Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1236 AM CDT Mon Jul 06 2026
Valid 061200Z - 071200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE EASTERN DAKOTAS AND WESTERN MINNESOTA...
...SUMMARY...
Widely scattered severe thunderstorms capable of large to very large
hail and severe wind gusts appear possible across the eastern
Dakotas and western Minnesota Monday afternoon and evening. More
isolated occurrences of damaging wind and large hail are possible
from the northern Rockies into northern High Plains and the lower
Mississippi Valley. Isolated to widely scattered damaging wind gusts
will be possible with the strongest storms in the southern
Mid-Atlantic and Carolinas.
...Synopsis...
A vigorous short-wave trough and associated 50-60 kt mid-level jet
streak will progress from southern Saskatchewan into northwest
Ontario with the southern fringe of modest height falls and stronger
mid-level flow situated along the international border. Elsewhere, a
vorticity maximum will move through AR within the base of a
mid-level trough over the lower MS Valley, while a separate
short-wave trough advances through OR into the northern Rockies.
At the surface, a cold front associated with the Canadian
disturbance will move south into the Dakotas and upper MS Valley,
while a backdoor-type cold front pushes south through parts of the
Mid-Atlantic. A lee trough will extend south from the front through
central VA into the Carolinas with some model signal for surface low
development along the trough over central VA.
...Upper Mississippi Valley into north-central Nebraska...
Boundary-layer dewpoints in the mid 60s to low 70s will coincide
with the northeast extension of an EML plume to yield moderate to
strong instability Monday afternoon ahead of the cold front with
MLCAPE of 2500-3500+ J/kg. The modest height falls aloft will
combine with frontal convergence to yield widely scattered
thunderstorms by mid afternoon in the Red River Valley. Subsequent
storm development is possible along the front as far south as
northwest or north-central NE by late afternoon or early evening.
The strongest deep-layer shear of 30-40 kt is forecast across the
Red River Valley with a vector orientation that is largely
perpendicular to the surface front. As such, supercells appear
possible initially with the primary hazard being large hail
potentially in excess of two inches. Effective SRH of generally less
than 100-150 m2/s2 is forecast into late afternoon, during the
period of more discrete storm modes, which may tend to limit a more
robust tornado threat. 00Z CAM guidance is in relatively good
agreement in depicting the upscale growth of storms into a linear
system by evening over eastern SD and western MN with an associated
risk for severe wind gusts.
Weaker vertical shear with southward extent from central SD into
northern NE is expected to limit the potential for organized storm
modes, though isolated occurrences of hail and severe wind gusts
appear possible with the strongest storms.
...Northeast Idaho through southern Montana and northern Wyoming...
The short-wave trough moving into the northern Rockies will be
attended by a belt of 35-40 kt winds at 500 mb, which will enhance
vertical shear across the region. Isolated to widely scattered
thunderstorms are expected to develop by mid to late afternoon from
the Bitterroot to Big Horn Mountains amidst a steep lapse rate and
at least modestly unstable environment. There is some model signal
that an MCS could evolve over northeast WY Monday evening.
Sufficient deep-layer shear will exist to support at least episodic
supercell and bowing structures capable of large hail and damaging
winds. The expected areal coverage of the severe weather threat
currently precludes higher wind and hail probabilities.
...Mid-Atlantic into the Carolinas...
A hot and very moist boundary layer is forecast in the vicinity of
the lee trough and surface low Monday afternoon with MLCAPE as high
as 2000-3000 J/kg. Forcing for ascent will be weak, as will vertical
shear. Nonetheless, convergence along the lee trough and backdoor
front is expected to foster scattered thunderstorms by early to mid
afternoon with the potential for upscale growth into loosely
organized clusters by late afternoon into evening. The presence of
steep low-level lapse rates will enhance downdraft potential with a
risk for damaging wind gusts with the strongest storms.
An upgrade to a level 2/Slight Risk is possible in later outlooks if
a preferred corridor of damaging wind potential becomes apparent in
future model data.
...Lower Mississippi Valley...
Forcing for ascent preceding the vorticity maximum mentioned in the
synopsis is expected to focus scattered afternoon thunderstorms from
AR into the Sabine and lower MS Valleys. Vertical shear will remain
relatively weak; however, the presence of a moist and moderately to
strongly unstable air mass (i.e., MLCAPE up to 2000-3000 J/kg) will
support vigorous up/downdrafts capable of isolated occurrences of
damaging winds and marginally severe hail.
..Mead/Moore.. 07/06/2026
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