Alert archive / Minnesota / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 182, NWS Duluth, MN

August 31, 2018Aitkin County, Minnesota

NWS Duluth, MN issued this severe thunderstorm warning at Aug 31, 2018, 8:11 PM CDT for Aitkin County, Minnesota. It was in force for 34 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, 8:11 PM CDT (01:11 UTC)
Expired
Aug 31, 2018, 8:45 PM CDT
In force
34 min
Issued by
NWS Duluth, MN
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

County Aitkin County, MN

The radar

The Duluth radar (KDLH), 95 km from the middle of the area, began a volume at 01:12 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.

IssuedProductOfficeLasted
Aug 31, 6:55 PM CDTSevere Thunderstorm WatchSPC5 hr

The nearest sounding before it

International Fa, MN (KINL), launched 00:00Z, 1.2 hours before the alert went out and 218 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 00:00Z on 2018-09-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 424 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 00:00Z on 2018-09-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 124 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
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 28 minutes earlier.

Area forecast discussion, Aug 31, 6:43 PM CDT, 1 hour 28 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 22 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, 3:19 PM CDT, 4 hours 52 minutes before
Special Weather Statement
National Weather Service Duluth MN
319 PM CDT FRI AUG 31 2018

MNZ010-312030-
Koochiching-
319 PM CDT FRI AUG 31 2018

...A LINE OF STRONG THUNDERSTORMS WILL AFFECT NORTHWESTERN
KOOCHICHING COUNTY...

At 319 PM CDT, strong thunderstorms were along a line extending from
near Birchdale, to 11 miles southwest of Manitou, to 14 miles
northwest of Lower Red Lake, and moving northeast at 35 mph.

Wind gusts up to 45 mph, dime size hail, heavy downpours, and
frequent cloud to ground lightning can be expected with these storms.

Locations impacted include...
Birchdale, Pelland, Loman, Manitou, and Indus.

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

These storms may intensify, please monitor local media outlets for
additional information and possible warnings from the National
Weather Service.

LAT...LON 4865 9423 4863 9384 4857 9380 4853 9382
      4852 9380 4853 9356 4845 9356 4824 9442
      4862 9442 4867 9426
TIME...MOT...LOC 2019Z 246DEG 31KT 4863 9406 4850 9416 4805 9529

Huyck
Local storm report, Aug 31, 4:22 PM CDT, 3 hours 49 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE DULUTH MN
422 PM CDT FRI AUG 31 2018

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

0340 PM     HAIL             1 NW LOMAN              48.52N 93.82W
08/31/2018  E0.25 INCH       KOOCHICHING        MN   AMATEUR RADIO

            RADAR ESTIMATED TIME.

&&

KC
Special weather statement, Aug 31, 5:56 PM CDT, 2 hours 15 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 5 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, 52 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, 1 minute 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.

IssuedProductOfficeCountiesLasted
Aug 31, 7:28 PM CDTSevere Thunderstorm WarningDLHAitkin, Carlton, Saint Louis47 min
Aug 31, 8:02 PM CDTSevere Thunderstorm WarningDLHCarlton, Lake, Saint Louis43 min
Aug 31, 8:07 PM CDTSpecial Marine WarningDLH53 min
Aug 31, 8:42 PM CDTSevere Thunderstorm WarningDLHCook, Lake, Saint Louis48 min
Aug 31, 8:47 PM CDTSevere Thunderstorm WarningDLHAitkin, Carlton, Saint Louis28 min
Aug 31, 8:56 PM CDTSevere Thunderstorm WarningDLHAitkin19 min
Aug 31, 9:00 PM CDTSpecial Marine WarningDLH60 min
Aug 31, 9:18 PM CDTSevere Thunderstorm WarningDLHAitkin, Carlton27 min
Aug 31, 9:24 PM CDTSevere Thunderstorm WarningDLHCook, Lake51 min
Aug 31, 9:26 PM CDTSpecial Marine WarningDLH64 min
Aug 31, 9:41 PM CDTSevere Thunderstorm WarningDLHCarlton, Saint Louis34 min
Aug 31, 10:02 PM CDTSevere Thunderstorm WarningDLHCarlton, Saint Louis28 min
Aug 31, 10:03 PM CDTSpecial Marine WarningDLH57 min
Aug 31, 10:08 PM CDTSevere Thunderstorm WarningDLHCook52 min
Aug 31, 10:11 PM CDTSpecial Weather StatementDLHLake34 min
Aug 31, 10:49 PM CDTSpecial Weather StatementDLHAitkin26 min
Aug 31, 10:54 PM CDTSpecial Marine WarningDLH51 min
Aug 31, 10:56 PM CDTAreal Flood AdvisoryDLHCarlton, Saint Louis64 min
Aug 31, 11:31 PM CDTSpecial Marine WarningDLH44 min
Aug 31, 11:42 PM CDTSpecial Weather StatementDLHCarlton33 min
Sep 1, 12:14 AM CDTSpecial Marine WarningDLH31 min
Sep 1, 12:16 AM CDTSpecial Weather StatementDLH44 min
Sep 1, 12:42 AM CDTSevere Thunderstorm WarningDLHLake, Saint Louis33 min
Sep 1, 12:46 AM CDTSpecial Marine WarningDLH44 min
Sep 1, 1:25 AM CDTSpecial Weather StatementDLHLake35 min
Sep 1, 4:18 AM CDTSpecial Weather StatementDLH27 min
Sep 1, 4:45 AM CDTSpecial Weather StatementDLH30 min
Sep 1, 4:46 AM CDTDense Fog AdvisoryDLHAitkin, Cass, Crow Wing, Itasca, Saint Louis2 hr
Sep 1, 7:02 AM CDTDense Fog AdvisoryDLHAitkin, Cass, Crow Wing, Itasca, Saint Louis58 min
Aug 31, 10:31 PM CDTSevere Thunderstorm WarningDLHDouglas29 min
Aug 31, 10:59 PM CDTSpecial Weather StatementDLHBayfield16 min
Aug 31, 11:15 PM CDTSpecial Weather StatementDLHBayfield45 min
Aug 31, 11:22 PM CDTSevere Thunderstorm WarningDLHAshland, Bayfield23 min
Aug 31, 11:36 PM CDTAreal Flood AdvisoryDLHBayfield, Douglas114 min
Aug 31, 11:47 PM CDTSpecial Weather StatementDLHAshland28 min
Sep 1, 9:11 AM CDTSpecial Weather StatementDLHPrice34 min

Nearby

Severe Thunderstorm Warnings in Minnesota, 2018Every 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.