WW 411 SEVERE TSTM IA MN 280950Z - 281400Z
URGENT - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Watch Number 411
NWS Storm Prediction Center Norman OK
450 AM CDT Sun Jun 28 2026
The NWS Storm Prediction Center has issued a
* Severe Thunderstorm Watch for portions of
Northwest into Northern Iowa
Southwest into Southern Minnesota
* Effective this Sunday morning from 450 AM until 900 AM CDT.
* Primary threats include...
Scattered damaging wind gusts to 70 mph possible
Isolated large hail events to 1 inch in diameter possible
SUMMARY...A squall line will move into the Watch area early this
morning and likely move east across the Watch. Scattered damaging
gusts (60 to 70 mph) are possible with the more intense portions of
the squall line.
The severe thunderstorm watch area is approximately along and 60
statute miles north and south of a line from 45 miles west southwest
of Worthington MN to 10 miles east southeast of Mason City IA. 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 410...
AVIATION...A few severe thunderstorms with hail surface and aloft to
1 inch. Extreme turbulence and surface wind gusts to 60 knots. A few
cumulonimbi with maximum tops to 500. Mean storm motion vector
27035.
...Smith
WW 0411 Status Updates
STATUS REPORT ON WW 411
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 25 E SUX TO
40 WNW SLB TO 20 W SPW TO 20 NNW SPW TO 25 E OTG TO 30 NE OTG TO
30 WSW RWF.
..JEWELL..06/28/26
ATTN...WFO...FSD...DMX...MPX...
STATUS REPORT FOR WS 411
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
IAC021-025-033-035-041-059-063-069-079-081-083-091-109-141-143-
147-151-187-189-195-197-281240-
IA
. IOWA COUNTIES INCLUDED ARE
BUENA VISTA CALHOUN CERRO GORDO
CHEROKEE CLAY DICKINSON
EMMET FRANKLIN HAMILTON
HANCOCK HARDIN HUMBOLDT
KOSSUTH O'BRIEN OSCEOLA
PALO ALTO POCAHONTAS WEBSTER
WINNEBAGO WORTH WRIGHT
MNC013-033-043-047-063-091-161-165-281240-
MN
. MINNESOTA COUNTIES INCLUDED ARE
BLUE EARTH COTTONWOOD FARIBAULT
FREEBORN JACKSON MARTIN
WASECA WATONWAN
WW 0410 Status Updates
STATUS REPORT ON WW 410
SEVERE WEATHER THREAT CONTINUES RIGHT OF A LINE FROM 35 ENE ONL
TO 40 WNW YKN TO 25 SSE MHE TO 10 E MHE TO 20 N MHE TO 10 E HON.
..JEWELL..06/28/26
ATTN...WFO...LBF...FSD...ABR...
STATUS REPORT FOR WS 410
SEVERE WEATHER THREAT CONTINUES FOR THE FOLLOWING AREAS
SDC009-027-061-067-079-083-087-097-099-101-111-125-127-135-
280940-
SD
. SOUTH DAKOTA COUNTIES INCLUDED ARE
BON HOMME CLAY HANSON
HUTCHINSON LAKE LINCOLN
MCCOOK MINER MINNEHAHA
MOODY SANBORN TURNER
UNION YANKTON
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.
MD 1365 CONCERNING SEVERE THUNDERSTORM WATCH 411... FOR FAR SOUTHERN MINNESOTA INTO NORTHERN AND EAST-CENTRAL IOWA
Mesoscale Discussion 1365
NWS Storm Prediction Center Norman OK
0734 AM CDT Sun Jun 28 2026
Areas affected...far southern Minnesota into northern and
east-central Iowa
Concerning...Severe Thunderstorm Watch 411...
Valid 281234Z - 281430Z
The severe weather threat for Severe Thunderstorm Watch 411
continues.
SUMMARY...A line of storms will continue to produce strong to severe
wind gusts over north-central Iowa, a portion of far south-central
Minnesota, and perhaps into more of central/east-central Iowa later
this morning.
DISCUSSION...A long-lived MCS continues to move east across southern
MN and northern IA, with the larger/stronger storms currently over
north-central IA. This area is within the instability gradient, with
access to a more favorable inflow air mass. While surface
temperatures are currently cooler into eastern IA, the favorable
southwesterly low-level jet should maintain theta-e advection this
morning, fueling the MCS.
A severe gust of 68 mph was measured earlier at Spencer, IA with the
stronger southern part of the bow, and recent radar trends also
indicate sporadic hail over 1.00" diameter is likely.
Additional storm cores within the warm advection zone just
south/east of the main bow have also increased recently, and brief
hail may occur with that activity. Otherwise, the threat of severe
wind gusts of 60 to 70 mph may gradually shift east/southeast over
IA, as the southern flank favors the more unstable air mass along
and west of the instability gradient. Storm gusts will also remain
possible over far southern MN this morning, despite weaker
instability as the system is quite organized.
