Alert archive / Minnesota / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 201, NWS Duluth, MN

September 12, 2018Cook County, Lake County, Minnesota

NWS Duluth, MN issued this severe thunderstorm warning at Sep 12, 2018, 5:46 PM CDT for Cook County, Lake County, Minnesota. It was in force for 44 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, 2018, 5:46 PM CDT (22:46 UTC)
Expired: Sep 12, 2018, 6:30 PM CDT
In force: 44 min
Issued by: NWS Duluth, MN
Area: Storm-based polygon
Hail: 1.0 in
Wind: 50.0 mph

Counties Cook County, MN, Lake County, MN

The radar

The Duluth radar (KDLH), 131 km from the middle of the area, began a volume at 22:46 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, 10.8 hours before the alert went out and 199 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 602 m above ground
0-6 km bulk shear: 43 kt
0-1 km storm-relative helicity: 44 m²/s²
0-3 km storm-relative helicity: 54 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 Duluth, MN wrote its last area forecast discussion before this severe thunderstorm warning went out at Sep 12, 3:10 PM CDT, 2 hours 36 minutes earlier.

Area forecast discussion, Sep 12, 3:10 PM CDT, 2 hours 36 minutes before

Area Forecast Discussion
National Weather Service Duluth MN
310 PM CDT Wed Sep 12 2018

.SHORT TERM...(This evening through Thursday)
Issued at 308 PM CDT Wed Sep 12 2018

Main issue in the short term this afternoon is the thunderstorm
activity set to move through Koochiching and (northwestern) Itasca
Counties.  The storms have seen some heavy rain and plenty of
lightning, but the environment would suggest they shouldn't get too
strong.  There is limited instability to work with (and it's all
elevated), however they are riding along the MUCAPE gradient and mid
level lapse rates rather strong of 8C/km.  Expect storms this
afternoon mainly to impact Koochiching County for the next few
hours, before the storms all lift north of the border.

The frontal boundary over the area this afternoon now extends from
near Duluth to just north of Brainerd and it will begin lifting
northward this afternoon, eventually lifting into Canada by 06Z
tonight.  As the front lifts northward, much drier air in the 850-
500mb layer will lift through the area from south to north, clearing
out current cloud cover and leading to partly cloudy to clear skies
overnight.

For Thursday, the ridging across the eastern half of the CONUS and
the western trough will continue to lead to a strong southwest to
northeast oriented jet from California through the western
Dakotas and toward Hudson Bay. This places us southeast of the
main jet and track of repeated upper level shortwaves, but
tomorrow afternoon we may get grazed by an upper level vort max,
so continued a chance for thunderstorms mainly north and west of
Grand Rapids.

.LONG TERM...(Thursday night through Wednesday)
Issued at 308 PM CDT Wed Sep 12 2018

The main story in the long term is the stagnant pattern that could
last several days.  Hurricane Florence is the big focus of the
overall pattern and it's potential affect on the progression of
systems.  The GFS and EC are a bit at odds with the progression
developing a strong system early next week with a frontal passage.
The GFS still wants to bring this front through Monday-Monday night,
while the slower ECMWF would bring it through on Tuesday.  Given the
presence of Florence, tend to lean toward a slower progression and a
continued stagnant pattern.

Showers and thunderstorms are going to be possible through the
weekend as the front from today starts to drift back south and stall
out across northern MN.  Temperatures will continue to be above
normal until the main cold front moves through sometime early to
middle of next week.

&&

.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
Issued at 1155 AM CDT Wed Sep 12 2018

Didn't make any significant changes to the previous forecasts,
with updates mainly to account for current conditions and trends.
Warm advection will push north through the first part of the
forecast, with the baroclinic zone and chances for precipitation
lifting north of the area as mid-level ridging becomes more
established. Could see some chances for SHRA/TSRA return after the
end of the period as another wave moves northeast along the
baroclinic zone.

&&

.PRELIMINARY POINT TEMPS/POPS...
DLH  62  77  65  76 /   0   0  30  20
INL  62  74  62  71 /  10  40  40  30
BRD  63  78  67  78 /   0   0  20  20
HYR  61  78  64  78 /   0   0  10  10
ASX  62  79  63  78 /   0   0  10  10

&&

.DLH WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
LS...Small Craft Advisory until 4 PM CDT this afternoon for LSZ140-
     141.

&&

SHORT TERM...WFO MPX
LONG TERM...WFO MPX
AVIATION...WFO MPX

Hazardous weather outlook, Sep 12, 5:21 PM CDT, 25 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>

In the hours before

Special weather statement, Sep 12, 4:43 PM CDT, 1 hour 3 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, Sep 12, 4:52 PM CDT, 54 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, Sep 12, 5:01 PM CDT, 45 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, 5:16 PM CDT, 30 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, Sep 12, 5:21 PM CDT, 25 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, 5:38 PM CDT, 8 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
Sep 12, 9:10 AM CDT	Special Weather Statement	DLH	Pine	50 min
Sep 12, 2:19 PM CDT	Special Weather Statement	DLH	Koochiching	26 min
Sep 12, 2:37 PM CDT	Special Weather Statement	DLH	Itasca	23 min
Sep 12, 2:40 PM CDT	Special Weather Statement	DLH	Koochiching	35 min
Sep 12, 3:05 PM CDT	Special Weather Statement	DLH	Koochiching	25 min
Sep 12, 3:17 PM CDT	Special Weather Statement	DLH	Saint Louis	13 min
Sep 12, 3:23 PM CDT	Severe Thunderstorm Warning	DLH	Itasca, Koochiching, Saint Louis	22 min
Sep 12, 3:31 PM CDT	Special Weather Statement	DLH	Koochiching	14 min
Sep 12, 3:42 PM CDT	Severe Thunderstorm Warning	DLH	Saint Louis	18 min
Sep 12, 3:47 PM CDT	Special Weather Statement	DLH	Koochiching	13 min
Sep 12, 3:58 PM CDT	Severe Thunderstorm Warning	DLH	Saint Louis	17 min
Sep 12, 4:01 PM CDT	Severe Thunderstorm Warning	DLH	Koochiching, Saint Louis	29 min
Sep 12, 4:11 PM CDT	Severe Thunderstorm Warning	DLH	Saint Louis	23 min
Sep 12, 4:30 PM CDT	Special Weather Statement	DLH		15 min
Sep 12, 4:43 PM CDT	Special Weather Statement	DLH		32 min
Sep 12, 5:16 PM CDT	Special Weather Statement	DLH		29 min
Sep 12, 5:38 PM CDT	Special Weather Statement	DLH		37 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.