NWS Norman Local Storm Report Question

[beaudodson]

Personally, I think it's much smarter for a forecast office to spend their limited funds and staff hours on training and research & development, and not chasing down every last F0-F1 spinup in a wheat field. Even if a barn or two is hit, or there is some significant tree damage, this can be handled with relatively high precision by looking at digital photos taken by the local media or emergency manager. Nor do I think it's smart to waste time and energy typing up a public info statement for every last one of these brief spin-ups just to satisfy the curiousity of a handful of weather weenies who can't wait another month or two for Storm Data (and Jeff, there is disclosure...it's in this publication).

Interesting comments. I believe, I could be wrong, that you miss the point. Local Storm Reports (unless you are talking just about public info statements days after an event - which you may be) are for

1. Emergency Management - to help them decide what to do next - blow the sirens or not blow the sirens to save lives
2. The media - so they can report the weather LIVE to the people who are interested (those in the path of the storm)
3. The public
4. Weather weenies (who cares honestly on this one) but they are there so I will include them


So your comment is a bit odd. Are you under the impressive that local storm reports are for weather weenies to get their kicks off because they called something in? If so then perhaps you have been mis-informed. They are not. Perhaps your comments are meant ONLY for the public information statements - down the road. A lot of this thread was more about local storm reports...thus my confusion on your statement.

There appears to be several topics in this thread now.

 

[Kiel Ortega]

So from here on out we will have incomplete storm information in some areas that could have been filled in. We will never know the EF Rating for the majority of OUN Tornadoes - from what it sounds like. If that is the case then why rate any tornado. Who cares then. I know researchers might.

Well, considering I am researcher who uses storm reports (mainly hail), I really couldn't care less about the rating of a tornado. I just need to know if one was there or not; which, for the most part, is well illustrated from all offices and in Storm Data. There are still problems with even the best surveyed storms as most location information is only saved to the 1/100th of a decimal degree which can cause some (relatively) large spatial errors; and time errors are the most common and sometimes ridiculous. So, as a researcher, one still has to QC the hell out of Storm Data when using it in a scientific setting(which is already QCed!). Strength is so tied into damage reports I don't understand why people would try to draw conclusions about a storm over a time period (say, for a climatology) or for a certain look of a storm. I personally don't understand the want of some people for ratings, other than curiosity. It's not a good way to draw any sort of conclusion other than the tornado hit something. Trust me, OUN (or any office for that matter) not surveying every tornado isn't going to hurt anything or anyone; and a few missed LSRs isn't the end of the world. I agree with Scharf, I'm more worried that they are giving me good information BEFORE a storm (i.e., warnings)

 

[beaudodson]

Well, considering I am researcher who uses storm reports (mainly hail), I really couldn't care less about the rating of a tornado. I just need to know if one was there or not; which, for the most part, is well illustrated from all offices and in Storm Data. There are still problems with even the best surveyed storms as most location information is only saved to the 1/100th of a decimal degree which can cause some (relatively) large spatial errors; and time errors are the most common and sometimes ridiculous. So, as a researcher, one still has to QC the hell out of Storm Data when using it in a scientific setting(which is already QCed!). Strength is so tied into damage reports I don't understand why people would try to draw conclusions about a storm over a time period (say, for a climatology) or for a certain look of a storm. I personally don't understand the want of some people for ratings, other than curiosity. It's not a good way to draw any sort of conclusion other than the tornado hit something. Trust me, OUN (or any office for that matter) not surveying every tornado isn't going to hurt anything or anyone; and a few missed LSRs isn't the end of the world. I agree with Scharf, I'm more worried that they are giving me good information BEFORE a storm (i.e., warnings)

Hmmm interesting. So the 1974 tornado outbreak was impressive without the ratings? Sure we would look back and realize there was a lot of destruction but the outbreak itself (along with many other outbreaks) stands out because of the extreme number of F4 and F5 tornadoes. As a researcher I am surprised that you don't find the intensity important. Odd actually. I guess not knowing hurricane intensity would not be important to you either. How about the number of days of 100+ weather during a severe heat wave? Is that important? Why would it be...it is just a number. No big deal. How about snowfall? Why do we need to know whether 4 inches of snow fell or if perhaps 6 inches of snow fell?

