Tornado or not?

[Tony Lyza]

This is from this afternoon before we were hit by 75 MPH winds. As this wall cloud hit my neighborhood, small debris (i.e. beach towels) were yanked straight up into the sky, and I never saw them hit the ground. My question is does this picture show a weak tornado and if so, should I report it to the NWS, who gave me a terrible time and needed a second 75 MPH wind report from my mom (another trained spotter) before making an LSR?
[attachmentid=365]

[Aaron Kennedy]

IMHO, you might as well ask if aliens are in there. No way to tell if there is a weak tornado based off a still image such as that. You didn't happen to take video did ya? ;)

BTW: I don't see much in the way of a funnel. Did you notice any rotation?
Aaron

[Tony Lyza]

IMHO, you might as well ask if aliens are in there. No way to tell if there is a weak tornado based off a still image such as that. You didn't happen to take video did ya? ;)

BTW: I don't see much in the way of a funnel. Did you notice any rotation?
Aaron
[/b]
I tried. I found it more important to report what I was seeing to the NWS. Between trying to take a couple pics and trying to explain to the met on duty that I was not only observing rotation off of radar <_< , I didn't get much, if any, useful video.

To answer your "btw," yes, the wall cloud was rotating, though it was not terribly impressive. It was a weak couplet on the velocity image also at that time.


[attachmentid=337]

[Angie Norris]

I don't see anything that would make me think funnel on the stills. "Straight up" motion would definitely indicate a pretty strong updraft/inflow area. Any damage in the area? Did you measure or estimate the winds?
WCMs and mets can be difficult to deal with at times, particularly if you're in an area that's not accustomed to severe weather (trust me...I know that from personal experience).
Angie

[Tony Lyza]

I don't see anything that would make me think funnel on the stills. "Straight up" motion would definitely indicate a pretty strong updraft/inflow area. Any damage in the area? Did you measure or estimate the winds?
WCMs and mets can be difficult to deal with at times, particularly if you're in an area that's not accustomed to severe weather (trust me...I know that from personal experience).
Angie
[/b]
We estimated the winds, which was very difficult considering the very strong construction practices and lack of trees in our area. As for the met, this was the second time I've had one of my reports ignored by LOT this year. Being a trained storm spotter that lives with another storm spotter that I make sure always agrees with me before I send a report, that greatly upsets me. Due to the good construction, damage was limited to yard furniture (tents, chairs, etc.).

[rdale]

"I was not only observing rotation off of radar"

Why were you discussing radar obs with him though? And the circle you drew is probably not rotation - that's antucyclonic which (while possible) did not occur with today's storms.

[Tony Lyza]

"I was not only observing rotation off of radar"

Why were you discussing radar obs with him though? And the circle you drew is probably not rotation - that's antucyclonic which (while possible) did not occur with today's storms.
[/b]
I was trying to assure them of my high confidence in what I was seeing since they have already ignored one of my reports once this year (a likely collapsing storm that produced severe wind here; never even got an LSR). And I wasn't the one that circled that; that was from a pro met/graduate student on another site. I recircled the area where, based off the pic and my obs from yesterday, the rotation was a bit more likely.

[attachmentid=339]

[rdale]

Still not seeing it... Do you have the after pics? I'd bet showing the damage from 75mph winds would help "prove" you saw 75 mph winds - but I see no evidence of a tornado on radar or in your "before" pic.

[Justin Turcotte]

Was there a WARNING out at the time? I wouldn't even bother reporting what you are seeing on radar as the radar op should have a clear picture with a solid knowledge base of radar products and operation.

A storm report should go something like this:
"This is John Doe, a trained storm spotter. Winds are estimated at 75 mph in this portion of My Town. Debris of this type is airborne". End. You may be asked for clarification or additional information.

The few reports I have made (I only make them for the more serious situations) have all been taken seriously. Chuck Doswell has some comments on his page germainly related to this topic.
Chuck Doswell (http://webserv.chatsystems.com/~doswell/integrity.html)

[Evan Bookbinder]

Tony,

On the right side of that image, your neighbor's "backyard" or yard sale (not sure which) has a number of objects that would have easily become airborne with a 75 mph (that's hurricane force) wind gust. Like others, where's the "after" picture?

Granted video would prove better, but the still provided, coupled with the radar imagery available, suggest that you were looking at a smaller scale gust front/outflow boundary, and not so much a wall cloud. Again (video) :)

Generally speaking, asking people to determine a 3 dimensional object from a single 2 dimensional image, is well, impossible.

Evan

[Tony Lyza]

Yeah Evan, I see what you're saying. There was definitely rotation, and the winds definitely reached 75 MPH (wish I had storm video). However, it does not appear anything near a tornado hit.

