SPC Jun 5, 2026 1630 UTC Day 1 Convective Outlook

LIVE MAP (ABOVE) ... SPC 1630Z Day 1 Outlook


Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1129 AM CDT Fri Jun 05 2026

Valid 051630Z - 061200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND
EVENING FROM NEBRASKA/KANSAS INTO NORTHERN ILLINOIS...AND FROM
CENTRAL MINNESOTA INTO CENTRAL WISCONSIN...

...SUMMARY...
Thunderstorms with large hail and severe wind gusts are expected to
develop late this afternoon and evening from parts of the central
Plains into the mid Missouri and mid Mississippi Valleys. Strong to
severe wind gusts and hail will also be possible in parts of the
upper Mississippi Valley.

...Central Plains into the Mid MS Valley...
Morning surface analysis places a low over northwest KS, near the
intersection of weak lee troughing and the western edge of a remnant
outflow boundary extending across southern NE. Upper 60s/low 70s
dewpoints are already in place east/southeast of this surface low
and outflow boundary. Southerly/southeasterly flow will persist
throughout the day, maintaining a large fetch of low-level moisture
advection from the southern Plains into the Mid MS Valley. Steeper
mid-level lapse rates are also emerging out of the central High
Plains, spreading gradually eastward over these moist low-levels
throughout the day. As a result, a corridor of strong to very strong
buoyancy is anticipated from south-central NE/north-central KS along
the IA/MO border into far west-central IL by the late afternoon.

Expectation is that the outflow boundary will gradually retreat
northward while the cold front progresses slowly southeastward
across SD and NE. Convective initiation is anticipated along both of
these boundaries, beginning over north-central KS/south-central NE
near the surface low at the outflow boundary/cold front
intersection. Most guidance indicates this initiation will occur
after 00Z, but earlier initiation appears possible given moist
low-levels, robust heating, and mesoscale convergence. Recent RAP
soundings indicate minimal convective initiation by 21Z.

Once initiation occurs, strong buoyancy (i.e. MLCAPE over 2500 J/kg)
will support intense updrafts capable of large to isolated very
large hail. Modest deep-layer shear (i.e. effective bulk shear less
than 30 kt) could limit storm organization, with a trend towards a
more outflow-dominant mode. The generally modest mid-level flow also
suggests upscale growth into an organized convective line is low.
Even so, a combination of convergence along the outflow and/or cold
front, as well as modest warm-air advection, will contribute to
additional storm development eastward into the Mid MS Valley.

...Upper Midwest...
Recent surface analysis shows a cold front extending from
north-central WI southwestward through central SD. A low exists
along this boundary near the ND/SD/WI border intersection. This low
is forecast to track eastward along the front as it gradually shifts
southeastward, moving in tandem with a shortwave trough moving
through the northern Plains into the Upper Midwest. Buoyancy will be
more limited here than areas farther south, but still sufficient for
a few stronger, more organized storms, particularly since the
deep-layer vertical shear will be stronger. Discrete storms with
large hail as the primary risk are possible early in the convective
cycle. Thereafter, a trend towards more bowing segments with
damaging gusts is expected. Multiple rounds of storms are possible,
and the overall coverage is expected to be high enough to merit
introducing 15% hail and wind probabilities.

...Lower MI...
An MCV (associated with an overnight MCS) is moving across northern
IL/far southern WI this morning. Activity associated with this MCV
is currently weak and non-severe, but potential for
re-intensification exists this afternoon as activity moves into
northern IN and southern lower MI. Cloud cover introduces some
uncertainty regarding daytime heating and resultant buoyancy.
However, if sufficient daytime heating can occur, steep lapse rates
and mesoscale organization of the MCS could result in sporadic
damaging winds.

..Mosier/Chalmers.. 06/05/2026


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SPC Jun 5, 2026 1300 UTC Day 1 Convective Outlook

LIVE MAP (ABOVE) ... SPC 1300Z Day 1 Outlook


Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0700 AM CDT Fri Jun 05 2026

Valid 051300Z - 061200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND
EVENING FROM NEBRASKA/KANSAS INTO NORTHERN ILLINOIS...

