Alert archive / Iowa / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 158, NWS Omaha, NE

June 19, 20184 counties in Iowa

NWS Omaha, NE issued this severe thunderstorm warning at Jun 19, 2018, 1:23 AM CDT for 4 counties in Iowa. It was in force for 41 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 19, 2018, 1:23 AM CDT (06:23 UTC)
Expired
Jun 19, 2018, 2:04 AM CDT
In force
41 min
Issued by
NWS Omaha, NE
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Fremont County, IA, Mills County, IA, Montgomery County, IA, Page County, IA

The radar

The Omaha radar (KOAX), 95 km from the middle of the area, began a volume at 06:24 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

Omaha, NE (KOAX), launched 00:00Z, 6.4 hours before the alert went out and 96 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, Omaha, NE at 00:00Z on 2018-06-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 992 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, Omaha, NE at 00:00Z on 2018-06-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 301 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
992 J/kg
Mixed-layer CIN
-119 J/kg
Mixed-layer LCL
896 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
301 m²/s²
0-3 km storm-relative helicity
336 m²/s²
Significant tornado parameter
0.0
Supercell composite
7.2

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 Omaha, NE wrote its last area forecast discussion before this severe thunderstorm warning went out at Jun 18, 11:35 PM CDT, 1 hour 48 minutes earlier.

Area forecast discussion, Jun 18, 11:35 PM CDT, 1 hour 48 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, Jun 18, 8:55 PM CDT, 4 hours 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>

In the hours before

Local storm report, Jun 18, 10:36 PM CDT, 2 hours 47 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 18, 10:37 PM CDT, 2 hours 46 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, Jun 18, 10:39 PM CDT, 2 hours 44 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 18, 11:59 PM CDT, 1 hour 24 minutes before
Special Weather Statement
National Weather Service Omaha/Valley Nebraska
1159 PM CDT MON JUN 18 2018

IAZ055-069-079-NEZ045-052-053-067-190530-
Pottawattamie IA-Mills IA-Harrison IA-Cass NE-Sarpy NE-Washington NE-
Douglas NE-
1159 PM CDT MON JUN 18 2018

...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN MILLS...WESTERN
POTTAWATTAMIE...SOUTHEASTERN HARRISON...NORTHEASTERN SARPY...
SOUTHEASTERN WASHINGTON...EASTERN DOUGLAS AND NORTHEASTERN CASS
COUNTIES UNTIL 1230 AM CDT...

At 1158 PM CDT, Doppler radar was tracking strong thunderstorms along
a line extending from 6 miles south of Fort Calhoun to near
Papillion. Movement was northeast at 40 mph.

Winds in excess of 40 mph and heavy rain will be possible with these
storms.

Locations impacted include...
Omaha, Council Bluffs, Bellevue, Papillion, La Vista, Ralston, Cedar
Creek, Offutt AFB, Carter Lake, Crescent, Lake Manawa State Park,
Camp Maha, Hitchcock Nature Center and Narrows River Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Heavy rain is also occurring with these storms, and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 4155 9570 4115 9572 4101 9612 4142 9607
TIME...MOT...LOC 0458Z 229DEG 35KT 4137 9601 4113 9605

MILLER
Special weather statement, Jun 19, 12:48 AM CDT, 35 minutes before
Special Weather Statement
National Weather Service Omaha/Valley Nebraska
1248 AM CDT TUE JUN 19 2018

IAZ079-090-NEZ067-068-190615-
Mills IA-Fremont IA-Cass NE-Otoe NE-
1248 AM CDT TUE JUN 19 2018

...SIGNIFICANT WEATHER ADVISORY FOR NORTHERN FREMONT...WESTERN
MILLS...NORTHEASTERN OTOE AND EASTERN CASS COUNTIES UNTIL 115 AM
CDT...

At 1248 AM CDT, Doppler radar was tracking a strong thunderstorm near
Murray, or 21 miles south of Omaha, moving northeast at 30 mph.

Wind gusts of 50 to 55 mph will be possible with this storm.