And Justin, as for my wind reports, that is how they were formatted exactly. Both of them that were rejected. Darn LOT. I made 3 calls yesterday. The first was to report the rotation, the second to report 60-70 MPH est. gusts, and the third to report 75 MPH winds as the storm got worse. The first one should not have an LSR, but the other two should have. The warning for my area specifically mentioned winds of 75-90 MPH. Why my reports were only recorded after my mom (another spotter) verified them is beyond me. Second case of no LSR after reporting a severe event to LOT this year (the first being a collapsing storm with est. 60 MPH winds).

Here is a pic from a friend's house about a mile west of me. Note on the left edge of the image the wall cloud/area of rotation (about 1/4 of it, at least), and then, the rain shaft (what I thought might have been a tornado).

http://pics.pr0gr4mm3r.com/1149018249-04370.jpg

[rdale]

I still don't see anything that resembles a wall cloud or rotation. How about your backyard pics - if 75mph winds came through the "after" pic should look a LOT different than the before you posted.

[Robert Dewey]

Looks like a wet microburst to me... I can't judge the 75MPH wind claim though, but 60-75MPH doesn't seem too unreasonable.

[rdale]

Alright - you got my interest ;> How can you tell that winds from a storm are 60-75mph based on the look of the rainshaft?

[Robert Dewey]

Alright - you got my interest ;> How can you tell that winds from a storm are 60-75mph based on the look of the rainshaft?
[/b]

You can't judge the wind by appearance of the rain shaft... I'm saying that it wouldn't surprise me based on other storm reports that were logged (up to 75KNTS); Tony's observation wasn't too far fetched IMO. I'm guessing this was a pulse severe storm, which are known to produce wet microbursts as they collapse.

[rdale]

Gotcha - thought you were photogrammatically analyzing the raindrops ;> I think anything will be cleared up once we see the damage pics.

[Tony Lyza]

Gotcha - thought you were photogrammatically analyzing the raindrops ;> I think anything will be cleared up once we see the damage pics.
[/b]
Sorry guys, I really don't have damage pics. It's all cleaned up, and I ran off to chase another cell in IL soon after our storm passed over. Geez, I gotta stop being an airhead and do what need be done. :( About 2 miles away, the same storm ripped the roof off of a pizza place, but I haven't driven past that area to get pictures. Also, the same storm produced 75 MPH winds a few miles SW of me in Crete, IL. I am confident in my wind estimate and the fact that the wall cloud (confirmed to be one by Tom Skilling) was rotating (weakly, as I have mentioned before).

[Alex Lamers]

Hey Tony,

We always get really excited when something is "happening in our own backyard" (I myself am guilty of this on many occasions) so some tend to turn into a reporter, trying to inflate the story for the best scoop (lol also occasionally guilty :D). Weather weenies like outdoing each other's stories methinks, so the reporting is probably an offshoot of that. So what I have learned to do is to first take a step back and refresh my brain and then look for only what I am SURE I am seeing. In this case it appears to be a wall cloud or gust front (stills don't show rotation so I can't say either way) and your estimated wind gust speed. Then I look for anything suspicious to make sure I'm not missing anything. However, unless you're reasonably confident in your observation its better not to call it in IMO and watch it to become more certain. I mean a rotating wall cloud is a rotating wall cloud and if you see an obvious one you should call it in, but if you just see a suspicious lowering from a distance...that can be in the grey area that I am talking about. A false tornado report would mean an extra trip out and more work for the NWS folk. IMO I don't see a tornado in there at all so I would have called in the wind gust estimate and perhaps made a note to tell them that i saw a cloud formation that looks suspicious but I cannot tell if its a rotating wall cloud yet (or something thereabouts).

Never heard anyone ask me for a second verification on my report before...that was strange. I wouldn't beat yourself up too much about it. Just roll with the punches and remember that we all get excited in the heat of the moment! :)

[Tony Lyza]

Hey Tony,

We always get really excited when something is "happening in our own backyard" (I myself am guilty of this on many occasions) so some tend to turn into a reporter, trying to inflate the story for the best scoop (lol also occasionally guilty :D). Weather weenies like outdoing each other's stories methinks, so the reporting is probably an offshoot of that. So what I have learned to do is to first take a step back and refresh my brain and then look for only what I am SURE I am seeing. In this case it appears to be a wall cloud or gust front (stills don't show rotation so I can't say either way) and your estimated wind gust speed. Then I look for anything suspicious to make sure I'm not missing anything. However, unless you're reasonably confident in your observation its better not to call it in IMO and watch it to become more certain. I mean a rotating wall cloud is a rotating wall cloud and if you see an obvious one you should call it in, but if you just see a suspicious lowering from a distance...that can be in the grey area that I am talking about. A false tornado report would mean an extra trip out and more work for the NWS folk. IMO I don't see a tornado in there at all so I would have called in the wind gust estimate and perhaps made a note to tell them that i saw a cloud formation that looks suspicious but I cannot tell if its a rotating wall cloud yet (or something thereabouts).

