Alert archive / Minnesota / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 114, NWS Twin Cities, MN

August 10, 2020Steele County, Waseca County, Minnesota

NWS Twin Cities, MN issued this severe thunderstorm warning at Aug 10, 2020, 4:16 AM CDT for Steele County, Waseca County, Minnesota. It was in force for 59 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Aug 10, 2020, 4:16 AM CDT (09:16 UTC)
Expired: Aug 10, 2020, 5:15 AM CDT
In force: 59 min
Issued by: NWS Twin Cities, MN
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Steele County, MN, Waseca County, MN

The radar

The Minneapolis radar (KMPX), 86 km from the middle of the area, began a volume at 09:20 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.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

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 nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 9.3 hours before the alert went out and 87 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 2342 J/kg
Mixed-layer CIN: -37 J/kg
Mixed-layer LCL: 1184 m above ground
0-6 km bulk shear: 22 kt
0-1 km storm-relative helicity: 107 m²/s²
0-3 km storm-relative helicity: 168 m²/s²
Significant tornado parameter: 1.0
Supercell composite: 10.5

Open this sounding in Storm Lab

The text

As transmitted.

579 
WUUS53 KMPX 100916
SVRMPX
MNC147-161-101015-
/O.NEW.KMPX.SV.W.0114.200810T0916Z-200810T1015Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Twin Cities/Chanhassen MN
416 AM CDT Mon Aug 10 2020

The National Weather Service in The Twin Cities has issued a

* Severe Thunderstorm Warning for...
  Steele County in south central Minnesota...
  Northeastern Waseca County in south central Minnesota...

* Until 515 AM CDT.

* At 416 AM CDT, a severe thunderstorm was located over Waseca, or 12
  miles west of Owatonna, moving east at 25 mph.

  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...
  Owatonna, Waseca, Medford, Clinton Falls, Merton, Moland,
  Deerfield, Waseca Airport, Steele Center, Bixby and Owatonna
  Airport.

This includes the following highways...
 Interstate 35 between mile markers 33 and 49.
 U.S. Highway 14 between mile markers 153 and 182.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4406 9365 4420 9356 4419 9305 4390 9305
TIME...MOT...LOC 0916Z 286DEG 20KT 4409 9348 

HAIL...1.00IN
WIND...60MPH
 
$$

CEO

1 follow-up statement

562 
WWUS53 KMPX 100942
SVSMPX

Severe Weather Statement
National Weather Service Twin Cities/Chanhassen MN
442 AM CDT Mon Aug 10 2020

MNC161-100951-
/O.CAN.KMPX.SV.W.0114.000000T0000Z-200810T1015Z/
Waseca MN-
442 AM CDT Mon Aug 10 2020

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN WASECA COUNTY IS
CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

LAT...LON 4400 9341 4420 9341 4419 9305 4390 9305
TIME...MOT...LOC 0941Z 286DEG 20KT 4405 9329 

$$

MNC147-101015-
/O.CON.KMPX.SV.W.0114.000000T0000Z-200810T1015Z/
Steele MN-
442 AM CDT Mon Aug 10 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 515 AM CDT
FOR STEELE COUNTY...

At 441 AM CDT, a severe thunderstorm was located near Owatonna,
moving east at 25 mph.

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...
Owatonna, Medford, Clinton Falls, Merton, Moland, Deerfield, Bixby,
Owatonna Airport and Steele Center.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 4400 9341 4420 9341 4419 9305 4390 9305
TIME...MOT...LOC 0941Z 286DEG 20KT 4405 9329 

HAIL...1.00IN
WIND...60MPH
 
$$

CEO

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 Aug 10, 3:49 AM CDT, 27 minutes earlier.

Area forecast discussion, Aug 10, 3:49 AM CDT, 27 minutes before

Area Forecast Discussion
National Weather Service Twin Cities/Chanhassen MN
349 AM CDT Mon Aug 10 2020

.SHORT TERM...(Today through Tuesday)
Issued at 349 AM CDT Mon Aug 10 2020

Large hail, heavy rainfall, and wind-producing storms that formed
ahead of an approaching cold front (and provided an impressive
lightning show for parts of the area Sunday night) will continue
to develop east/southeast early this morning, riding along the
instability gradient along the MN/WI border. By mid-morning the
severe threat will have diminished, but a few showers could
persist along the Iowa border. Drier air works into the area this
afternoon bringing clearing skies, and reducing dewpoints into the
40s and 50s. High temperatures today will be a few degrees cooler
than climatological normals, with highs in the 75-80 degree
range. Lows tonight will be pleasant in the low to mid 50s. Dry
weather continues on Tuesday as weak ridging influences the local
weather, although temperatures will moderate several degrees with
highs in the low to mid 80s.

