Alert archive / Minnesota / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 10, NWS Duluth, MN

June 21, 2020Saint Louis County, Minnesota

NWS Duluth, MN issued this severe thunderstorm warning at Jun 21, 2020, 12:00 PM CDT for Saint Louis County, Minnesota. It was in force for 45 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Jun 21, 2020, 12:00 PM CDT (17:00 UTC)
Expired
Jun 21, 2020, 12:45 PM CDT
In force
45 min
Issued by
NWS Duluth, MN
Area
Storm-based polygon
Hail
1.0 in
Wind
50.0 mph

County Saint Louis County, MN

The radar

The Duluth radar (KDLH), 86 km from the middle of the area, began a volume at 17:01 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.

The nearest sounding before it

International Fa, MN (KINL), launched 12:00Z, 5.0 hours before the alert went out and 126 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, International Fa, MN at 12:00Z on 2020-06-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 111 joules per kilogram.LCLLFCEL10008507005003002001001 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, International Fa, MN at 12:00Z on 2020-06-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 83 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
111 J/kg
Mixed-layer CIN
-107 J/kg
Mixed-layer LCL
973 m above ground
0-6 km bulk shear
46 kt
0-1 km storm-relative helicity
83 m²/s²
0-3 km storm-relative helicity
92 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

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 Duluth, MN wrote its last area forecast discussion before this severe thunderstorm warning went out at Jun 21, 6:52 AM CDT, 5 hours 8 minutes earlier.

Area forecast discussion, Jun 21, 6:52 AM CDT, 5 hours 8 minutes before
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Hazardous weather outlook, Jun 21, 3:51 AM CDT, 8 hours 9 minutes before
Hazardous Weather Outlook
National Weather Service Duluth MN
351 AM CDT Sun Jun 21 2020

MNZ010>012-018>021-025-026-033>038-WIZ003-004-006-009-220900-
Koochiching-North St. Louis-Northern Cook/Northern Lake-
North Itasca-Central St. Louis-Southern Lake/North Shore-
Southern Cook/North Shore-North Cass-South Itasca-South Cass-
Crow Wing-Northern Aitkin-South Aitkin-Carlton/South St. Louis-
Pine-Ashland-Iron-Burnett-Price-
351 AM CDT Sun Jun 21 2020

This Hazardous Weather Outlook is for portions of northeast
Minnesota and northwest Wisconsin.

.DAY ONE...Today and Tonight

Chances of thunderstorms will increase this afternoon and continue
through the overnight hours tonight. An isolated strong to severe
storm will be possible, for areas along and south of a line from
Brainerd, MN to Carlton, MN to Mercer, WI. Large hail and damaging
winds are the main threats.

.DAYS TWO THROUGH SEVEN...Monday through Saturday

There will be continued low chances for thunderstorms for Monday
through Wednesday.

.SPOTTER INFORMATION STATEMENT...

Skywarn spotters may be needed this afternoon and evening.

WIZ001-002-007-008-220900-
Douglas-Bayfield-Washburn-Sawyer-
351 AM CDT Sun Jun 21 2020

This Hazardous Weather Outlook is for portions of northwest
Wisconsin.

.DAY ONE...Today and Tonight

Dense fog has developed early this morning for these areas of
northwest Wisconsin. A Dense Fog Advisory has been issued. The fog
is expected to dissipate between 8 to 9 AM.

Chances of thunderstorms will increase this afternoon and continue
through the overnight hours tonight. An isolated strong to severe
storm will be possible, for areas along and south of a line from
Brainerd, MN to Carlton, MN to Mercer, WI. Large hail and damaging
winds are the main threats.

.DAYS TWO THROUGH SEVEN...Monday through Saturday

There will be continued low chances for thunderstorms for Monday
through Wednesday.

.SPOTTER INFORMATION STATEMENT...

Skywarn spotters may be needed this afternoon and evening.

