Alert archive / Minnesota / Severe Thunderstorm Warnings in 2026

Severe Thunderstorm Warning 52, NWS Twin Cities, MN

May 17, 2026Martin County, Watonwan County, Minnesota

NWS Twin Cities, MN issued this severe thunderstorm warning at May 17, 2026, 7:32 PM CDT for Martin County, Watonwan County, Minnesota. It was in force for 58 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
May 17, 2026, 7:32 PM CDT (00:32 UTC)
Expired
May 17, 2026, 8:30 PM CDT
In force
58 min
Issued by
NWS Twin Cities, MN
Area
Storm-based polygon
Tornado
Possible
Hail
1.0 in
Wind
60.0 mph

Counties Martin County, MN, Watonwan County, MN

The radar

The Minneapolis radar (KMPX), 139 km from the middle of the area, began a volume at 00:35 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

TimeReportWhereRemark
May 17, 7:45 PM CDTHAIL 1.25Lewisville, MNDelayed photo report of hail shared by broadcast media. Time estimated by radar.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

Did it verify

Verified. The Iowa Environmental Mesonet's Cow matched one storm report to this severe thunderstorm warning; the first came 13 minutes after it went out.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
May 17, 6:12 PM CDTTornado WatchSPC6 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 0.5 hours before the alert went out and 137 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Minneapolis, MN at 00:00Z on 2026-05-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Minneapolis, MN at 00:00Z on 2026-05-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 154 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1101 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
154 m²/s²
0-3 km storm-relative helicity
237 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

601 
WUUS53 KMPX 180032
SVRMPX
MNC091-165-180130-
/O.NEW.KMPX.SV.W.0052.260518T0032Z-260518T0130Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Twin Cities/Chanhassen MN
732 PM CDT Sun May 17 2026

The National Weather Service in the Twin Cities has issued a

* Severe Thunderstorm Warning for...
  Northwestern Martin County in south central Minnesota...
  Watonwan County in south central Minnesota...

* Until 830 PM CDT.

* At 732 PM CDT, severe thunderstorms were located along a line from
  6 miles west of Butterfield to 8 miles southwest of Sherburn.

  HAZARD...60 mph wind gusts and quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Hail damage to vehicles is expected. Expect wind damage to
           roofs, siding, and trees.

* Locations impacted include...
  Dunnell, Butterfield, Sherburn, Odin, Trimont, Ormsby, Foxlake,
  Echols, Welcome, St. James, South Branch, St James Airport, La
  Salle, Grogan, Fairmont, Truman, Northrop, Lewisville and Madelia.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Seek shelter inside a well-built structure and stay away from
windows. These storms are capable of producing damaging winds and
large hail.

Tornadoes can develop quickly from severe thunderstorms. Seek shelter
immediately in an interior room on the lowest floor of a well-built
structure.

A Tornado Watch remains in effect until 100 AM CDT Monday for a
portion of south central Minnesota.

&&

LAT...LON 4404 9486 4411 9468 4411 9437 4385 9437
      4361 9443 4354 9485 4385 9485 4385 9486
TIME...MOT...LOC 0031Z 247DEG 27KT 4393 9491 4377 9487 4358 9486

TORNADO...POSSIBLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

MPG
2 follow-up statements
972 
WWUS53 KMPX 180059
SVSMPX

Severe Weather Statement
National Weather Service Twin Cities/Chanhassen MN
759 PM CDT Sun May 17 2026

MNC091-165-180130-
/O.CON.KMPX.SV.W.0052.000000T0000Z-260518T0130Z/
Martin MN-Watonwan MN-
759 PM CDT Sun May 17 2026

...SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 830 PM CDT FOR
NORTHWESTERN MARTIN AND WATONWAN COUNTIES...

At 759 PM CDT, severe thunderstorms were located along a line from
over St. James to near Fairmont.

HAZARD...Ping pong ball size hail and 60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...People and animals outdoors will be injured. Expect hail
         damage to roofs, siding, windows, and vehicles. Expect wind
         damage to roofs, siding, and trees.

Locations impacted include...
  Trimont, Butterfield, Odin, Foxlake, Ormsby, Welcome, Echols,
  Sveadahl, St. James, South Branch, Fairmont, St James Airport, La
  Salle, Northrop, Grogan, Truman, Lewisville and Madelia.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Seek shelter inside a well-built structure and stay away from
windows. These storms are capable of producing damaging winds and
large hail.

