RSS Mesoscale Discussions from Storm Prediction Center
SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0231 AM CDT Mon Jul 06 2026
Valid 081200Z - 091200Z
...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS WEDNESDAY INTO
WEDNESDAY NIGHT ACROSS PARTS OF THE CENTRAL GREAT PLAINS INTO UPPER
MIDWEST...
...SUMMARY...
Clusters of strong thunderstorms with potential to produce severe
hail and wind may evolve across parts of the Upper Midwest into
central Great Plains Wednesday through Wednesday night.
...Discussion...
It appears that notable remnant mid-level troughing will begin to
dig southeast of the Hudson Bay vicinity Wednesday through Wednesday
night, while an upstream short wave trough pivots northeast then
north of the Canadian Rockies toward the Northwest Territories.
Within the westerlies to the south of this regime, subtle mid-level
ridging may overspread the northern Rockies, with similar amplitude
downstream troughing digging across the northern Great Plains, Upper
Midwest and Great Lakes region.
Beneath this regime, a weak cold front, perhaps reinforced by
convective outflow in some locations, is forecast to overspread much
of the remainder of the Upper Midwest/adjacent Great Lakes and
middle Missouri Valley vicinity by late Wednesday night. This may
be preceded across parts of the central Great Plains by conglomerate
convective outflow emanating from considerable thunderstorm
development spreading off the Laramie Range/Front Range vicinity,
within steering flow trending northwesterly through the period.
...Great Plains/Upper Midwest...
Steeper mid-level lapse rates associated with a remnant plume of
elevated mixed-layer air may become increasingly confined to the
higher plains during this period. However, seasonably high moisture
content along/ahead of the southward advancing cold front may still
become supportive of mixed-layer CAPE of 1500-2000+ J/kg with
daytime heating.
It remains uncertain whether an evolving cluster of storms, and/or a
possible significant MCV emerging from it, will support continuing
or renewed organized thunderstorm development posing a risk for
severe wind gusts into and through the Upper Midwest during the day
Wednesday. However, it is possible that destabilization in its wake
could become sufficient to support strong thunderstorm development
posing a risk for severe hail and wind, ahead of the southward
advancing cold front later Wednesday into Wednesday night.
Otherwise, guidance suggests considerable thunderstorm activity,
initiating off the higher terrain of southeastern Wyoming through
central Colorado by late Wednesday, may gradually intensify and
consolidate within a more unstable environment near a broad/weak
surface cyclone developing across the high plains. Aided by a
nocturnally strengthening low-level jet, there appears at least
potential for this activity to organize with potential to swaths of
strong to severe surface gusts Wednesday evening, after initially
posing a risk for severe hail and localized downbursts.
..Kerr.. 07/06/2026
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Day 4-8 Outlook
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0400 AM CDT Mon Jul 06 2026
Valid 091200Z - 141200Z
...DISCUSSION...
Medium-range model output continues to indicate the evolution of an
increasingly prominent mid/upper high across the lower Colorado
Valley and Plateau late this week into next weekend, which may
continue expanding and encompassing a significant portion of the
interior U.S. by early next week. How far north and northeast this
builds remains unclear; however, a plume of very warm elevated
mixed layer air advecting on strengthening flow around the northern
through northeastern periphery of this anticyclonic regime will
contribute to an environment conditionally conducive to organized
severe thunderstorm development.
It appears that this could focus anywhere from the central
Canadian/U.S. border vicinity through the Great Lakes into the
Northeast. By early next week (the Day 8-9 time frame), in
particular, at least some output suggests that a vigorous short wave
trough rounding the ridge may be accompanied by strong cyclogenesis,
which could promote widespread strong to severe thunderstorm
development across parts of New England into northern Mid Atlantic.
Given the uncertainties associated with the extended time frame and
model spread/discrepancies, severe weather probabilities remain less
than 15 percent for this period, but it is possible that this could
change sometime in later outlook updates for this period.
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