Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1251 AM CDT Tue May 12 2026
Valid 121200Z - 131200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS THE
FLORIDA PENINSULA AND PARTS OF THE MIDWEST/GREAT LAKES...
...SUMMARY...
Severe storms will be possible at least on an isolated basis across
parts of the Florida Peninsula today, and potentially parts of the
Great Lakes to Lower Missouri Valley and south-central Plains late
this afternoon and early evening.
...Florida Peninsula...
A front will settle southward today in advance of a low-latitude
shortwave trough crossing the northeast Gulf. A moist and
potentially unstable environment will exist during the afternoon,
especially across the central Peninsula where MLCAPE could exceed
1500 J/kg, although early day clouds and convection near/south of
the front leads to some uncertainty regarding destabilization
details. Regardless, storms should steadily increase in coverage and
intensity through late morning into the afternoon, initially across
the north-central Peninsula, maximizing toward the east coast,
although additional storms may move inland from the Gulf.
Strengthening mid/high-level winds will support upwards of 30-40 kt
effective shear and fairly long/semi-straight hodographs, which
could yield some transient supercell structures pending sufficient
destabilization. Damaging winds and hail will be possible at least
on an isolated basis, and a tornado could occur as well,
particularly near the effective front. A greater confidence in
destabilization and the possibility of more sustained
storms/supercells could warrant a Slight Risk upgrade.
...Wisconsin/Lake Michigan to south-central Plains...
A shortwave trough over the Canadian Prairies will dig southeastward
and amplify toward the Upper Great Lakes through this evening, with
a cold front moving southeastward across these regions. Low-level
moisture will be limited near/ahead of the front, but advection may
be sufficient to counteract mixing to allow surface dewpoints to
reach the 50s F by late afternoon/early evening.
In tandem with the strongest forcing for ascent, and in vicinity of
the surface low/front, isolated to widely scattered development is
initially expected, and most probable, late in the afternoon/early
evening across eastern Wisconsin, with additional storms possible
farther southwest near the front across Illinois/Missouri and
potentially into southeast Kansas/northeast Oklahoma. Where storms
develop/sustain, steep lapse rates and strong west-northwesterly
flow aloft could yield some severe storms capable of hail/damaging
wind.
...Western Oregon/southern Washington...
A few stronger storms with gusty winds and/or sub-severe hail could
develop late in the afternoon and evening regionally in advance an
upper-level trough approaching the coastal Pacific Northwest.
Strengthening deep-layer winds and steepening lapse rates could
plausibly yield some stronger storms, although the potential for
sustained/organized severe storms is currently expected to remain
low.
..Guyer/Weinman.. 05/12/2026
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