The Royal Meteorological Society and The Royal Photographic Society have announced the finalists of the 2016 Weather Photographer of the Year competition. Drawn from more than 800 entries, in two age categories, the judges are now asking the public to pick a winner. Here are the finalists.
Early this year, unusually cold Arctic stratospheric air reached down as far as the UK. This triggered sightings of rare and beautiful polar stratospheric (nacreous) clouds. I had to go down to Alloa for a course and took an old compact digital camera with me, just in case any displays were visible from that part of the country.
Plynlimon (752m; 2,467ft) is a beautiful hill massif in northern Ceredigion, mid-Wales, north of the A44, between Llangurig and Aberystwyth. I walk this hill regularly in all seasons, and winter is my favourite time of year here.
The otherwise benign summit plateau can be transformed into raw Arctic tundra-like conditions, which presents challenges even for well-equipped walkers. Days of blown snow and spindrift from powerful and freezing north-easterly winds had accumulated on every windward vertical surface into bizarrely shaped natural sculptures. This stile and wire fence became a thing of beauty, with the glowing translucent fluting of the ice emphasised by the Sun's backlighting.
Based on the forecast from the night before, my son James and I left home at 04:30 to travel up to north Suffolk to Herringfleet Mill, a location we had not visited before.
When we arrived at the mill, the temperature was -4C, with freezing fog making for very atmospheric conditions. I particularly like the way this photo captures the Sun burning through the mist, with the reed beds covered in white hoar frost and the mill shrouded in mist. The conditions and location give the image a real sense of an East Anglian winter.
The image was taken in Punta Banco, a small village on the Pacific coast of Costa Rica, and shows a very rare type of lightning called a sprite.
The storm was far out at sea during a new Moon, so there was very little light. And, as a result, the stars were spectacular. I set up the frame to include the pulsing storm and the Milky Way as I liked the contrast. Just after I started the 30-second exposure, this sprite strike illuminated the sky, shooting up into the atmosphere, my jaw dropped, and I assumed that it would have blown out the image, but I was thrilled to witness it.
This is a clash between two storm cells in New Mexico, each with its own rotating updraft. It appeared as though one updraft was anti-cyclonic, resulting in a very turbulent scene.
It was a fantastic sight to watch, and it's the rarity of such scenes that keep drawing me back to the US plains each year.
This low-precipitation super-cell formed late in the day over Broken Bow in south-east Nebraska. The rotation was evident through the striations and twisting updraft referred to as a barber's pole.
The storm was particularly striking at this stage due to the eruption of mammatus cloud from the anvil that was constantly being lit up with lightning. A stunning spectacle, which we photographed for over an hour from the same spot due to the slow-moving nature of the storm.
The photo was taken from the cable car to Mount Cheget, Kabardino-Balkaria, Russia.
The Guanabara is a 240m [787ft] long super-tanker and was loaded with crude oil from the Australian north west offshore oil fields at Barrow Island. I was able to photograph the ship later, when it docked, and I was invited on board to meet the captain and the crew who were "on watch" when the ship was hit.
One crewman had been fishing off the port side and had only just returned inside when the ship was hit.
Shortly after taking the shot, the lightning cell closed on my position on the beach and I grabbed up my equipment and ran for my life. I had just closed the car door when the lightning hit close by and took out all the lights in the area.
My image was taken along the bank of the River Brue in Glastonbury, Somerset.
The flat, open, exposed landscape of the Somerset levels is punctuated by drainage channels and waterways which gives it a unique character. Cool evenings when followed by clear mornings tend to give rise to a blanket of mist rising off the water and grassland, creating an ethereal feel to the landscape especially at sunrise before the mist burns away.
This picture was taken from the edge of Macclesfield Forest, Cheshire, looking west towards the radio telescope at Jodrell Bank and beyond. The weather was cold, and a north-westerly wind blew this shower of hail to engulf the telescope.
I'd headed up towards Kinder Scout in the Peak District from Hope, via Win Hill, crossing Crookstone Out Moor, where this photo was taken. It was difficult to get an exposure which showed both the snow and exposed the scene correctly, but I feel this blurred snowdrop effect captures it perfectly.
Having followed this storm up the A1 road, we finally found ourselves following it, with the setting Sun illuminating the mammatus clouds on its back edge.
This was taken at the first lay-by we found between Tadcaster and York, away from the A64, with the sweep of the road acting as a perfect guide for the eye towards the centre of the storm. How could you not grab the camera from the boot and photograph this scene?
I work for British Antarctic Survey at the Halley Research Station in Antarctica, and I'm a member of the four-people science team. Some of the most important research conducted at Halley is the meteorological and ozone observations programme, and part of my role is to participate in the met observations.
On this particular day, I was on met duty and we saw the Sun halo for most of the day. This was caused by diamond dust, a phenomenon where ice particles of specific shape are being carried by the light breeze in the air, causing the light to refract into a halo. The amount of diamond dust varied throughout the day, but at one time, just after lunch, it intensified dramatically, creating one of the most beautiful solar halos I've seen!
While on a photographic trip to several national parks in the USA, I visited Mono Lake in Mono County, California. Around sunset, I watched as an impressive storm slowly made its way down from the Sierra Nevada mountains on to the lake.
The image I captured shows the inner harbour wall at Whitehaven, Cumbria, being hit by a monstrous wave, dwarfing the surrounding man-made structures. I had travelled from County Durham to the west coast of Cumbria as the UK was being hit by a series of Atlantic storms sending tidal surges and strong gale-force westerly winds, which made for ideal conditions for large swells at Whitehaven.
My photograph was taken on a frosty January morning in North Yorkshire, UK. The frost had formed on a car windscreen, looking like large feathers. I was attracted by the colours resulting from the low early morning Sun.
Orographic cloud winds around and over the unmistakable profile of the Matterhorn in Switzerland.
I have been chasing storms since 1989. I first chased in the USA in 2000, and 2013 was my 12th trip and also my most memorable. This storm in Nebraska was so beautiful, taking on many forms during its life, ending with one of the most spectacular shows I have ever witnessed and had the pleasure to photograph.
It shows a barber's-pole structure corkscrew updraft into this super-cell during its end cycle, still spitting lighting and growling in the dark, a truly wonderful sight and experience I will never forget.
On the hills, we were shrouded until late morning, when a clear way emerged along the ridge towards Foel Fras in the Carneddau, Snowdonia.
This is a classic severe weather set-up in the high plains of Colorado near the town of Wray, which yielded one of the most photogenic tornadoes of the year.
We were just ahead of the storm as the tornado started and tracked with it as it grew from a fine funnel to a sizeable cone tornado. At this moment, the twister was at its most photogenic while its parent super-cell continued to be manageable. We were among a number of people, including those you see in the shot, nervously enjoying the epic display nature put on for us.
My family and I went for a walk at Covehithe, Suffolk, in an attempt to capture such a photo, as we'd seen the forecast was stormy and had thought Covehithe as being a suitable location to shoot in in such conditions.
There were similarly good photos everywhere I looked, but this one really stood out: the rainbow, the hail lines, the storm front, and nice light on the clouds.
I decided to take a photo of Snowdon in the first sunrise winter light. It was a lucky shoot, completely unexpected, as I climbed up to [the] Glyders' summit.
The photo was taken in Cheltenham, Gloucestershire, on my iPhone, when on a bus travelling through the town centre. It began to rain, and the lights glared through, causing a blur and blend of colours.
You can cast your vote for your favourite image on the Weather Photographer of the Year website.
The Weather Photographer of the Year exhibition will go on tour around the UK later this year
All photographs courtesy RMet-RPS Weather Photographer of the Year 2016.