453
ACUS01 KWNS 160538
SWODY1
SPC AC 160536

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1236 AM CDT Wed Jul 16 2025

Valid 161200Z - 171200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ON WEDNESDAY OVER
PARTS OF THE CENTRAL HIGH PLAINS...AND PORTIONS OF THE 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 and Mid-Atlantic states.

...Upper MS Valley...
A large but weakening linear MCS is tracking slowly eastward into
western MN/IA.  00z model consensus shows a convectively enhanced
upper trough and MCV will emerge from this activity, tracking into
parts of WI and northern IL by Wednesday afternoon.  Strong heating
and ample low-level moisture will be in place over the warm sector
of this MCV, but weak mid-level lapse rates will limit CAPE values
to around 2000 J/kg.  Present indications are that thunderstorms
will intensify by mid-afternoon across this region and spread
eastward toward Lake Michigan and western Lower MI by evening.  The
strongest cells will pose a risk of damaging wind gusts.  Enhanced
vertical shear near the MCV may also result in a tornado or two.

...WY/CO...
The belt of primary mid-level westerlies will extend across WY later
today, with the southern fringe of stronger flow aloft over northern
CO.  Ample mid-level moisture will encourage scattered afternoon
thunderstorms over the mountains and foothills of CO/southern WY,
with storms moving into the adjacent plains by mid-afternoon.
Backed low-level winds will result in favorable deep-layer shear for
a few organized/supercell storms capable of large hail and damaging
winds through the afternoon and early evening.

...NY/PA/WV...
Current water vapor loops shows a subtle shortwave trough and weak
mid-level jet max over southern IL.  This feature will track
northeastward up the OH Valley and into parts of OH/WV/PA by
Wednesday afternoon.  Forcing associated with this feature, combined
with a warm/humid air mass will promote multiple clusters of
thunderstorms affecting the region.  Forecast soundings show rather
weak mid-level lapse rates, weak winds in the lowest 4km, and
considerable mid-level moisture limiting downdraft potential.  Will
therefore maintain only MRGL at this time, but acknowledge some risk
of scattered wind damage across this region later today.

..Hart/Thornton.. 07/16/2025

$$