RSS Mesoscale Discussions from Storm Prediction Center
SPC 1630Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1124 AM CDT Thu Jul 02 2026
Valid 021630Z - 031200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON
AND EVENING ACROSS PARTS OF EASTERN SOUTH DAKOTA...SOUTHWEST
MINNESOTA...AND NORTHWEST IOWA....
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE DAKOTAS
INTO THE WESTERN GREAT LAKES...OVER THE SOUTHERN APPALACHIANS AND
TENNESSEE VALLEY...AND OVER WESTERN KANSAS...
...SUMMARY...
Scattered severe storms will be possible from the northern Plains
into the Midwest and Great Lakes regions today into tonight, as well
as across the southern Appalachians and Tennessee Valley this
afternoon and early evening.
...SD to WI...
Morning water vapor imagery shows several weak and/or convectively
induced shortwave troughs moving across the northern Plains into the
Upper Midwest. This area will have widespread marginal to moderate
afternoon CAPE and dewpoints in the 60s to lower 70s. This leads to
a forecast of a large area of potential thunderstorm development,
but with weak/nebulous forcing and general height-rises aloft. As
such, the overall confidence in this forecast is not very high.
Storms are likely to focus along a boundary currently evident from
southern SD into central IA. Convection currently developing in
northern IA near the boundary should continue to intensify through
the afternoon and track into southern WI/northern IL with a severe
wind/hail threat.
Other intense thunderstorm clusters are expected to develop along
the SD/NE portion of the boundary by mid/late afternoon, also with a
risk of large hail and damaging wind gusts.
...Western KS...
Full sunshine and dewpoints in the 60s will lead to a region of
strong instability over western KS this afternoon. Most CAM
solutions suggest at least isolated thunderstorms form along the
KS/CO border and spread slowly eastward during the evening. A
deeply mixed boundary layer and sufficient CAPE suggest a risk of
damaging wind gusts in the strongest cells.
...TN Valley/Southern Appalachians...
A widespread very moist and unstable air mass is present today
across this region, with full sunshine leading to steep low-level
lapse rates and MLCAPE values over 4000 J/kg. Weak forcing under an
upper ridge limits confidence in timing/location of storms.
However, widely scattered thunderstorm development should eventually
result in merging outflows and the risk of gusty/damaging winds this
afternoon and early evening across the region.
..Hart/Halbert.. 07/02/2026
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SPC 2000Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0300 PM CDT Thu Jul 02 2026
Valid 022000Z - 031200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FOR PARTS OF
EASTERN SOUTH DAKOTA INTO FAR SOUTHWEST MINNESOTA AND EXTREME
NORTHWEST IOWA...
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR PORTIONS OF
THE NORTHERN HIGH PLAINS TO THE GREAT LAKES...WESTERN KANSAS...AND
PARTS OF THE TENNESSEE VALLEY...
...SUMMARY...
Scattered severe storms are still possible from the northern Plains
into the Midwest and Great Lakes regions today into tonight, as well
as across the southern Appalachians and Tennessee Valley this
afternoon and early evening.
...20Z Update...
Much of the previous forecast remains generally on track, especially
for portions of the central High Plains, the TN Valley, and northern
New England.
However, appreciable uncertainty still exists regarding the
potential for focused corridors of severe across much of the
northern Plains into the Great Lakes. Relatively robust supercell
evolution has occurred along mesoscale surface baroclinic
boundaries, amid generally weak upper-level support, to support
instances of 2-3 inch diameter hail over central/eastern SD, as well
as instances of brief and modest rotation with storms over
northeastern IA. Please see MCDs 1440-1441 for short-term details of
convective evolution. However, these storms are moving roughly
normal to boundary orientation, putting the duration of higher-end
severe into question. At least for portions of the Upper Midwest
though, there is a modest signal of an MCS traversing a baroclinic
boundary along the WI/IL border for multiple hours. A locally
greater concentration of damaging gusts could accompany this
activity through the afternoon, though confidence in this scenario
is not overly high either. Many of the ongoing storms (especially
over SD) are occurring over portions of the open warm sector
relatively early in the diurnal heating cycle, casting uncertainty
regarding the impacts the ongoing storms will have on later
afternoon initiation and evolution along other mesoscale boundaries.
As such, prudence was exercised in favor of making only minor
changes to the outlook to reflect the latest guidance consensus.
..Squitieri.. 07/02/2026
.PREV DISCUSSION... /ISSUED 1124 AM CDT Thu Jul 02 2026/
...SD to WI...
Morning water vapor imagery shows several weak and/or convectively
induced shortwave troughs moving across the northern Plains into the
Upper Midwest. This area will have widespread marginal to moderate
afternoon CAPE and dewpoints in the 60s to lower 70s. This leads to
a forecast of a large area of potential thunderstorm development,
but with weak/nebulous forcing and general height-rises aloft. As
such, the overall confidence in this forecast is not very high.