.LONG TERM...(Tuesday night through Sunday)
Issued at 349 AM CDT Mon Aug 10 2020

Semi-zonal flow prevails through much of next week, with
precipitation opportunities supplied by ripples of shortwave
energy in the fast-moving westerly flow. The first of these
chances for showers and thunderstorms arrives Wednesday as return
flow ensues, and then chances persist through the weekend as
western troughing shifts into the north central CONUS.
Temperatures will be near to slightly above normal through the
period.

&&

.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1234 AM CDT Mon Aug 10 2020

VFR conditions for most locations overnight as a cold front pushes
through the region. This cold front could produce some MVFR
ceilings, and spark a few thunderstorms. As of now, the majority
of the thunder activity will be at KMSP.

KMSP...
Thunderstorms will continue through at least the next couple of
hours at KMSP. A few could produce some hail. Eventually a cold
front will move through the region and push these storms east.
Expect northwest winds and VFR conditions once the storm passes.

/OUTLOOK FOR KMSP/
TUE...VFR. Wind SW at 5-10 kt.
WED...VFR. Wind SE at 10 kt.
THU...VFR with MVFR/TSRA possible. Wind SE at 10G20 kt.

&&

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

SHORT TERM...LS
LONG TERM...LS
AVIATION...JRB

Hazardous weather outlook, Aug 9, 7:39 PM CDT, 8 hours 37 minutes before

Hazardous Weather Outlook
National Weather Service Twin Cities/Chanhassen MN
739 PM CDT Sun Aug 9 2020

MNZ041>045-047>070-073>078-082>085-091>093-WIZ014>016-023>028-
110045-
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-
739 PM CDT Sun Aug 9 2020

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

.DAY ONE...Tonight.

There is still a Slight Risk of severe thunderstorms today and
tonight, but the potential is trending downward. The primary
threats are damaging winds, large hail, and heavy rainfall.

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

Periodic thunderstorms are possible Wednesday through Saturday.
Severe storms are not expected at this time.

.SPOTTER INFORMATION STATEMENT...

SKYWARN spotter activation may be needed if storms develop later
this evening.

jrb

In the hours before

Local storm report, Aug 10, 3:36 AM CDT, 40 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
336 AM CDT MON AUG 10 2020

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

0336 AM     HAIL             2 S OGILVIE             45.80N 93.42W
08/10/2020  M1.00 INCH       KANABEC            MN   TRAINED SPOTTER

&&

Special weather statement, Aug 10, 3:58 AM CDT, 18 minutes before

Special Weather Statement
National Weather Service Twin Cities/Chanhassen MN
358 AM CDT Mon Aug 10 2020

MNZ062-063-070-WIZ024-100930-
Washington-Dakota-Ramsey-Pierce-
358 AM CDT Mon Aug 10 2020

...A STRONG THUNDERSTORM WILL AFFECT NORTHEASTERN DAKOTA...SOUTHERN
WASHINGTON...SOUTHEASTERN RAMSEY AND NORTHWESTERN PIERCE COUNTIES...

At 358 AM CDT, a strong thunderstorm was located over South St. Paul,
or near St. Paul, moving southeast at 45 mph.

Wind gusts up to 50 mph and dime size hail are possible with this
storm.

Locations impacted include...
St. Paul, Woodbury, Maplewood, Cottage Grove, Inver Grove Heights,
Oakdale, Hastings, Rosemount, South St. Paul, West St. Paul, Mendota
Heights and St. Paul Park.

Torrential rainfall is also occurring with this storm, and may cause
localized flooding. Do not drive your vehicle through flooded
roadways.

LAT...LON 4492 9313 4498 9303 4483 9267 4466 9289
TIME...MOT...LOC 0858Z 302DEG 40KT 4489 9300

JRB

Local storm report, Aug 10, 3:59 AM CDT, 17 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
359 AM CDT MON AUG 10 2020

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

0257 AM     HAIL             BUFFALO                 45.18N 93.88W
08/10/2020  M1.00 INCH       WRIGHT             MN   PUBLIC

&&

LS

Local storm report, Aug 10, 4:00 AM CDT, 16 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
400 AM CDT MON AUG 10 2020

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

0241 AM     HAIL             BUFFALO                 45.18N 93.88W
08/10/2020  M2.00 INCH       WRIGHT             MN   PUBLIC

&&

LS

Local storm report, Aug 10, 4:01 AM CDT, 15 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
401 AM CDT MON AUG 10 2020

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

0310 AM     HEAVY RAIN       BUFFALO                 45.18N 93.88W
08/10/2020  M3.75 INCH       WRIGHT             MN   PUBLIC

            SINCE 5 AM SUNDAY, 8/9/20.

