Impact-based Warnings: What impact?

[Mike Johnston]

A few days ago there was a tornado warning issued for Yuma county, Colorado. Since this was within the coverage of the Goodland, KS WFO, it was included in the central region and therefore the Impact-Based Warning experiment. So, one of the impacts included in the warning was for extensive tree damage. Only one problem: there are almost no trees in Yuma county, Colorado. A cursory look at satellite pictures shows only a few trees immediately adjacent to a creek and resorvoir, hardly anything of impact to human settlement. Probably >95% of the county is completely without trees. So, my question is for you proponents of this impact based warning system: just how accurate are these so-called impacts? Are the likely impacts actually tailored to the physical environment of the area being warned? Most likely, they just seem like a canned set of messages taken from some bureaucratic database. Why not just let the local WFO warning forecaster compose the threat in his own words? If the NWS central region is serious about this experiment, they're going to have to get alot more sophisticated.

 

[M Conder]

I dunno. Did the polygon cover the towns of Yuma or Wray? Even on the high plains there are going to be quite a few trees in towns.

 

[Mike Johnston]

Just going from memory, I recall it was for a decent chunk of the southern and eastern part of the county...almost certainly didn't include Yuma, might or might not have included Wray. But that's beside the point. My question is whether these "impact statements" are actually specific to the area being warned or just general statements picked out of a hat? Do we really have the capability of forecasting a tornado's intensity and short-term path, then combining that with the specific physical characteristics of a given, limited location to state what the likely impacts will be?

There was supposed to be a study done of this experiment based on last year's demonstration project, but I've yet to see one. The overall false alarm rate is what - over 70%? Now, if you picked out each impact statement and analyze whether it truly verified, what do you suppose the false alarm rate would be?

 

[rdale]

The impact wording is locked in. I've mentioned that to CRHQ and they are looking into it. It also told Indiana residents that their crops would get damaged.

There is a study but the results were not very good, and the NWS has not released it publicly yet.

 

[Elaine Spencer]

Are the likely impacts actually tailored to the physical environment of the area being warned?

Well, I don't think the main concern should be attempting to predict the degree of landscape damage or building damage. If we're going to have locally tailored impact statements, I would suggest they focus more on particularly vulnerable groups or activities within the warned area.

For example, if the warned area includes a lake where lots of people go boating, fishing and camping, an impact statement could say "Boats and other watercraft may be capsized. Tents and campers may be overturned."

Or if there is a large outdoor gathering (festival, fair, fireworks) taking place in the warned area: "This warning includes the Super Mega Fest. Persons attending this event may be pelted with large hailstones. (This actually happened in Ft. Worth some years ago) Tents, carnival rides and performance stages may become unstable or collapse due to high winds." (Think Indiana State Fair).

Of course this would take some advance planning on the part of the WFO, but IMO would be preferable to just using canned statements. Also, if the impact is presented as a possibility ("may") rather than as a certainty or prediction ("will") could it mitigate some of the concerns about false alarms?

 

[Stan Rose]

The impact wording is locked in.

Not true. The statement is 'canned' but it can be edited prior to dissemination. So really, the issue is whether the warning met can and should do so. If he/she can, then obviously that might be a good thing. In general, though, the initial warning is supposed to go out as quickly as possible, with followup SVSs that provide further detail.
As for trees, i just looked on Google Earth and randomly zoomed in on a few buildings. They were surrounded by trees, too numerous to count! In general, buildings/infrastructure in rural areas like that often are surrounded by trees. So i don't think it's extraneous info.
Is there room for improvement? Of course, there always is!

 

[rdale]

Not true. The statement is 'canned' but it can be edited prior to dissemination.

No, it absolutely cannot. The experiment requires mandatory use of those phrases. This was per an agreement between Central Region and the union.

WFO IND sent out a few that they edited, and they were quickly reminded of their error. You may be thinking of the non-IBW warnings.

 

[Stan Rose]

No, it absolutely cannot. The experiment requires mandatory use of those phrases. This was per an agreement between Central Region and the union.

WFO IND sent out a few that they edited, and they were quickly reminded of their error. You may be thinking of the non-IBW warnings.

Can you refer me to those edited warnings?? I'd love to know since I'm in CR and I haven't seen any agreement that prevents me from adding information to an impact statement, or even taking out mention of 'tree damage' if there are no trees. Things in WARNGEN that are uneditable are made uneditable. Those impacts can be edited! Please correct me!

 

[rdale]

I'm not going to copy-n-paste stuff from a private discussion, but Mike Hudson made it clear when I asked about the "tree & crop" issue that the statements are not to be edited in any way by any forecast office. The warnings from IND said "damage to vehicles is possible" for the same impact based storm that IWX used the crop & car damage "expected" phrase with. Mike said he contacted the MIC at IND and it would not happen again.

Trust me - I'm on the side for allowing them to be edited. According to the IBW experiment "rules" that is not allowed.

 

[Stan Rose]

I'm not going to copy-n-paste stuff from a private discussion, but Mike Hudson made it clear when I asked about the "tree & crop" issue that the statements are not to be edited in any way by any forecast office. The warnings from IND said "damage to vehicles is possible" for the same impact based storm that IWX used the crop & car damage "expected" phrase with. Mike said he contacted the MIC at IND and it would not happen again.

Trust me - I'm on the side for allowing them to be edited. According to the IBW experiment "rules" that is not allowed.

OK--i checked, and you are correct--they can't be edited (well, they CAN be edited, but you're not allowed to, lol) Nice how this wasn't made clear to us...
I agree there should be more flexibility.
anyhow, I have already forwarded my concerns to the union, and i expect if enough feedback is given changes may be made.

 

[Mike Johnston]

A question for you NWS guys: why is this IBW experiment a union issue? What would the public's safety in the form of weather warnings even remotely have to do with a labor issue?

 

[rdale]

Anything that makes any change to a forecaster's work flow has to be approved by the union. I asked if the hail/wind tags could be expanded outside of Central Region, and it is a lengthy process. Even though the data is there and the forecaster probably wants to...

 

[Robert S. Thompson]

I'm under the impression that the vast majority of people do not hear the exact warning wording. Instead they get an abbreviated version from television, radio, text message, their friends, etc. So I believe impact statements are more for the broadcasters, first responders, and others who actually read the warning and can either tell people what to do or prepare for what the actual impacts. (Whether this is the intention of the impact statements is another discussion.) Since these folks would (presumably) know their locale quite well, I would think that they would know which impact statements are most important for their area.

 

[rdale]

Broadcasters really have no need for this, even if they don't know a thing about radar (ugh) they still usually can get a feel from the NWSChat discussions. Most EMs end up not reading the full text because they are in the heart of the storm. If you tell an EM that the crops in his area are going to be damaged, that might even reduce credibility since he will be certain you aren't familiar with his area?

 

[Chris Nuttall]

A question for you NWS guys: why is this IBW experiment a union issue? What would the public's safety in the form of weather warnings even remotely have to do with a labor issue?

Anything that makes any change to a forecaster's work flow has to be approved by the union.

Rdale pretty much hit it on the head. It's a pretty big change in forecaster warning methodology and workload, so it constitutes a "change in working conditions." It may seem trivial, but think of it like a check-and-balance type of thing. Sometimes the changes aren't a big deal, but other times the union is needed to keep something from getting thrown onto the forecasters that is not yet ready for prime time.

I wanted to change to a different software for composing and logging LSRs. Informally, I showed the staff members what they thought of it. Then, I went to my local union steward with a list of pros and cons, who then met with our MIC to decide whether to proceed, and to come up with a timeline before switching that would allow me to train everyone one-on-one.