KRGX Dome Collapse

Chris Nuttall

Chris Nuttall

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The dome of the Reno/Virginia Peak (KGRX) WSR-88D collapsed in high winds during the morning of Dec. 19, 2008. The radar is located at 8299 feet in elevation. The Reno WFO has a write-up on their website about it.
http://www.wrh.noaa.gov/rev/current/KRGXDomeFailure.pdf

The pictures really remind me of the radome in Texas that collapsed during a tornadic storm a few years ago. I think that was El Paso. Someone correct me if I'm wrong.
 
Chris Nuttall said:
The dome of the Reno/Virginia Peak (KGRX) WSR-88D collapsed in high winds during the morning of Dec. 19, 2008. The radar is located at 8299 feet in elevation. The Reno WFO has a write-up on their website about it.
http://www.wrh.noaa.gov/rev/current/KRGXDomeFailure.pdf

The pictures really remind me of the radome in Texas that collapsed during a tornadic storm a few years ago. I think that was El Paso. Someone correct me if I'm wrong.
Click to expand...

Close. I think it was DFX, Lauhglin AFB which is not too far from Del Rio.
 
i have a question, why is it that those two domes caved in instead of just fly off altogether?

you would think that something that could put such a dent into the dome might knock it off the tower...it just strikes me a bit odd that the dome remains on top of the tower when the winds can cause such damage...
 
Terry Tyler said:
i have a question, why is it that those two domes caved in instead of just fly off altogether?

you would think that something that could put such a dent into the dome might knock it off the tower...it just strikes me a bit odd that the dome remains on top of the tower when the winds can cause such damage...
Click to expand...
Hey Terry:
I think they erect well-built towers that take high wind speeds into consideration. The dome itself is round - and by definition has little wind resistance. I think what happened was - that the material used to cover the dome was exceeded by the forward wind speed that it was engineered to handle.
:eek:
 
wind load, surface area, etc.

Rob Wadsworth said:
Hey Terry:
I think they erect well-built towers that take high wind speeds into consideration. The dome itself is round - and by definition has little wind resistance. I think what happened was - that the material used to cover the dome was exceeded by the forward wind speed that it was engineered to handle.
:eek:
Click to expand...

I'll further that thought by saying it likely was a failure of the seems found within the dome/sphere structure. It is at the seems that likely had the failure due to the higher wind load pressure exhibited on that side of the dome/sphere. The wind load factor is likely why the same type of failure has been seen before. It is the obvious weak link in the structure. The metal tower below, being of minimal surface area is very steady in comparison (although likely was moving a bit too with 100+ mph winds). It is also good to point out that steel is flexible, and can bend.

Luckily, I believe that the NWS/NOAA has one or two additional radars. Sometimes in the cycle of maintenance or replacement (like we just had here in DC/LWX), there is a radar that can be quickly shipped and replaced. Of course, the radar may not have been damaged enough for replacement, just the dome/sphere, which also is likely to have a reserve.
 
Yeah, and I'm sure that the dome material failure was due to the weaker radar-permeable material; but what material would that be? The dome had some kind of inner-frame failure to be shaped like it was. There may have been some object being propelled twards added to this scenario that could have bashed it in. Must have been one very large or sustained gust - or a propelled object, and that tower's number must have been up - so to speak...
 
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Nick Smith said:
I don't think any of the 88Ds ever got hit this bad:

WSR-57 sampled by a tornado in 1973

http://brenttornado.wordpress.com/brent-tornado-on-centreville-radar/

Of course there was the Miami '57 during Andrew.
Click to expand...

Thanks for that link, Nick! I grew up just up the road from Centreville/Brent and one of my uncles lived there during the tornado (and still does today.) It's amazing that it's almost a forgotten event to most everyone down here except those who lived through it and witnessed it.
 
Mike,
When I first began to visit Huntsville (right after the 1974 Superoutbreak), there was talk among weathfolk about the previous year's storm that had taken out the radar. One comment I heard several times was a thought that the vortex tube had actually become horizontal while in contact with the ground. Have you ever heard anything in relation to that?
 
It's funny, my first visit to a National Weather Service office was CKL. One of the met techs there was a regular patron at a store/bar/dance hall my mom use to go to down near Heiberger and he hooked us up with a tour. Of course this was in 1978 and you would have never known what had happened five years prior. I can still remember the high I was on when I left there with an arm full of brochures, facsimile charts and even a couple of MDR plotting charts not mention being there for the balloon launch. It was like Christmas for a 10 year old weather geek!

BTW, the last time I was down there (about 2 and a half years ago), the pedestal and radome were still in place:

P5280761.jpg


Honestly Dave, I never heard much about any eyewitness reports except my uncle who lost his roof (he lived just northwest of Brent near the intersection of AL 5 and old US82.) I really wish that an image or two would surface someday of that tornado. But considering the territory it traveled, I know that's highly unlikely. Might make for an interesting case study and the opportunity to go interview some of the people who lived through and possibly witnessed the event.
 
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I've been wracking my brain trying to remember where I heard that account. I keep thinking it was from a Skywarn training session here in Huntsville that I had attended--I think--in 1975. I had stayed after to ask the weather guys about the 1974 storms and what they had experienced, and I think that was where one of them said that they thought the funnel had become horizontal not far from the ground.

Could be wrong, especially from this length of time...

I do remember someone at that briefing showing a photo of mammatus and saying something like "you have to watch those to see if any of them start spinning; they can drop a tornado." Sounds like he had it confused with wall cloud activity.
 
Following up, I had a nice email from the gentleman who has the Brent tornado website up, and he said that though he couldn't verify it (as he was inside the radar building when it hit), some of the witnesses he talked to said that the tornado did appear to become horizontal while going through Brent's Main Street, appearing to be "rolling on the ground."

I wonder if they had perhaps a limited view and a horizontal vortex predeeded the main funnel, perhaps distracting them from seeing the vertical component behind it.

Anyway, it wasn't just a faulty memory on my part. I appreciate the update from the gentleman who took time to email me.
 
Well, what was left of the radome has been taken out by another wind event which occurred Christmas Eve and Christmas Day. Peak wind this go around was "only" 95 mph but with the weakened state the radome was already in, catastrophic damage occurred including damage to the radar dish itself. Needless to say, Reno will be without radar coverage for some time to come. Check out added pics from pages 7-9...

http://www.wrh.noaa.gov/rev/current/KRGXDomeFailure.pdf
 
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