Tornadoes can develop quickly from severe thunderstorms. Seek shelter
immediately in an interior room on the lowest floor of a well-built
structure.

A Tornado Watch remains in effect until 100 AM CDT Monday for a
portion of south central Minnesota.

&&

LAT...LON 4404 9486 4411 9468 4411 9437 4385 9437
      4361 9443 4357 9471 4374 9473 4381 9477
      4385 9485 4385 9486
TIME...MOT...LOC 0032Z 247DEG 27KT 4393 9492 4375 9484 4356 9480

TORNADO...POSSIBLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.50 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

MPG
069 
WWUS53 KMPX 180121
SVSMPX

Severe Weather Statement
National Weather Service Twin Cities/Chanhassen MN
821 PM CDT Sun May 17 2026

MNC091-165-180131-
/O.EXP.KMPX.SV.W.0052.000000T0000Z-260518T0130Z/
Martin MN-Watonwan MN-
821 PM CDT Sun May 17 2026

...SEVERE THUNDERSTORM WARNING WILL EXPIRE AT 830 PM CDT FOR
NORTHWESTERN MARTIN AND WATONWAN COUNTIES...

The storms which prompted the warning have moved out of the area.
Therefore, the warning will be allowed to expire. A Severe
Thunderstorm Warning still remains in effect for northeast Martin
county until 9 pm.

A Tornado Watch remains in effect until 100 AM CDT Monday for a
portion of south central Minnesota.

&&

LAT...LON 4404 9486 4411 9468 4411 9437 4385 9437
      4361 9443 4357 9471 4374 9473 4381 9477
      4385 9485 4385 9486
TIME...MOT...LOC 0059Z 247DEG 27KT 4401 9466 4383 9457 4364 9454

$$

MPG

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Twin Cities, MN wrote its last area forecast discussion before this severe thunderstorm warning went out at May 17, 6:40 PM CDT, 52 minutes earlier. Its key messages:

  • Severe thunderstorms likely this evening, with the highest risk across southern Minnesota (level 3 out of 5).
  • Initial storms will have potential for large to very large hail (2-3") and tornadoes.
  • Individual storms will quickly form into a line as they progress through MN and WI. Significant severe wind (70-80+ mph) will become the primary hazard with brief QLCS tornadoes possible across south-central MN.
  • Another round of thunderstorms is likely Monday night. Severe thunderstorms are possible across southeast Minnesota & western Wisconsin.
Area forecast discussion, May 17, 6:40 PM CDT, 52 minutes before
Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
640 PM CDT Sun May 17 2026

.KEY MESSAGES...

- Severe thunderstorms likely this evening, with the highest
  risk across southern Minnesota (level 3 out of 5).

- Initial storms will have potential for large to very large
  hail (2-3") and tornadoes.

- Individual storms will quickly form into a line as they
  progress through MN and WI. Significant severe wind (70-80+
  mph) will become the primary hazard with brief QLCS tornadoes
  possible across south-central MN.

- Another round of thunderstorms is likely Monday night. Severe
  thunderstorms are possible across southeast Minnesota &
  western Wisconsin.

&&

.DISCUSSION...
Issued at 124 PM CDT Sun May 17 2026

Today is setting up to have potential to be a higher end day for
portions of the Enhanced Risk area. Latest visible satellite
imagery shorting plenty of clearing with the low-level cloud
deck through much of MN, but especially across the southern
portion of the state. A bubbling cu field is beginning to
develop ahead of ongoing convection tied to the surface low near
the NE/SD state line. Surface winds are largely out of the
SE/ESE for MN and western WI, and dewpoints have been steadily
increasing through the day so far. The best environment is
across southern MN where dewpoints have climbed into the 60s
already and plenty of clearing is allowing for efficient
daytime heating, priming the environment for intense convection
later today.