..Jewell.. 06/28/2026
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...DVN...ARX...MPX...DMX...FSD...
LAT...LON 44629430 44479362 43919273 43049210 42149175 41869199
41699247 41819336 42269390 42519446 42639495 42869507
43289445 43789414 44069412 44629430
MOST PROBABLE PEAK WIND GUST...55-70 MPH
MOST PROBABLE PEAK HAIL SIZE...1.00-1.75 IN
SPC 1300Z Day 1 Outlook
Day 1 Convective Outlook
NWS Storm Prediction Center Norman OK
0744 AM CDT Sun Jun 28 2026
Valid 281300Z - 291200Z
...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FOR THE DAKOTAS
AND PORTIONS OF MINNESOTA AND IOWA AND PARTS OF THE CAROLINAS...
...SUMMARY...
Severe thunderstorms are possible this morning over northern Iowa
and southern Minnesota, and mainly tonight across the Dakotas. Large
to very large hail and severe winds are the primary hazards.
Thunderstorms capable of scattered wind damage are possible in parts
of the Carolinas.
...Dakotas to IA/WI through tonight...
Radar mosaic this morning shows a bow echo moving eastward along the
MN/IA border primarily north of a buoyancy gradient/warm frontal
zone. Occasional severe gusts (60-70 mph) have been observed with
this MCS the past couple of hours. Expecting more of an
east-southeastward motion with the linear system with a continued
risk for wind damage before perhaps weakening near the MS River
towards midday/early afternoon.
Farther west, a belt of south-southwesterly midlevel flow near 50 kt
will be maintained from CO to the Dakotas, east of the broad closed
low over the northern Great Basin/Rockies. A separate lee cyclone
is expected to form in the vicinity of northeast CO this afternoon
and then progress northeastward across NE/SD overnight. In the wake
of the morning storms, richer low-level moisture will advect
northward in tandem with a warm front. Model guidance continues to
delay storm development for much of the day as an EML overspreads a
destabilizing airmass across the north-central US. A few storms
will be possible in ND during the afternoon with perhaps an isolated
severe risk developing.
Much of the severe threat will likely focus after dark immediately
north of the lee cyclone into SD. Westward advection of richer
moisture and ascent preceding the surface cyclone (and subtle
embedded speed maxima aloft) will likely support elevated
thunderstorm development overnight across western SD into southern
ND. The environment will favor elevated supercells and small
thunderstorm clusters capable of large to very large hail and severe
gusts.
Farther east, a zone of low-level warm advection will be focused
across WI by late evening/early tonight along the northeast edge of
the warm elevated mixed layer. Sufficient moistening above the
surface and large CAPE will favor the potential for at least
isolated large hail/strong gusts with largely elevated storms
tonight.
...Carolinas/southern VA this afternoon/evening...
A convectively augmented mid-level disturbance over the southern
Appalachians will move into the Piedmont by this afternoon. A moist
airmass sampled by area 12 UTC raobs (PW near 2 inches) will
heat/destabilize to the south of a patch of clouds more prevalent
over western NC. By early to mid afternoon, steepened 0-2 km lapse
rates and a belt of slightly stronger westerly 3-6 km flow (30 kt)
may act to loosely organize cold pools of developing thunderstorm
clusters. Isolated to scattered wind damage (50-60 mph gusts) will
be the primary hazard with the more intense water-loaded
thunderstorm cores.
...West TX late this afternoon/evening...
Strong surface heating and deep mixing along a sharpening dryline
will allow high-based thunderstorm development from late afternoon
through late evening. Flow aloft will be weak, but inverted-V
profiles will favor isolated severe outflow gusts of 60-75 mph.
..Smith/Jewell.. 06/28/2026
Day 4-8 Outlook
Day 4-8 Convective Outlook
NWS Storm Prediction Center Norman OK
0346 AM CDT Sun Jun 28 2026
Valid 011200Z - 061200Z
...DISCUSSION...
Relatively little change is expected in the upper-level pattern from
mid to late this week. A broad trough in the West will bring
southwesterly flow across the Rockies and parts of the Plains. In
the East, an upper ridge will persist. During the weekend, models
are in general agreement that the upper ridge will flatten and
broaden across the southern U.S. This pattern will favor the
maintenance of a very moist airmass within parts of the Plains into
the Midwest and Southeast. The lack of more notable mid-level and
surface features decrease predictability with regard to where severe
convection may occur. That being said, subtle surface
boundaries/shortwave troughs may promote convective development each
day within parts of the Plains/Midwest. Trends in model guidance
will continue to be monitored, but confidence remains low in placing
severe probabilities.
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