RSS Mesoscale Discussions from Storm Prediction Center
WW 421 SEVERE TSTM IA MN WI 300800Z - 301500Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 421
NWS Storm Prediction Center Norman OK
300 AM CDT Tue Jun 30 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Northern Iowa
Southern and Southeast Minnesota
Western and West-Central Wisconsin
* Effective this Tuesday morning from 300 AM until 1000 AM CDT.
* Primary threats include...
Scattered damaging winds and isolated significant gusts to 75
mph possible
Isolated large hail events to 1 inch in diameter possible
SUMMARY...A cluster of severe thunderstorms will move into the Watch
area tonight and likely move east-northeast across the Watch area
through the early to mid morning. The linear cluster will pose a
risk for scattered severe gusts (60 to 75 mph).
The severe thunderstorm watch area is approximately along and 55
statute miles north and south of a line from 20 miles west northwest
of Fairmont MN to 50 miles east of Eau Claire WI. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU1).
PRECAUTIONARY/PREPAREDNESS ACTIONS...
REMEMBER...A Severe Thunderstorm Watch means conditions are
favorable for severe thunderstorms in and close to the watch area.
Persons in these areas should be on the lookout for threatening
weather conditions and listen for later statements and possible
warnings. Severe thunderstorms can and occasionally do produce
tornadoes.
&&
OTHER WATCH INFORMATION...CONTINUE...WW 420...
AVIATION...A few severe thunderstorms with hail surface and aloft to
1 inch. Extreme turbulence and surface wind gusts to 65 knots. A few
cumulonimbi with maximum tops to 550. Mean storm motion vector
24045.
...Smith
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WW 420 SEVERE TSTM IA MN NE SD 300455Z - 300900Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 420
NWS Storm Prediction Center Norman OK
1155 PM CDT Mon Jun 29 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Northwest Iowa
Extreme southwest Minnesota
Northeast Nebraska
Extreme southeast South Dakota
* Effective this Monday night and Tuesday morning from 1155 PM
until 400 AM CDT.
* Primary threats include...
Scattered damaging winds and isolated significant gusts to 80
mph likely
Scattered large hail and isolated very large hail events to 2
inches in diameter possible
SUMMARY...Storms in northeast Nebraska have shown a tendency to
cluster over the past hour with an increase in the potential for
severe outflow gusts of 60-80 mph, and the cluster is expected to
move northeastward toward northwest Iowa and vicinity. The stronger
embedded storms will also be capable of producing large hail of 1-2
inches in diameter.
The severe thunderstorm watch area is approximately along and 50
statute miles east and west of a line from 40 miles southwest of
Norfolk NE to 35 miles north northwest of Spencer IA. For a complete
depiction of the watch see the associated watch outline update
(WOUS64 KWNS WOU0).
PRECAUTIONARY/PREPAREDNESS ACTIONS...
REMEMBER...A Severe Thunderstorm Watch means conditions are
favorable for severe thunderstorms in and close to the watch area.
Persons in these areas should be on the lookout for threatening
weather conditions and listen for later statements and possible
warnings. Severe thunderstorms can and occasionally do produce
tornadoes.
&&
OTHER WATCH INFORMATION...CONTINUE...WW 417...WW 418...WW 419...
AVIATION...A few severe thunderstorms with hail surface and aloft to
2 inches. Extreme turbulence and surface wind gusts to 70 knots. A
few cumulonimbi with maximum tops to 600. Mean storm motion vector
24035.
...Thompson
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WW 0421 Status Updates
STATUS FOR WATCH 0421 HAS NOT BEEN ISSUED YET
Read more
WW 0420 Status Updates
STATUS REPORT ON WW 420
THE SEVERE WEATHER THREAT CONTINUES ACROSS THE ENTIRE WATCH AREA.
FOR ADDITIONAL INFORMATION SEE MESOSCALE DISCUSSION 1392
..DEAN..06/30/26
ATTN...WFO...FSD...OAX...
STATUS REPORT FOR WS 420
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
IAC021-035-041-059-093-119-141-143-149-167-193-300840-
IA
. IOWA COUNTIES INCLUDED ARE
BUENA VISTA CHEROKEE CLAY
DICKINSON IDA LYON
O'BRIEN OSCEOLA PLYMOUTH
SIOUX WOODBURY
MNC063-105-133-300840-
MN
. MINNESOTA COUNTIES INCLUDED ARE
JACKSON NOBLES ROCK
NEC003-011-027-039-043-051-119-139-141-167-173-179-300840-
NE
. NEBRASKA COUNTIES INCLUDED ARE
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WW 0419 Status Updates
STATUS REPORT ON WW 419
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 30 NE AXN TO
45 SSE RRT.
..KERR..06/30/26
ATTN...WFO...DLH...FGF...