...SUMMARY...
Thunderstorms with large hail and severe wind gusts are expected to
develop late this afternoon and evening from parts of the central
Plains into the mid Missouri and mid Mississippi Valleys. Isolated
severe wind gusts and hail will also be possible in parts of the
upper Mississippi Valley.

...NE to IA...
A large upper ridge is present today across the southern U.S., with
stronger westerlies over the northern tier of states. One shortwave
trough is noted over SD tracking east-southeastward. This feature
will provide large-scale ascent to parts of the Midwest states
today, leading to scattered clusters of thunderstorms. One area of
expected convective initiation will be late this afternoon along a
retreating surface boundary extending from south-central NE into
southern IA. Ample low-level moisture will reside in the frontal
zone with dewpoints in the low 70s and MLCAPE values over 3000 J/kg.
Activity should develop around 00z along the boundary and track
slowly eastward. Sufficient deep-layer shear suggests a risk of
supercells capable of large hail. Low-level winds are not expected
to be particularly strong, limiting a more robust tornado risk.
Activity will likely congeal and track eastward across southern
IA/northern MO and eventually northern IL through the evening with a
hail/damaging wind risk.

...Northern IL to Lower MI...
A large decaying MCS is moving across northern MO this morning.
While this activity will likely remain non-severe through the
morning, potential for re-intensification exists this afternoon as
activity moves into northern IN and southern lower MI. If
sufficient daytime heating can occur, steep lapse rates and
mesoscale organization of the MCS could result in sporadic damaging
winds.

...MI/WI...
A broad area of 60s dewpoints and broken cloud cover will lead to
moderate CAPE values this afternoon from southern MN into much of
WI. As the aforementioned shortwave trough approaches this
afternoon, cooling aloft and strengthening wind fields will promote
organized structures with any convection that can form. Model
guidance varies considerably on the cover of storms in this area,
but a conditional risk of large hail and damaging winds is present.
Will maintain only MRGL risk for this area for now, but an upgrade
to SLGT could be needed today if later model guidance indicates
greater coverage of afternoon/evening storms.

..Hart/Wendt.. 06/05/2026


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SPC Jun 5, 2026 0600 UTC Day 1 Convective Outlook

LIVE MAP (ABOVE) ... SPC 1200Z Day 1 Outlook


Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0230 AM CDT Fri Jun 05 2026

Valid 051200Z - 061200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE CENTRAL PLAINS...AND MID MISSOURI AND MID MISSISSIPPI VALLEYS...

...SUMMARY...
Thunderstorms with large hail and severe wind gusts are expected to
develop late this afternoon and evening from parts of the central
Plains into the mid Missouri and mid Mississippi Valleys. Isolated
severe wind gusts and hail will also be possible in parts of the
upper Mississippi Valley from this afternoon into the early evening.

...Central Plains/Mid Missouri and Mid Mississippi Valleys...
At mid-levels, a shortwave trough and an associated jet streak will
move eastward today from the northern Plains into the upper
Mississippi Valley. At the surface, a low will deepen across
northeast Kansas, with a trough in place from the low northeastward
into western Iowa. Moisture advection will occur to the east of the
low across the mid Missouri Valley, where surface dewpoints will
increase into the upper 60s and lower 70s F. As surface temperatures
warm today, a pocket of strong instability will develop from
northeast Kansas and southeast Nebraska into southwest Iowa.
Convective initiation will be hampered by a capping inversion in
place throughout much of the afternoon. The cap is forecast to
weaken during the late afternoon or early evening, which will allow
for convective initiation. Thunderstorms are expected to develop
along the northern edge of the stronger instability near the surface
trough. This convection will likely move east-southeastward across
eastern Nebraska and south-central Iowa during the early to mid
evening. Storms will eventually affect parts of northern Missouri
and north-central Illinois.

RAP forecast soundings in the early evening to the south of Omaha
and Des Moines have MLCAPE in the 3000 to 4000 J/kg range with 0-6
km shear around 35 knots, and 500-700 mb lapse rates near 7.5 C/km.
This environment will support supercells with large hail. Hailstones
greater than 2 inches in diameter will be possible with the more
dominant supercells. Cell coverage is expected to steadily increase
during the early to mid evening. This should result in a transition
to linear mode with a line gradually becoming organized. During this
process, the potential for wind damage is expected to increase, and
a few wind gusts could exceed 70 mph along the more intense parts of
the line. The wind-damage threat will likely develop eastward across
parts of the mid Mississippi Valley during the mid to late evening,
as either the line approaches from the west or more storms initiate.

