spc ac 301730
day 2 convective outlook
nws storm prediction center norman ok
1230 pm cdt mon mar 30 2026
valid 311200z - 011200z
...there is a slight risk of severe thunderstorms across the lower
great lakes region...
...summary...
scattered severe thunderstorms are expected through the day and into
the evening hours tuesday across parts of the great lakes/midwest.
damaging gusts and severe hail are the main concerns. isolated
severe storms may also extend southwestward into parts of the
southern plains.
...midwest and great lakes region...
embedded within the mid-latitude westerlies, a low-amplitude
midlevel wave and accompanying 80-90-kt speed max will advance
eastward from the northern plains/manitoba across ontario and quebec
through the period. in the low-levels, an east/west-oriented
quasi-stationary warm front will extend from new england westward to
a weak low over lower mi, with a cold front trailing
west-southwestward from the low into the central plains. in response
to the migratory wave, the surface low will move eastward along the
frontal zone during the day, before the trailing cold front
overspreads the region during the evening/overnight hours.
showers and thunderstorms will likely be ongoing along the frontal
zone on tuesday morning, and it is unclear if/when this early-day
activity will diminish, given persistent low-level warm advection
amid deep moisture. nevertheless, current expectations are that
these storms and/or additional storms will intensify while
spreading/developing east-southeastward across the lower great lakes
into the northeast during the afternoon. here, upper 50s to lower
60s dewpoints beneath steep midlevel lapse rates/eml will contribute
to at least weak to moderate surface-based buoyancy along/south of
the frontal zone. this buoyancy, coupled with 40-50 kt of effective
shear, will favor organized clusters and the potential for a few
semi-discrete supercells initially -- capable of producing scattered
damaging wind gusts and some large hail. given clockwise-curved
low-level hodographs, a couple tornadoes cannot be ruled out either,
though this remains more conditional. with time, upscale growth into
several lines/clusters will promote a continued risk of damaging
winds and some embedded tornado risk as storms spread
east-southeastward into the evening/overnight hours. depending on
boundary-layer recovery, a greater severe risk may materialize from
parts of lower mi into far southwest ny and northwest pa.
...southern plains...
strong diurnal heating amid steep deep-layer lapse rates along a
north/south-oriented dryline should promote isolated thunderstorm
development by late afternoon into the evening. antecedent dry air
and weak forcing for ascent cast uncertainty on storm coverage.
however, any storms that do form will be capable of producing
isolated large hail and locally severe gusts -- given moderate
surface-based buoyancy and around 20-30 kt of effective shear.
..weinman.. 03/30/2026
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note: the next day 2 outlook is scheduled by 0600z