I disagree 100% with your comments. Ratings are important and have been recognized by most tornado experts as such. They may not be important to you but they are to a lot of people. I don't think it is more out of curiosity either. Ratings give a better understanding of the intensity of a storm system overall. You might have 12 F0 and F1 tornadoes hit Illinois and Missouri...impressive? Maybe. But if you have 12 tornadoes and six of them were F4 and F5 then is that more impressive? Of COURSE it is. Absolutely.

Knowing the ratings of tornadoes is important in understanding what types of conditions are most likely to produce significant tornadoes.

Obviously OUN thinks "significant" tornadoes are important. Why? Are they just curious? Doubtful.

Again, sorry, but I totally disagree with your dismissal of the EF Scale. Obviously a lot of smart people/scientists - Dr Fujita and others - found it to be important.

 

[Jay McCoy]

Ooops...someone needs to learn about google http://www.srh.noaa.gov/oun/wxevents/20070505/
In fact, go to http://www.srh.noaa.gov/oun/wxevents

Can't comment on the "wedge", except I know Rick surveyed Sweetwater and from what I hear, that took awhile and so I bet he didn't have the daylight to get up to Vici. Further, it didn't sound like the Vici "wedge" was really that significant (as in, all I heard was minor house damage). Remeber too, that the NWS office gets information that you don't know about. I didn't know that some counties will survey damage and then send the reports to the NWS. With the new EF scale, what's the point to surveying unless the damage sounds significant?

I obviously missed that report from 5-5-7 and thats my bad so I apologize. I wasnt trying to olffend anybody at OUN but I was responding to Ricks post....

"Concerning surveys...we do not survey every single tornado report we receive. Due to resource limitations and other factors, we survey what we believe to be "significant tornadoes." So far this year, we have not had any significant tornadoes in our CWA. "

I Consider an EF-3 that hits Sweetwater to be significant as I believe the Arnette tornado was. No it didnt destroy the town but it was very strong, damaged man made structures and should have been rated. To me if there is any kind of damage whether it be a barn, house, school, etc.. it should be surveyed. There are plenty out in open country to skip but any damage to manmade structures deserves a rating. Thats from a taxpayer's point of view not a chaser's.

Again I ask what is the criteria for it being surveryed?? Are there set guidelines or just the WCM's opinion? Does there have to be 10 houses hit instead of 2 or injuries. How do you know if its significant unless you survery it. It may only hit 1 house but have been strong enough to be rated an EF4 or 5. It shouldnt take mass destruction to get the NWS to rate it. Thats like saying I wont respond to a wreck because it only involves 1 vehicle instead of 2 or 3 even if the injuries may be critical. I wont know unless I respond. Wish I could pick and choose the wrecks or fires I work.

 

[Tony Lyza]

Well, considering I am researcher who uses storm reports (mainly hail), I really couldn't care less about the rating of a tornado. I just need to know if one was there or not; which, for the most part, is well illustrated from all offices and in Storm Data. There are still problems with even the best surveyed storms as most location information is only saved to the 1/100th of a decimal degree which can cause some (relatively) large spatial errors; and time errors are the most common and sometimes ridiculous. So, as a researcher, one still has to QC the hell out of Storm Data when using it in a scientific setting(which is already QCed!). Strength is so tied into damage reports I don't understand why people would try to draw conclusions about a storm over a time period (say, for a climatology) or for a certain look of a storm. I personally don't understand the want of some people for ratings, other than curiosity. It's not a good way to draw any sort of conclusion other than the tornado hit something. Trust me, OUN (or any office for that matter) not surveying every tornado isn't going to hurt anything or anyone; and a few missed LSRs isn't the end of the world. I agree with Scharf, I'm more worried that they are giving me good information BEFORE a storm (i.e., warnings)

5/5/07 had at least 63 tornadoes. 5/31/85 had 40 tornadoes. So far, none of the ratings from 5/5/07 got no violent ratings, while while 5/31/85 got 10. If we removed the ratings from the two events, many would interpret 5/5/07 being much worse. There would be no way to scientifically distinguish the significance of the '85 outbreak over the '07 outbreak.