Never heard anyone ask me for a second verification on my report before...that was strange. I wouldn't beat yourself up too much about it. Just roll with the punches and remember that we all get excited in the heat of the moment! :)
[/b]
Hi Alex!

1) I never called it in as a tornado in my report. I knew it was at least a wall cloud because it was in the updraft of this odd storm. I observed it for about a minute, noted weak rotation, confirmed it on Doppler radar, and called it in as a "rotating wall cloud."

2) Having been through what was confirmed to be 90+ MPH winds in a terrible supercell on 7/17/03, I am very confident in my estimation of ~75 MPH. It also fits reasonably well with a 75 MPH report to the southwest of me, and two 70 MPH reports of me, all with the same storm.

3) They never "asked" for a second report. They just never created an LSR for my 60-70 MPH report or my 75 MPH report (which was made about 5 minutes after the 60-70 MPH report as the storm grew worse). This happened this year also when we got ~60 MPH winds from a collapsing cell that had no warning on it on 5/17. This time, though, my mom (as I stated, another trained spotter), called just in order to get a gosh darn LSR on the darn storm. My only reasoning for this error on LOT's part is that I live on the border between a town that was listed in the warning and one that was not (I officially live in the town that was NOT in the warning). I gave my position as the SW edge of my town. Maybe they thought that since I don't live in one of the towns in the warning that it was a false report? I just don't know. Then again, I called to report 8" of standing water in the south suburbs on a storm chase that I went on (the aforementioned one) and an LSR was never written on that. Maybe they just ignore me because I'm a teenager; then again, they sure as heck took my 60 MPH report on 3/12. I just don't know with LOT anymore.

[rdale]

"I knew it was at least a wall cloud because it was in the updraft of this odd storm."

Finding it near the updraft does NOT mean it is a wall cloud.

"confirmed it on Doppler radar"

The radar image you posted does NOT show rotation, and it certainly wouldn't be picking up rotation in a wall cloud.

I would not take Tom Skilling's "confirmation" of the above pic being a wall cloud as a real confirmation. There are PLENTY of chasers with MUCH MORE experience than Tom who already explained to you why that can't be done with a simple still photo.

What type of damage was done? At the least that awning should be a long way away from your neighbor's house and his yard furniture should be downstream too.

[nickgrillo]

In all honesty, I don't see anything that resembles a wall cloud in neither of the those stills... I see a high-based (possibley slightly elevated in terms of inflow) storm -- with a very outflow-ish looking lowering. I was chasing that afternoon in northcentral and northeast IA, and all of the storms that I witnessed were charactorized by excessive outflow given the incredibley weak deep-layer shear and considerable dewpoint depressions. I'm not saying that a storm cannot organize slightly in these conditions -- especially in cases of local-scale effects that may increase rotation in deep convection (e.g. increased low-level vorticity along an OFB).

Remember that shelf clouds can exhibit excessive turbulance that may resemble rotation. I'm not saying this is the absolute case, but from your photos above -- I see nothing but a high-based, outflow-ish looking storm (and that is not a wall cloud). I am not surprised by the severe wind gusts, since the atmosphere favored decent downburst potential (e.g. dry adiabatic low-level lapse rates) on the 29th -- but nothing more than "pulse" cells (which is pretty much all there was).

[rdale]

Nothing like 3 days of CAPE to 3000-ish all WASTED on lack of winds! Next time we see those numbers around here will be...???...

[Tony Lyza]

"I knew it was at least a wall cloud because it was in the updraft of this odd storm."

Finding it near the updraft does NOT mean it is a wall cloud.

"confirmed it on Doppler radar"

The radar image you posted does NOT show rotation, and it certainly wouldn't be picking up rotation in a wall cloud.

I would not take Tom Skilling's "confirmation" of the above pic being a wall cloud as a real confirmation. There are PLENTY of chasers with MUCH MORE experience than Tom who already explained to you why that can't be done with a simple still photo.

What type of damage was done? At the least that awning should be a long way away from your neighbor's house and his yard furniture should be downstream too.
[/b]

The awning became wedged in a corner of their house, and tons of lawn furniture, ornaments, pool toys, you name it, was strewn around the neighborhood.

I nearly find it funny that the same folks here that claim they cannot determine anything from a single photo are so quickly dismissing me even though I am the only one who actually viewed the whole storm. I observed it, and, though I'm not an "experienced" storm chaser, I have been trained to know what I'm seeing. I watched the storm agonizingly approach, I watched its every move, its evolution. There was decent inflow into the wall cloud, and the real "fun" activity (the severe wind) started AFTER the feature passed. Was it an impressive wall cloud? Hell no. Was there strong rotation? Definitely not the case. However, I've been trained to know what I see, and I KNOW WHAT I SAW.

