Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1254 AM CDT Wed May 27 2026
Valid 271200Z - 281200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE MID-ATLANTIC...
...SUMMARY...
Thunderstorms with severe wind gusts will be possible today across
parts of the Mid-Atlantic and Ohio Valley. Isolated wind gusts and
hail will also be possible in the western Great Lakes and from the
southern Texas Panhandle into west Texas and far western Oklahoma.
...Mid-Atlantic/Ohio Valley...
An upper-level trough will move southeastward today across the Great
Lakes. Flow ahead of the trough will be westerly over the Ohio
Valley and Mid-Atlantic. At the surface, a cold front will move
southward into the Ohio Valley. South of the front, dewpoints in the
60s F will contribute to pockets of moderate instability by
afternoon. As low-level convergence and instability maximizes near
the front, thunderstorms are expected to form and move
east-southeastward across the Ohio Valley and Mid-Atlantic.
RAP forecast soundings just ahead of the front in northern Virginia
at 21Z have MLCAPE near 1200 J/kg with 0-6 km shear around 40 knots.
This will support organized thunderstorms, potentially in the form
of multiple short severe line segments. During the mid to late
afternoon, low-level lapse rates are forecast to peak near 7.5 C/km,
which will be favorable for a wind-damage threat. Hail will also be
possible within the stronger cores.
...Western Great Lakes...
Northwesterly mid-level flow will be in place across the western
Great Lakes today, as a shortwave trough moves southeastward across
the region. At the surface, a pocket of maximized low-level moisture
will be located over Wisconsin, where MLCAPE is expected to peak in
the 1500 to 2500 J/kg range. Thunderstorms that form during the
afternoon that have access to moderate instability and steep
low-level lapse rates could have potential for isolated wind gusts.
Hail could also occur.
...Southern Texas Panhandle/West Texas/Far Western Oklahoma...
At low-levels, a moist and unstable airmass is forecast to advect
northward across west Texas into the southern Texas Panhandle today.
A zone of low-level convergence will likely develop over the
southern Texas Panhandle, with upslope flow to the north of this
feature. As surface temperatures warm during the day, scattered
thunderstorm development is expected near the convergence zone. RAP
forecast soundings to the south and east of Amarillo at 21Z have
steep low to mid-level lapse rates with large surface
temperature-dewpoint spreads. This may be enough for isolated severe
wind gusts and hail.
..Broyles/Chalmers.. 05/27/2026
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