Sunday 28 November 2010

Snow, Thunder, Lightening

I woke at 6am this morning. I was still in that half sleep of not being sure I was awake or dreaming, when I saw a flash and heard a peel of thunder. Sleep ensued quickly as I am not one for rising at that time on a week day, never mind on a Sunday. It was with amazement that there were several flashes of lightening and thunder around noon, whilst it was still snowing outside. I can't ever recall this combination of weather in North East Scotland, nor have I heard of it either.

I have just googled this and according to Wikipedia it appears to be called "thundersnow" and it has the following features:

- a thunderstorm with snow falling as the primary precipitation instead of rain
- the snowfall acts as an acoustic suppressor of the thunder
- in the United States, March is their peak month of formation, and on average, only 6.3 events are reported per year
- the thunder also is unique and instead of a typical "clap" and "roll" the thunder sounds like a large electrical arc or a blown transformer without the reverberation
- thunderstorms with snow are more likely to occur near the coast, where the relative warmth near the sea meets the colder condiions inland

This article also noted that:

On the 26th and 27th leading into the 28th of November 2010, Aberdeen, Scotland experienced thundersnow, including hail stones which were of golfball size. A thundersnow event was also reported in Perth and Dundee in Scotland, in the early hours of the 28th of November, 2010.


The STV website noted that Dundee's Police HQ had been struck by lightnening during the storm:


Police in Dundee arrived at their snow-covered headquarters this morning - to find the building had been struck by lightning.

Snow and thunderstorms brought double trouble to the east coast overnight, a rare phenomenon caused by freezing cold air moving over warmer water.

And Tayside Police's HQ was struck by lightning at around 6.30am, affecting the phone network across the city.

Emergency 999 calls were not affected but the force had to initiate plans to re-establish non-emergency lines from its fallback facility located in Perth.

Superintendent David Tonks, head of the force's communications centre, said: "Members of the public can be reassured that 999 lines and all other IT systems are not affected.

"The non-emergency system is of a resilient design and has never previously failed.

"However, from speaking to the specialists in this area this morning, it is clear that despite the best efforts of engineers it is impossible to prevent complex systems from being affected in such extreme conditions.

"I am though sorry for any inconvenience caused."

STV weatherman Sean Batty said: "We are getting thundersnow in places because of the very cold air travelling over warmer water in the North Sea.

"That creates large clouds and thunder, especially in the east."


Gavin Keymer created a facebook page dedicated to this event entitled "I survived the great Dundee thunder-snow-storm! 28/11/10" and the page said that it was, "The time of the near-apocalypse in Dundee & Tayside. This storm, of biblical proportions, brought catastrophe to Dundee, teaching us that it is actually possible to have snow and thunder and lightning at the same time!"

0 comments:

Post a Comment