And Nick, we have something in this area called the lake breeze that was acting to organize and intensify the storms in this area all day that day. It even helped them to congeal into a couple MCSs. The same type of situation developed a normal "pulse" storm on 7/17/03 into a massive HP supercell with 90+ MPH winds and tennis-ball-sized hail (under slightly more favorable wind profiles, of course). What was going on in NE IA was not of the severity of the situation in this area.

[rdale]

"I nearly find it funny that the same folks here that claim they cannot determine anything from a single photo are so quickly dismissing me even though I am the only one who actually viewed the whole storm."

Those are two completely separate issues... 1) You CANNOT determine anything from a single photo.

2) You aren't being dismissed - we're just curious to see the damage and how you rated it 75mph winds.

The questions came when you thought that it was a tornado, and when you matched it up with the radar. 1) There was no tornado, 2) What you showed on radar was not rotation.

[nickgrillo]

Alright, I went ahead and downloaded some WSR-88D data from KLOT during that selected period... The storm was obviously just a pulse storm, and exhibited linear structure on radar. You have to remind yourself that the day had ~10kts deep-layer shear at the very most, and extreme instability (for most of the region) -- and even in most cases when a lake breeze boundary is involved with this type of background environment -- you'll still get multicellular/pulse deep convection (which would be capable of damaging downbursts, and large hail given the extreme CAPE associated with the parcels ingested). I'm looking at the scan at the time of the 75mph report over Schererville (IN) and the only thing I could even see in the velocity scan (in every tilt) would be just a tad of horizontal shear along the thunderstorms gust front between Highland and Gary.

The thunderstorm weakened rapidly as it pushed northeast towards Lake MI towards 2140 UTC, as it moved away from the instability on land (which was augmented by the excessive insolation/diabatic heating and considerable low-level moisture). It was your typical multicellular/linear-type structure that you'd see on days like this. According to the KLOT SVR issued for Lake Co, another spotter reported a 75mph gust further west in Will Co.

[Jeff Snyder]

While I agree with most of you, let's try to be as considerate as possible. We were not there; Tony was the only one on here who actually saw everything. Yes, the photo doesn't show much, but that doesn't necessarily mean nothing was there before or after this photo. Photos can never show rotation, given that a photo is taken at an instant at time, while rotation requires a change in position with time... Yes, we can't see rotation, but what does that mean? In addition, the WSR-88D, given it's resolution, can only very very very rarely capture the actual tornado. Most of the time, rotation on radar is not an identiification of the actual tornado (and yes, I know we all know that). My point being is that there have been tornadoes in a lot stranger-looking storms. So, while radar doesn't show much in terms of velocity, that doesn't necessarily mean that a tornado was not there. It's not bad to question a photo (for clarification or interpretation reasons), but let's just all try to be as considerate as we can (not saying we aren't -- just a reminder).

[rdale]

It might sound like we're ganging up - but seriously we're not. Thanks to emotion-less means of communication ;>

[Tony Lyza]

Alright, I went ahead and downloaded some WSR-88D data from KLOT during that selected period... The storm was obviously just a pulse storm, and exhibited linear structure on radar. You have to remind yourself that the day had ~10kts deep-layer shear at the very most, and extreme instability (for most of the region) -- and even in most cases when a lake breeze boundary is involved with this type of background environment -- you'll still get multicellular/pulse deep convection (which would be capable of damaging downbursts, and large hail given the extreme CAPE associated with the parcels ingested). I'm looking at the scan at the time of the 75mph report over Schererville (IN) and the only thing I could even see in the velocity scan (in every tilt) would be just a tad of horizontal shear along the thunderstorms gust front between Highland and Gary.

The thunderstorm weakened rapidly as it pushed northeast towards Lake MI towards 2140 UTC, as it moved away from the instability on land (which was augmented by the excessive insolation/diabatic heating and considerable low-level moisture). It was your typical multicellular/linear-type structure that you'd see on days like this. According to the KLOT SVR issued for Lake Co, another spotter reported a 75mph gust further west in Will Co.
[/b]
Hey Nick!

Could you please post or PM me a couple radar grabs? I don't have an advanced radar system (yet), and even though I am extremely confident of what I saw, a little more research never hurt anything. :)

[beau_gjerdingen]

I volunteer at the WFO in Minneapolis, MN and work many of the severe events... And for what its worth, that forecaster was likely doing his job in not filing the LSR. We have been instructed to only file wind LSRs with specific (Meaning 10" Diamater Branches...Siding ripped off home etc) damage. Wind speed is only to be put into an LSR when the winds have been measured with an anemometer.

