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

   CLICK TO GET WUUS01 PTSDY1 PRODUCT

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z