Supercell - Severe storms and tornadoes.
 

Here's a quick edit of some of the storm footage that I shot over the last couple of weeks. I need to re-do the grade as this was done with an older version of Resolve on my laptop so was only rendered with a half resolution de-bayer. The new version of resolve is out now and this does a full de-bayer of F5 footage so it will look much better.

Re: Supercell - Severe storms and tornadoes.
 

Nice. Looks like you had a productive season. Stay safe.

Re: Supercell - Severe storms and tornadoes.
 

wow those storm cells in your part of the world are something. Thanks for sharing Alister. Must make you nervous not just for your life, as the sadly recently departed. But also just weather abusing expensive camera kit!
Likewise stay safe

regards

Adam

Re: Supercell - Severe storms and tornadoes.
 

Is that the F5 tornado that tore through Oklahoma?

Re: Supercell - Severe storms and tornadoes.
 

With the climate change I think you stormchasers will have some exiting years ahead, if only they where not so destructive and tearing peoples life's apart. I saw a docu last year from our Belgian weather forecaster who went to the usa to follow some storm-chasers and she was amazed how advanced the technology was some where using to predict the storm paths. They where able to get her very close to a building tornado and while she was standing outside with her filmcrew filming her she started to cry just from emotion as it was a very overwhelming feeling. I guess that must be one of the reasons why people feel the urge to chase a storm, I can imagine it makes you feel very small and humble when you experience a tornado.

Re: Supercell - Severe storms and tornadoes.
 

Some beautiful shots there.

Re: Supercell - Severe storms and tornadoes.
 

That was a really good collection of storm shots.

As I look at the turbulence I see energy. Think of a room fan, one of those about 18" or larger that sit on a dresser top that oscillate back and forth blowing air around the room. What, maybe 1/4 horsepower? Now think of the massive air flows in the weather front - how many horsepower does that equate to? A bunch!

A few decades ago I used to fly (pilot a plane) and there was a new "safety" news letter that came out. One of the articles was about safety in weather and it was about this guy in a single-engine (Mooney, I think) that flew through one of these storm fronts with thunder storms. There were a few things that surprised me:
1. That this was actually printed in a safety news letter,
2. That his wings weren't ripped off, and,
3. That he survived it.

My memory of his description of this event was that of sheer terror.

Personally, I absolutely hated flying in anything with severe turbulence. A Cessna has a pretty good track record because of it's struts but the joints only have ONE bolt. What if that bolt failed? There is such a thing as fatigue failure. Not things one likes to think about while pens, charts, etc. are flying around in the cockpit.

If 2/3 rds of good video is good audio, the ending was an excellent choice and said a lot. i.e., silence.

Re: Supercell - Severe storms and tornadoes.
 

The Mooney story I recall was a female pilot who got caught in severe turbulence associated with a storm in which she pulled a lot of Gs recovering from a downdraft. She landed the plane and as she was taxiing off the runway the gear fell off. When they inspected the plane the wings were bent from the G forces.

Re: Supercell - Severe storms and tornadoes.
 

Hi Alistair,
I didn't see any rolling shutter problems in the shots with the lightnings - why?
Thank you
Ulf

Re: Supercell - Severe storms and tornadoes.
 

Here is pretty much the same video with a few small tweaks but now in 4K.

The technology used for storm chasing can be pretty advanced. I have as a minimum a satellite based real time weather radar feed, mobile internet with special software to download and display raw radar data with GPS and mapping overlays, access to raw forecast model data and a mobile weather station that can be used to measure temperature, dew point, pressure and wind speed. The first couple of hours of each day are spent making a weather forecast using computer model data and sometimes good old fashioned paper charts and coloured pencils. Sometimes it's tiny weather features like maybe a little bit of cold air left behind by a thunderstorm the day before that will determine exactly where the strongest storms will form. Then there is a lot of driving, I drove 3,500 miles in 9 days getting these shots.
The tornado in the video is not the one from Moore or El-Reno in Oklahoma. I will not chase storms near big cities, there is too much traffic and too many lookie-loos clogging the roads. It looks like traffic may have been a large factor in the recent storm chaser deaths. Certainly a lot of chasers had very close calls during the El-Reno tornado as the roads were almost totally blocked by traffic and because the tornado was so big getting away was all but impossible. The 3 tornadoes in the clip were all close to the town of Bennington in Kansas.

The F5 has a normal CMOS rolling shutter. The scan speed is quite fast, but it does suffer from flash banding. To mitigate this I use the slowest practical shutter speed to maximise the time between sensor scans (integration period). This way the chances are that the lightning will occur between scans. At night I use a 2 frame slow shutter, during the day when lightning is my target I turn the shutter off and shoot at 24/25p. Like this about 85% of the lightning shots are fine, 10% marginally affected and about 5-10% seriously affected. Of course the F55 with it's global shutter would be a better choice specifically for lightning but my budget simply wouldn't stretch that far. I expect when I go to Arizona to shoot the monsoon lightning storms I'll rent an F55.