STATUS REPORT FOR WT 419
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
MNC001-007-021-035-057-061-115-159-300540-
MN
. MINNESOTA COUNTIES INCLUDED ARE
AITKIN BELTRAMI CASS
CROW WING HUBBARD ITASCA
PINE WADENA
THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE
REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL
INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES
CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES.
Read more
WW 0418 Status Updates
STATUS REPORT ON WW 418
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 20 SSE OLU
TO 25 SE BUB TO 15 SSW YKN.
A NEW SEVERE WEATHER WATCH WILL LIKELY BE ISSUED FOR MUCH OF
REMAINING VALID PORTIONS OF WW BY 05Z.
..KERR..06/30/26
ATTN...WFO...GID...OAX...LBF...
STATUS REPORT FOR WS 418
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
NEC003-011-023-027-037-039-053-077-107-119-125-139-141-167-173-
175-179-183-300500-
NE
. NEBRASKA COUNTIES INCLUDED ARE
ANTELOPE BOONE BUTLER
CEDAR COLFAX CUMING
DODGE GREELEY KNOX
MADISON NANCE PIERCE
PLATTE STANTON THURSTON
VALLEY WAYNE WHEELER
THE WATCH STATUS MESSAGE IS FOR GUIDANCE PURPOSES ONLY. PLEASE
REFER TO WATCH COUNTY NOTIFICATION STATEMENTS FOR OFFICIAL
INFORMATION ON COUNTIES...INDEPENDENT CITIES AND MARINE ZONES
CLEARED FROM SEVERE THUNDERSTORM AND TORNADO WATCHES.
Read more
WW 0417 Status Updates
STATUS REPORT ON WW 417
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 SE YKN TO
20 E FSD TO 25 NNE SPW.
A NEW SEVERE WEATHER WATCH WILL LIKELY BE ISSUED ACROSS MUCH OF
REMAINING VALID PORTION OF WW BY 05Z.
..KERR..06/30/26
ATTN...WFO...FSD...MPX...ABR...
STATUS REPORT FOR WS 417
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
IAC035-059-119-141-143-149-167-193-300500-
IA
. IOWA COUNTIES INCLUDED ARE
CHEROKEE DICKINSON LYON
O'BRIEN OSCEOLA PLYMOUTH
SIOUX WOODBURY
NEC043-051-300500-
NE
. NEBRASKA COUNTIES INCLUDED ARE
DAKOTA DIXON
SDC027-083-127-300500-
SD
. SOUTH DAKOTA COUNTIES INCLUDED ARE
Read more
No Mesoscale Discussions are in effect as of Tue Jun 30 08:16:08 UTC 2026.
SPC 1200Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
1255 AM CDT Tue Jun 30 2026
Valid 301200Z - 011200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS NORTHERN
WISCONSIN AND THE UPPER PENINSULA OF MICHIGAN...PARTS OF NEW YORK
AND VERMONT...AND PORTIONS OF THE CENTRAL/SOUTHERN PLAINS......
...SUMMARY...
Severe thunderstorms will be possible from parts of the central High
Plains into the Upper Midwest, and across parts of the Northeast on
today.
...Synopsis...
An upper-level low will move into Saskatchewan/Manitoba today, with
west southwesterly flow aloft overspreading portions of northern
Minnesota into northern Wisconsin and the Upper Peninsula of
Michigan. A frontal boundary will extend from a surface low across
Manitoba southward across the Upper Midwest into the Central Plains,
with a dryline extending southward into the Southern Plains. Across
the Northeast, enhanced northwesterly flow aloft will impinge upon
the northeastern periphery of a high amplitude ridge across the
eastern US.
...Upper Midwest/Great Lakes...
A southwesterly low-level jet is set to increase across
central/northern Wisconsin by late afternoon. This in combination
with forcing for ascent from the upper-level trough should support
convection developing near the surface boundary across northern
Wisconsin into the Upper Peninsula of Michigan. To the south/east of
the boundary, a very moist air mass with 70s dewpoints is forecast.
Strong to extreme instability is forecast across this region amid
strong deep layer shear profiles, supporting initial supercells
capable of large hail, damaging wind, and perhaps a tornado. With
time, clustering may support potential for an increase in damaging
wind potential.
Guidance also suggests further development may occur by late evening
across portions of Nebraska into northern Iowa as the surface
boundary begins to shift northward with a short-wave impulse
rotating through the upper trough. This will pose some potential for
damaging wind and hail through the late evening/overnight period.
Forecast soundings suggests this activity may remain elevated,
leading to lower confidence in higher probabilities.
...Northeast...
