2011-04-09 DISC: NE/IA

[Simon Andersen]

Looking at the weird undulating trajectory tornado C had I bet the final path width will be razed way down, and the 2 miles of adjacent damage will be attributed to interacting downbursts. Maybe the merger with D can account for a record width near the junction, but D was alot smaller. A merge can also result in an actual increase, we saw this behavior in 1990 where the Goessel F5 grew to enormous proportions after it merged with the Hesston F5.

 

[Jeff Duda]

Jeff,

The mesocyclone in your velocity pic is not that which was associated with the "Arthur" tornado. It began earlier than the Arthur tornado and is indeed associated with the wedge in your picture in question. I saw this wedge in the lightning for multiple minutes as I headed east on the road that runs just south of Ricketts, and then as I turned north on US59. It disappeared behind precipitation some time before I stopped on the east/west road 3 miles north of Schleswig (the road that runs on the county line which is black in my pic) to film the Arthur tornado develope. I was about one mile east of US59 on that county line road when I stopped to film, and the tornado was about due north of me and moving off to the east-northeast or northeast. On my video this tornado occurred from about 8:19 pm to at least 8:26 pm.

Just confirming that it was indeed a wedge that you photographed and the 8:04 pm time you have matches up with when I was seeing the wedge to my northwest as I was driving east, just west of US59 and then north on US59 toward and past Schleswig.

So let me make sure I understand your post correctly. You think that I have a tornado in the image I posted that is not the Arthur tornado. I don't see this tornado on any NWS storm survey, so maybe it was very short lived and/or didn't do any damage.

------------------------------------------------

Also, someone mentioned that they think the Onawa-Pocahontas storm was the only one to produce a tornado. FSD confirmed a tornado southwest of Cherokee from one of the other storms, so at least one other one was tornadic. It's possible that more than one other one produced a tornado, but since almost every chaser was on the one storm, it's possible that if other tornadoes occurred with other cells, they may have gone unnoticed, especially if they were weak or produced little damage.

I'm going to grab the radar data from this case and have a look at it to see what it looked like. I wasn't getting timely or even regular updates on GR3 while in the midst of the chase, so I don't know totally what it looked like. From what others are saying and from my own personal opinion of this storm, it may have been doubly-cyclic in the sense that it may have had 3 mesos simultaneously at certain times. I seem to remember saying to my chase partners that three separate wall clouds were visible at various times after dark.

 

[Dean Baron]

No - I'm not really calling anyone out. I haven't been on the forum for a long time and I am just trying to ask some philosophical questions to help me try and understand what has happened to the chaser community.

I mean - I understand that people feel that they are (or are with) veteran chasers etc. and therefore feel relatively in control of the situation - but since when did that equate to "let's go drive into this tornado right in front of us"? Chasers have absolutely no way of knowing what sort of wind fields they are going to experience, what sort of airborne debris you will encounter, or even if multiple vortices with higher windspeeds may form outside of the main circulation you are targeting.

I am just wondering what difference there is in viewing a tornado from 1/4 mile away on a road, versus viewing it from inside it's outer debris sheath. I mean - apart from having your view obscured by atomized rain/dust if you do "enter it"......which actually lends weight to the argument NOT to enter the tornado.

Cheers,

KP

Oh snap , this thread is about to blow up.

_____

Finally got my pic of the radar to save to my computer. Mods feel free to delete my previous post on page 2 if you want. Storm relative velocity .5*.

 

[Rob H]

No - I'm not really calling anyone out. I haven't been on the forum for a long time and I am just trying to ask some philosophical questions to help me try and understand what has happened to the chaser community.

Technology is getting better, scientific knowledge is growing, and chasers are more experienced. Close encounters are nothing new. Maybe some of the chasers that lost windows on Saturday would have better input on their philosophy behind getting close. I just chase storms for myself, and do my best to stay safe while taking part in a dangerous hobby.

We had a perfectly oriented road, and a tornado that wasn't outwardly doing anything that caused concern for our well-being. I hope that all my risk assessments are in line with reality, as they were on this chase. Driving home in heavy rain at 3am, standing outside with lightning nearby, and stopping to help in Mapleton with power lines and natural gas all around me were considerably more dangerous in my opinion.

GPS, Google Maps, and some trigonometry based on my still images show that we were 1/2 mile away while the tornado was lifting, and closer to 1 mile away while it was briefly at EF-3 strength.

