spc ac 171730
day 2 convective outlook
nws storm prediction center norman ok
1230 pm cdt fri apr 17 2026
valid 181200z - 191200z
...there is a slight risk of severe thunderstorms across parts of
the upper ohio valley and central appalachians...
...summary...
scattered strong to severe thunderstorms capable of damaging winds
and hail will be possible on saturday across the upper ohio valley
and central appalachians. isolated severe hail is also possible
across parts of central texas.
...synopsis...
an amplified midlevel trough will advance eastward from the upper ms
valley to the great lakes/oh valley on saturday. at the same time, a
cold front extending from lower mi south-southwestward into
south-central tx will move east-southeastward across the oh, tn, and
lower ms valley during the day. remnant showers and thunderstorms
will be ongoing along the eastward-moving front at the start of the
period, though this lingering/early-morning activity is generally
expected to be sub-severe.
...upper oh valley and central appalachians...
as the cold front continues eastward into the upper oh valley and
central appalachians into the afternoon, diurnal heating amid a
narrow corridor of upper 50s to lower 60s dewpoints will contribute
to marginal surface-based destabilization immediately ahead of the
front. this, combined with around 40-50 kt of effective shear
oriented oblique to the front, should favor a mix of organized
clusters and perhaps a couple supercell structures -- posing a risk
of scattered damaging wind gusts and isolated severe hail.
additionally, a remnant 30-40 kt south-southwesterly low-level jet
will yield modest low-level shear/hodograph curvature, and a tornado
or two will be possible with the more organized storms.
...central tx...
high-resolution guidance is in relatively good agreement, depicting
elevated thunderstorms evolving behind the cold front during the
morning and early afternoon. steep midlevel lapse rates atop the
frontal surface and elongated/straight hodographs (around 50 kt of
effective shear) could lead to isolated severe hail with any
elevated supercells that evolve.
...lower ms and tn valleys...
a couple strong storms will also be possible immediately ahead of
the front as it impinges on the lower ms and tn valleys during the
afternoon, given around 40 kt of deep-layer shear and a weakly
unstable air mass. however, displacement from the deep-layer forcing
for ascent accompanying the trough, and skinny cape profiles, limits
confidence in the severe risk here -- precluding probabilities at
this time.
..weinman.. 04/17/2026
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note: the next day 2 outlook is scheduled by 0600z