Bleary-eyed aurora chasers captured stunning Northern Lights images off the North Wales coast earlier this morning, once cloud had cleared. Many are likely to be back tonight (Wednesday, November 12) as solar activity continues to surge.
A huge X5.1 solar flare was recorded on Tuesday morning and is "likely Earth-directed", fuelling predictions of a major geomagnetic storm tonight. In the latest Met Office forecast, this is rated at G4 "severe" - the second highest level on its scale and a step up from last night's G3 storm.
In this scenario, GPS satellite navigation could be "degraded for hours", affecting mobile devices and satellite communications as the Earth's atmosphere is bombarded with charged particles. The Met Office said aurora "may be seen across the whole of the UK".
For those able to see last night's Northern Lights, they were amongst the strongest of the year so far. Some aurora watchers predict that, weather permitting, tonight's lights will be stronger still, perhaps even the best for years. An online forecaster is even predicting "one of the strongest displays in the last 100 years" with views as far south as Spain.
The Met Office said eight regions on the visible side of the sun are currently active. In an alert, the national forecaster said: "Increasing risk of geomagnetic activity with multiple coronal mass ejection arrivals.
"Risk of Strong-Severe geomagnetic storms days 1 and 2 (12/13 November). Ongoing chance of further Strong solar flares." A solar radiation storm warning is also in effect. Join the North Wales Live Whatsapp community now
For those hoping to see the Northern Lights, there is one major obstacle. Cloud is forecast to cover much of the UK this evening, with only southeast England likely to see any breaks. After midnight, cloud is expected to start clearing from the southwest, opening up possibilities for night owls and early risers in Wales and Cornwall.
The Met Office's G4 geomagnetic storm alert is in effect from noon today (Wednesday, November 12) until 11.59pm on Thursday, November 13.
Ongoing solar activity means auroras could remain visible for several days. However this will depend on the trajectory and configuration of the resulting coronal mass ejections.
In the Southern Hemisphere, the Met Office expects "visible aurora" across southern New Zealand tonight with a chance of sightings across northern New Zealand and Tasmania where skies are clear.
Aurora are caused by large flares - explosions - on the sun which throw huge volumes of charged particles out into space. When these particles are captured by the Earth's magnetic field, they collide with gas molecules in the atmosphere to create a geomagnetic storm.
These collisions give off energy as light, forming colourful and mesmerising displays in the night sky.
For optimum sightings, find somewhere high up with minimal light pollution and unobstructed views. Sign up for the North Wales Live newsletter sent twice daily to your inbox