244
ACUS02 KWNS 151734
SWODY2
SPC AC 151732

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1232 PM CDT Tue Jul 15 2025

Valid 161200Z - 171200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS THE FRONT
RANGE AND THE WESTERN GREAT LAKES REGION...

...SUMMARY...
Scattered strong to severe thunderstorms are possible Wednesday
afternoon and evening from parts of the central High Plains to the
Great Lakes.

...Front Range and High Plains...
A shortwave trough over the northern Rockies will intensify as it
moves eastward across the central US Wednesday. A cold front across
the Front Range and High Plains will continue to sag slowly
southward as surface moisture deepens behind it. Within the broad up
slope flow regime, scattered storm development is expected across
the higher terrain of the central Rockies and High Plains by early
afternoon Wednesday. Enhanced mid-level flow will support initial
supercells capable of hail and isolated damaging gusts. Local
terrain effects and enhanced low-level shear near the front may also
allow for a tornado or two. Scattered severe storms expand in
coverage across the I-25 corridor through the afternoon before
moving eastward into the plains through the evening.

How far east the severe threat will extend remains uncertain as
cooler temperatures and lingering inhibition are likely to be in
place behind the front. Should sufficient upscale growth take place,
an MCS may develop and merge with additional convection farther east
before continuing south/southeastward across the central Plains
overnight. This would support a continued risk for at least isolated
damaging gusts.

...Central Plains...
As the cold front continues to move southward across the central
Plains, lingering inhibition and forcing for ascent displaced to the
north should limit convective development along the front through
much of the day However, warm surface temperatures and 60s-70s F
surface dewpoints will support large buoyancy along the front. As a
30-40 kt low-level jet increases into the evening, storm development
is expected with increasing low-level warm air advection. Isolated
damaging gust are possible.

...Great Lakes...
A convectively augmented shortwave trough over the central Plains
will quickly move eastward along the sagging cold front. Ascent from
this feature will aid in developing a wave cyclone along the front,
enhancing the low-level flow field across parts of WI and northern
IL. An ongoing arc of storms near the surface low should gradually
re-intensify through the morning and into the early afternoon.
Moderate MLCAPE and strengthening flow aloft will support a mix of
cells and clusters. The primary risk is expected to be damaging
gusts, though enlarged low-level hodographs and 100-200 J/kg of
MLCAPE below 3km AGL may support some tornado risk with the more
cellular elements. With time gradual upscale growth into a more
linear structure is expected near the western shores of Lake
Michigan with a continued risk for damaging gusts.

To the east, strong heating of a very humid air mass is expected
across Lower Michigan through the afternoon. Scattered to widespread
storms are likely along the typical lake breeze fronts. Vertical
shear will be weaker through the afternoon, though at least some
enhancement of the flow field could support isolated damaging gusts
with scattered to numerous storms expected.

There is some potential for a more organized line/cluster of storms
on the western side of the lake to move eastward across Lake
Michigan late in the evening and through the overnight hours.
Stronger flow aloft near the shortwave trough could support damaging
gust and brief tornado potential across parts of northern Lower
Michigan overnight. Higher severe probabilities could be needed if
confidence in this convective scenario increases in future outlooks.


...Upper OH valley...
Widespread thunderstorms are expected across the region in response
to a shortwave impulse. Modest instability is forecast amid a very
moist airmass. While vertical shear will remain fairly limited, some
slight enhancement near the upper trough could support a few
longer-lived storm clusters. Isolated strong gusts/wet microbursts
could occur, with the more intense storms.

...Northern Gulf Coast...
Scattered to numerous thunderstorms associated with Invest 93L will
occasionally move onshore across the northern/central Gulf Coast
Wednesday and Wednesday night. Enhancement of low and mid-level
easterly shear north of the weak surface circulation may support a
few longer-lived cells near the coast. Sporadic damaging gusts and
perhaps a brief tornado are possible, though confidence in this
convective scenario is very low.

..Lyons.. 07/15/2025

$$