Alert archive / Iowa / Mesoscale Discussions in 2020

Mesoscale Discussion 1449

August 10, 202023 counties in Iowa

The Storm Prediction Center issued this mesoscale discussion at Aug 10, 2020, 9:45 AM CDT for 23 counties in Iowa. It was in force for 90 min.

The area

The outline as issued.

The facts

Issued
Aug 10, 2020, 9:45 AM CDT (14:45 UTC)
Expired
Aug 10, 2020, 11:15 AM CDT
In force
90 min
Issued by
the Storm Prediction Center
Concerning
Severe thunderstorm watch 425
All 23 counties

Adair County, IA, Audubon County, IA, Boone County, IA, Calhoun County, IA, Carroll County, IA, Cass County, IA, Dallas County, IA, Greene County, IA, Grundy County, IA, Guthrie County, IA, Hamilton County, IA, Hardin County, IA, Jasper County, IA, Madison County, IA, Mahaska County, IA, Marion County, IA, Marshall County, IA, Polk County, IA, Poweshiek County, IA, Story County, IA, Tama County, IA, Warren County, IA, Webster County, IA

The radar

The Des Moines radar (KDMX), 16 km from the middle of the area, began a volume at 14:48 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 12:00Z, 2.8 hours before the alert went out and 209 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 12:00Z on 2020-08-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2619 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 12:00Z on 2020-08-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 103 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
2619 J/kg
Mixed-layer CIN
-283 J/kg
Mixed-layer LCL
1590 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
103 m²/s²
0-3 km storm-relative helicity
100 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

<!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>

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 9, 10:59 PM CDTMesoscale DiscussionSPCAllamakee, Bremer, Buena Vista, Butler, Calhoun, Carroll and 32 more3 hr
Aug 10, 3:19 AM CDTMesoscale DiscussionSPCLyon, O'Brien, Osceola, Plymouth, Sioux, Woodbury116 min
Aug 10, 6:06 AM CDTSevere Thunderstorm WatchSPCBuena Vista, Cherokee, Clay, Dickinson, Ida, Lyon and 6 more5 hr
Aug 10, 7:46 AM CDTMesoscale DiscussionSPCIda, Monona, Plymouth, Woodbury89 min
Aug 10, 8:40 AM CDTMesoscale DiscussionSPCAdair, Adams, Appanoose, Audubon, Boone, Calhoun and 39 more65 min
Aug 10, 8:56 AM CDTSevere Thunderstorm WatchSPCAdair, Audubon, Black Hawk, Boone, Bremer, Butler and 30 more5 hr
Aug 10, 10:42 AM CDTMesoscale DiscussionSPCAllamakee, Buchanan, Cedar, Chickasaw, Clayton, Clinton and 18 more93 min
Aug 10, 11:00 AM CDTMesoscale DiscussionSPCBoone, Dallas, Jasper, Mahaska, Marion, Marshall and 5 more60 min
Aug 10, 11:26 AM CDTSevere Thunderstorm Watch PDSSPCBenton, Buchanan, Cedar, Clayton, Clinton, Delaware and 17 more7 hr
Aug 10, 12:14 PM CDTMesoscale DiscussionSPCBenton, Cedar, Clinton, Iowa, Jackson, Johnson and 10 more91 min
Aug 10, 1:36 PM CDTMesoscale DiscussionSPCClinton, Jackson, Scott114 min

Nearby

Mesoscale Discussions in Iowa, 2020Every mesoscale discussion in 2020

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.