With the axis of an upper trough to be stationed over Sydney and temperatures aloft of -22C, it wouldn't take much heating to get storm development. A rain band had produced rainfall over Sydney during the morning and lasted until at least late morning.
A brief clearing and it could be seen a band of cumulus were showing signs of development to the south and southwest. An area of convergence with NW winds meeting the southeasterly and northeasterly boundary was situated near Castle Hill. Although storms developed further south, an intense storm developed along this regional convergence tripe point and produced a swathe of hail across the Quakers Hill to Schofields region and the storm redeveloped northwest.
Unfortunately, the hail dumped over those areas and only moderate rain progressed beyond this region.
All I can say we almost did not chase today but last day of the trip for 2018, we gave it a go with a 7 hour drive. Arrived near Lincoln Nebraska had a coffee and watched as a large cumulus rapidly developed just to our east. After a close shave with hail we manoeuvred our way to the southern side.
I was astonished to see a wall cloud nearby. Finally in position, things ramped up rapidly. From wall cloud to rapid rotation then tornado siren then funnel cloud!. Someone reported a tornado on the river from this. We could not see this!
The storm maintained a couple of wall clouds and continued to threaten tornadoes. This occurred at least 2 or 3 times. The main large wall cloud maintained for at least an hour. It looked at one stage that the storm was going outflow dominant. We were about to leave and under the very low base alas rotation - followed by multi-vortices! Perhaps weak but still very impressive behaviour! This behaviour lasted about a minute but it may have been visible behind the rain from a different angle based on other chasers perspective!
What a day!! It was a high contrast heaven complete with low bases, dynamic supercell and beautiful wall cloud and structure! Then the storm lined out rapidly and we were in fill retreat south to get west as we have to leave Denver tomorrow!
Low and behold who was in front of us on the way south to Kansas - Jane ONeill, Clyve Herbert and team! So we had steak together!
Tornado was on video - either video stills or picture from Fredrick Muscat!
By the way I believe that the two separate reported tornadoes where from different mesocyclones.
Can anyone confirm this with dropper radar please?
Fredrick saw a power flash few minutes prior the tornado as well just north of the road.
Ok this was the SE Nebraska 11th June tornadic supercell. This was the last tornado phase with pencil tornado behaviour. Of course, I had my wide angle lens on being caught by surprise. We were very close to the tornado though so you can still see the behaviour! Best to view in full screen - HD as well. Contrast is enhanced somewhat to show the behaviour. ( there were request from those who were further away seeing a wedge - this proves otherwise!) By the way ignore my violent rotation comment - it was strong rotation but it is 2018 after all! This was believe it or not the first mesocyclonic tornado for Fredrick Muscat