Storms are likely to focus along a boundary currently evident from
southern SD into central IA. Convection currently developing in
northern IA near the boundary should continue to intensify through
the afternoon and track into southern WI/northern IL with a severe
wind/hail threat.
Other intense thunderstorm clusters are expected to develop along
the SD/NE portion of the boundary by mid/late afternoon, also with a
risk of large hail and damaging wind gusts.
...Western KS...
Full sunshine and dewpoints in the 60s will lead to a region of
strong instability over western KS this afternoon. Most CAM
solutions suggest at least isolated thunderstorms form along the
KS/CO border and spread slowly eastward during the evening. A
deeply mixed boundary layer and sufficient CAPE suggest a risk of
damaging wind gusts in the strongest cells.
...TN Valley/Southern Appalachians...
A widespread very moist and unstable air mass is present today
across this region, with full sunshine leading to steep low-level
lapse rates and MLCAPE values over 4000 J/kg. Weak forcing under an
upper ridge limits confidence in timing/location of storms.
However, widely scattered thunderstorm development should eventually
result in merging outflows and the risk of gusty/damaging winds this
afternoon and early evening across the region.
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SPC 1730Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
1217 PM CDT Thu Jul 02 2026
Valid 031200Z - 041200Z
...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM CENTRAL
NEBRASKA INTO WESTERN IOWA...
...SUMMARY...
Scattered wind damage and large hail are expected from parts of
Nebraska into Iowa Friday. Isolated to scattered severe storms are
also possible extending eastward from the northern/central Plains
into the Midwest, Tennessee Valley, and Mid-Atlantic.
...Synopsis...
An upper high will remain over the Appalachians and Carolinas, with
a somewhat weaker ridge aloft extending westward into the southern
Rockies. Relatively cool midlevel temperatures will generally
stretch from the northern Plains and across much of the Great Lakes
an Northeast, as modest mid and high level westerlies persist. In
the low levels, substantial moisture and instability will persist
across those same areas, as south to southwest surface winds
maintain 70s F dewpoints around the northern periphery of a
southeast U.S. surface high. An east-west oriented boundary will
stretch from the northern Plains eastward across the Great Lakes
region, with various clusters of thunderstorms throughout the period
within this unstable zone.
...Northern/Central Plains...
Any outflows from overnight convection are likely to mix, with
strong instability developing. Cells will form over the northern
High Plains initially with localized hail and wind. Larger coverage
of storms will occur from southern SD into northern NE during the
mid/late afternoon, with general upscale growth into one or more
MCSs. However, supercells may occur initially with large hail and a
brief tornado. Supporting a severe MCS will be ample precipitable
water, strong instability, and an increasing southerly low-level jet
during the evening. Additional isolated hail or wind may occur near
the surface trough into western KS and toward the TX Panhandle where
temperatures will be hot.
...Much of the Midwest to the Lower Great Lakes and across NY, PA
and NJ...
The entire corridor stretching from northern IL/southern WI into NY
and NJ will destabilize with daytime heating and robust moisture.
Storms are most likely from WI/IL during the late afternoon, and
also near the Lower Great Lakes, affecting OH, PA, NY. Modest
westerlies aloft and the uncapped air mass across the area will
support a few longer-lived clusters of storms capable of damaging
wind gusts. Some of the activity may proceed into western New
England into early evening.
...TN Valley and northern GA...
Within the weak easterly flow regime aloft, just south of the upper
ridge, storms are expected to form during the afternoon with the
very moist and unstable air mass. Mid 70s F dewpoints will again
lead to strong instability, with multicell clusters moving
west/northwest by mid/early afternoon. Locally damaging wind gusts
are possible.
..Jewell.. 07/02/2026
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SPC 1930Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0220 PM CDT Thu Jul 02 2026
Valid 041200Z - 051200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN
COLORADO INTO WESTERN KANSAS...AND FROM EASTERN OHIO/WEST VIRGINIA
EASTWARD ACROSS THE I-95 CORRIDOR...
...SUMMARY...
Scattered storms will be possible from the central Plains into the
Midwest and Mid-Atlantic this Fourth of July (Saturday). The
greatest concentration of strong to severe storms will be within
portions of the Mid-Atlantic, and over parts of the central Plains
late.
...Parts of the Mid Atlantic...
Stronger mid to high level winds exist over the Northeast, though 30
kt at 500 mb will extend as far south as Maryland. A surface trough
will deepen during the day near the I-90 corridor, where 70s F
dewpoints will contribute to moderate instability. Storms may
develop both within the instability plume from OH into PA, and
within the heated surface trough from VA into PA/NJ. Strong wind
gusts will be common, with some severe/damaging gusts likely late
afternoon through early evening during peak heating.
...Central High Plains...
Scattered strong to severe storms may develop near the Front Range
as surface winds back to easterly late in the day. This will bring
moisture westward toward the higher terrain, with most models
showing a few cells developing late afternoon with localized hail
and wind potential. Good direction shear and steep lapse rates aloft
will favor large hail. Storms may then persist into western NE and
KS, with potential areas of severe wind gusts.
..Jewell.. 07/02/2026
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