Based on satellite and hi-res model data, we expect timing to be
maybe slightly earlier than forecast this morning, but generally
along the same timeframe. Supercells and storm clusters will
develop across Nebraska and South Dakota during the afternoon
(around 3-5pm) and progress slightly northeastward into
southwest MN and northern IA (around 6-7pm). At this point,
storms will be tied to the triple point and situated in a
favorable environment for large to very large hail (2-3" in
diameter) and damaging wind gusts (60+ mph). Storms will quickly
develop into a line along the cold front and turn into a
significant wind (70-80+ mph), QLCS setup with line-embedded
tornadoes possible within that Enhanced Risk area (stretching
from Redwood Falls, MN over to Owatonna, MN and south). Forecast
soundings show increasing low-level shear and humped hodographs
in the region ahead of the line, which is also reflected in
models like the RRFS and HRRR producing a zone of STP values of
5+ across southern MN. Typically QLCS tornadoes are weaker than
supercell tornadoes, so we really want to highlight that there
is higher- end potential with today's environment compared to
your average QLCS setup. Any tornadoes that develop will likely
still be brief, like any typical QLCS setup, though the strength
of the tornadoes may be capped at an EF2 level rather than EF1.
This is all in general-speak, but the point is that the higher-
end environment warrants being prepared for slightly stronger
tornadoes than you typically get with linear setups (around
here at least). The main time window for this to move through is
between 7-10pm. The faster the line develops, the quicker it
will move east.

To the north of the main line, we should still see a surge of
low-level moisture as the low tracks northeast. The overall
environment just is not as impressive north of the Enhanced Risk
region, due to the limited northern progression of the warm
front today. It will be high shear/low CAPE setup for much of
our forecast area today, but especially for areas north of the
Redwood Falls to Owatonna line. A Slight Risk (level 2/5)
remains in place to cover this threat for scattered severe storm
potential. The primary hazards will be damaging wind (60+ mph)
and large hail (1"+ in diameter). Any high end potential will be
limited, including the tornado risk. Storms will move through
the western MN to St Cloud, MN region around 6-8pm, the Twin
Cities metro and eastern MN around 9-11pm, and eventually
progress through western WI around 11pm-1am. The severe threat
will begin to decrease as the line progresses into WI given that
there will likely be scattered storms ahead the cold front,
limiting the environment.

The severe threat for Monday continues to decrease, and although
there is still a Slight Risk (level 2/5) extending from south-
central MN into west-central WI, we expect that region to shift
even further southeast after we realize our round of storms this
evening. We will struggle to build in any real instability and
deep layer shear will become more limited as well. In reality,
tomorrow will likely feel like a typical rainy Spring day with
cool showers and storms through much of the second half of the
day. Isolated chances for severe weather will exist, mainly for
areas along I-35 and east during the evening.

A much drier, and seasonably cool pattern will set up for the
rest of the week. Temperatures on Tuesday will be about 10-15
degrees below average, and we could once again have concern for
patchy frost overnight (lows in the mid-low 30s) into Wednesday
for areas in west- central MN near Stevens, Douglas, and Todd
counties. It won't be until Friday that we see our next notable
chance for rain as a shortwave develops over the Northern
Plains. It looks to be a slow- progressing pattern that would
provide us with additional chances for showers and storms
throughout the rest of Memorial Day weekend, though confidence
is low at this time.

&&

.AVIATION /00Z TAFS THROUGH 00Z TUESDAY/...
Issued at 628 PM CDT Sun May 17 2026

Main concern is line of storms over southwest MN. MKT is the
only field with much of a severe potential with this line,
though several hours of TSRA are expected at MSP and WI
terminals. Besides the line of storms, we've seen storms develop
ahead of hit within the LLJ and associated WAA that will result
in the several hours of TS threat we have. Behind the line, we
will dry out, with MVFR/IFR cigs slowly building east across
southern MN. Did delay the arrival of MVFR cigs some, but by
sunrise Monday, we should see widespread MVFR/IFR cigs over the
area that will stay in place this period. By the end of this
period, we should see showers developing by the late afternoon
as the next wave approaches from the southwest.

KMSP...Scattered shra/tsra currently down by MKT will be in the
MSP VCNTY between 1z and 2z. This is out ahead of what will be
the northern end of the severe line of storms to our south that
will move through roughly between 4z and 6z. By the end of the
period, the next round of showers will be rapidly developing,
with another round of shra/tsra expected to develop between 0z
and 2z (Monday evening) that will last into Monday night.
Doesn't look like we have a big severe risk with this activity,
just heavy rain and lightning.

/OUTLOOK FOR KMSP/
TUE...MVFR cigs becoming VFR. Wind NW 10-15G25kts.
WED...VFR. Wind lgt and vrb.
THU...VFR. Wind SE 10G20kts.

&&

.MPX WATCHES/WARNINGS/ADVISORIES...
MN...None.
WI...None.