Locations impacted include...
Plattsmouth, Glenwood, Pacific Junction, Murray, Union, Nehawka,
Tabor, Thurman and Randolph.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

&&

LAT...LON 4075 9596 4097 9605 4115 9573 4077 9548
TIME...MOT...LOC 0548Z 245DEG 24KT 4095 9593

KERN
Special weather statement, Jun 19, 12:59 AM CDT, 24 minutes before
Special Weather Statement
National Weather Service Omaha/Valley Nebraska
1259 AM CDT TUE JUN 19 2018

IAZ069-079-080-090-091-190645-
Pottawattamie IA-Mills IA-Page IA-Fremont IA-Montgomery IA-
1259 AM CDT TUE JUN 19 2018

...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN FREMONT...
MONTGOMERY...MILLS...SOUTHEASTERN POTTAWATTAMIE AND NORTHERN PAGE
COUNTIES UNTIL 145 AM CDT...

At 1259 AM CDT, Doppler radar was tracking a strong thunderstorm near
Malvern, or 26 miles southeast of Omaha, moving northeast at 35 mph.

Wind gusts of 50 to 55 mph will be possible with this storm.

Locations impacted include...
Red Oak, Shenandoah, Oakland, Villisca, Malvern, Treynor, Carson,
Essex, Stanton, Farragut, Emerson, Elliott, Riverton, Macedonia,
Silver City, Henderson, Randolph, Hastings, Grant and Imogene.

LAT...LON 4069 9558 4119 9573 4139 9517 4135 9515
      4116 9516 4116 9493 4079 9493
TIME...MOT...LOC 0559Z 237DEG 29KT 4104 9559

KERN

The office that day

Everything else NWS Omaha, NE issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 18, 7:13 PM CDTSevere Thunderstorm WarningOAXThurston32 min
Jun 18, 7:43 PM CDTSpecial Weather StatementOAXKnox32 min
Jun 18, 9:43 PM CDTSpecial Weather StatementOAXButler32 min
Jun 18, 10:11 PM CDTSpecial Weather StatementOAXWayne34 min
Jun 18, 10:20 PM CDTSpecial Weather StatementOAXSaunders40 min
Jun 18, 10:37 PM CDTSpecial Weather StatementOAXThurston38 min
Jun 18, 11:59 PM CDTSpecial Weather StatementOAXDouglas31 min
Jun 19, 12:29 AM CDTSevere Thunderstorm WarningOAXCass, Douglas, Sarpy31 min
Jun 19, 6:24 AM CDTSpecial Weather StatementOAXColfax36 min
Jun 19, 6:29 AM CDTSpecial Weather StatementOAXBoone31 min
Jun 19, 6:51 AM CDTSevere Thunderstorm WarningOAXBoone, Platte24 min
Jun 19, 7:15 AM CDTAreal Flood AdvisoryOAXDouglas, Sarpy3 hr
Jun 19, 8:00 AM CDTAreal Flood AdvisoryOAXDouglas, Sarpy3 hr
Jun 19, 8:48 AM CDTAreal Flood WarningOAXDouglas3 hr
Jun 19, 9:44 AM CDTRiver Flood WarningOAXNemaha43 days
Jun 19, 9:44 AM CDTRiver Flood WarningOAXRichardson36 days
Jun 19, 3:16 PM CDTFlash Flood WatchOAXCass, Dodge, Douglas, Gage, Jefferson, Lancaster and 6 more16 hr
Jun 19, 3:55 PM CDTSevere Thunderstorm WarningOAXJefferson, Saline65 min
Jun 19, 4:51 PM CDTSevere Thunderstorm WarningOAXLancaster, Saline54 min
Jun 19, 5:00 PM CDTSevere Thunderstorm WarningOAXJefferson30 min
Jun 19, 5:09 PM CDTSpecial Weather StatementOAXLancaster36 min
Jun 19, 5:28 PM CDTSpecial Weather StatementOAXJefferson47 min
Jun 19, 5:34 PM CDTAreal Flood AdvisoryOAXJefferson3 hr
Jun 19, 5:42 PM CDTSpecial Weather StatementOAXLancaster33 min
Jun 19, 6:07 PM CDTFlash Flood WarningOAXJefferson3 hr
Jun 19, 6:13 PM CDTFlash Flood WarningOAXGage, Lancaster, Saline3 hr
Jun 18, 7:29 PM CDTSpecial Weather StatementOAXShelby31 min
Jun 18, 11:50 PM CDTAreal Flood AdvisoryOAXMills, Pottawattamie3 hr
Jun 19, 12:48 AM CDTSpecial Weather StatementOAXMills27 min
Jun 19, 12:59 AM CDTSpecial Weather StatementOAXMills, Montgomery46 min
Jun 19, 6:06 PM CDTSpecial Weather StatementOAXShelby39 min

Nearby

Severe Thunderstorm Warnings in Iowa, 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.