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.

Number of Events to Show:

Top 10 Largest:

JSON Webservice for the data below:
https://mesonet.agron.iastate.edu/json/mcd_bysize.py?count=10&sort=DESC

YearNumberIssuance UTCSize (sq km)
200716362007-08-03T21:58Z2349853.06
20089082008-05-14T00:11Z687809.50
201916922019-08-10T22:53Z582290.14
200823782008-11-14T20:17Z575220.33
201019992010-10-26T11:00Z549717.84
20051162005-01-22T12:41Z513759.37
20051162005-01-22T12:41Z513759.37
200620842006-10-06T21:47Z508957.12
200620842006-10-06T21:47Z508957.12
200315982003-07-04T04:23Z502015.64

Top 10 Smallest:

JSON Webservice for the data below:
https://mesonet.agron.iastate.edu/json/mcd_bysize.py?count=10&sort=ASC

YearNumberIssuance UTCSize (sq km)
2017782017-01-20T11:44Z387.12
201922072019-12-16T18:39Z622.69
201922062019-12-16T17:33Z723.71
200324702003-10-29T07:01Z894.48
20169292016-06-15T02:39Z921.62
20034462003-04-08T12:53Z942.17
20034462003-04-08T12:53Z942.17
200919972009-09-08T04:19Z1197.68
200919972009-09-08T04:19Z1197.68
201410482014-06-18T01:29Z1247.07