Humans are simply terrible at estimating wind speed, myself included. We almost always waaaay overestimate the wind even when we try our best to be conservative with our estimates.

[Tony Lyza]

I volunteer at the WFO in Minneapolis, MN and work many of the severe events... And for what its worth, that forecaster was likely doing his job in not filing the LSR. We have been instructed to only file wind LSRs with specific (Meaning 10" Diamater Branches...Siding ripped off home etc) damage. Wind speed is only to be put into an LSR when the winds have been measured with an anemometer.

Humans are simply terrible at estimating wind speed, myself included. We almost always waaaay overestimate the wind even when we try our best to be conservative with our estimates.
[/b]
Thank you for that valuable information, Beau! Unfortunately, my problems with LOT did not stop with this storm. As I mentioned in a previous post, my chase team and I embarked on a very short chase after this bad storm. We went to the south suburbs of Chicago, where we observed several areas where the roadways were covered with up to 8" of water. I called in the report, making sure to identify myself as a storm spotter. I gave my observation, the town, even the actual streets where the flooding was taking place. Still, an LSR was never written on that report. So, I understand what you are saying, but that still doesn't lessen my feelings toward LOT in this incident.

I just thought of something else. LOT took my report of estimated 60 MPH winds with a squall line on 3/12, so I know that they do take estimated wind speeds.

[Robert Dewey]

DTX takes estimated wind speeds...

Even with an anemometer, it's still usually an approx. estimation at best. You might be witnessing winds of 75MPH destroy a large tree across the street, but your anemometer (with you standing behind the car) might be reporting 45-55MPH. I think using a combination of visual and instrumental readings would be best.

[John Wetter]

Someone once told me that if you can take the picture somewhere and the first thing someone says is "cool tornado," then it's a tornado. Other than that, and it's just a 'something'.

-John

[Chris Nuttall]

Thank you for that valuable information, Beau! Unfortunately, my problems with LOT did not stop with this storm. As I mentioned in a previous post, my chase team and I embarked on a very short chase after this bad storm. We went to the south suburbs of Chicago, where we observed several areas where the roadways were covered with up to 8" of water. I called in the report, making sure to identify myself as a storm spotter. I gave my observation, the town, even the actual streets where the flooding was taking place. Still, an LSR was never written on that report. So, I understand what you are saying, but that still doesn't lessen my feelings toward LOT in this incident.[/b]

Correct me if I'm wrong, but I don't believe LSRs are issued for flooding.

[Tony Lyza]

Correct me if I'm wrong, but I don't believe LSRs are issued for flooding.
[/b]
LOT does issue LSRs for flooding, especially street flooding.

[nickgrillo]

Tony,

Sorry for the wait... I have been busy:

http://www.midwestchase.com/2006/5-29-06-radar-stormtrack-1.gif

http://www.midwestchase.com/2006/5-29-06-radar-stormtrack-2.gif

Note the velocity scan (lowest 0.5deg tilt) -- no rotation visible from any of the storms.

[Tony Lyza]

Tony,

Sorry for the wait... I have been busy:

http://www.midwestchase.com/2006/5-29-06-radar-stormtrack-1.gif

http://www.midwestchase.com/2006/5-29-06-radar-stormtrack-2.gif

Note the velocity scan (lowest 0.5deg tilt) -- no rotation visible from any of the storms.
[/b]
Sorry to be such a pest Nick ;) , but do you have an earlier image (say 10-20 min prior to this image). The storm had already passed my location by the time of that image.

[Joe Nield]

Tony,

Sorry for the wait... I have been busy:

http://www.midwestchase.com/2006/5-29-06-radar-stormtrack-1.gif

http://www.midwestchase.com/2006/5-29-06-radar-stormtrack-2.gif

Note the velocity scan (lowest 0.5deg tilt) -- no rotation visible from any of the storms.
[/b]

You'd want to look at storm relative motion to get a better handle on rotation than you can with base velocity.

[Tony Lyza]

You'd want to look at storm relative motion to get a better handle on rotation than you can with base velocity.
[/b]
Thanks Joe! I knew that, but I didn't even notice! Sheesh. :rolleyes:

[Marc Austin]

