Alert archive / Iowa / Mesoscale Discussions in 2018
Mesoscale Discussion 306
The Storm Prediction Center issued this mesoscale discussion at May 1, 2018, 3:16 PM CDT for 30 counties in Iowa. It was in force for 89 min.
The area
The outline as issued.
The facts
- Issued
- May 1, 2018, 3:16 PM CDT (20:16 UTC)
- Expired
- May 1, 2018, 4:45 PM CDT
- In force
- 89 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 40%
All 30 counties
Audubon County, IA, Black Hawk County, IA, Boone County, IA, Bremer County, IA, Buena Vista County, IA, Butler County, IA, Calhoun County, IA, Carroll County, IA, Cerro Gordo County, IA, Crawford County, IA, Floyd County, IA, Franklin County, IA, Greene County, IA, Grundy County, IA, Guthrie County, IA, Hamilton County, IA, Hancock County, IA, Hardin County, IA, Harrison County, IA, Humboldt County, IA, Ida County, IA, Monona County, IA, Pocahontas County, IA, Pottawattamie County, IA, Sac County, IA, Shelby County, IA, Story County, IA, Webster County, IA, Woodbury County, IA, Wright County, IA
The radar
The Des Moines radar (KDMX), 102 km from the middle of the area, began a volume at 20:17 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 watches that followed
Watches SPC issued over any of the same counties within four hours of this discussion.
The nearest sounding before it
Omaha, NE (KOAX), launched 12:00Z, 8.3 hours before the alert went out and 181 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.
- Mixed-layer CAPE
- 787 J/kg
- Mixed-layer CIN
- -48 J/kg
- Mixed-layer LCL
- 955 m above ground
- 0-6 km bulk shear
- 53 kt
- 0-1 km storm-relative helicity
- 74 m²/s²
- 0-3 km storm-relative helicity
- 57 m²/s²
- Significant tornado parameter
- 0.3
- Supercell composite
- 2.2
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.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 1, 10:24 AM CDT | Mesoscale Discussion | SPC | Appanoose, Clarke, Decatur, Jasper, Lucas, Madison and 10 more | 3 hr |
| May 1, 2:47 PM CDT | Tornado Watch | SPC | Harrison, Monona, Pottawattamie, Shelby | 9 hr |
| May 1, 5:00 PM CDT | Mesoscale Discussion | SPC | Cass, Fremont, Mills, Montgomery, Page, Pottawattamie | 2 hr |
| May 1, 5:47 PM CDT | Severe Thunderstorm Watch | SPC | Adair, Allamakee, Audubon, Benton, Black Hawk, Boone and 44 more | 6 hr |
Nearby
Mesoscale Discussions in Iowa, 2018Every mesoscale discussion 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.