A belt of 45 kt northwesterly flow aloft will overspread portions of
the Northeast this afternoon. Guidance suggests that thunderstorms
will develop across the region by the afternoon. Deep layer shear
around 35-40 kts and moderate instability thunderstorm development
is forecast across the region. This will support transient
supercells before one or more clusters/bowing segments develop and
spread south and eastward with damaging wind potential. A stronger
supercell or two may be capable of a tornado or two.
...Southern/Central High Plains...
A mid-level shortwave will eject across the central Plains this
afternoon, with widely scattered thunderstorm development expected
near the surface trough/dryline in the afternoon/evening. A
southerly low-level jet is progged to increase across the area
through the evening. Moderate to strong instability is progged amid
steep low to mid-level lapse rates. Initial high-based convection
will pose potential for large hail and damaging wind. With
clustering/consolidation along outflows, the damaging wind threat
will increase with potential for instances of significant winds
70-80 mph.
...Southeastern US...
Forecast guidance depicts 25-35 kt mid-level northeasterly flow on
the southern periphery of an upper high centered over the OH/TN
Valley. A very moist air mass will be present across much of the
region and strong destabilization is forecast amid strong daytime
heating. Forecast soundings depict around 20-30 kt effective shear
magnitudes, supporting some risk of organized cells/clusters.
Isolated damaging wind gusts are possible as activity develops
west/southwest through early evening.
..Thornton/Chalmers.. 06/30/2026
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SPC 0600Z Day 2 Outlook
Day 2 Convective Outlook
NWS Storm Prediction Center Norman OK
0107 AM CDT Tue Jun 30 2026
Valid 011200Z - 021200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE
MID-MISSOURI VALLEY INTO CENTRAL WISCONSIN...
...SUMMARY...
Isolated to scattered strong to severe storms will again be possible
from the central Plains into the Upper Midwest as well the Northeast
on Wednesday. Severe wind gusts and large hail are the main
concerns.
...Mid-Missouri Valley into central Wisconsin...
Models are in general agreement that a cluster/MCS will be ongoing
in the eastern South Dakota/southern Minnesota vicinity early
Wednesday morning. There is at least some potential for damaging
surface gusts with this activity. Further intensification could also
occur as the airmass destabilizes in parts of Wisconsin into the
afternoon. However the early day activity evolves, an outflow
boundary from this activity will serve as a focus for additional
afternoon thunderstorms. 70+ F dewpoints to the south of the
boundary will again promote strong to locally extreme buoyancy.
Moderate to strong mid-level winds on the southern flank of the
upper trough in Canada will allow for 40-55 kt of effective shear
near the surface boundary. Initial supercells will be capable of
large to isolated very large (around 2-2.5 in.) hail and perhaps a
tornado or two. Given the instability, strong downdrafts will likely
lead to upscale growth relatively quickly. The risk for
severe/damaging winds will become the primary hazard with time,
particularly if an MCS can develop. A Slight Risk has been added to
cover both potential scenarios.
...Northeast...
The forecast continues to be uncertain given the nebulous forcing
for ascent. Nonetheless, substantial buoyancy will be in place
across the region (3000-5000 J/kg MLCAPE). Effective shear of 35-40
kt will promote some storm organization. Model guidance shows
variable solutions from more isolated cellular activity to a cluster
moving southeastward out of Canada. Given the low confidence in
placing more organized activity, a Marginal Risk will be maintained
for now. Damaging winds and isolated large hail will be possible.
...Central High Plains...
Thunderstorm development is expected within the lee trough during
the afternoon. A deeply-mixed boundary layer will promote potential
for severe winds especially if any clustering can occur. Shear will
be modest and severe coverage is expected to be isolated.
...Southeast...
Strong buoyancy will be in place during the afternoon given rich
moisture (70+ F dewpoints). Shear will be quite weak with some minor
enhancement in the lower Mississippi Valley. Models do show some
potential for clustering, but the location is quite variable. Lack
of even subtle features to focus convection keeps confidence in a
more organized damaging wind threat low.
..Wendt.. 06/30/2026
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SPC 0730Z Day 3 Outlook
Day 3 Convective Outlook
NWS Storm Prediction Center Norman OK
0234 AM CDT Tue Jun 30 2026
Valid 021200Z - 031200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE BLACK
HILLS VICINITY INTO PARTS OF THE MIDWEST...
...SUMMARY...
Strong to severe storms will be possible from the northern Plains
into the Midwest and Great Lakes regions on Thursday. Isolated
strong to severe storms may also occur in the Tennessee
Valley/Southeast as well as parts of the Northeast.
...Synopsis...
Upper ridging will continue in the East with broad cyclonic flow in
the West. Embedded shortwave troughs will likely impact the northern
Plains. Another shortwave trough embedded within northwesterly flow
aloft will move into parts of the Northeast. A stalled surface
boundary will be present from the northern High Plains into the
Upper Midwest with a lee trough/weak surface low developing in the
High Plains.
