034
ACUS02 KWNS 170615
SWODY2
SPC AC 170613

Day 2 Convective Outlook CORR 1
NWS Storm Prediction Center Norman OK
0113 AM CDT Tue Jun 17 2025

Valid 181200Z - 191200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM SOUTHERN
LOWER MICHIGAN INTO NORTHWEST OH...INDIANA...SOUTHERN
ILLINOIS/MISSOURI...AND EXTREME WESTERN KENTUCKY...

CORRECTED FOR TORNADO GRAPHIC

...SUMMARY...
Strong to severe storms are expected on Wednesday from parts of
southern Missouri northeastward into southern lower Michigan.
Damaging winds, isolated hail, and a few tornadoes will be possible.
More isolated severe storms may develop across the southern Plains.

...Synopsis...
Extensive antecedent convection results in some uncertainty
regarding synoptic details on Wednesday. In general, a convectively
enhanced mid/upper-level trough is forecast to move across parts of
the mid/upper MS Valley into the Great Lakes. In conjunction with
this trough, a deepening surface low will move from parts of
IA/northern MO toward lower MI by Wednesday night.

To the east, one or more weak midlevel shortwave troughs may move
across parts of the Mid Atlantic and Northeast, along the northwest
periphery of an upper-level ridge off of the Carolina coast.

...MI southwestward into the mid MS and OH Valleys...
Convection associated with a remnant MCS may be ongoing Wednesday
morning from parts of IA/northern MO into the Ozarks. Outflow and
lingering cloud cover from this remnant MCS, and the intensity of
possible MCV-like enhancement to the primary shortwave trough, will
influence severe potential from parts of the mid MS Valley and OH
Valley into northern IL/IN and lower MI.

To the south/east of any remnant outflow, and along/south of a warm
front that will move northward in conjunction with the deepening
surface low, diurnal heating of a richly moist environment (with
dewpoints in the 70s F) will result in moderate to strong buoyancy,
with MLCAPE ranging from 1000-1500 J/kg near the warm front, to
greater than 2500 J/kg across the warm sector. Renewed storm
development will be possible during the afternoon near the warm
front and across the weakly capped warm sector. Midlevel flow is
generally forecast to increase to 40-50 kt across the warm sector,
providing sufficient effective shear for supercells and organized
clusters.

Potential for supercells capable of all severe hazards (including a
tornado threat) may become maximized in closer proximity to the
surface low and warm front across parts of IL/IN and lower MI, where
backed surface winds will support favorable low-level shear/SRH. A
corridor of greater tornado probabilities may eventually need to be
considered, depending on trends regarding the intensity and track of
the surface low.

Farther southwest along the outflow-reinforced cold front, somewhat
weaker upper-level flow may result in more of a tendency for storm
clustering, but effective shear will still be sufficient for
organized convection, and storms will be capable of producing
scattered damaging winds, isolated hail, and possibly a couple
tornadoes.

Some severe threat could persist well into the evening and even into
late Wednesday night as storms spread eastward, especially if the
stronger model solutions regarding the strength of the midlevel
shortwave trough and surface low end up closer to reality.

...Southern Plains...
Large-scale ascent will generally become more nebulous with
southwestward extent into the southern Plains, though at least
isolated storm development will be possible near the cold front
during the late afternoon and evening. While coverage is uncertain,
strong to extreme buoyancy and modestly favorable deep-layer shear
will support a threat of severe hail and wind with any storms that
develop and persist within this regime.

...Mid Atlantic vicinity...
Rather strong heating of a moist environment will result in moderate
to strong buoyancy Wednesday afternoon from parts of the Carolinas
into the Mid Atlantic. Scattered diurnal storm development will be
possible along/east of the Blue Ridge, and potentially farther north
and east into parts of DE/NJ and eastern PA. Guidance generally
depicts a belt of 35-45 kt midlevel flow across the region, to the
northwest of the upper-level ridge off of the Carolina coast. This
modest flow enhancement could result in some storm organization,
with large PW and steepened low-level lapse rates resulting in a
threat for at least isolated damaging wind, and perhaps some small
to marginally severe hail.

...Parts of far northeast MT into ND and northwest MN...
Despite generally limited low-level moisture, relatively steep lapse
rates and cool temperatures aloft may support a pocket of moderate
destabilization across parts of far northeast MT and ND into
northern MN Wednesday afternoon. Wind profiles will be relatively
weak and unidirectional, but a couple stronger cells or clusters
will be possible during the afternoon and evening, with localized
potential for hail and strong to severe gusts.

..Dean.. 06/17/2025

$$