And as Jeff and others have mentioned, the DIs for trees can significantly modify the database by giving the ability to give tornadoes appropriately higher ratings. A survey shouldn't be done for a tornado that is reported to do no damage or light damage to trees, but if it is reported as doing significant damage (i.e., one of the LSRs from 5/5/07 in Woodward County reports a home being destroyed and there were reports here of chasers finding hot water heaters in ditches), I'd see it prudent that a survey be done if at all possible.

The Fujita Scale was originally implemented by Allen Pearson to improve the SPC tornado database by differenciating between different severity tornadoes. This data can be especially important in pattern recognition, knowing which patterns produce a few weak tornadoes, a small number but higher intensity tornadoes (i.e. 8/28/90, 7/13/04), a high number of weaker tornadoes (5/30/04), or a high number with many strong/violent tornadoes (3/12/06, 4/11/65, 5/31/85, 4/3/74, etc.). Many times, the differences between the severity of outbreaks may be very small environmental changes (3-5°F Td difference, 5kt deep layer shear, etc.). If we cannot quantitatively depict the severity of tornado outbreaks per given atmospheric setup, it becomes harder to deduce the potential risk to life and property posed by any given setup. For this reason and this reason alone, the tornado ratings are important to have preserved and readily available.

 

[Kiel Ortega]

Hmmm interesting. So the 1974 tornado outbreak was impressive without the ratings? Sure we would look back and realize there was a lot of destruction but the outbreak itself (along with many other outbreaks) stands out because of the extreme number of F4 and F5 tornadoes. As a researcher I am surprised that you don't find the intensity important. Odd actually. I guess not knowing hurricane intensity would not be important to you either. How about the number of days of 100+ weather during a severe heat wave? Is that important? Why would it be...it is just a number. No big deal.

It's a pretty slow day for me, so I'll just continue (this is hitting a tangent and the mods might want to split this off)...it's not the number...it's how the number is derived. Tornado ratings are off damage...damage happens if the tornado hits something. An outbreak of a lot of tornadoes is impressive...regardless of rating. Last time I checked, outbreaks were a large NUMBER of tornadoes; you start putting large number of tornadoes in any region, it's going to hit something. That being said, I would say the ICT CWA had an outbreak of tornadoes on May 5 2007...17 tornadoes in a an area of a county and a half or so. All were EF0-1. Large number of tornadoes, still an impressive situation.

As far as hurricanes go, it's a more definite system. It's based on wind speed. Thus it doesn't matter if the hurricane hits anything or not, it can still be rated fairly. Number of severe heat days ? I don't even know how to respond...

I disagree 100% with your comments. Ratings are important and have been recognized by most tornado experts as such. They may not be important to you but they are to a lot of people. I don't think it is more out of curiosity either. Ratings give a better understanding of the intensity of a storm system overall. You might have 12 F0 and F1 tornadoes hit Illinois and Missouri...impressive? Maybe. But if you have 12 tornadoes and six of them were F4 and F5 then is that more impressive? Of COURSE it is. Absolutely.

Knowing the ratings of tornadoes is important in understanding what types of conditions are most likely to produce significant tornadoes.

There's a problem in the logic. If a tornado doesn't hit anything, you can make no ACTUAL conclusion of its intensity. It has to hit something for a good estimate for intensity (that or have mobile radar obs which are not a common occurance). You're caught up WAY too much in the numbers; a rating is completely bias to location. Move any F5 to an empty field and you get an F0. That's why I don't care about intensity...no one can draw a really good conclusion about a tornadoes intensity when it's such a relative rating system. True, you need to the tornadoes to hit something to get the rating and thus make conclusions about environments...I'm not going to argue against that. But there's a problem with doing that in that some tornadoes may have been significant, are not rated significant (due to little damage), thus the environment for that storm is a non-significant...which leads to what we have today: a large overlap of parameters for sig/non-sig environments.

 

[Rick Smith]

I obviously missed that report from 5-5-7 and thats my bad so I apologize. I wasnt trying to olffend anybody at OUN but I was responding to Ricks post....

"Concerning surveys...we do not survey every single tornado report we receive. Due to resource limitations and other factors, we survey what we believe to be "significant tornadoes." So far this year, we have not had any significant tornadoes in our CWA. "

I Consider an EF-3 that hits Sweetwater to be significant as I believe the Arnette tornado was.

That quote is from 14 months ago back in 2006, when this thread was started.