 

[Danny Neal]

This was our view of the wedge from 7 miles to the south looking north. Even from 7 miles away it looks absolutely gargantuan. I am not surprised it is up there in the 2 mile wide category. As someone eluded to above though, most likely a 1.5+ mile wide circulation with swath of winds (likely rfd) doing damage adjacent.

 

[Jeff Duda]

This was our view of the wedge from 7 miles to the south looking north. Even from 7 miles away it looks absolutely gargantuan. I am not surprised it is up there in the 2 mile wide category. As someone eluded to above though, most likely a 1.5+ mile wide circulation with swath of winds (likely rfd) doing damage adjacent.

I would like to raise some discussion that might dispute the actual width of the tornado in question. I saw at least one occurrance of a nearly-ground-scraping meso that had multiple suction vortices going below it on Saturday night. Not to pick on your picture in particular, Danny (but that's the first picture of it I have seen), but from so far away, can you truly confirm that this is a fully condensed tornado at the ground? It looks like there's a bit of a hill between you and the tornado. It can be hard enough to see 7 miles away even in daylight, but at night, it's gotta be excruciatingly tough. Is it possible that this tornado was actually a multiple vortex tornado below a ground-scraping mesocyclone that had enough vortices active to give the appearance of one solid tornado from a distance and from damage surveys? I've never been in the middle of a multiple vortex tornado, but I'm guessing the winds even outside of the individual vortices are pretty high and turbulent considering the amazingly complex air flow that occurs with such tornadoes. Also, as others have mentioned, it could be a combination of that and inflow/RFD winds causing damage around the fringes of the tornado's path. I guess I'm just somewhat skeptical of the actual width of the tornado itself given the visual evidence presented thus far.

 

[jeremy wilson]

I'm just wondering what your reasoning was behind proactively driving into the outer circulation of this tornado?

Thanks,

KP

Who cares!!!

Every chaser can chase however they want, whenever they want and with whomever they want. I absolutely love Darins video. If our window hadn't busted we would've been that close. I thought we all got sick of the whole how close is too close debate about two years ago.

Chase how ya wanna chase and let others be. If it bothers you don't watch the video. If a chaser does something to jepordize the safety of the public or other chasers they'll be dealt with by law enforcement or ripped to shreds on Stormtrack.

 

[Danny Neal]

I would like to raise some discussion that might dispute the actual width of the tornado in question. I saw at least one occurrance of a nearly-ground-scraping meso that had multiple suction vortices going below it on Saturday night. Not to pick on your picture in particular, Danny (but that's the first picture of it I have seen), but from so far away, can you truly confirm that this is a fully condensed tornado at the ground? It looks like there's a bit of a hill between you and the tornado. It can be hard enough to see 7 miles away even in daylight, but at night, it's gotta be excruciatingly tough. Is it possible that this tornado was actually a multiple vortex tornado below a ground-scraping mesocyclone that had enough vortices active to give the appearance of one solid tornado from a distance and from damage surveys? I've never been in the middle of a multiple vortex tornado, but I'm guessing the winds even outside of the individual vortices are pretty high and turbulent considering the amazingly complex air flow that occurs with such tornadoes. Also, as others have mentioned, it could be a combination of that and inflow/RFD winds causing damage around the fringes of the tornado's path. I guess I'm just somewhat skeptical of the actual width of the tornado itself given the visual evidence presented thus far.

Yeah, I am 90% sure it was on the ground, I used Matt Cumberland's photos as his was shot with an actual camera and not my video stills... I have a couple video stills I can post as well that may confirm or deny your belief. It was this point also that pretty stout cone tornado was in progress about a mile to the right of this large mass.....

I guess I can't truly say for 100% certain it wasn't just a big merry go round putting down suction vorticies (see 6/17/10 and 5/29/04) but for a good 6 minutes this black mass went unchanged as just a solid black boiling mass. At no time did I see it lift or see lightning underneath it making me believe it was just a ground scrubber. That doesn't mean it couldn't have been, but I wasn't up to getting up there to find out for sure. I guess the NWS survey coupled with SN reports of a large wedge, along with my own video evidence leads me to believe that at SOME point it was at least a mile wide. Circulation itself could have been up to 3 miles wide, but as far as the width of the actual tornadic winds, well? I dunno lol

 

[James McCormick]

FSD confirmed a tornado southwest of Cherokee from one of the other storms, so at least one other one was tornadic.