...Black Hills into Iowa/Minnesota...
A subtle shortwave trough is evident in model guidance. This feature
will move into Wyoming/Montana and eventually the western Dakotas.
Convection appears likely to develop within the higher terrain (Big
Horns/Black Hills) and move into an airmass with increasingly rich
low-level moisture to the east. Convection should be able to
organize along the surface boundary with around 40 kt of effective
shear parallel to the boundary itself. Additional convection is also
possible along the stationary front as low-level warm advection
increases. Though there is some variability in where any eventual
MCS will propagate, there is enough confidence to include a 15%
severe probability area that encompasses the envelope of potential
tracks. The environment would support significant hail with
supercells and significant winds with an organized MCS.
...Northeast...
Ahead of a cold front attendant from a surface low in Quebec,
convection will be possible during the afternoon. The timing of the
convection, and thus the available buoyancy, is not entirely
certain. Damaging wind gusts and large hail would be possible.
...Tennessee Valley into Southeast...
A subtle easterly wave rotating around the upper anticyclone will
promote afternoon convection within a very moist and unstable
airmass. Given the mid-level lapse rates will fairly steep, storms
will likely be capable of damaging downburst winds despite weak
shear.
..Wendt.. 06/30/2026
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SPC Day 1 Fire Weather Outlook
Day 1 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1247 AM CDT Tue Jun 30 2026
Valid 301200Z - 011200Z
...CRITICAL FIRE WEATHER AREA FOR NORTHEAST ARIZONA...EASTERN
UTAH...WESTERN COLORADO...AND FAR NORTHWEST NEW MEXICO...
...Synopsis...
Broad upper-level troughing will remain over the West with a
shortwave moving from the southern Great Basin into the central
Rockies. Southwest mid-level flow of 30-50 knots will overspread the
greater Four Corners region as downslope flow and lee troughing are
expected again on the central/southern High Plains.
...Greater Four Corners Region...
Stronger southwest flow aloft will mix to the surface across the
greater Four Corners region, resulting in southwest sustained winds
of 15-25 mph amid minimum RH of 5-15%. Northeast Arizona through
eastern Utah, western Colorado, and into far northwest New Mexico
will have critical fire weather conditions for several hours, likely
beginning by late morning and continuing into the evening. Locally
extremely critical conditions are possible (5-20% probabilities) in
eastern Utah and western Colorado during the afternoon, while
locally critical fire weather conditions are likely along/east of
the Sangre de Cristo Mountains into the Front Range. Elevated
conditions are expected in portions of eastern Colorado and
northeast New Mexico amid southerly winds of 15-20 mph and minimum
RH of 15-20%, but the duration and magnitude are likely to be
limited by thunderstorms in the afternoon and evening.
Isolated mixed wet/dry thunderstorms are likely across portions of
north-central New Mexico into south-central Colorado. Wetter storms
and greater storm coverage are likely to the south and east of the
IsoDryT area. Deep pyroconvection is possible on active large fires
in the vicinity of the overlap of elevated/locally critical fire
weather conditions and the IsoDryT area.
..Nauslar.. 06/30/2026
...Please see www.spc.noaa.gov/fire for graphic product...
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SPC Day 2 Fire Weather Outlook
Day 2 Fire Weather Outlook
NWS Storm Prediction Center Norman OK
1259 AM CDT Tue Jun 30 2026
Valid 011200Z - 021200Z
...CRITICAL FIRE WEATHER AREA FOR NORTHEAST ARIZONA...SOUTHEAST
UTAH...WESTERN COLORADO...AND NORTHWEST NEW MEXICO...
...Synopsis...
Broad upper-level troughing will continue over the West with
multiple shortwave troughs rotating through the flow. While flow
weakens aloft, deep well-mixed boundary layers will develop as
stronger winds aloft will mix to the surface again bringing another
day of dry and windy conditions to the greater Four Corners region.
...Greater Four Corners Region...
Critical fire weather conditions are expected again across northeast
Arizona, southeast Utah, western Colorado, and northwest New Mexico.
South-southwest sustained winds of 15-20 mph amid minimum RH of
3-10% will develop by the afternoon and continue into the evening.
Some forecast guidance suggests that the Critical area may have more
locally critical conditions. However, swaths of HREF 50%+
probabilities of critical winds/RH along with nearly a week of
dry/windy conditions for this region, and the active large wildfires
across the region justify a Critical area. Additionally, the drier
and windier forecast guidance has been more accurate and reliable
for this region recently. Locally elevated fire weather conditions
are expected from the eastern slopes of the southern Sierra across
the southern Great Basin. South-southwest winds of 10-20 mph amid
minimum RH of 8-20% are likely across this area.
..Nauslar.. 06/30/2026
...Please see www.spc.noaa.gov/fire for graphic product...
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