&&

LS

Local storm report, Aug 10, 4:02 AM CDT, 14 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN
402 AM CDT MON AUG 10 2020

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

0341 AM     HAIL             1 W ROBBINSDALE         45.03N 93.35W
08/10/2020  M1.00 INCH       HENNEPIN           MN   PUBLIC

&&

LS

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 9, 7:52 PM CDT	Special Weather Statement	MPX	Hennepin	23 min
Aug 9, 8:13 PM CDT	Special Weather Statement	MPX	Hennepin	47 min
Aug 9, 8:47 PM CDT	Special Weather Statement	MPX	Scott	88 min
Aug 9, 9:00 PM CDT	Special Weather Statement	MPX	Scott	30 min
Aug 9, 9:21 PM CDT	Special Weather Statement	MPX	Carver	54 min
Aug 9, 9:30 PM CDT	Severe Thunderstorm Warning	MPX	Carver	45 min
Aug 9, 9:39 PM CDT	Severe Thunderstorm Warning	MPX	Hennepin, Scott	51 min
Aug 9, 10:14 PM CDT	Special Weather Statement	MPX	Hennepin	46 min
Aug 9, 10:27 PM CDT	Severe Thunderstorm Warning	MPX	Anoka, Hennepin, Sherburne, Wright	48 min
Aug 9, 10:27 PM CDT	Severe Thunderstorm Warning	MPX	Dakota, Hennepin, Scott	27 min
Aug 9, 10:48 PM CDT	Severe Thunderstorm Warning	MPX	Wright	57 min
Aug 9, 11:16 PM CDT	Severe Thunderstorm Warning	MPX	Hennepin	44 min
Aug 9, 11:40 PM CDT	Severe Thunderstorm Warning	MPX	Wright	50 min
Aug 9, 11:56 PM CDT	Severe Thunderstorm Warning	MPX	Hennepin	49 min
Aug 10, 12:28 AM CDT	Severe Thunderstorm Warning	MPX	Wright	32 min
Aug 10, 12:41 AM CDT	Severe Thunderstorm Warning	MPX	Hennepin	49 min
Aug 10, 12:42 AM CDT	Special Weather Statement	MPX	Hennepin	63 min
Aug 10, 12:54 AM CDT	Severe Thunderstorm Warning	MPX	Carver, Hennepin	51 min
Aug 10, 1:21 AM CDT	Severe Thunderstorm Warning	MPX	Dakota, Hennepin, Scott	39 min
Aug 10, 1:29 AM CDT	Special Weather Statement	MPX	Hennepin	61 min
Aug 10, 1:48 AM CDT	Flash Flood Warning	MPX	Carver, Hennepin, Scott	4 hr
Aug 10, 1:57 AM CDT	Severe Thunderstorm Warning	MPX	Dakota, Hennepin, Washington	48 min
Aug 10, 2:04 AM CDT	Severe Thunderstorm Warning	MPX	Meeker, Wright	26 min
Aug 10, 2:08 AM CDT	Severe Thunderstorm Warning	MPX	Rice, Scott	37 min
Aug 10, 2:20 AM CDT	Severe Thunderstorm Warning	MPX	Dakota, Scott	40 min
Aug 10, 2:31 AM CDT	Severe Thunderstorm Warning	MPX	Wright	44 min
Aug 10, 2:41 AM CDT	Severe Thunderstorm Warning	MPX	Dakota, Rice, Scott	49 min
Aug 10, 2:43 AM CDT	Severe Thunderstorm Warning	MPX	Carver, Scott	32 min
Aug 10, 3:06 AM CDT	Severe Thunderstorm Warning	MPX	Anoka, Hennepin	54 min
Aug 10, 3:15 AM CDT	Severe Thunderstorm Warning	MPX	Kanabec, Mille Lacs	45 min
Aug 10, 3:29 AM CDT	Severe Thunderstorm Warning	MPX	Dakota, Goodhue, Rice	46 min
Aug 10, 3:34 AM CDT	Special Weather Statement	MPX	Sherburne	56 min
Aug 10, 3:46 AM CDT	Severe Thunderstorm Warning	MPX	Rice	44 min
Aug 10, 3:58 AM CDT	Special Weather Statement	MPX	Dakota	32 min
Aug 10, 4:10 AM CDT	Severe Thunderstorm Warning	MPX	Goodhue, Rice	50 min
Aug 10, 5:08 AM CDT	Severe Thunderstorm Warning	MPX	Freeborn, Steele, Waseca	22 min
Aug 10, 5:27 AM CDT	Severe Thunderstorm Warning	MPX	Goodhue, Rice	17 min
Aug 10, 7:44 AM CDT	Special Weather Statement	MPX	Blue Earth	31 min
Aug 10, 8:03 AM CDT	Special Weather Statement	MPX	Waseca	27 min
Aug 10, 8:10 AM CDT	Severe Thunderstorm Warning	MPX	Waseca	35 min
Aug 10, 8:36 AM CDT	Severe Thunderstorm Warning	MPX	Freeborn, Steele	28 min

Nearby

Severe Thunderstorm Warnings in Minnesota, 2020 Every severe thunderstorm warning in 2020

Sources

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