Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0800 PM CDT Mon Jul 27 2026
Valid 280100Z - 281200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE OHIO VALLEY...
...SUMMARY...
Thunderstorms with severe wind gusts and hail are expected this
evening across parts of the Ohio Valley. Additional storms with
severe wind gusts are also expected from Lower Michigan southward
into Ohio. A few strong gusts will also be possible in parts of the
central Plains and in south-central Arizona.
...Ohio Valley/Great Lakes...
On water vapor imagery, a mid-level shortwave trough is moving
southward through the Ohio Valley. Ahead of this feature, a moist
and unstable airmass is in place with surface dewpoints in the 70s
and low 80s F. The RAP has a pocket of strong instability located
from western Kentucky into southern Indiana, where MLCAPE is
estimated in the 3500 to 4500 J/kg range. Scattered strong to severe
storms are ongoing along the northern edge of the stronger
instability, and the storms are being supported by large-scale
ascent associated with the shortwave trough. In addition, the
WSR-88D VWP at Louisville has 0-6 km shear of 30 to 35 knots
suggesting a potential for organized severe storms will continue
this evening. Severe wind gusts will be possible with supercells and
short bowing line segments. The greatest coverage of severe is
expected to be over southern Indiana and far northern Kentucky...see
MCD 1774.
Further north into Lower Michigan, scattered strong thunderstorms
are ongoing ahead a subtle shortwave trough evident on water vapor
imagery. Short-term model forecasts suggest these storms will expand
in coverage and move southward across Lower Michigan into Ohio
during the late evening and early overnight period. Along this
corridor, the RAP has MLCAPE in the 1000 to 1500 J/kg range with 40
to 50 knot of deep-layer shear. This should support a wind-damage
threat with organized short line segments.
...Central Plains...
At mid-levels, a subtle shortwave trough is currently moving over
the top of a ridge in the central High Plains. Ahead of the
shortwave trough, scattered strong thunderstorms are ongoing along
the western edge of a pocket of strong instability. The RAP
currently shows MLCAPE over central Nebraska in the 4000 to 5500
range. Even though forecast soundings near the instability maximum
have low to mid-level wind speeds generally less than 20 knots, the
instability combined with very steep low-level lapse rates may be
enough for isolated severe wind gusts for a few more hours this
evening.
...Arizona...
The latest surface analysis shows a sufficiently moist airmass in
place over the southern half of Arizona, where dewpoints are mostly
in the mid to upper 50s F. Within the moist air, the RAP has a
pocket of moderate instability with MLCAPE in the 1500 to 2500 J/kg
range. Thunderstorm have developed along the northern edge of the
stronger instability. These storms will move westward across
south-central Arizona this evening, and may pose a threat for severe
wind gusts due to very steep low to mid-level lapse rates...MCD
1772.
..Broyles.. 07/28/2026
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