Topic: 29th May 2004 Oklahoma City tornadic supercell

[Jimmy Deguara]

Hi,

Just to add some variety in topical discussion, here is another case study - this time about a storm David and I as well as other chased in 2004 - May 29th 2004 in central Oklahoma. This storm is peculiar as it suggest a fairly classic structure and massive hook on radar yet visually it could be considered as an HP supercell (high precipitation).

Here are some video stills of the event:

http://www.australiasevereweather.com/video/stills/2004/20040529.html

This is by far the largest supercell David and I have ever chased and probably compares in size to the likes of Greensburg and Hallam supercells. Could it be considered as a mega supercell sometimes talked about in reports?

Here is a radar analysis - the storm easily covers the size of Oklahoma City despite passing the northern outskirts.

http://www.accuweather.com/adcbin/public/radarplus_gallery.asp?gallery=040529

I will try using this map to determine the size of the mesocyclone of the event.

Regards,

Jimmy Deguara

[Mike]

Phew!   The immense depth of the cell is gigantic as it covers the OK area.  There's no arguing the enormous power given the video still shots.  What was the risk potential percentage number for severe weather that the NWS or NOAA gave this area at the time, Jimmy?
I remember Nick telling me that even with a percentage number of say 2% you'd get monster supercells ?

Mike

[Jimmy Deguara]

Mike,

Interesting point and quite valid on this day. Without going off topic with regards to this specific cell, the day comprised of several isolated supercells - all tornadic apparently in the southern Nebraska, northern Kansas, southern Kansas and central Oklahoma region. The southern Kansas supercell was the most prolific tornado producer.

The risk level on this day was a high risk covering a region so large that it would take 6 hours to travel from south to north of this risk coverage area. The moderate risk are stretched even further afield into northern Nebraska from memory. The day was what I would call potent - tornadoes were certain - any supercell that developed would virtually if sustained become tornadic!

Getting back to the southern Oklahoma City cell mentioned specifically in this topic, the supercell was so large and dominant that all cells to its north within Oklahoma vanished. The supercell progressed across to north east Oklahoma and took control of the whole state of Oklahoma - no other cells developed until very late when the storm entered into extreme northeastern Oklahoma.

Regards,

Jimmy Deguara