Five things you might not know about thunderstorms

20 03 2013

1. Lighting can strike twice. The empire state building in New York has been struck by lightning as many as 48 times in one day.
2. The average flash of lightning would light a 100 watt light bulb for three months.
3. Lightning can strike in volcanic ash clouds. Not much is known about volcanic lightning, but we’re using it to help track ash clouds.

Volcanic lightning

Volcanic lightning

4. Thunderstorms can trigger asthma. The Met Office has worked with the NHS and Asthma UK to try and understand why.
5. The most thundery part of the earth is the island of Java where the annual frequency of thunderstorms is about 220 days per year.





Top ten: spookiest weather conditions

30 10 2012

As it’s halloween  tomorrow, we’ve taken a look at the top ten spookiest weather conditions. From well known scary weather – like thunder and lightning and sea mist, to lesser-known phenomena such as brocken spectre and fall streak holes.

  1. Fall streak hole. Also known as a hole punch cloud, these clouds sometimes cause people to think the world is ending, especially when wispy vigra clouds are descending from the hole. The exact conditions that cause them to occur are still debated.
  2. Sea mist. This occurs when mild air moves over the sea, which is cooler. It can be particularly spooky when sea mist comes in during the day and visibility is drastically reduced.
  3. Sunsets. Although often considered beautiful, some particularly vibrant red sunsets can create a spooky effect.
  4. Dust storms. Dust and sand storms can be whipped up rapidly by strong winds in arid regions. Dust storms can look particularly ominous as they approach as they can be up to 40 metres high.
  5. Whistling wind. Windy conditions can be scary when they blow through objects causing a whistling sound.
  6. Brocken spectre. This effect is produced when an observer stands above the upper surface of a cloud – on a mountain or high ground – with the sun behind them. When they view their shadow the light is reflected back in such a way that a spooky circular ‘glory’ appears around the point directly opposite the sun.
  7. Roll clouds. These ominous looking clouds are a type of arcus cloud usually associated with a thunderstorm or a cold front. As these rare clouds often appear to be ‘rolling’ they often cause fear that severe weather is on the way.
  8. Thunder and lightning. One of the most common forms of ‘scary weather’, thousands of thunderstorms are taking place at any one time across the globe.  The lightning you see during a thunderstorm is a large electrical spark caused by electrons moving from one place to another, while the rumble of thunder is caused by the noise of intense heating and expansion of the air along the path of the lightning.
  9. Clouds over a full moon. This spooky effect occurs when clouds partially cover a full moon.
  10. Fog. Fog forms when relatively moist and mild air close to the ground cools quickly, causing the moisture in the air to condense (at which point it becomes visible to the human eye). This normally happens in autumn and winter under clear skies, which allows heat from the ground to escape quickly to cause rapid temperature drops.

What weather conditions do you find the spookiest?





Severe weather expected in parts of Spain and southern France

19 10 2012

This weekend looks set to be a very wet one over parts of Spain and southern France as very warm, humid air and an active weather front combine to bring heavy rain and thunderstorms.

The frontal system stretches from Scandinavia, across southeastern Britain to North Africa and it’s on the southern side of this that we are likely to see torrential, thundery downpours bringing the risk of flash flooding.

Visible satellite image 3.30pm 19 October 2012

Southeastern Spain, from Murcia to Valencia and Cuenca, may see some of the heaviest rain on Saturday, but it’s the north and east of Spain and parts of southern France that are most at risk from the torrential downpours through the weekend. Here there could be 100 to 200 mm of rain falling in a short space of time across quite a wide area, with the risk of up to 300 mm of rain possible in places.

Some severe thunderstorms are also likely across parts of Morocco and Algeria, with gusty winds generating dust storms.





Met Office in the News: “Tropical Storms to hit Wimbledon”?

26 06 2012

There have been several articles in the Daily Express over the last couple of days reporting ‘Summer is on the way at last’ with temperatures set to reach 34 Celsius this week and ‘Tropical storms set for Wimbledon’.

These headlines are unfortunately wide of the mark and rather misleading, both by implying that hot and sunny weather is on the way and that Wimbledon will be hit by tropical storms.

Although the Met Office has spoken to the Daily Express, the forecasts featured in the stories have not come from the Met Office, but from an independent forecaster.

The Met Office forecast for this week is for a couple of days of warm, humid and rather cloudy weather across much of the UK, with temperatures reaching 26 or 27 Celsius in any sunshine. For more detail you can find the latest weather forecast on our website.

It is our understanding that the temperatures of 34 deg C referenced in the articles are actually feels like temperatures taken from the website of an independent forecaster rather than actual air temperature. This is not made clear within the article and is potentially misleading.

The inference – through the lack of reference to the original source of the forecasts – that these forecasts have come from the Met Office is very misleading for the public, and potentially damages the reputation not only of the Met Office, but the wider weather forecasting community.

The Met Office is a world leader in meteorological science and our forecasts are recognised the world over as some of the best in the world. We are proud to be trusted to give the best possible guidance on the weather by the public and we report the weather exactly as it is.








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