551
ACUS01 KWNS 070548
SWODY1
SPC AC 070546

Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1246 AM CDT Sun Jun 07 2026

Valid 071200Z - 081200Z

...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE NORTHERN PLAINS...

...SUMMARY...
Severe thunderstorms with large hail, damaging wind gusts and an
isolated tornado threat are expected today across parts of the
northern Plains. An isolated threat for tornadoes and severe wind
gusts will be possible from parts of eastern Oklahoma and
southeastern Kansas eastward across the Ozarks. Strong wind gusts
will also be possible in the mid Mississippi Valley and in the
Mid-Atlantic.

...Northern Plains...
An upper-level trough will move eastward across the northern Rockies
today. Ahead of the trough, mid-level heights will gradually fall
across the northern Plains. At the surface, a trough of low pressure
will deepen in the western Dakotas as a cold front advances eastward
across the northern High Plains. Surface dewpoints near the surface
trough will be in the lower to mid 60s F which will enable moderate
instability to develop around midday. During the afternoon,
thunderstorms are expected to form along the front and further east
near the surface trough as low-level convergence increases. Although
cells will initially be discrete, convection is expected to grow
upscale into a line during the evening.

At 21Z, RAP forecast soundings near the surface trough in western
North Dakota have 0-6 km shear in the 40 to 50 knot range with
700-500 mb lapse rates near 8.5 C/km. This environment will be
favorable for supercells with large hail. The more dominant
supercells may be capable of producing hailstones greater than 2
inches in diameter. Low-level shear may be strong enough for an
isolated tornado threat as well. Supercells will be favored in the
late afternoon when cells will likely be discrete. In the early
evening, a quick transition to linear mode is expected, although
rotating elements will continue to be possible in the line itself.
As the line develops, severe wind gusts will become more likely.
Intense parts of the line could be capable of producing wind gusts
above 75 mph.

...Eastern Oklahoma/Southeast Kansas/Ozarks/Mid Mississippi
Valley...
An upper-level trough will move northeastward across the central
U.S. today, over the top of a moist and unstable airmass. Surface
dewpoints from eastern parts of the southern and central Plains into
the mid Mississippi Valley will be in the upper 60s and lower 70s F.
This will contribute to the development of moderate instability by
afternoon. Random areas of maximized low-level convergence are
expected this afternoon which will lead to the formation of
scattered thunderstorms. Deep-layer shear of 25 to 30 knots should
be sufficient for isolated supercells. Storm-relative helicity could
reach 200 m2/s2 in a few areas, which would support an isolated
tornado threat. Strong wind gusts will also be possible with this
threat extending eastward into the mid Mississippi Valley. The
wind-damage threat will be greatest in the mid to late afternoon as
low-level lapse rates become steep.

...Mid-Atlantic...
An upper-level trough and an associated cold front will move across
the Mid-Atlantic today. Ahead of the front, surface dewpoints in the
mid 60s F will contribute to moderate instability by afternoon.
Thunderstorms will develop near and to the south of the front during
the mid to late afternoon. RAP forecast soundings ahead of the front
suggest that 0-3 km lapse rates will peak near 8 C/km, which should
support a potential for isolated severe wind gusts.

..Broyles/Supinie.. 06/07/2026

$$