317
ACUS03 KWNS 161928
SWODY3
SPC AC 161927

Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0227 PM CDT Thu Jul 16 2026

Valid 181200Z - 191200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PARTS OF THE
OHIO VALLEY AND LOWER GREAT LAKES INTO THE MID-ATLANTIC...

...SUMMARY...
Strong to severe thunderstorms are expected across portions of the
Ohio Valley and lower Great Lakes into the Mid-Atlantic, mainly
Saturday afternoon into the evening. Some threat may linger into
late Saturday night.

...Ohio Valley into the Mid Atlantic and vicinity...
Some amplification of a mid/upper-level trough is expected over the
northeastern CONUS on Saturday, as multiple shortwaves move through
the base of the trough. The primary surface low is expected to
deepen as it moves across southern Quebec toward northern Maine. A
trailing cold front will move through parts of the Ohio Valley and
Northeast. A remnant surface front initially draped from western PA
toward the Delmarva region is forecast to lift northeastward as a
warm front through the period.

As deep-layer flow strengthens atop a richly moist and destabilizing
warm sector, organized severe potential is expected to develop
across a relatively broad region from the Ohio Valley into the Mid
Atlantic, with at least an isolated threat potentially reaching
parts of New England. Uncertainties include the influence of
early-day convection and potential persistent smoke on the
northeastward extent of substantial surface-based destabilization.

Along the cold front, the greatest relative threat is currently
expected from the lower Great Lakes into eastern parts of the Ohio
Valley, where stronger 850-700 mb flow (around 25-40 kt) is
forecast. Organized cells/clusters capable of damaging wind and
isolated hail may evolve along/ahead of the front and spread
eastward. Rich boundary-layer moisture and modest enhancement to
low-level SRH may also result in some tornado threat, depending on
storm-mode evolution. Favorable moisture/buoyancy will also extend
westward along/ahead of the front into parts of the Midwest and
lower Ohio Valley, but there may be more of a tendency for
convection to be undercut by the front with westward extent.

Farther south/east, organized convection may evolve or reintensify
near the effective warm front by afternoon into parts of PA/NJ, and
also develop into parts of MD/VA along/east of a surface trough.
Very warm temperatures and steepening low-level lapse rates will
become supportive of damaging-wind potential, and isolated hail may
also occur. Some tornado threat could also evolve in closer
proximity to the warm frontal zone.

An extensive frontal QLCS may develop by evening, and continue to
pose some wind-damage threat for as long as it persists into
Saturday night.

...Northern Rockies vicinity...
Compared to previous days, some drying from the west is expected
across parts of MT on Saturday, as a mid/upper-level shortwave
trough moves across parts of BC/AB through the day. High-based
convection is still expected from ID into southwest MT and vicinity,
though relatively weak buoyancy and deep-layer shear should limit
storm organization. Some overlap of stronger deep-layer shear and
moderate buoyancy is forecast to occur across parts of northern MT,
but storm coverage within this regime is uncertain, with stronger
large-scale ascent currently expected to remain north of the
international border.

..Dean.. 07/16/2026

$$