&&

DISCUSSION...BED
AVIATION...MPG
Hazardous weather outlook, May 17, 2:21 PM CDT, 5 hours 11 minutes before
Hazardous Weather Outlook
National Weather Service Twin Cities/Chanhassen MN
221 PM CDT Sun May 17 2026

MNZ041>045-047>070-073>078-082>085-091>093-WIZ014>016-023>028-
181930-
Douglas-Todd-Morrison-Mille Lacs-Kanabec-Stevens-Pope-Stearns-
Benton-Sherburne-Isanti-Chisago-Lac Qui Parle-Swift-Chippewa-
Kandiyohi-Meeker-Wright-Hennepin-Anoka-Ramsey-Washington-
Yellow Medicine-Renville-McLeod-Sibley-Carver-Scott-Dakota-
Redwood-Brown-Nicollet-Le Sueur-Rice-Goodhue-Watonwan-Blue Earth-
Waseca-Steele-Martin-Faribault-Freeborn-Polk-Barron-Rusk-
St. Croix-Pierce-Dunn-Pepin-Eau Claire-
221 PM CDT Sun May 17 2026

This Hazardous Weather Outlook is for portions of central and
southern Minnesota, and west central Wisconsin.

.DAY ONE...Tonight.

A severe weather event is possible this evening and tonight.
Thunderstorms will be capable of producing large hail, damaging
winds, and a few tornadoes. Damaging winds will be the primary
hazard. The best chance for significant severe wind will be along
the I-90 corridor in southern Minnesota.

Please ensure you have multiple ways to receive warnings.

.DAYS TWO THROUGH SEVEN...Monday through Saturday.

Another round of thunderstorms is possible Monday evening and
Monday night. A few severe thunderstorms are possible, mainly
across southeast Minnesota & western Wisconsin.

.SPOTTER INFORMATION STATEMENT...

SKYWARN spotter activation will likely be needed this evening
through tonight.

BPH

In the hours before

Local storm report, May 17, 7:15 PM CDT, 17 minutes before
Preliminary Local Storm Report
National Weather Service Twin Cities/Chanhassen MN
715 PM CDT Sun May 17 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0712 PM     Tornado          3 WSW Northrop          43.71N 94.49W
05/17/2026                   Martin             MN   Law Enforcement

            Short rope tornado northwest of Fairmont
            north of mile marker 99 along I-90.
            Confirmed by law enforcement and trained
            spotter.

&&

TDH
Local storm report, May 17, 7:22 PM CDT, 10 minutes before
Preliminary Local Storm Report
National Weather Service Twin Cities/Chanhassen MN
722 PM CDT Sun May 17 2026

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0710 PM     Hail             4 ENE Butterfield       43.97N 94.71W
05/17/2026  M0.70 Inch       Watonwan           MN   Public

            Picture/video via social media.

&&

TDH

The office that day

Everything else NWS Twin Cities, MN issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 17, 7:11 PM CDTSevere Thunderstorm WarningMPXBrown, Watonwan49 min
May 17, 7:12 PM CDTTornado Warning Tornado observedMPXBlue Earth, Martin, Watonwan33 min
May 17, 7:40 PM CDTTornado WarningMPXFaribault, Martin35 min
May 17, 7:40 PM CDTTornado WarningMPXMartin, Watonwan24 min
May 17, 7:48 PM CDTTornado WarningMPXBlue Earth, Martin, Watonwan42 min
May 17, 8:10 PM CDTSevere Thunderstorm WarningMPXBlue Earth, Faribault, Martin50 min
May 17, 8:49 PM CDTSevere Thunderstorm WarningMPXBlue Earth, Faribault, Freeborn, Waseca43 min
May 17, 9:19 PM CDTSevere Thunderstorm WarningMPXBlue Earth, Faribault, Martin, Watonwan56 min
May 17, 9:36 PM CDTTornado WarningMPXFaribault, Martin39 min
May 17, 9:52 PM CDTTornado WarningMPXFaribault, Freeborn53 min
May 17, 10:33 PM CDTSevere Thunderstorm Warning Considerable damage threatMPXFreeborn27 min
May 17, 11:26 PM CDTSpecial Weather StatementMPXGoodhue34 min

Nearby

Severe Thunderstorm Warnings in Minnesota, 2026Every severe thunderstorm warning in 2026

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.