Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1243 AM CDT Tue May 19 2026
Valid 191200Z - 201200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM PARTS OF THE
SOUTHERN PLAINS INTO THE MID MISSISSIPPI VALLEY...AND LOWER GREAT
LAKES...
...SUMMARY...
Widely scattered severe thunderstorms will be possible today from
the southern Plains northeastward into the mid Mississippi Valley
and lower Great Lakes. Damaging winds and hail will be the primary
threats. A greater threat for large hail is expected in the southern
High Plains.
...Ozarks/Mid Mississippi and Ohio Valleys/Lower Great Lakes...
At mid-levels today, a shortwave trough and an associated 75 to 90
knot jet streak will move northeastward into the upper Mississippi
Valley. At the surface, a cold front will advance southeastward
through the lower Missouri Valley and Great Lakes. Along and ahead
of the front, surface dewpoints will mostly be in the mid to upper
60s F. This will contribute to the development of moderate
instability over much of the pre-frontal airmass. Increasing
low-level convergence near the front and warming surface
temperatures will support scattered thunderstorm development by
afternoon. Along much of the front, 0-6 km shear is forecast to be
between 25 to 35 knots, suggesting that enough shear will be present
for organized storms. The potential for severe wind gusts will be
greatest along the leading edge of line segments that form in areas
that heat up the most. The severe threat is expected to persist into
the evening.
...Southern Plains...
A mid-level shortwave trough will move northeastward into the
southern High Plains today. Ahead of the trough, a moist and
unstable airmass will be located over much of the southern Plains
with surface dewpoints the upper 60s and lower 70s F. In response to
surface heating, moderate instability will develop over much of the
moist sector, with MLCAPE likely peaking in the 3000 to 4000 J/kg
range in many areas. Increasing low-level convergence near the front
will lead to thunderstorm development during the afternoon. The
greatest convective coverage is forecast across west-central and
north-central Texas, where low-level flow will be maximized. Ahead
of the developing storms, forecast soundings by late afternoon show
moderate deep-layer shear and steep mid-level lapse rates. This
environment will support a potential for supercells with large hail,
mainly with cells in the stronger instability that can remain
discrete. A threat for severe wind gusts is also expected, with this
threat increasing if a cold pool can organize during the late
afternoon or evening. The severe threat could impact parts of the
Texas Hill Country and east Texas later in the evening, before the
threat becomes more isolated.
..Broyles/Squitieri.. 05/19/2026
Read more
SPC Forecast Products·