Alert archive / Minnesota / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 207, NWS Duluth, MN

September 12, 2011Cook County, Minnesota

NWS Duluth, MN issued this severe thunderstorm warning at Sep 12, 2011, 2:33 PM CDT for Cook County, Minnesota. It was in force for 42 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
Sep 12, 2011, 2:33 PM CDT (19:33 UTC)
Expired
Sep 12, 2011, 3:15 PM CDT
In force
42 min
Issued by
NWS Duluth, MN
Area
Storm-based polygon
Hail
1.0 in
Wind
70.0 mph

County Cook County, MN

The radar

The Duluth radar (KDLH), 166 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

International Fa, MN (KINL), launched 12:00Z, 7.6 hours before the alert went out and 221 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 2011-09-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1282 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 2011-09-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 220 square meters per square second.193958Sfc1 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
1282 J/kg
Mixed-layer CIN
-118 J/kg
Mixed-layer LCL
1276 m above ground
0-6 km bulk shear
44 kt
0-1 km storm-relative helicity
220 m²/s²
0-3 km storm-relative helicity
272 m²/s²
Significant tornado parameter
0.0
Supercell composite
3.5

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 Sep 12, 12:56 PM CDT, 1 hour 37 minutes earlier.

Area forecast discussion, Sep 12, 12:56 PM CDT, 1 hour 37 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, Sep 12, 9:25 AM CDT, 5 hours 8 minutes before
HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE DULUTH MN
925 AM CDT MON SEP 12 2011

MNZ010>012-018>021-025-026-033>038-WIZ001>004-006>009-131030-
KOOCHICHING-NORTHERN ST. LOUIS-NORTHERN COOK/NORTHERN LAKE-
NORTHERN ITASCA-CENTRAL ST. LOUIS-SOUTHERN LAKE/LAKESHORE-
SOUTHERN COOK/LAKESHORE-NORTHERN CASS-SOUTHERN ITASCA-
SOUTHERN CASS-CROW WING-NORTHERN AITKIN-SOUTHERN AITKIN-
CARLTON/SOUTHERN ST. LOUIS-PINE-DOUGLAS-BAYFIELD-ASHLAND-IRON-
BURNETT-WASHBURN-SAWYER-PRICE-
925 AM CDT MON SEP 12 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR NORTHEAST MINNESOTA AND
NORTHWEST WISCONSIN.

.DAY ONE...TODAY AND TONIGHT

THUNDERSTORMS WILL BE POSSIBLE OVER MUCH OF THE NORTHLAND
TODAY...EXCEPT THE FAR SOUTHWEST. SOME OF THE STORMS MAY BE
SEVERE...ESPECIALLY OVER THE ARROWHEAD...PORTIONS OF THE IRON
RANGE...TWIN PORTS...AND A GOOD PORTION OF NORTHERN WISCONSIN THIS
AFTERNOON AND EVENING. THE MAIN THREATS WILL LARGE HAIL AND
DAMAGING WINDS.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

A COLD AIR MASS WILL SETTLE IN OVER THE NORTHLAND DURING THE
MIDDLE OF THE WEEK BRINGING NEAR OR BELOW FREEZING MORNING
TEMPERATURES...AND AREAS OF FROST...WEDNESDAY AND THURSDAY.

.SPOTTER INFORMATION STATEMENT...

SKYWARN SPOTTER ACTIVATION MAY BE NEEDED THIS AFTERNOON INTO THE
EVENING.

LSZ121-140>148-131030-
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-
925 AM CDT MON SEP 12 2011

THIS HAZARDOUS WEATHER OUTLOOK IS FOR THE NEARSHORE WATERS OF
WESTERN LAKE SUPERIOR.

.DAY ONE...TODAY AND TONIGHT

WINDS OF 20 TO 30 KNOTS WILL BE COMMON THIS AFTERNOON AND EVENING. A
SMALL CRAFT ADVISORY IS IN EFFECT FOR THE ENTIRE NEARSHORE WATERS OF
WESTERN LAKE SUPERIOR.

THUNDERSTORMS WITH WINDS IN EXCESS OF 30 KNOTS ARE EXPECTED THIS
AFTERNOON AND EVENING OVER THE WATERS OF LAKE SUPERIOR. A FEW OF
THE STORMS WILL HAVE THE POTENTIAL TO BECOME SEVERE WITH DAMAGING
WINDS AND LARGE HAIL.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY

A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR PERSISTENT GUSTY
NORTHWEST WINDS AND HAZARDOUS WAVE CONDITIONS THROUGH TUESDAY NIGHT.

KK

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, Sep 12, 1:22 PM CDT, 1 hour 11 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>
Special weather statement, Sep 12, 2:13 PM CDT, 20 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.

IssuedProductOfficeCountiesLasted
Sep 12, 4:04 AM CDTSmall Craft AdvisoryDLH65 hr
Sep 12, 1:22 PM CDTSpecial Weather StatementDLHCook38 min
Sep 12, 2:13 PM CDTSpecial Weather StatementDLHCook62 min
Sep 12, 3:26 PM CDTSpecial Weather StatementDLHLake34 min
Sep 12, 3:40 PM CDTSevere Thunderstorm WarningDLHCook, Lake50 min
Sep 12, 4:15 PM CDTSpecial Weather StatementDLHCarlton30 min
Sep 12, 4:17 PM CDTSevere Thunderstorm WarningDLHCook58 min
Sep 12, 4:21 PM CDTSpecial Weather StatementDLHLake24 min
Sep 12, 4:29 PM CDTSpecial Weather StatementDLHCarlton16 min
Sep 12, 4:47 PM CDTSpecial Marine WarningDLH50 min
Sep 12, 4:47 PM CDTSevere Thunderstorm WarningDLHSaint Louis13 min
Sep 12, 4:49 PM CDTSpecial Marine WarningDLH26 min
Sep 12, 4:56 PM CDTSpecial Marine WarningDLH49 min
Sep 12, 5:23 PM CDTSpecial Marine WarningDLH52 min
Sep 12, 4:41 PM CDTSpecial Weather StatementDLHDouglas19 min
Sep 12, 4:45 PM CDTSpecial Weather StatementDLHDouglas30 min
Sep 12, 5:02 PM CDTTornado WarningDLHDouglas18 min
Sep 12, 5:19 PM CDTSevere Thunderstorm WarningDLHBayfield, Douglas24 min
Sep 12, 5:31 PM CDTSevere Thunderstorm WarningDLHBayfield, Douglas29 min
Sep 12, 5:54 PM CDTSpecial Weather StatementDLHBayfield36 min
Sep 12, 6:00 PM CDTSevere Thunderstorm WarningDLHBayfield, Douglas, Sawyer45 min
Sep 12, 6:15 PM CDTSpecial Weather StatementDLHAshland, Iron60 min
Sep 12, 6:41 PM CDTSevere Thunderstorm WarningDLHAshland, Bayfield, Sawyer34 min
Sep 12, 6:50 PM CDTSpecial Weather StatementDLHIron25 min

Nearby

Severe Thunderstorm Warnings in Minnesota, 2011Every severe thunderstorm warning in 2011

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.