Topic: April 30 to May 8, 2007 - Including the Greensburg Kansas EF5 Tornado

[Mike]

Hell, those stills are so sureal.  No wonder tornadoes are so dangerous at night given those images.  Does the larger first pic show the tornado in the centre Jimmy?

Mike

[Jimmy Deguara]

Mike,

Yes that image was the one I was looking for for confirmation (after some brightening) to show straight edges of a tornado still strong but not as wide as earlier in its life cycle. The images below the large one if you click to enlarge have evidence of the tornado behind the scud but not as clear as the enlarged image above. The tornado would have been in the previous images as well but wrapped in rain. Perhaps Brad can also upload his images showing the tornado. Brad and Ray suggest what they saw was a very large tornado - not sure if this is what they saw or something larger and earlier.

This collection of stills was one of the most difficult to deal with taking litereally hours to prepare but thankfully being David's camera it is as modern as it gets in terms of the quality (on the prosumer range).

In terms of chasing at night, yes it is extremely dangerous and is one of the reasons the local sheriff lost his life - not sure what were the details but perhaps he misjudged the tornado's size trying to use the lightning flashes as a guide to where the tornado was. Anyone have details to cofirm this? In general, if a tornado is approaching and relatively close, it becomes very difficult to judge or even observe the tornado if you had not been observing the tornado in the first place. Further, on approach to route 283 SW of Greensburg, the tornado was smaller and then became larger. So even if the tornado was observed earlier, repositioning can easily make you lose perspective.

Now back to the topic.

Regards,

Jimmy Deguara

[Jimmy Deguara]

I guess those that cannot view the Stormtrack forum, I felt given the spectacular nature of these images, and showing the enormous size of the tornado, I would include them here:






Photographs copyright by

__________________
mike scantlin

Link my blog and I will gladly return the favor.
http://mikescantlin.chaseblogs.com

[Mike]

Are you kidding me?  That thing was huge.  Anything that fills the camera frame is just plain scarey.  Tell you what, you guys have done pretty well considering you could have encountered a lot more danger.  Great work.

Mike

[Jimmy Deguara]

That massive wedge was hidden in rain by the time we got to it but I am possibly thinking the edge may be visible on one of tehe video frames I had posted hard to tell.

This was an incredible chase particularly for those who saw what is presented in these images.

Regards,

Jimmy Deguara

[Jimmy Deguara]

Just tracked down the tornado emergency warning for Greensburg that we heard on the Noaa radio:
-----------------
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DODGE CITY KS
941 PM CDT FRI MAY 4 2007

KSC097-050300-/O.CON.KDDC./O.CON.KDD/O.CON.KDDC./O.CON.KDDC.
KIOWA KS-941 PM CDT FRI MAY 4 2007

…A TORNADO WARNING REMAINS IN EFFECT UNTIL 1000 PM CDT FOR CENTRAL
KIOWA COUNTY…

…A TORNADO EMERGENCY FOR GREENSBURG….
AT 937 PM CDT…NATIONAL WEATHER SERVICE METEOROLOGISTS AND STORM
SPOTTERS WERE TRACKING A LARGE AND EXTREMELY DANGEROUS TORNADO. THIS
TORNADO WAS LOCATED 5 MILES SOUTH OF GREENSBURG…MOVING NORTH AT 20
MPH.

A VIOLENT TORNADO WAS ON A DIRECT PATH FOR PORTIONS OF GREENSBURG…
ESPECIALLY THE EASTERN PORTIONS OF TOWN. TAKE IMMEDIATE TORNADO
PRECATIONS…THIS IS AN EMERGENCY SITUATION FOR GREENSBURG!!

A TORNADO WATCH REMAINS IN EFFECT UNTIL 200 AM CDT SATURDAY MORNING
FOR SOUTHWESTERN KANSAS.

LAT…LON 3749 9936 3745 9929 3760 9901 3764 9936

------------------
This is when I went ballistic - I knew people were most likely going to get killed. It was a warning like no other I had heard in my storm chasing career! Even reading it now sends a shiver down my spine.

Here is a link to the account from the duty forecaster that night in the Dodge City office

http://www.underthemeso.com/blog/?p=364

Blog and website by Mike Umscheid - Duty Forecaster at the Dodge City National Weather Service Office.

Regards,

Jimmy Deguara

[Jimmy Deguara]

Hi,

Here is another view of the Greensburg tornado monster




http://kotv.com/news/national/story/?id=126697


http://www.weatherusa.net/blog/entry.php?id=49

Regards,

Jimmy Deguara

[Jimmy Deguara]

And now for some nice lightning and supercell structure of the Greensburg tornadic supercell:





Courtesy of Florida Lightning  http://www.floridalightning.com  BY MARTIN KUCERA


Regards,

Jimmy Deguara

[Mike]

Jimmy. would you rate the Greensburg supercell as the scariest you have witnessed given what we know now and what you knew at the time of chasing it?  The photo of it just beggars belief.

