Alert archive / Illinois / Mesoscale Discussions in 2012
Mesoscale Discussion 1979
The Storm Prediction Center issued this mesoscale discussion at Sep 21, 2012, 4:59 PM CDT for 29 counties in Illinois; City of Saint Louis, Missouri. It was in force for 91 min.
The area
The outline as issued.
The facts
- Issued
- Sep 21, 2012, 4:59 PM CDT (21:59 UTC)
- Expired
- Sep 21, 2012, 6:30 PM CDT
- In force
- 91 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 40%
All 30 counties
Bond County, IL, Clay County, IL, Clinton County, IL, Crawford County, IL, Cumberland County, IL, Edwards County, IL, Effingham County, IL, Fayette County, IL, Franklin County, IL, Hamilton County, IL, Jackson County, IL, Jasper County, IL, Jefferson County, IL, Lawrence County, IL, Macoupin County, IL, Madison County, IL, Marion County, IL, Montgomery County, IL, Perry County, IL, Randolph County, IL, Richland County, IL, Saint Clair County, IL, Saline County, IL, Shelby County, IL, Wabash County, IL, Washington County, IL, Wayne County, IL, White County, IL, Williamson County, IL, City of Saint Louis, MO
The radar
The Evansville,IN radar (KVWX), 106 km from the middle of the area, began a volume at 22:00 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
Lincoln, IL (KILX), launched 12:00Z, 10.0 hours before the alert went out and 173 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 2528 m above ground
- 0-6 km bulk shear
- 63 kt
- 0-1 km storm-relative helicity
- 120 m²/s²
- 0-3 km storm-relative helicity
- 152 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
<!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 |
|---|---|---|---|---|
| Sep 21, 1:36 PM CDT | Mesoscale Discussion | SPC | Bureau, Cass, Champaign, Christian, Clark, Clay and 40 more | 84 min |
| Sep 21, 6:30 PM CDT | Mesoscale Discussion | SPC | Clark, Clay, Coles, Crawford, Cumberland, Douglas and 10 more | 3 hr |
| Sep 21, 12:45 AM CDT | Mesoscale Discussion | SPC | Barry, Carter, Christian, Douglas, Howell, Lawrence and 10 more | 2 hr |
Nearby
Mesoscale Discussions in Illinois, 2012Mesoscale Discussions in Missouri, 2012Every mesoscale discussion in 2012
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.