LSZ121-140>148-220900-
Bayfield to Oak Point WI-Grand Portage to Grand Marais MN-
Grand Marais to Taconite Harbor MN-
Taconite Harbor to Silver Bay Harbor MN-
Silver Bay Harbor to Two Harbors MN-Two Harbors to Duluth MN-
Duluth MN to Port Wing WI-Port Wing to Sand Island WI-
Sand Island to Bayfield WI-Oak Point to Saxon Harbor WI-
351 AM CDT Sun Jun 21 2020

This Hazardous Weather Outlook is for portions of the Nearshore
waters of western Lake Superior.

.DAY ONE...Today and Tonight

Chances of thunderstorms will return across western Lake Superior
this afternoon and evening. A strong storm will be possible, but
severe storms appear to be unlikely.

.DAYS TWO THROUGH SEVEN...Monday through Saturday

There will be low chances for thunderstorms for Tuesday and
Wednesday.

JTS

More information may be obtained at the following web address:
http://www.weather.gov/duluth (all lower case)

In the hours before

Special weather statement, Jun 21, 11:34 AM CDT, 26 minutes before
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      <h1 id="headline">This service is currently unavailable.</h1>
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The office that day

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

IssuedProductOfficeCountiesLasted
Jun 21, 11:34 AM CDTSpecial Weather StatementDLHSaint Louis26 min
Jun 21, 12:30 PM CDTSpecial Weather StatementDLHCarlton30 min
Jun 21, 12:51 PM CDTSpecial Weather StatementDLHLake9 min
Jun 21, 12:56 PM CDTSpecial Weather StatementDLH19 min
Jun 21, 1:15 PM CDTSevere Thunderstorm WarningDLHSaint Louis15 min
Jun 21, 1:27 PM CDTSpecial Marine WarningDLH18 min
Jun 21, 1:36 PM CDTSpecial Weather StatementDLHLake24 min
Jun 21, 1:46 PM CDTSpecial Marine WarningDLH44 min
Jun 21, 1:55 PM CDTSpecial Weather StatementDLH35 min
Jun 21, 2:57 PM CDTSpecial Marine WarningDLH63 min
Jun 21, 3:43 PM CDTSpecial Weather StatementDLHLake32 min
Jun 21, 4:33 PM CDTSpecial Weather StatementDLHSaint Louis27 min
Jun 21, 4:51 PM CDTSpecial Weather StatementDLHSaint Louis24 min
Jun 21, 5:12 PM CDTSpecial Weather StatementDLHLake33 min
Jun 21, 3:04 AM CDTDense Fog AdvisoryDLHBayfield, Douglas, Sawyer, Washburn6 hr
Jun 21, 1:39 PM CDTSpecial Weather StatementDLHWashburn21 min
Jun 21, 2:01 PM CDTSpecial Weather StatementDLHDouglas29 min
Jun 21, 2:31 PM CDTSpecial Weather StatementDLHBayfield29 min
Jun 21, 2:34 PM CDTSpecial Weather StatementDLHBayfield26 min
Jun 21, 2:54 PM CDTSevere Thunderstorm WarningDLHAshland, Bayfield36 min
Jun 21, 3:02 PM CDTSevere Thunderstorm WarningDLHBayfield, Douglas28 min
Jun 21, 3:09 PM CDTSpecial Weather StatementDLHSawyer36 min
Jun 21, 3:32 PM CDTSevere Thunderstorm WarningDLHAshland, Sawyer28 min
Jun 21, 3:54 PM CDTSevere Thunderstorm WarningDLHAshland, Price, Sawyer51 min
Jun 21, 4:11 PM CDTSpecial Weather StatementDLHAshland34 min
Jun 21, 5:35 PM CDTSpecial Weather StatementDLHSawyer25 min
Jun 21, 6:31 PM CDTSpecial Weather StatementDLHAshland29 min
Jun 21, 6:38 PM CDTSpecial Weather StatementDLHIron37 min

Nearby

Severe Thunderstorm Warnings in Minnesota, 2020Every 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.