I really must agree with Jeff. I know that some of you may consider yourselves very good at reading all the data and making your decision based solely on the data, but you have to understand that there are so many things taking place in the atmosphere. There is no way that data alone can represent every single thing that is occuring in the atmosphere at a specific location and time, especially within such a small area. Even data is estimated and is often delayed and sometimes inaccurate. Tony was the one on the ground witnessing the storm, it's motion, and it's structure. It is fine to have an opinion about what he says, and it's fine to disagree with him and tell him that you disagree with his arguments in a sensible manner. Comments such as this:
I would not take Tom Skilling's "confirmation" of the above pic being a wall cloud as a real confirmation. There are PLENTY of chasers with MUCH MORE experience than Tom[/b]

are completely disrespectful and unnecessary. Our chase team has also made reports of severe weather, some of which have been obvious tornadoes with power flashes and debris clouds, that no one has paid attention to. So what happens? Well people don't get warned and for all we know, people's lives are put into danger because egotistical NWS employees sit behind a desk and say "naaa... there's no way there's a tornado there, look that this radial velocity scan.. look at the shear... look at the hodographs... it's not possible, these people are just imagining it." We are certified storm spotters and we know darn well what we are seeing on the ground. I'm not saying that because we're storm spotters they should listen to everything we say, but when we report a torando and give them a spotter number and tell them our location and where we believe the tornado is.. you would think someone would do something! It's just really frustrating because it's not only taking our observations and throwing them in the trash, it's putting people's lives at risk, and that's a game that nobody should be playing. Sitting at a desk with all the data you could possibly imagine and ignoring someone's observations on the ground based on your observations of the data is like reading Cliff's notes for some famous work of literature and saying "I know every detail of that book. Right down to each word on each page" It's time to listen up and quit assuming that just because you know how to read scew-T's and hodographs and you can estimate the MLCape values on a given day at a given time that you can choose tell someone what they are or aren't seeing.

[rdale]

Where was the disrespect? 1) We already concluded that you cannot make a detemination of that being a wall cloud based on one picture alone. 2) Tom is _not_ a chaser, so why would we give his opinion more merit than all the chasers here who indicated that likely is not a wall cloud?

Put yourself in Tom's shoes - any idea how many pictures he gets from people who want to know if that's a tornado? Based on the number I get from a small market, I'd bet he can hire someone full time just to analyze them ;> Or he can just agree with people's interp and move on. No disrespect to him. I don't think he cares that people know he's not a chaser, nor was that a personal attack or anything related. He's not a chaser, so it seems to be a valid argument to include that in the discussion.

Regarding the picture - I feel completely confident given my knowledge of radar and Skew-T's and the atmosphere, that Tony was not looking at a tornado.

[nickgrillo]

As for the base velocity and SRM: I didn't think it was a big deal, since the storms were moving so slow (generally ~15kts or less)... And neither products featured rotation.

Originally posted by Marc Austin
I really must agree with Jeff. I know that some of you may consider yourselves very good at reading all the data and making your decision based solely on the data, but you have to understand that there are so many things taking place in the atmosphere. There is no way that data alone can represent every single thing that is occuring in the atmosphere at a specific location and time, especially within such a small area. Even data is estimated and is often delayed and sometimes inaccurate. Tony was the one on the ground witnessing the storm, it's motion, and it's structure. It is fine to have an opinion about what he says, and it's fine to disagree with him and tell him that you disagree with his arguments in a sensible manner.

LOL I'm not making my decision based soley on the data... I have seen well over a thousand storms in the past few years of chasing, and from what I can see from the picture(s) is a high-based, outflow dominant thunderstorm (with a linear lowering). Of course there are many things going on in the atmosphere... However, every one must remember that tornadoes are extremely rare iin any storm at any given location at any time. This storm was a pulse-type multicellular band -- and while it's certainly possible that this storm could have stretched some type of near-ground vorticity and produced a tornadic circulation -- it's unlikely by the pics given (since I can see nothing).

For that matter, there were several tornadoes reported (and confirmed) last week from the same type of storms -- but there was photographic evidence as well (these WERE tornadoes) -- and the WSR-88D DID exhibit low-level rotation on the most of those storms (including one of them all the way in central MI -- although, that one did not produce to my knowledge).

[Paul Austin]

The picture doesn't prove or disprove anything. The presence of a wall cloud is neither a necessary nor sufficient condition for the presence of a tornado. The snapshot is of one instant in time before or after which a tornado could have actually been observed, even in an outflow-dominated storm, however brief or unlikely. Nothing can be verified from this particular photo (or practically any single photo, for that matter.)

The frustration with reports is shared, however. Since when does a trained spotter have to provide proof of an observation when lead time is ticking away? I realize accuracy of reports is important, especially with post-event surveys, and I know estimations can be suspect, and the "crying wolf" response should be avoided. But when a report is made by a trained spotter with the well-being of nearby residents a primary concern, shouldn't the matter at least be investigated without a cynical viewpoint? I guess I can't speak of Tony's account - I wasn't there, but on three separate occasions, I have reported a tornado on the ground with no warning ever issued. The LSR is another issue, but my concern is for the residents. If my report is going to be ignored, why should I take the time. I could simply keep my attention on the spectacle before me and on my camera, etc. But the responsible thing to do is to report the observation. We are trained to make the observation, report it, and leave the decisions to the NWSO. I accept this, I just wish the NWS employee I report to could observe exactly what I am reporting. I don't waste mine or anyone else's time reporting events I am not thoroughly convinced of. I know that numerous non-tornado thingies are reported as tornados or funnels every year, even by storm spotters, but if a storm is capable of producing or has already produced, one would think an observation would be taken more seriously - just my experience and two cents.

