows and orographic forcing for ascent will be the primary
drivers of storm development today. Convection across OK/TX will
probably persist and gradually intensify in tandem with downstream
boundary-layer heating. Within predominately weak deep-layer shear,
slow-moving and mainly disorganized updrafts will dominate. Sporadic
strong to marginal severe gusts along with small to marginally
severe hail will be possible in a mix of cells/clusters.

Modestly enhanced mid/upper-level north-northwesterlies over the
higher terrain of NM/CO 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 NM.

...Mid-South/TN Valley to the southern Piedmont...
A pulse storm environment characterized by weak effective bulk shear
but moderate buoyancy will support a threat for erratic wet
microbursts from mid-afternoon to early evening.

..Grams/Thornton.. 07/12/2025

$$