Alert archive / Oregon / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 1, NWS Portland, OR

June 20, 2018Linn County, Oregon

NWS Portland, OR issued this severe thunderstorm warning at Jun 20, 2018, 2:22 PM PDT for Linn County, Oregon. It was in force for 23 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: Jun 20, 2018, 2:22 PM PDT (21:22 UTC)
Expired: Jun 20, 2018, 2:45 PM PDT
In force: 23 min
Issued by: NWS Portland, OR
Area: Storm-based polygon
Hail: 1.0 in
Wind: 50.0 mph

County Linn County, OR

The radar

The Portland,OR radar (KRTX), 140 km from the middle of the area, began a volume at 21:23 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

Medford/Jackson, OR (KMFR), launched 12:00Z, 9.4 hours before the alert went out and 237 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: 1850 m above ground
0-6 km bulk shear: 20 kt
0-1 km storm-relative helicity: 25 m²/s²
0-3 km storm-relative helicity: 91 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 Portland, OR wrote its last area forecast discussion before this severe thunderstorm warning went out at Jun 20, 9:49 AM PDT, 4 hours 33 minutes earlier.

Area forecast discussion, Jun 20, 9:49 AM PDT, 4 hours 33 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, Jun 20, 1:22 PM PDT, 1 hour 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, Jun 20, 1:51 PM PDT, 31 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, Jun 20, 1:53 PM PDT, 29 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, Jun 20, 1:58 PM PDT, 24 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, Jun 20, 2:14 PM PDT, 8 minutes before

Special Weather Statement
National Weather Service Portland OR
214 PM PDT WED JUN 20 2018

ORZ011-202145-
Northern Oregon Cascades OR-
214 PM PDT WED JUN 20 2018

...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN LINN COUNTY UNTIL
245 PM PDT...

At 213 PM PDT, Doppler radar was tracking a strong thunderstorm near
Tombstone Summit, or 24 miles south of Detroit. This storm was nearly
stationary.

Dime size hail and winds in excess of 30 mph will be possible with
this storm.

Locations impacted include...
Tombstone Summit and Santiam Junction.

This includes the following highways in Oregon...
 U.S. Highway 20 east of Albany near mile marker 57, and between mile
markers 59 and 77.
 State Highway 22 east of Salem between mile markers 70 and 81.
 State Highway 126 from McKenzie Bridge to the Santiam Highway
between mile markers 1 and 11.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If threatening weather approaches your area, take shelter in a sturdy
building.

Torrential rainfall is also occurring with this storm, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 4427 12198 4429 12221 4438 12222 4452 12217
      4459 12195 4445 12190 4434 12188
TIME...MOT...LOC 2113Z 213DEG 1KT 4438 12203

Weagle

The office that day

Everything else NWS Portland, OR issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jun 20, 1:22 PM PDT	Special Weather Statement	PQR	Linn	23 min
Jun 20, 1:51 PM PDT	Special Weather Statement	PQR	Linn	24 min
Jun 20, 1:53 PM PDT	Special Weather Statement	PQR	Lane	22 min
Jun 20, 2:14 PM PDT	Special Weather Statement	PQR	Linn	31 min
Jun 20, 2:42 PM PDT	Special Weather Statement	PQR	Linn	33 min
Jun 20, 2:46 PM PDT	Special Weather Statement	PQR	Linn	29 min
Jun 20, 2:54 PM PDT	Severe Thunderstorm Warning	PQR	Lane	36 min
Jun 20, 2:57 PM PDT	Special Weather Statement	PQR	Clackamas	33 min
Jun 20, 3:06 PM PDT	Severe Thunderstorm Warning	PQR	Linn	24 min
Jun 20, 3:08 PM PDT	Severe Thunderstorm Warning	PQR	Marion	37 min
Jun 20, 3:33 PM PDT	Severe Thunderstorm Warning	PQR	Clackamas	27 min
Jun 20, 3:42 PM PDT	Special Weather Statement	PQR	Hood River	33 min
Jun 20, 3:54 PM PDT	Severe Thunderstorm Warning	PQR	Clackamas	17 min
Jun 20, 3:58 PM PDT	Special Weather Statement	PQR	Hood River	47 min
Jun 20, 4:32 PM PDT	Severe Thunderstorm Warning	PQR	Clackamas	28 min
Jun 20, 4:53 PM PDT	Special Weather Statement	PQR		37 min
Jun 20, 1:58 PM PDT	Special Weather Statement	PQR	Skamania	32 min

Nearby

Severe Thunderstorm Warnings in Oregon, 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.