Topic: Tornado Humpty Doo, Northern Territory: 29 Nov 2008

[cloudfairy]

thats the rural area.....don't know if it helps
it's from 05:30Z to 18:30Z with 17:30Z missing.

[Jimmy Deguara]

Satellite imagery although nice to see storms in action cannot really indicate much within the storm environment. We really need radar and particularly doppler to see anything in relation to this tornado. I would have thought that the meteorologists on duty would have taken some interest in the event and exchanged with you willingly...

Best of luck Mike,

Regards,

Jimmy Deguara

[cloudfairy]

As soon as they look a bit more relaxed I will ask them for the doppler

[Mike]

Indeed Jimmy.  I've emailed my contact and he's been on duty but they tend to drop everything when the monsoon ramps up and Renate is my only saving grace simply because she's in the office studying and is helping to gather info.  I've asked for the Doppler loop also.  The info will come in time...  Satpics show decent storms but a lot of anvil wash also so not much to go on there, so i agree with that.

[Mike]

Drove out to the location today to try and locate a damage path or anything from this funnel.  There were some downed trees but I doubt these were from this funnel (if it indeed caused any damage) and more likely from strong storms of late.  There was a track of downed trees along side the road but they looked too old to be the ones if they had been knocked over by it.

I've still got the feelers out to the locals in the area to get back to me if anyone mentions to them they have damage from that storm.  BoM here are keen to find out a little more on it but don't have the time at the moment to go out surveying of sorts, so it's left to me.  They have emailed thanking me for the images and report but indicated they are still flat out with handling the monsoon and the lows around us, but invited me to come and chat to them.

From the area this funnel was seen it's in heavy bush and may be on someone's property.  Most homes in that area have acreage of between 2-7 acres, so access is difficult and they don't tend to clear much bushland.  The main area of interest is between the Arnhem Highway and Power Road, there is no access to the bushland from what I saw, but hopefully someone will come forward with any additional info for me.

I'm visiting BoM next week so I'll be asking to see any archived Doppler etc from the day and asking questions so maybe that might clear things up atmospherically wise for us.

[Mike]

BoM Met officer's assessment 16/1/09

I visited the bureau this morning and Michael Foley was kind enough to locate some Doppler and also utilize 3D cross section images from the storm that produced this funnel.  Renate sat in also (cloudfairy) and gave some worthwhile input and questions as we searched - onya!

The archived stills from the satellite (which had this special camera mounted on it for the 3D graphics to view) showed this particular storm to have a very strong updraft core and indeed did sit fore of a low level boundary (Correct, Nick!).  There was a sea breeze pushing inland from NE to SW towards a collective group of cells which built during the loops and these were the storms we also saw either side of the highway close to us forming and anviling out.

Doppler showed some winds turning towards those shown away from radar.  Although the wind profiles indicated not much in the way of vorticity he did not rule out the possibility of a short lived funnel and due to the 10 minute captures this particular satellite takes it may have missed it.  The funnel I saw probably lived for about 2-3 minutes and he said that could be the root problem of it not showing up on Doppler.

 There was evidence of a - ..... damn forgot the terminology .....something along the lines including the word 'hook' - but I knew what he was talking about when he mentioned it.  We looped several times and the one closest to that particular ET showed good strong shear in the middle of the core but no further which we agreed this may be why the funnel's length was shortish compared to the storm.  The loops don't show the cell at its strongest stage - the images kind of skipped that vital frame on viewing it and Doppler was much the same.  The missing link was just not captured for that 5 minutes needed.

Looking at their particular radar (not remotely similar to the public viewed one online) you could clearly see the stronger areas of the storm interior and there were red spikes which indicated strong updraft/downdrafts in one region of it.

Nothing more we can do in terms of data - everything was pretty ideal for it, we just don't have the capture from the satellite.  Unless I find a damage path or one resembling a track then that's it in a nutshell.  He did conclude that it might have been a gustnado given what he interpreted but did not state it categorically as being final.

They've kept the photo and things for the next Storm Spotters report anyway and if i find a damage path of any kind out there then I should report it straight away to him - might have to go with that GPS option I posted earlier.  Hope this was of use everyone, sure was to me.

[cloudfairy]

 There was evidence of a - ..... damn forgot the terminology .....something along the lines including the word 'hook' - but I knew what he was talking about when he mentioned it.  We looped several times and the one closest to that particular ET showed good strong shear in the middle of the core but no further which we agreed this may be why the funnel's length was shortish compared to the storm.  The loops don't show the cell at its strongest stage - the images kind of skipped that vital frame on viewing it and Doppler was much the same.  The missing link was just not captured for that 5 minutes needed.

Hook echo, it is when the echo looks like a bow. There is a bit of vorticity on its edges.