Mike

[Jimmy Deguara]

Hi Mike,

Sorry to not get back to you on your question. Yes this specific storm chase was one of frustrations and emotions. It was a massive event and I guess we were amongst it a little late of course to see the massive wedge but I know most other chasers were not even near the storm! That made us as a team feel that we had achieved something on this event. The video stills listed in this thread also confirmed what the guys Brad and Ray were seeing. The chase was one hell of an emotional roller-coaster ride.

http://australiansevereweather.com.au/storm_news/2001/docs/200105-04.htm still ranks as the top chase being it was in the day time and we traversed with the whole time and were relaxed. It was also our first big tornado and in our first year in the plains - certainly an eye opener.

Getting back on the topic of Greensburg, the following link sent my Andrej Matko from this forum and also who came on the trip is a sensational image! It shows satellite tornadoes around the large developing tornado!

http://iatse354.com/354/Chases/Gburg/pages/0041.htm



Regards,

Jimmy Deguara

[Andrej Matko]

I see Jimmy already posted this image. I found it on the Stormtrack forum in a thread Andrea Griffa started to gather Greensburg tornado images. What shocked me the most were these images (video captures) that are showing satellite tornadoes. This particular capture is in quite good quality and resolution and shows the all three tornadoes very clearly. Amazing stuff.

I guess the conditions were extremely dangerous for chasing. These satellite tornadoes can easily catch you off guard, and they seemed to be quite some distance away from the main circulation. In places where you feel save...

What I also find interesting is the lowering/bulge on the left of the tornado. What do you guys think about it? Is this the "add-on" to the existing tornado, maybe two circulations that joined? If you check the images when the tornado was full-blown wedge, you won't see it anymore. For instance, if you would draw the line from where the bulge ends to the ground, I think you would get the shape, tornado had later in the development. Actually, I think this images show exactly what I have in mind.

Plenty of rotation everywhere.


Almost joined...



And the result...


This supercell truly was a multi-vortex (multi-tornado?) beast.


I guess this trucker didn't have a slightest clue about what just missed him.


Check the rest of images here --> http://iatse354.com/354/Chases/Gburg/index.htm

[Mike]

After viewing those photos Andrej i think they could be suction vortices around the main exterior of the visible funnel in different stages.  Although it's not uncommon to have several funnels, perhaps the one on the LHS was progressing towards being a funnel but did not eventuate, the one on the RHS def looks like a suction vortice.  You can also see in the second last photo a suction vortice hidden within the funnel.   Any others got views on the question?

(I don't like the digital enhancement at all!  Perhaps it's to protect the image from those who may pinch it....)

Mike

[Jimmy Deguara]

Mike,

Can you lead me to your source of information regarding suction vortices and satellite tornado differences.

I would say this has a suction vortice:

http://iatse354.com/354/Chases/Gburg/images/0020.jpg

Regards,

Jimmy Deguara

[Mike]

Too many sources to remember ! - I've just read a whole lot on them through websites and from other articles found online and browsed.  This video of Dr Greg Forbe's explanation during a large tornado which showed three suction vortices is here:

http://www.weather.com/multimedia/videoplayer.html?clip=2635&collection=topstory&from=vid_brws2&tab=3&nav=84

I also read a while back on Fujita's theory on suction vortices (Fujita T, 1981, Tornadoes and downbursts in the context of generalized planetary scales, Journal of the Atmospheric Sciences, 38[8], pages 1511-1534.) and also his theory after he got hold of that amazing 35mm tornado film from the Xenia event.

 I understand that satellite tornadoes form next to the original funnel and then dissappear only to reappear on the other side (circulating per se) and that suction vortices are as a result of the separate wind flow vortices turning anticlockwise and clockwise next to each other within the thunderstorm and that the separate vortices usually are seen in the storm's dissipating stage, but initially the funnel can actually contain more than one vortex but co-joins to create the main funnel when at the mature stage and what we see once grounded.

I remember seeing a wonderful computer animation of wind profiles within a supercell and you think I can find it again?  No!  I'll hunt it down and post the link.  It's the best i've seen and the amount of wind direction, vorticity and inflow/outflow profiles blew me away. Air is not just sucked in and blown out - it's litterally blown apart and dispersed to all regions of the storm!

Just found one of my printed resources - it can be found at http://docs.lib.noaa.gov/rescue/mwr/098/mwr-098-01-0029.pdf  It's 45 pages long in PDF form but it is Fujita's assessment on the 1965 Palm Sunday tornado outbreak. He gives explanations and theory on suction vortices and the like.... It's Fujita - what more can one say.


Mike

[Jimmy Deguara]

Mike,

I understand that satellite tornadoes form next to the original funnel and then dissappear only to reappear on the other side (circulating per se)

Do you think it is as general as this?

My main issue is that you corrected Anrej in saying that all were suction vorticies or am I mistaken? I would have thought that a funnel reaching the ground would be classed as a tornado and that being it circulated around the major vortex is a satellite tornado. However, I have not sourced definitions myself. So I could be wrong.

Regards,

Jimmy Deguara