Alert archive / Minnesota / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 183, NWS Duluth, MN

August 31, 2018Cook County, Lake County, Saint Louis County, Minnesota

NWS Duluth, MN issued this severe thunderstorm warning at Aug 31, 2018, 8:42 PM CDT for Cook County, Lake County, Saint Louis County, Minnesota. It was in force for 48 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 31, 2018, 8:42 PM CDT (01:42 UTC)
Expired: Aug 31, 2018, 9:30 PM CDT
In force: 48 min
Issued by: NWS Duluth, MN
Area: Storm-based polygon
Hail: 0.75 in
Wind: 70.0 mph

Counties Cook County, MN, Lake County, MN, Saint Louis County, MN

The radar

The Duluth radar (KDLH), 106 km from the middle of the area, began a volume at 01:44 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 watch it was issued in

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

Issued	Product	Office	Lasted
Aug 31, 6:55 PM CDT	Severe Thunderstorm Watch	SPC	5 hr

The nearest sounding before it

International Fa, MN (KINL), launched 00:00Z, 1.7 hours before the alert went out and 171 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: 424 J/kg
Mixed-layer CIN: -144 J/kg
Mixed-layer LCL: 964 m above ground
0-6 km bulk shear: 46 kt
0-1 km storm-relative helicity: 124 m²/s²
0-3 km storm-relative helicity: 134 m²/s²
Significant tornado parameter: 0.0
Supercell composite: -0.4

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 Aug 31, 6:43 PM CDT, 1 hour 59 minutes earlier.

Area forecast discussion, Aug 31, 6:43 PM CDT, 1 hour 59 minutes before

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

Hazardous weather outlook, Aug 31, 2:49 PM CDT, 5 hours 53 minutes before

Hazardous Weather Outlook...UPDATED
National Weather Service Duluth MN
249 PM CDT Fri Aug 31 2018

MNZ010>012-018>021-025-026-033>038-WIZ001>004-006>009-011130-
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-Douglas-Bayfield-Ashland-Iron-Burnett-Washburn-Sawyer-Price-
249 PM CDT Fri Aug 31 2018

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

.DAY ONE...This afternoon and Tonight

Thunderstorms are likely this afternoon through early Saturday
morning over much of the Northland. Some storms will be strong to
severe with large hail, damaging wind gusts, torrential rainfall,
and frequent lightning. A tornado cannot be entirely ruled out.
The heavy rain could lead to flash flooding, mainly over northwest
Wisconsin and adjacent counties of northeast Minnesota where
soils are nearly saturated. Heavy rain has also become more likely
along portions of the north shore, especially between the crest
of the ridge and the lake. A Flash Flood Watch remains in effect
until 7 AM Saturday and now includes the north shore and Price
County Wisconsin.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday

Several rounds of thunderstorms are expected during the upcoming
week. Repeated heavy rainfall may cause flooding. Some of storms
may be severe.

.SPOTTER INFORMATION STATEMENT...

SKYWARN Spotters will be needed tonight.

LSZ121-140>148-011130-
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-
249 PM CDT Fri Aug 31 2018

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

.DAY ONE...This afternoon and Tonight

Thunderstorms are possible over the nearshore waters of western
Lake Superior this afternoon through early Saturday morning, with
some strong to severe thunderstorms possible. The main threats
will be large hail and wind gusts greater than 35 knots, along
with frequent lightning.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday

Several rounds of thunderstorms are expected from Sunday through
the upcoming week. Some of the storms may be strong to severe.

Huyck/DAP

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, Aug 31, 5:56 PM CDT, 2 hours 46 minutes before

Special Weather Statement
National Weather Service Duluth MN
556 PM CDT FRI AUG 31 2018

MNZ025-033-034-312315-
Crow Wing-North Cass-South Cass-
556 PM CDT FRI AUG 31 2018

...AN AREA OF STRONG THUNDERSTORMS WILL AFFECT SOUTHWESTERN CASS AND
WESTERN CROW WING COUNTIES...

At 556 PM CDT, an area of strong thunderstorms was located over
Wadena County, moving east at 50 mph.

Wind gusts up to 50 mph, nickel size hail, torrential rainfall, and
frequent cloud to ground lightning can be expected with these storms.

Locations impacted include...
Baxter, Breezy Point, Pequot Lakes, Nisswa, Pine River, Backus,
Poplar, Leader, Gull Lake, Woman Lake, Lake Shore, East Gull Lake,
Oshawa, Jenkins, Chickamaw Beach, Lake Ada, Casino, Esterdy,
Pontoria, and Big Portage Lake.

Seek shelter inside a sturdy building and away from windows until
these storms pass. Get off area lakes now and seek shelter on shore
in a sturdy shelter or a hard-topped vehicle.

