spc ac 091919
day 3 convective outlook
nws storm prediction center norman ok
0219 pm cdt tue jun 09 2026
valid 111200z - 121200z
...there is an enhanced risk of severe thunderstorms across
northeast missouri...eastern iowa...northern/central
illinois...southern wisconsin...northwest indiana...and southwest
lower michigan...
...summary...
scattered to numerous severe storms capable of potentially strong
tornadoes, large hail, and destructive winds appear likely from
portions of the lower missouri and mid mississippi valleys into the
upper great lakes. more sporadic occurrences of damaging wind and
large hail are possible across the southern plains, upper ohio
valley and lower great lakes toward the mid-atlantic coast.
...synopsis...
a compact but potent upper shortwave trough, characterized by a
60-80 kt 500 mb jet streak, will move across the central plains and
upper midwest/great lakes vicinity on thursday. a strong low-level
jet will likely be oriented across parts of mo/ks/ok thursday
morning. some weakening of this feature will occur as it spreads
northeast through the morning, but re-invigoration of the low-level
jet is forecast by mid/late afternoon.
at the surface, low pressure initially over central ks will develop
northeast toward lake michigan through 00z, and cross the
international border by 12z friday. a cold front/composite outflow
from prior convection is expected to be oriented from northern
wi/upper mi southwestward into northwest ok by midday. the northern
extent of the boundary will progress eastward across much of the
great lakes and mid-ms valley through the period, while the western
extent stalls over ok and the tx panhandle.
...upper great lakes to lower mo/mid-ms and lower ohio valleys...
an mcs may be ongoing in the vicinity of eastern ne/southwest ia
thursday morning. ahead of this feature and the aforementioned cold
front, a very moist airmass will remain in place across the midwest
(upper 60s/low 70s dewpoints). strong destabilization will be
possible (2500-4500 j/kg). reintensification or redevelopment of
morning convection is possible as this activity encounters the
instability gradient from eastern ia into northern il and lower mi.
favorable vertical shear profiles will support supercells and bowing
segments capable of significant wind gusts, large hail (with more
discrete convection), and strong tornadoes through the afternoon,
centered on eastern ia, northern il, far southern wi and perhaps as
far east as southern lower mi/northern in.
with time, additional convection will develop along the cold front
from central il into southwest mo. very large hail and damaging wind
gusts will be the main hazard with this activity as it spread
east/southeast across the ozarks and toward the lower ohio valley
through evening.
...southern plains...
convective coverage is a bit more uncertain with southwest extent
into ok/tx. stronger large-scale ascent will be focused further
northeast, but strong instability, rich boundary layer moisture and
steep lapse rates near the sagging cold front and a dryline should
foster at least isolated storm development where capping can be
overcome. supercells in this environment would pose a risk for
severe wind gusts and large hail.
...upper ohio valley to mid-atlantic...
a weak disturbance is forecast to move through an upper ridge across
the region, resulting in modest enhancement to northwesterly flow
aloft. strong heating and rich boundary layer moisture will support
moderate destabilization during the afternoon/early evening.
scattered thunderstorms will pose a risk for strong to isolated
severe wind gusts and sporadic wind damage.
..leitman.. 06/09/2026
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note: the next day 3 outlook is scheduled by 0730z