Ah, interesting. I stand corrected. Anything that was in Buena Vista or Cherokee Counties was a separate supercell (or even a third supercell). I think the Ida/Sac county tracks that were so close together were the result of one supercell that cycled rapidly and produced several tornadoes within a few moments of each other. But it is interesting that two storms co-existed for a short period of time in fairly close proximity to each other.

 

[Jon Gacke]

re; Mapleton - Just want to mention how really cool it was to see chasers stopping
what they were doing and lending a hand to those folks well into the evening.
Cool heads, helping hands and no sensationalism.
Way to go people!
Jon Gacke

 

[Zack Hargrove]

Here is the best picture we could get of the Pocahontas wedge. It is only a video still and a low quality one at that, but we were fairly close and to me it looks like the sucker was definitely solid on the ground the whole way across... well we didn't even get it all in the frame... but anyways... judge for yourselves as its not the greatest quality. Was the tornado 2-3 miles wide? Maybe not, but it was massive I believe.

 

[mikegeukes]

NWS Omaha: Mapleton Iowa Tornado
http://www.crh.noaa.gov/news/display_cmsstory.php?wfo=oax&storyid=66512&source=0

 

[Jeff Duda]

I'm going to grab the radar data from this case and have a look at it to see what it looked like. I wasn't getting timely or even regular updates on GR3 while in the midst of the chase, so I don't know totally what it looked like. From what others are saying and from my own personal opinion of this storm, it may have been doubly-cyclic in the sense that it may have had 3 mesos simultaneously at certain times. I seem to remember saying to my chase partners that three separate wall clouds were visible at various times after dark.

After having had a look at the level 2 data from KOAX and KDMX, I now realize why it seemed so hard to stay in the right place when chasing this storm. It was a damn drunken, lumbering beast! It wobbled so badly on its track it's amazing. The velocity data from it isn't great, but there are scans showing obvious cycling/double mesos, and then there are scans that are just bizzarre.

This is a reflectivity loop of the storm from birth to about 0400 UTC (26.0 MB)

The first three images show the Galva tornado on the left and one or more of the Odebolt tornadoes developing within the donut hole in reflectivity. Notice the lack of a hook associated with the Galva tornado, and other possible circulations within this mess.

After the Arthur-Early tornado weakens and the Nemaha 2-3 mile wide wedge begins (looks like there is another donut hole in reflectivity, Early is about to get slammed with an RFD even though a tornado had already passed west of town:

The massive wedge continues moving northeast and it appears a second circulation/tornado is developing back to the southwest near Newall:

With the number of hook echoes flying around moving every which way, it is no surprise to me to see such different tornado paths. I honestly don't think the Des Moines office covered them all. They may never be able to, especially if one tornado followed a similar damage path as another one. There'd be no way to distinguish the tracks.

 

[Jesse Risley]

I went ahead and uploaded a segment of my unedited video that was not included with the main version that I published earlier. My original thought was that no one wanted to watch endless video of gustnadoes, but after reviewing the video when the debate morphed into exactly what this feature was, I took a closer look. I notice that there is some circulation in the clouds above the dust swirl on the ground, and for a brief moment you can see what appears to be some sort of a funnel shape.

However, reviewing mesoanalysis data, LCLs were still a tad high when the activity started (see below), and that was mentioned by Jon Davies in his blog. After consulting with some fellow chasers in the area when this happened (app. 15-20 minutes prior to Mapleton), it's possible that this is some sort of gustnado/RFD/weak tornado hybrid activity trying to form. This was filmed shortly after the controversial TOR report was made after the cell went SVR warned.

 

[Bill Doms]

I received an email from the grandson of one of the victims...here is a clip of the email:

I came across your spectacular photos of the April 9th, 2011 tornado event in Northwest Iowa and thought you may be the chaser from Minnesota that stopped at my grandfather's farm just south of Newell, Iowa to help him. If so, you have my profound thanks and admiration. He lives on that farm alone, since the passing of my grandmother nearly two years ago. That farm was his life and is now in ruins, but he is safe, thanks to an anonymous chaser.

If you are the chaser who stopped to help this gentlemen, please PM me. The grandson would like to speak to you.