spc ac 210723
day 3 convective outlook
nws storm prediction center norman ok
0223 am cdt sun jun 21 2026
valid 231200z - 241200z
...there is a slight risk of severe thunderstorms for portions of
the central high plains...
...summary...
scattered severe storms are expected across the central high plains
on tuesday with isolated severe storms possible into the upper
midwest. large hail and damaging wind gusts will be the primary
threats.
...synopsis...
a low-amplitude ridge across the western conus will build slowly
northward as a trough moves south from alberta into the northern
plains. as this pattern continues to evolve, mid-level flow will
strengthen across the rockies and into the plains. this will result
in strengthening lee cyclogenesis across the southern high plains.
farther east, a cold front will move off of the east coast during
the day tuesday.
...central high plains into the central plains...
strengthening upslope flow to the north of the developing lee
cyclone should result in storm development by mid-afternoon across
eastern colorado on tuesday. as mid-level flow strengthens to near
50 knots, this strong shear combined with moderate to strong
instability will support supercells capable of large to very large
hail and some severe winds. expect these supercells to eventually
congeal into one or more clusters as they move east during the
evening, with an increasing severe wind threat.
...upper midwest...
a weak surface low associated with the mid-level trough moving south
out of canada will settle into the upper midwest on tuesday. a cold
front will extend southwestward from this feature with dewpoints
into the low 60s ahead of it. this should produce sufficient
instability for scattered storm development. some damaging wind
gusts may be possible with the strongest storms.
...southeast...
a cold front will move off the east coast during the day on tuesday.
most guidance shows the front offshore before sufficient instability
develops for a severe storm threat along the georgia, south
carolina, and north carolina coasts. therefore, have not added
probabilities at this time. however, if the cold front slows or if
greater instability develops than currently forecast, a marginal
risk may be needed in later outlooks.
..bentley.. 06/21/2026
click to get wuus03 ptsdy3 product
note: the next day 3 outlook is scheduled by 1930z