Top 10 SPC Mesoscale Convective Discussions by Size
The IEM maintains a database of NWS Storm Prediction Center Mesoscale Convective Discussions (MCD)s. These products contain a polygon for the alerted region for the product. This page provides an unofficial listing of the top 10 largest and smallest polygons associated with the MCDs.
Pro Tip: If you want to use this data, try copying the table contents and pasting into a spreadsheet program like Excel.
Top 10 Largest:
JSON Webservice for the data below:
https://mesonet.agron.iastate.edu/json/mcd_bysize.py?count=10&sort=DESC
| Year | Number | Issuance UTC | Size (sq km) |
|---|---|---|---|
| 2008 | 908 | 2008-05-14T00:11:00Z | 687809.50 |
| 2019 | 1692 | 2019-08-10T22:53:00Z | 582290.14 |
| 2008 | 2378 | 2008-11-14T20:17:00Z | 575220.33 |
| 2010 | 1999 | 2010-10-26T11:00:00Z | 549717.84 |
| 2005 | 116 | 2005-01-22T12:41:00Z | 513759.37 |
| 2005 | 116 | 2005-01-22T12:41:00Z | 513759.37 |
| 2006 | 2084 | 2006-10-06T21:47:00Z | 508957.12 |
| 2006 | 2084 | 2006-10-06T21:47:00Z | 508957.12 |
| 2003 | 1598 | 2003-07-04T04:23:00Z | 502015.64 |
| 2009 | 54 | 2009-01-28T05:31:00Z | 471200.23 |
Top 10 Smallest:
JSON Webservice for the data below:
https://mesonet.agron.iastate.edu/json/mcd_bysize.py?count=10&sort=ASC
| Year | Number | Issuance UTC | Size (sq km) |
|---|---|---|---|
| 2017 | 78 | 2017-01-20T11:44:00Z | 387.12 |
| 2019 | 2207 | 2019-12-16T18:39:00Z | 622.69 |
| 2019 | 2206 | 2019-12-16T17:33:00Z | 723.71 |
| 2003 | 2470 | 2003-10-29T07:01:00Z | 894.48 |
| 2016 | 929 | 2016-06-15T02:39:00Z | 921.62 |
| 2003 | 446 | 2003-04-08T12:53:00Z | 942.17 |
| 2003 | 446 | 2003-04-08T12:53:00Z | 942.17 |
| 2009 | 1997 | 2009-09-08T04:19:00Z | 1197.68 |
| 2009 | 1997 | 2009-09-08T04:19:00Z | 1197.68 |
| 2014 | 1048 | 2014-06-18T01:29:00Z | 1247.07 |