LAT...LON 4680 9479 4680 9466 4687 9466 4696 9427
      4637 9426 4636 9473 4638 9473 4638 9476
      4639 9478
TIME...MOT...LOC 2255Z 254DEG 46KT 4665 9476

 Miller

Local storm report, Aug 31, 6:06 PM CDT, 2 hours 36 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DULUTH MN
606 PM CDT FRI AUG 31 2018

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

0603 PM     HAIL             2 S BACKUS              46.79N 94.51W
08/31/2018  M0.25 INCH       CASS               MN   TRAINED SPOTTER

&&

SG

Local storm report, Aug 31, 7:19 PM CDT, 1 hour 23 minutes before

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

Local storm report, Aug 31, 8:10 PM CDT, 32 minutes before

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

Local storm report, Aug 31, 8:16 PM CDT, 26 minutes before

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

Local storm report, Aug 31, 8:19 PM CDT, 23 minutes before

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 31, 7:28 PM CDT	Severe Thunderstorm Warning	DLH	Aitkin, Carlton, Saint Louis	47 min
Aug 31, 8:02 PM CDT	Severe Thunderstorm Warning	DLH	Carlton, Lake, Saint Louis	43 min
Aug 31, 8:07 PM CDT	Special Marine Warning	DLH		53 min
Aug 31, 8:11 PM CDT	Severe Thunderstorm Warning	DLH	Aitkin	34 min
Aug 31, 8:47 PM CDT	Severe Thunderstorm Warning	DLH	Aitkin, Carlton, Saint Louis	28 min
Aug 31, 8:56 PM CDT	Severe Thunderstorm Warning	DLH	Aitkin	19 min
Aug 31, 9:00 PM CDT	Special Marine Warning	DLH		60 min
Aug 31, 9:18 PM CDT	Severe Thunderstorm Warning	DLH	Aitkin, Carlton	27 min
Aug 31, 9:24 PM CDT	Severe Thunderstorm Warning	DLH	Cook, Lake	51 min
Aug 31, 9:26 PM CDT	Special Marine Warning	DLH		64 min
Aug 31, 9:41 PM CDT	Severe Thunderstorm Warning	DLH	Carlton, Saint Louis	34 min
Aug 31, 10:02 PM CDT	Severe Thunderstorm Warning	DLH	Carlton, Saint Louis	28 min
Aug 31, 10:03 PM CDT	Special Marine Warning	DLH		57 min
Aug 31, 10:08 PM CDT	Severe Thunderstorm Warning	DLH	Cook	52 min
Aug 31, 10:11 PM CDT	Special Weather Statement	DLH	Lake	34 min
Aug 31, 10:49 PM CDT	Special Weather Statement	DLH	Aitkin	26 min
Aug 31, 10:54 PM CDT	Special Marine Warning	DLH		51 min
Aug 31, 10:56 PM CDT	Areal Flood Advisory	DLH	Carlton, Saint Louis	64 min
Aug 31, 11:31 PM CDT	Special Marine Warning	DLH		44 min
Aug 31, 11:42 PM CDT	Special Weather Statement	DLH	Carlton	33 min
Sep 1, 12:14 AM CDT	Special Marine Warning	DLH		31 min
Sep 1, 12:16 AM CDT	Special Weather Statement	DLH		44 min
Sep 1, 12:42 AM CDT	Severe Thunderstorm Warning	DLH	Lake, Saint Louis	33 min
Sep 1, 12:46 AM CDT	Special Marine Warning	DLH		44 min
Sep 1, 1:25 AM CDT	Special Weather Statement	DLH	Lake	35 min
Sep 1, 4:18 AM CDT	Special Weather Statement	DLH		27 min
Sep 1, 4:45 AM CDT	Special Weather Statement	DLH		30 min
Sep 1, 4:46 AM CDT	Dense Fog Advisory	DLH	Aitkin, Cass, Crow Wing, Itasca, Saint Louis	2 hr
Sep 1, 7:02 AM CDT	Dense Fog Advisory	DLH	Aitkin, Cass, Crow Wing, Itasca, Saint Louis	58 min
Aug 31, 10:31 PM CDT	Severe Thunderstorm Warning	DLH	Douglas	29 min
Aug 31, 10:59 PM CDT	Special Weather Statement	DLH	Bayfield	16 min
Aug 31, 11:15 PM CDT	Special Weather Statement	DLH	Bayfield	45 min
Aug 31, 11:22 PM CDT	Severe Thunderstorm Warning	DLH	Ashland, Bayfield	23 min
Aug 31, 11:36 PM CDT	Areal Flood Advisory	DLH	Bayfield, Douglas	114 min
Aug 31, 11:47 PM CDT	Special Weather Statement	DLH	Ashland	28 min
Sep 1, 9:11 AM CDT	Special Weather Statement	DLH	Price	34 min

Nearby

Severe Thunderstorm Warnings in Minnesota, 2018 Every severe thunderstorm warning in 2018

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.