On Oct 15th I observed and filmed a couple of storms near the Sunshine Coast that developed in the afternoon.
The first was the Caboolture storm which went on to split and disappear out of sight but not before showing a bit of inflow structure after it split.
Right mover 4-20pm app
Left mover at 4-43pm app
The other storm of interest which developed further west started showing a lowered inflow area on the NW side after around 4-50pm
Bellthorpe-Stoney creek storm 4-56pmapp
I continued filming this storm which went on to produce a very interesting and suspect "feature" at 5-01 which lasted app one minute in development.
Initially I got excited but on reviewing the footage at various contrasts it became evident what had occurred was not straight forward textbook funnel to the ground as I of course had hoped.
Here is the Bris 128 rain rate @ 5-00pm showing both a nicely developed Caboolture right mover which now appears to be a supercell with a right mover hook out over Morton Bay. Also highlighted is the developing Bellthorpe-stoney creek storm which appears to me as at best a developing / marginal supercell at this point.
Bris doppler at 5-01pm
Here is the footage of the Bellthorpe-Stony Creek Storm. With the structure in question at a few different contrasts at the end.
Now exactly what was going on... in the footage...
(initial timelapse section of the film is run at 30x normal speed, the contrasted closeup structure sections of the film have been sped up by a factor of 2x for the first 2 and 4x for the last. The ridge top in the closeup footage is app 17km distant)
The long and the short of it is I'm still not convinced or sure.... Thanks to those (including Jimmy) who have reviewed and given there thoughts on what was happening..
I will list my thoughts and throw it open as to what happened.
couple of other things of interest-
1:55-2:27 "neck" of bell lowering seems to be rotating in an anti-cycloninc direction or at least drawn on right hand side towards the rear.
A funnel appears to be visible at base of RFB in a wall cloud like structure, as the bell scud disapates 1:27, 2,27-2.36, 3:21-3:24.
This funnel area is apparent as a lowering after the bell scud has disapated highlighted in the pic below, the remnants of the funnel goes highlight rotation. Moving from right to left at the rear indicating anti-clockwise rotation in that portion of the storm base.
Another point to note the Bell lowering/Scud has a base which does not rise where the Scud below it moves rapidly upward.
There appears to be several possible ground vortices and also one possible point where a funnel almost appears to have organised for app 10 seconds (real time)
Funnel "like" structure behind rising scud below the base of the "bell lowering"-
Again same possible funnel like structure near ground a few seconds later-
and app 30seconds (real time) later what appears to be 2 remnant rotating vortex like structures on ground. The one on the left is stationary the one on the right is moving to the right.
Now I pinned down the locations in the above image & I've checked the immediate ridge area in several traverses near the ridge top at the location of the suspected vortices's in the above pic and in between and also checked for damage along the ridge top up to 500m Nth and 1km Sth, and sadly no cigar- whatsoever,.. at least on/near the ridge top.
So either the funnel "IF" present was further back behind the rising scud and if damage occured it was further toward the west base of the ridge or in open ground ( I did check from a distance but, if the damage was not overly severe it was certainly not visible from a distance)
So my thoughts are the storm was a developing supercell which did go on to show better signs of being a supercell in the next couple of radar images before being engulfed by the approaching storms from the west. The event was more borderline supercellular/non supercellular and although to me it appears to have at least produced a clear funnel at the cloud base. Funnel structure behind the bell lowering is obscured, and below the bell scud it is at best conjectural, or was fairly weak, or short lived or all three.
So what are we left with an interesting feature which I would list as far as tornadoes are concerned between the "possible to unlikely" category Unless of course clear evidence is located on the ground.
Anyone willing to take up the battle with the Lantena Gods?