Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1259 AM CDT Thu Aug 07 2025
Valid 071200Z - 081200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR PARTS OF
NORTH DAKOTA...
...SUMMARY...
Scattered severe thunderstorms are expected later today into
tonight. The most likely corridor is centered on North Dakota, where
a few tornadoes, very large hail, and significant severe gusts are
possible.
...Northern Great Plains...
Significant severe storms capable of producing wind gusts of 75+
mph, very large hail, and possibly a few tornadoes are still
expected in an area centered on ND later today into tonight.
A mid/upper-level trough is forecast to amplify over parts of the
Northwest/northern Rockies today as it moves eastward. One or more
low-amplitude vorticity maxima may precede the larger-scale trough
and move across the northern Great Plains during the afternoon and
evening. A surface low is forecast to gradually deepen across the
northern High Plains. Rich low-level moisture beneath steep midlevel
lapse rates will result in strong to extreme buoyancy within the
warm sector of this cyclone, and also near/north of a baroclinic
zone that will extend east/northeast of the low. This instability
combined with moderate deep-layer shear will result in a very
favorable conditional environment for severe storms.
Guidance generally depicts one or more intense storm clusters moving
across ND sometime later today into tonight, but considerable spread
remains regarding timing of the primary threat, and the duration and
coverage of supercells. There is some potential for morning elevated
convection to become increasingly organized with time, with renewed
development during the afternoon possible near the surface low and
baroclinic zone.
Any supercells within this regime would pose a threat of very large
hail, along with some tornado potential, especially near the
baroclinic zone. A tendency toward clustering and MCS development is
expected with time, increasing the threat for one or more swaths of
significant severe wind, along with some potential for line-embedded
tornadoes. The southern and eastern extent of higher-end severe
potential remains uncertain, due to differences regarding storm
timing and the position of the main baroclinic zone.
Farther west, isolated to widely scattered supercells may develop
within a moderately unstable post-frontal regime from central into
eastern MT. Elongated hodographs and steep lapse rates will support
severe hail and wind potential with these cells. Some clustering
remains possible within this regime as well, and depending on the
evolution of downstream convection, storms that initiate in MT may
eventually spread into western/central ND late tonight with a
continued severe threat.
...IL/eastern IA into WI and western upper MI...
Some potential for strong to locally severe storms remains evident
within a broad area from IL/eastern IA into WI and western upper MI,
though uncertainty remains regarding the potential for a more
organized threat somewhere within this broader area.
Guidance varies regarding the evolution of morning convection across
parts of IA/MO, and whether a well-defined MCV will emerge from this
area. However, even a weak MCV or other low-amplitude vorticity
maxima may aid in scattered to widespread storm development late
this afternoon into the evening, within a modest low-level warm
advection regime. Deep-layer flow will be relatively modest, but
rich moisture and moderate to strong buoyancy will support a threat
for at least isolated hail and damaging wind.
..Dean/Weinman.. 08/07/2025
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