[MatthewCarman]

Weather is very unpredictable and is something we do not know much about. It is hard to tell what was occuring with the pictures given as they dont appear to show anything in the form of a funnel/tornado and the radar shows no rotation that I can see. Having that said we were not there and tony was and since weather is so unprediactable it is possible tony did see a funnel/tornado and a wall cloud. You must remember weather is very wierd and hard to understand so one can never know what realy happens with a storm unless he is there and watching it. The movie night of the twisters everyone thought it was to cold if I am correct and none believed there would be tornadoes and look what happend? that movie is based on a true story is it not? Just an example of how weather can do the unexpected. I wasint there so i cant say there was or wasint a tornado. I would say no because of the picture and the radar but tony was watching the storm and says he saw a wallcloud and a tornado so I am going to take his word for it. I am curious who is Tom Skilling? is he a NWS Met? And I was curious how much you have chased rdale as I dont remember hearing of you chasing storms in the past so I was wondering? Do you have a weather site? No offence to anyone or disrespect just my point of view. -MatthewCarman.

[Danny Neal]

hmmm LOT must not like you too much tony haha ive reported a severe weather event whenever i have witnessed it around my neck of the woods on the southside of chi town and they have included it in the LSR, but another reason is because i am in constant radio contact, using skywarn, you relay it to net-control and the gentleman running the severe weather net will then relay it to the weather service, maybe that could be a route for you in joining ham radio and going that route?? just a thought

[Tony Lyza]

Let me type the whole series of events here to hopefully clear up what appears to be some confusion due to my fractured presentation of what happened.

I do now know that this was not a tornado. However, I am very sure that there was rotation; as I have mentioned NUMEROUS times, it was very weak (it took over a minute of intense observation in order to verify it. I NEVER reported a tornado; I did report a "wall cloud rotating very weakly" because when a spotter sees rotation, they are supposed to call it in. After the wall cloud passed completely over, the downburst hit, and hit with avengence. I called in a report of 60-70 MPH winds with flying debris. Shortly thereafter, the wind picked up even more. Some of the smaller trees were bent to between 45-60°. Large lawn furniture was blowing around, as was that tent seen in the picture. After discussion with the other trained spotter in my house (my mom), we concurred that the winds had approached 75 MPH; I proceeded to call in the report. The person who recorded the report (who, if he also typed the LSRs, appears to be new to the LOT office at the very least) thanked me for the report. I then proceeded to contact my chase team to try to get some decent pics of the MCS congealing in NE IL (I'm easily pleased when it comes to storms). We left soon after the storm; however, I did check to see if my report was recorded; it wasn't. My mom called in the report to verify it; only then was an LSR written on it. The chase team and I left to catch up to the MCS moving through the south suburbs. We didn't catch it in time. By the time we got there, it was pouring rain, with near zero visibility. We ran into several areas of standing water of up to 8" (urban flooding). We called in the report. Even though LOT does record flood LSRs, our's was never recorded.

That was the series of events from that day. I hope that helps.


Weather is very unpredictable and is something we do not know much about. It is hard to tell what was occuring with the pictures given as they dont appear to show anything in the form of a funnel/tornado and the radar shows no rotation that I can see. Having that said we were not there and tony was and since weather is so unprediactable it is possible tony did see a funnel/tornado and a wall cloud. You must remember weather is very wierd and hard to understand so one can never know what realy happens with a storm unless he is there and watching it. The movie night of the twisters everyone thought it was to cold if I am correct and none believed there would be tornadoes and look what happend? that movie is based on a true story is it not? Just an example of how weather can do the unexpected. I wasint there so i cant say there was or wasint a tornado. I would say no because of the picture and the radar but tony was watching the storm and says he saw a wallcloud and a tornado so I am going to take his word for it. I am curious who is Tom Skilling? is he a NWS Met? And I was curious how much you have chased rdale as I dont remember hearing of you chasing storms in the past so I was wondering? Do you have a weather site? No offence to anyone or disrespect just my point of view. -MatthewCarman.
[/b]
Skilling is a very intelligent, very reputable, and very well-respected broadcast meteorologist on WGN-TV in Chicago.

Also, that "The Night of the Twisters" movie is just terrible. It is loosely based off of a book that is based off 6/3/80 (with fictional characters and plot); the movie, however, is terrible. The day itself was nothing like in the movie.