Rick

 

[Kevin Scharfenberg]

So your comment is a bit odd. Are you under the impressive that local storm reports are for weather weenies to get their kicks off because they called something in? If so then perhaps you have been mis-informed. They are not. Perhaps your comments are meant ONLY for the public information statements - down the road. A lot of this thread was more about local storm reports...thus my confusion on your statement.

Well I was talking about surveys and follow-up info statements, but I also agree with the idea of not immediately issuing an LSR for every last tornado report, given the very high percentage that pan out to be bogus. I agree that a given tornado report should not be given an LSR until there is some corroborating evidence beyond 1 or 2 calls.

From Jay McCoy:
I Consider an EF-3 that hits Sweetwater to be significant as I believe the Arnette tornado was. No it didnt destroy the town but it was very strong, damaged man made structures and should have been rated.

Are you talking about the Arnett tornado or Sweetwater? Sweetwater WAS rated. If Arnett did actually hit a structure or two (I'm not sure it did), then a rating from the accompanying photos will probably suffice.

To me if there is any kind of damage whether it be a barn, house, school, etc.. it should be surveyed. There are plenty out in open country to skip but any damage to manmade structures deserves a rating. Thats from a taxpayer's point of view not a chaser's.

Are we talking about surveys or ratings here? A rating can be done (and is often done) with photographs and/or good descriptions and does not require wasting NWS manpower in driving hundreds of miles to take a picture of a barn roof being peeled off.

Again I ask what is the criteria for it being surveryed?? Are there set guidelines or just the WCM's opinion?

A survey is generally at the discretion of the WFO staff (usually the WCM), and I'm perfectly okay with that. The WCMs are not clueless idiots that some on here are making them out to be. If they can assign a good rating with a few photographs and descriptions from the local EM and media, I completely agree with their decision not to waste their limited office resources on it.

How do you know if its significant unless you survery it.

Uhm, well, if ___ County EM director calls up and says a couple of barns had some minor damage and a few trees were knocked down, provides a few photos, and the damage is in a narrow path consistent with a strong low-level mesocyclone and a visual tornado report, I can be pretty sure it was a tornado that was not "significant".

It shouldnt take mass destruction to get the NWS to rate it. Thats like saying I wont respond to a wreck because it only involves 1 vehicle instead of 2 or 3 even if the injuries may be critical.

Again, are you talking about surveys, ratings, or response? You seem to be mixing the 3 up. No survey does not equal no response. No survey does not equal no rating.

 

[beaudodson]

It's a pretty slow day for me, so I'll just continue (this is hitting a tangent and the mods might want to split this off)...it's not the number...it's how the number is derived. Tornado ratings are off damage...damage happens if the tornado hits something. An outbreak of a lot of tornadoes is impressive...regardless of rating. Last time I checked, outbreaks were a large NUMBER of tornadoes; you start putting large number of tornadoes in any region, it's going to hit something. That being said, I would say the ICT CWA had an outbreak of tornadoes on May 5 2007...17 tornadoes in a an area of a county and a half or so. All were EF0-1. Large number of tornadoes, still an impressive situation.

As far as hurricanes go, it's a more definite system. It's based on wind speed. Thus it doesn't matter if the hurricane hits anything or not, it can still be rated fairly. Number of severe heat days ? I don't even know how to respond...

There's a problem in the logic. If a tornado doesn't hit anything, you can make no ACTUAL conclusion of its intensity. It has to hit something for a good estimate for intensity (that or have mobile radar obs which are not a common occurance). You're caught up WAY too much in the numbers; a rating is completely bias to location. Move any F5 to an empty field and you get an F0. That's why I don't care about intensity...no one can draw a really good conclusion about a tornadoes intensity when it's such a relative rating system. True, you need to the tornadoes to hit something to get the rating and thus make conclusions about environments...I'm not going to argue against that. But there's a problem with doing that in that some tornadoes may have been significant, are not rated significant (due to little damage), thus the environment for that storm is a non-significant...which leads to what we have today: a large overlap of parameters for sig/non-sig environments.

Well of course the system isn't perfect. The system will never be perfect. That doesn't mean we throw the baby out with the bath-water. We will never know the true strength of EVERY tornado. That doesn't mean we shouldn't strive to understand tornado intensity based on what we have. To just dismiss the rating system makes no sense to me. Tony made a lot of good points - above.