spc ac 010601
day 2 convective outlook
nws storm prediction center norman ok
0101 am cdt wed jul 01 2026
valid 021200z - 031200z
...there is a slight risk of severe thunderstorms from the northern
plains into the upper midwest...
...summary...
strong to severe storms will be possible from the northern plains
into the midwest and great lakes regions on thursday. isolated
strong to severe storms may also occur in the tennessee
valley/southeast as well as parts of the northeast.
...northern plains into mid-missouri valley...
broad cyclonic flow aloft across the rockies will promote a lee
trough and a modest surface low in the vicinity of the black hills.
a surface boundary will arc from eastern montana into northern south
dakota and southern minnesota. moisture advection into the high
plains will couple with higher terrain of mt/wy/sd as well as the
surface boundary to initiate convection during the afternoon.
supercells will be likely initially with an attendant risk of large
to very-large hail, severe winds, and a tornado or two. mid-level
lapse rates of 8-9 c/km will promote rapid intensification and
strong downdrafts. couple this with modest effective shear of 40-45
kt and upscale growth will be likely with time. an mcs is possible
and would likely track along the surface boundary. wind gusts of 75+
mph would be possible with this activity.
while most guidance does not show development along the surface
boundary towards the mid-missouri valley, there will be weak warm
advection ongoing through the day that will increase by late
afternoon. should storms develop here, they would likely be more
isolated/cellular. a similar threat for large/very-large hail and
severe gusts would exist along with a locally greater tornado
threat. this would especially be the case if storms can remain
discrete into the evening when low-level shear increases. depending
on whether this activity develops/evolves, this will have an impact
on the spatial extent of a greater threat for severe winds into the
evening and beyond. given that uncertainty, the slight risk will be
maintained with potential increases in wind probabilities in
subsequent outlooks as confidence increases.
...midwest...
convection is expected to be ongoing in parts of the region. at
least an isolated threat for damaging winds and large hail would
exist with this activity. there remain some potential for
intensification to occur as storms move east during the day. the
slight risk remains in place into far western lower michigan to
account for this potential. later in the afternoon, redevelopment is
possible along the outflow from earlier activity. the most robust
model signals are in iowa and parts of wisconsin. large hail would
be possible especially in iowa where mid-level lapse rates would be
steeper. otherwise damaging winds would be the main threat. a
tornado or two could occur, but low-level shear will be rather weak.
...northeast...
strong buoyancy and modest shear will again be in place across the
region. at least isolated storms are possible during the afternoon.
damaging winds should be the main threat with this activity.
isolated large hail may occur with the strongest storms, but modest
mid-level lapse rates will limit this threat. some guidance does
show more organized activity moving into the region from
ontario/quebec, but this may not occur until late afternoon.
confidence in that scenario occurring is too low for an increase in
wind probabilities.
...tennessee valley/southeast...
strong heating of a very moist airmass will promote scattered to
numerous storms during the afternoon. congealing outflows will help
to organize activity even with very weak shear. given mid-level
lapse rates of 7-7.5 c/km, at least marginally severe storms will be
possible. damaging winds are the expected hazard.
..wendt.. 07/01/2026
click to get wuus02 ptsdy2 product
note: the next day 2 outlook is scheduled by 1730z