...Upper Mississippi Valley...
A mid-level shortwave trough will move eastward into the upper
Mississippi Valley today, where a moist and unstable airmass will be
in place. Scattered thunderstorms are expected to develop ahead of
the trough during the afternoon across parts of central Minnesota
and central to northern Wisconsin. These storms will move eastward
toward the Great Lakes during the late afternoon and early evening.
MLCAPE in the 1500 to 2500 J/kg range, along with 0-6 km shear of 30
to 35 knots will support an isolated severe threat. A potential for
severe wind gusts and hail will be possible with the stronger short
multicell line segments.

..Broyles/Lyons.. 06/05/2026


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SPC Jun 5, 2026 0100 UTC Day 1 Convective Outlook

LIVE MAP (ABOVE) ... SPC 0100Z Day 1 Outlook


Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0757 PM CDT Thu Jun 04 2026

Valid 050100Z - 051200Z

...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
THE NORTHERN PLAINS...

...SUMMARY...
Severe thunderstorms capable of large to very large hail and
damaging winds are possible this evening across much of South Dakota
into parts of northern Nebraska and south-central Minnesota.
Isolated large hail and severe wind gusts will also be possible in
parts of the central Plains and mid Missouri Valley.

...Northern Plains/Upper Mississippi Valley...
At mid-levels, west-southwesterly flow is evident over much of the
north-central U.S. A shortwave trough is evident on water vapor
imagery over the far western Dakotas. At the surface, a 1002 mb low
is analyzed in eastern Wyoming with a quasi-stationary front
extending northeastward into central South Dakota and north-central
Minnesota. An axis of low-level moisture is located from near the
Black Hills east-northeastward across South Dakota into
south-central Minnesota, where surface dewpoints are in the lower to
mid 60s F. Along and near this axis, the RAP has MLCAPE mostly in
the 1500 to 2500 J/kg range. Scattered strong to severe
thunderstorms are ongoing near the instability axis in the vicinity
of the Black Hills in southwestern South Dakota. The latest 00Z
sounding at Rapid City has 0-6 km shear around 50 knots with 700-500
mb lapse rates near 8 C/km. This will support supercells with large
hail. Hailstones of greater than 2 inches in diameter will be
possible for a few more hours this evening. The wind-damage threat
will likely increase if a cell cluster can become organized and move
into central South Dakota later this evening...see MCD 983. The
southern edge of any cluster could impact parts of northern Nebraska
later this evening.

Further east into eastern South Dakota, a cluster of strong to
severe thunderstorms is ongoing. The 00Z sounding at Aberdeen has
MUCAPE around 1800 J/kg with 0-6 km shear near 40 knots, and a
700-500 mb lapse rate just above 7 C/km. This should support
supercells with large hail early this evening. 0-3 km lapse rates
near 7.5 C/km will also be favorable for severe wind gusts. The
severe threat is expected to increase in southeast and central
Minnesota later this evening, as the storms in eastern South Dakota
move along the instability axis.

...Central Plains/Mid Missouri Valley...
A mid-level shortwave trough is evident on water vapor imagery over
eastern Kansas. At the surface, a moist airmass is in place from
much of central and eastern Kansas northeastward into Iowa, where
surface dewpoints are in the upper 60s to near 70 F. Moderate to
strong instability is analyzed by the RAP from central Kansas into
far western Missouri. Scattered thunderstorms are ongoing along the
northern edge of the stronger instability from northeast Kansas into
southwest Iowa. These storms are being supported by a low-level
speed max of 35 to 45 knots, and could be associated with a threat
for isolated severe wind gusts and hail this evening. As low-level
flow increases from this evening into the overnight period, the
redevelopment of storms may occur over parts of central and eastern
Kansas, where a continued marginal severe threat will be possible.

..Broyles.. 06/05/2026


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