Two Hour Tornado Leadtime?

[rdale]

Such a good article about CASA - then they say they plan pinpoint warnings two hours in advance

http://abcnews.go.com/Technology/Story?id=5253363&page=1

 

[Joel Wright]

That'd be one hell of an accomplishment if they really could increase warning lead time to 2hrs, AND lower false alarm rates.

With as fast as supercell thunderstorms change and evolve, warning lead times can only go out so far, obviously.

At any rate, sounds like this radar network will be a nice supplement to the already much improved radar network here in the lower 48.

 

[Greg Stumpf]

Without watching that video clip, I'm sure they are talking about CASA's contribution to future Warn On Forecast (WOF) research, which is aimed at probabilistically forecasting tornadoes using numerical models assimilating high resolution radar data. This is in contrast to today's "warn on detection" paradigm in which very short term tornado prediction is mostly based on extrapolation of current conditions rather than an actual numerical forecast.

WOF research is very nascent, and we are still years away from anything that could be considered useful forecast and warning guidance. But note that the research is aiming toward the development of probabilistic tornado warning guidance - so the notions of false alarm and lead time are going to be very different than what you think of today.

 

[Kiel Ortega]

I didn't watch the clip...but they may also be mis-applying (IMO, and it's been done before) research a friend of mine did where with ONE case, he got about 2 hours lead time on a tornado in a numerical model when he was assimilating CASA radar data. He didn't get it when he did WSR-88D only or no radar data (if I recall correctly). Unfortunately, I think the model took about a day to run.

 

[Jim Saueressig]

Its based on using an array of smaller radars on cell towers etc to all interact with each other and paint a picture under the curvature of the earth to get a better more accurate radar picture.

earth curvature creates an "umbrella" close to the ground that radars can't see; this new system, called Collaborative Adaptive Sensing of the Atmosphere (CASA), is designed to look under that umbrella, where severe weather, like tornadoes, and hail actually form.

In order to achieve that, CASA is built around a system of radars that are low to the ground, on cell phone towers, for example, and scan smaller areas.

That being said it seems like a total bogus sales pitch to help gather funding for the project with claims of 2 hour leads because while I can see that a few minutes added to a warning by being able to see lower in the storms in fringe areas might be possible I don't see much more advantage.

Unlike existing weather radars, however, the CASA radars also communicate with one another, so if a tornado is tearing through an Iowa town for example, the radars can communicate with each other and follow it as it travels its path instead of continuing to examine random areas that aren't experiencing any storm activity.

This is what the weather service is doing with current radars themselves, they watch them and where they are going. even adding a few more of the current radars could help this.

I think it boils down to an over hyped sales pitch to get funding for a super expensive product that will add little to our current radar system.

he study is facing a funding review from the National Science Foundation later this year and questions of infrastructure and cost are likely to be asked, said Kloesel, who declined to give cost estimates, saying they were out of date and not ready to be published. But whatever the cost, he says that as far as the researchers are concerned, the system is ready to be used.

 

[Chris Nuttall]

One of the current areas of study with this network is using multiple-Doppler analysis to gain a more thorough understanding of the 3D wind field inside a supercell. That's one of the reasons why that testbed in placed in SW Oklahoma.

I think it boils down to an over hyped sales pitch to get funding for a super expensive product that will add little to our current radar system.

Another goal is to see if these radars can be deployed to fill in the holes of the current 88D coverage, especially in rough terrain where deploying a full blown 88D is not possible. That's part of the study with the test bed in Puerto Rico. Given that these can be installed on pre-existing cell phone towers and are much less expensive than installing a new 88D, I don't see how you can say that it will add little to our current network.

If successful, I can easily see this filling in radar gaps in northern Missouri, SE OK and the OK Panhandle.

 

[Kiel Ortega]

I think it boils down to an over hyped sales pitch to get funding for a super expensive product that will add little to our current radar system.

Actually, forecasters who have viewed CASA data (during the Hazardous Weather Testbed's Experimental Warning Program) find it incredibly useful and see it as a great tool for not only radar holes, but also the increased confidence (which should help lower the FAR) for warnings due to great coverage of CASA radars near the surface.

Further, the goal for CASA is to be cheap...so I'm not sure where you're getting "super expensive"

 

[Eric Flescher]

CASA on TV ABC news

CASA was part of the ABC regular news that included this special info that I saw.

Well done and very informative.

Good comparison visual of the advantage of the CASA very regular which is encable of wrapping and seeing over the horizon.

The system will be most helpful and save lives no doubt

 

[rdale]

This is what the weather service is doing with current radars themselves, they watch them and where they are going.

No... What it means is if that there is one big supercell, the radars will change their scan strategies so they all focus on that major storm.

 

[Jim Saueressig]

No... What it means is if that there is one big supercell, the radars will change their scan strategies so they all focus on that major storm.

So it will pay less attention to other development and miss something?

I cant say the rest of you are wrong in anyway but when I see wording like that in the funding section I start thinking about wasted money. I can see where additional radar in some of the holes would help immensely but the way this is written they need a lot more than "hole" coverage in order for the radars to do their thing. if they were to replace existing radars as a whole maybe it wouldn't be so expensive but side by side seems pointless to an extent.

Maybe if they could prove it is valuable and useful in a small test area with the companies funding then I would be less likely to complain about public funding.

 

[rdale]

So it will pay less attention to other development and miss something?

No, it won't miss anything but clear air... To clarify - it will add additional scans in the area of interest. It continues a full base scan.

if they were to replace existing radars as a whole maybe it wouldn't be so expensive but side by side seems pointless to an extent.

Maybe you should hit their website and read all about it instead of relying on a simple news story

Maybe if they could prove it is valuable and useful in a small test area

That's what they are doing now... Watching the data during some of this season's storms has been quite impressive. I assume you've looked at some of the archived stuff before "complaining"?

 

[Jim Saueressig]

No, it won't miss anything but clear air... To clarify - it will add additional scans in the area of interest. It continues a full base scan.

Thanks for the clarification.

Maybe you should hit their website and read all about it instead of relying on a simple news story

Possibly

I assume you've looked at some of the archived stuff before "complaining"?

Nope!