[rdale]

I'm not sure how that movie got thrown into the mix ;> This marks my 20th year chasing, 90% of which has been in MI/OH/IN/IL.

My specialty is radar interpretation - I speak at conferences nationwide (primarily to broadcast mets) and even hop into Canada every few years!

[Gabe Garfield]

LOL I'm not making my decision based soley on the data... I have seen well over a thousand storms in the past few years of chasing, and from what I can see from the picture(s) is a high-based, outflow dominant thunderstorm (with a linear lowering).
[/b]

How can you tell that the storm is outflow dominated? Outflow dominance in a storm is sometimes difficult to assess even when you have 360 degrees of viewing freedom. If I remember correctly, there were several chasers (some quite experienced) who erroneously thought the Hiawatha, KS supercell of June 4th, 2005 had become outflow dominated. Much to their chagrine, the storm produced a highly photogenic tornado only minutes after they left the storm. I don't see how you can obtain this important information from a photo that only shows a very small portion of the storm.

Gabe

[Tony Lyza]

I'm certain that this was a wall cloud. This is a picture of the view from my house:
[attachmentid=365]

This is from my friend's a mile or so west of me. It shows the back of the wall cloud, and the dowburst (with the 75 MPH winds) that followed:
http://pics.pr0gr4mm3r.com/1149018249-04370.jpg

I know that I've already posted these pics, but I'm trying to make my case here.

[rdale]

It's really not a big deal... The friends pic doesn't really show anything that resembles a wall cloud to me, let alone rotation. But we've completely concluded over and over that you can make such a determination from a pic (or two.) All this started off with was figuring out if what you saw in the very first post was a tornado - and it clearly was not.

[nickgrillo]

I'm sorry if I sounded like I made the judgement to determin outflow dominance in the storm too quickly (or too loosely) -- but I guess I've seen too many storms identical to this one around this region during the late spring and summer (and tended to make the quick calls based on the two photographs and my own expierence and observations).

1. There was virtually no environmental flow on the 29th anywhere east of the cold frontal boundary (drapped across the eastern Dakotas and curved southwestward) -- with absolutely no mid-upper flow to seperate the updraft from the downdraft (which results in inflow being cutoff from the updraft -- which leads to quick termination of "pulse" cells).
2. All of the deep convection initiated well east of the boundary -- in zones of low-level WAA and lake breeze boundaries (especially in the case of the northern IL cluster) from differential heating.
3. Large dewpoint depressions and dry adiabatic low-level lapse rates from excessive surface heating allowed for plentiful evaporative cooling / downburst potential to occur with all of the storms (with many of the stronger cells dumping marginally severe hailstones and strong downbursts across the region during the afternoon).

All of the convection was made up of "pulse" (i.e. short duration) convective bands/clusters that ingested ample amounts of boundary layer buoyancy (some areas containing 3000-4000 j/kg SBCAPE) -- yet no environmental shear anywhere in the region.

I'm sorry, but I see nothing that represents a wall cloud anywhere in those images.

[Marc Austin]

I'm sorry, but I see nothing that represents a wall cloud anywhere in those images.[/b]

I agree. I personally don't see anything that appears to be a wall cloud or a tornado. I do see what appears to be a very heavy rain/hail core and very strong winds can indeed be expected from such a storm. I understand that one photo, even two.. hell.. even a half dozen pictures of this type cannot verify a torndo, but they also cannot deny that there might have been some circulation in the clouds above... this has already been determined throughout this thread. Nick... I wasn't negating your arguments, I am just tired of people with large egos ignoring plain and simple observation and opting to not issue warnings at times when people's lives and property may be at risk. Your arguments seemed sensible and rational... Other's who have posted to this thread seem to have let their egos leak out into their comments. I don't see a tornado here, but for all I know, it's wrapped up in rain and hail. And as Paul, my brother mentioned, there is no need for a wall cloud in order for there to be a tornado. Just because you are good at interpreting radar imagery doesn't mean that you can tell me what I saw and what I witnessed... that's basically my point and I think some people could benefit from it.

[rdale]

I don't sense anyone posting with an ego... If you recall (way back in the beginning) he posted an image saying that the radar indicated rotation. The radar image does NOT indicate rotation. Can a tornado occur without rotation on radar? Certainly. But if part of your "proof" of a tornado is rotation on radar, but it's a misinterpretation, the proof fails ;>

Again there is no tornado in that picture. Nobody (now) says there is. Or that there was one before, or after. Tony made it clear he did not report a tornado and did not see evidence of one. So given 1) spotter says no tornado 2) damage indicates no tornado 3) radar shows no rotation 4) environment doesn't support tornado 5) no pictures show a tornado - it is safe to say, without anyone's ego being hit, that there was no tornado with that storm.