605
ACUS02 KWNS 161728
SWODY2
SPC AC 161726

Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1226 PM CDT Thu Jul 16 2026

Valid 171200Z - 181200Z

...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS FOR PARTS OF
WESTERN MT/NORTHERN ID...AND ALSO FOR PARTS OF THE UPPER MIDWEST AND
NORTHERN GREAT LAKES...

...SUMMARY...
Strong to potentially severe storms are possible on Friday across
parts of western Montana and northern Idaho, and also across parts
of the northern Great Lakes region.

...Parts of the Upper Midwest/Great Lakes...
A mid/upper-level shortwave trough initially over central SK/AB is
forecast to move southeastward toward the Upper Great Lakes by the
end of the period. Multiple low-amplitude vorticity maxima may
precede this shortwave within west-northwesterly flow aloft. A
surface low is forecast to move east-southeastward through the day
near Lake Superior, as a trailing cold front moves through the
Dakotas and MN. A remnant surface front initially draped from
northern IL/IN into central WI is forecast to move northeastward as
an effective warm front.

Details of convective evolution remain uncertain through the period
across the region. An elevated storm cluster and possible MCS may be
ongoing at the start of the period near northeast MN and adjacent
portions of Ontario, with other convection possible to the cool side
of the effective warm front across WI. In the wake of morning
convection, at least isolated diurnal storm development will be
possible along the cold front, and also near its intersection with
the effective warm front. Within the warm sector, moderate buoyancy
and sufficient deep-layer shear will conditionally support a threat
for organized cells/clusters, with a threat of hail and damaging
winds. Any persistent supercell could also pose at least a brief
tornado threat, especially in closer proximity to the surface low
and warm front. One or more storm clusters may evolve Friday night
and move east-southeastward across the northern Great Lakes region,
potentially posing an isolated severe threat.

No upgrade in probabilities has been at this time, due to
uncertainties regarding recovery in the wake of morning convection
across northern WI and Upper MI, and also regarding storm coverage
along the cold front into eastern MN. However, Slight Risk (level 2
of 5) equivalent probabilities may eventually be needed for some
part of the region.

...Western MT/northern ID...
A favorable thermodynamic profile is again expected across parts of
western MT and vicinity on Friday, with steep lapse rates and MLCAPE
potentially in the 1000-1500 J/kg range. Deep-layer flow may be
somewhat weaker (compared to D1/Thursday) as a mid/upper-low moves
well to the northwest, but backed surface winds and modest veering
with height will still provide sufficient effective shear for
occasional storm organization. Isolated hail and severe gusts could
accompany the strongest storms. Some guidance suggests potential for
outflow-driven storm clustering, which may result in a corridor of
locally greater wind potential, though this scenario remains
uncertain at this time.

...Parts of the Ohio Valley into the Southeast...
A broad area of nebulous damaging-wind potential is expected to
evolve from parts of the Ohio Valley into the Southeast, mainly
during the afternoon. Across the Ohio Valley vicinity, rich moisture
and moderate buoyancy within a weakly capped environment will result
in development of scattered to numerous thunderstorms. Deep-layer
flow/shear will remain quite weak, which should limit storm
organization.

A similar thermodynamic environment will extend into parts of the
Mid-South and Southeast. Weak northwesterly low/midlevel flow may
allow for development of small southeastward moving clusters across
parts of TN/MS/AL, though weak deep-layer shear should temper storm
organization.

Due to the disorganized nature of any damaging-wind threat, wind
probabilities have been withheld, though addition of probabilities
across parts of the region is possible, if trends support any
mesoscale corridors of greater threat.

...Florida...
Most CAM guidance suggests vigorous storm development just offshore
of the FL Gulf Coast Friday morning, in association with a weak
midlevel trough/low. The morning convection may tend to remain just
offshore, but additional storm development is expected by afternoon
across much of the peninsula. Weak deep-layer shear and uncertainty
regarding mesoscale details precludes the introduction of wind
probabilities, though localized strong to severe gusts cannot be
ruled out.

..Dean.. 07/16/2026

$$