spc ac 130726
day 3 convective outlook
nws storm prediction center norman ok
0226 am cdt fri mar 13 2026
valid 151200z - 161200z
...there is an enhanced risk of severe thunderstorms from northeast
arkansas into indiana...
...summary...
potential for a widespread damaging wind event along with a few
tornadoes exists from sunday afternoon through sunday night from
northeast texas to southwest lower michigan. the greatest threat
appears to be from northeast arkansas into indiana during the
evening and overnight hours.
...discussion...
on sunday, a powerful upper trough will move across the plains
during the day, with a strong midlevel speed max nosing into mo by
00z. shortly thereafter and over the next 12 hours, the trough will
rapidly deepen, with an intense mid and high level jet developing
across ar, mo, il and in.
at the surface, low pressure is forecast to move across northern mo
and into il, with a prominent cold front extending southwestward
across mo western ar, and northeast tx. low-level moisture quality
will gradually improve throughout the period, with mid 50s f into
southern mo by 00z and as far north as in and oh by 12z monday
morning.
initial activity will occur along the cold front during the late
afternoon where instability will be strongest, perhaps as high as
1000 j/kg from ar into tx. it should be noted that substantial
variability exists among models regarding instability and capping,
though strong ascent near the front should mitigate these factors.
hail and damaging gusts may occur with the late afternoon activity.
of greatest concern is potential for a severe squall line capable of
widespread wind damage, along with a few tornadoes, developing
during the evening across northeast ar, southeast mo, much of
southern il, central and southern in, western ky and tn. the shear
environment will be rapidly increasing during this time, and while
forecast soundings show low levels of instability, it will be more
than sufficient to sustain a strongly forced qlcs, producing
corridors of significant wind damage and a few embedded tornadoes.
southerly winds at 850 mb along the front may exceed 70 kt, with a
very strong frontal surge out of the west.
the envelope of greatest threat will likely shift in later outlooks
as the event nears and predictability increases.
..jewell.. 03/13/2026
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note: the next day 3 outlook is scheduled by 1930z