Alert archive / Michigan / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 51, NWS Marquette, MI

August 21, 2020Dickinson County, Marquette County, Menominee County, Michigan

NWS Marquette, MI issued this severe thunderstorm warning at Aug 21, 2020, 2:33 PM CDT for Dickinson County, Marquette County, Menominee County, Michigan. It was in force for 30 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
Aug 21, 2020, 2:33 PM CDT (19:33 UTC)
Expired
Aug 21, 2020, 3:03 PM CDT
In force
30 min
Issued by
NWS Marquette, MI
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

Counties Dickinson County, MI, Marquette County, MI, Menominee County, MI

The radar

The Marquette radar (KMQT), 52 km from the middle of the area, began a volume at 19:36 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

Green Bay/Straub, WI (KGRB), launched 12:00Z, 7.6 hours before the alert went out and 180 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, Green Bay/Straub, WI at 12:00Z on 2020-08-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 27 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, Green Bay/Straub, WI at 12:00Z on 2020-08-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 64 square meters per square second.1939Sfc1 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
27 J/kg
Mixed-layer CIN
-410 J/kg
Mixed-layer LCL
1482 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
64 m²/s²
0-3 km storm-relative helicity
121 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

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 Marquette, MI wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 21, 12:39 PM CDT, 1 hour 54 minutes earlier.

Area forecast discussion, Aug 21, 12:39 PM CDT, 1 hour 54 minutes before
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Hazardous weather outlook, Aug 21, 3:44 AM CDT, 10 hours 49 minutes before
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In the hours before

Special weather statement, Aug 21, 1:45 PM CDT, 48 minutes before
Special Weather Statement
National Weather Service Marquette MI
245 PM EDT Fri Aug 21 2020

MIZ004-005-010-011-211915-
Marquette MI-Baraga MI-Iron MI-Dickinson MI-
245 PM EDT Fri Aug 21 2020

...SPECIAL WEATHER STATEMENT...

At 243 PM EDT/143 PM CDT/, Doppler radar was tracking strong
thunderstorms along a line extending from near Three Lakes to 10
miles northwest of Watson. Movement was southeast at 15 mph.

Half inch hail, winds in excess of 30 mph and brief torrential
rainfall will be possible with these storms.

Locations impacted include...
Watson, Michigamme, Squaw Lake, Lake Michigamme, Witch Lake, Three
Lakes, Republic, Big Bass Lake, Arnold, Northland, McFarland,
Anderson Lake, Ned Lake and Bone Lake.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, seek shelter until these storms pass.

&&

LAT...LON 4641 8843 4660 8827 4618 8723 4598 8741
TIME...MOT...LOC 1843Z 302DEG 12KT 4649 8828 4614 8753

Rolfson
Special weather statement, Aug 21, 2:16 PM CDT, 17 minutes before
Special Weather Statement
National Weather Service Marquette MI
316 PM EDT Fri Aug 21 2020

MIZ004-005-010>012-211930-
Marquette MI-Baraga MI-Iron MI-Menominee MI-Dickinson MI-
316 PM EDT Fri Aug 21 2020

...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN IRON...NORTHERN
DICKINSON...NORTH CENTRAL MENOMINEE...SOUTHWESTERN MARQUETTE AND
SOUTH CENTRAL BARAGA COUNTIES UNTIL 330 PM EDT/230 PM CDT/...

At 315 PM EDT/215 PM CDT/, Doppler radar was tracking strong
thunderstorms along a line extending from 6 miles south of Three
Lakes to near La Branche. Movement was southeast at 15 mph.

Penny size hail, wind gusts up to 50 mph, and torrential rainfall
will be possible with these storms.

Locations impacted include...
Watson, Michigamme, Squaw Lake, Witch Lake, U.S. 141 between
Covington and Amasa, Republic, Ralph, Silver Lake near Channing,
Arnold, Northland, Ned Lake and Bone Lake.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Frequent cloud to ground lightning is occurring with these storms.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle. Persons in campgrounds should
consider seeking sturdy shelter until these storms pass.

&&

LAT...LON 4644 8855 4653 8805 4599 8724 4598 8736
      4592 8736 4588 8746
TIME...MOT...LOC 1915Z 301DEG 13KT 4647 8823 4593 8741

Rolfson

The office that day

Everything else NWS Marquette, MI issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 21, 12:12 AM CDTSpecial Weather StatementMQTBaraga48 min
Aug 21, 9:07 AM CDTMarine Dense Fog AdvisoryMQT10 hr
Aug 21, 1:45 PM CDTSpecial Weather StatementMQTDickinson30 min
Aug 21, 2:16 PM CDTSpecial Weather StatementMQTDickinson14 min
Aug 21, 3:01 PM CDTSevere Thunderstorm WarningMQTDickinson, Iron44 min
Aug 21, 3:17 PM CDTAreal Flood AdvisoryMQTDelta, Dickinson, Marquette, Menominee118 min
Aug 21, 3:24 PM CDTSevere Thunderstorm WarningMQTDelta, Menominee51 min
Aug 21, 3:46 PM CDTSevere Thunderstorm WarningMQTDickinson44 min
Aug 21, 3:52 PM CDTSevere Thunderstorm WarningMQTDelta, Menominee38 min
Aug 21, 4:04 PM CDTSpecial Marine WarningMQT86 min
Aug 21, 4:30 PM CDTSpecial Weather StatementMQTMenominee30 min
Aug 21, 4:32 PM CDTSpecial Weather StatementMQTDickinson28 min
Aug 21, 4:40 PM CDTSevere Thunderstorm WarningMQTDickinson35 min
Aug 21, 4:58 PM CDTSpecial Weather StatementMQTMenominee47 min
Aug 21, 5:05 PM CDTSevere Thunderstorm WarningMQTMenominee25 min
Aug 21, 5:17 PM CDTSevere Thunderstorm WarningMQTMenominee25 min
Aug 21, 5:21 PM CDTSpecial Marine WarningMQT24 min
Aug 21, 5:26 PM CDTSevere Thunderstorm WarningMQTIron34 min
Aug 21, 5:28 PM CDTSpecial Marine WarningMQT32 min
Aug 21, 5:59 PM CDTSpecial Marine WarningMQT31 min
Aug 21, 6:01 PM CDTSpecial Weather StatementMQTIron44 min
Aug 21, 6:08 PM CDTAreal Flood AdvisoryMQTHoughton, Iron3 hr
Aug 21, 6:09 PM CDTSevere Thunderstorm WarningMQTIron24 min
Aug 21, 6:13 PM CDTSpecial Weather StatementMQTGogebic47 min
Aug 21, 6:24 PM CDTSpecial Marine WarningMQT36 min
Aug 21, 6:51 PM CDTAreal Flood AdvisoryMQTGogebic, Ontonagon3 hr

Nearby

Severe Thunderstorm Warnings in Michigan, 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.