Day 364: Mt. Rainier's incredible cloud shows make 2011's Seattle rains worth it

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    Scott Sistek Scott Sistek | 09:00 AM, Friday, 30 December 2011

    (Scott Sistek is a meteorologist and producer for He has been producing weather reports for broadcast and the web since 1994 and can be found on the 'Partly to Mostly Bloggin' weather blog. Keep up to date with Scott via @scottSKOMO)

    Distance travelled ~ 934'891'200 km

    The Pacific Northwest is known for its beauty, from the lush greenery to the tranquil waters to the majestic mountains. But no mountain is as iconic to the Northwest as Mt. Rainier, which stands just over 14,000 feet tall about 70 miles southeast of Seattle.

    But while the Seattle area is world famous for its rainy, cloudy weather, at times, Mt. Rainier can act like its own paintbrush and using the sky as its canvas, bring a whole new awe-inspiring level to a "cloudy" sky. Thanks to it's status as the tallest peak around and its unique position to catch the moist jet stream, it flows in off the Pacific Ocean - Mt. Rainier can create its own weather patterns.

    Perhaps the most dramatic are its frequent lenticular cloud displays. Seen maybe a dozen times a year, it still looks amazing every time it's showcased.

    The cloud is formed when warm, moist air runs into the surface of Mt. Rainier. The mountain's topography forces the air upward, which cools and condenses the air -- turning it into a cloud. As the air sinks back on the other side of the mountain, it dries out and the cloud dissipates. That's why it just hangs over or near the summit area. (Although it looks like it is "hanging" over the mountain, air is continually flowing over the summit.)

    Sometimes if the atmospheric set up is just right, you can get layers upon layers of stacked lenticular clouds that combine to make dramatic shapes -- many times mistaken for UFOs years ago.

    lenticular cloud

    Image credit: David Embrey

    Locals have used this cloud as a sign that rainy weather is on the way -- many locals might think the cloud is the mountain's version of an umbrella? -- as that cloud usually occurs with west or southwesterly flow in the upper atmosphere, a usual precedent to rainy weather. However, that's not always the case -- especially in the summer. Then, it can just be an indication that we have a good westerly, marine flow and that it won't be too hot anytime soon.

    Or on rare occasions, the mountain can have the opposite effect, as seen here:

    lenticular cloud, mt rainier

    Image credit: John Meadows

    This time, the mountain caused some turbulence that created some sinking air in the vicinity of the mountain peak. Sinking air dries as it does so, in essence "eating" away a hole in the cloud!

    Finally, when the mountain isn't creating or destroying clouds, it can just put on a show using the clouds that are already there.

    In the autumn and early winter in the Seattle area, the Sun's position on the horizon during sunrise is just in the exact right spot to where Mt. Rainier will cast a shadow against a cloud layer!

    lenticular cloud

    Image courtesy of Nick Lippert/YouNews


    So while yes, it rains a lot around here, there are plenty of advantages to living in an area with such unique terrain and meteorology!

    Make your submissions by the end of the year

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    Aira Idris Aira Idris | 17:30 PM, Friday, 23 December 2011

    Distance travelled ~ 917'792'800 km

    Who would have thought we'd be closing the submissions for the Flickr group so soon. It's only been a year, right? But that's what it's always been about. Our annual round trip. And sad to say, but 2012 is looking mighty close.

    To all who have submitted photos to the pool, the team say a huge thank you! Over two thousand weather and astronomy images have been submitted by a selection of great photographers - photos that will continue to be available to view long after the production ends.

    The date you want to remember for the photography pool is 31st December 2011 - as if you'd forget new years eve :-). Submissions after this date will not be able to be made.

    I'll leave you with images of the Aurora Australis, acquired by astronauts on board the International Space Station September 11, 2011 as the ISS orbit pass descended over eastern Australia. Magnificent.


    Wishing you all a Merry xmas!


    Day 298: Thailand floods in pictures

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    Aira Idris Aira Idris | 17:30 PM, Tuesday, 25 October 2011

    Distance travelled ~ 765'997'600 km

    Across Asia, several areas are severely flooded after unusually heavy monsoon rains since July. Over 200 houses were swept away by flash floods in Burma, where up to 50 people are thought to have died. Thailand and Cambodia are also badly affected, with the worst flooding in 50 years.


    Flooding street in Bangkok


    flooded street bangkok, thailand


    flooded shop in bangkok thailand


    The above images captured by Alexis Taylor 23 October. "They were taken in the center of Bangkok town...10 min from Khaosan road on foot. The hotel I was staying in on Khao San was bricking the doors up - 1 meter high. You have to enter over sand bags"


    flooded china town in bangkok thailand


    Ari Honka took this photo of the first signs of flooding in China Town, Bangkok on 23 October.



    Pathumthani province



    Pathumthani province


    The above images were captured by Derek Armstrong 23 October. "The exact location is outside my house on the Rangsit Nakon Nayok highway which is normally a very busy road linking Bangkok with NE Thailand. It is located in Pathumthani province, just to the north of Bangkok and about 10km from the old Don Mueang Airport.

    The situation has deteriorated somewhat as the level of the klong(canal) is now climbing up to near the brim of the temporary sandbag/clay dykes. The road is also flooding over both sides and spilling into the canal as a result of water run-off from the North (see attached pictures taken yesterday at 9.00 am, Monday 24th October). We are now virtually marooned as we cannot get out of our estate to travel to Bangkok. Vipavadee Rangsit Road, to the west, where Don Mueang airport is located is heavily flooded now. To the east, we cannot access the Outer Ring Road, as there is heavy flooding up to Rangsit Klong 6 where that road is located."

    In a constant search for equilibrium

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    Jonathan Renouf | 11:00 AM, Wednesday, 5 October 2011

    (Jonathan Renouf is an Executive TV Producer making documentaries for the BBC Science department. His most recent projects are 'Wonders of the Universe' with Brian Cox, history of global warming "Earth: The Climate Wars", the BAFTA nominated "Earth: Power of the Planet" and the highly popular and critically acclaimed 'How Earth Made Us', which transmitted in January and February 2010. Here he shares his insights on making 23 Degrees (working title) due to transmit early 2012.)

    Distance travelled ~ 713'844'800 km

    A couple of days ago my baby son woke me up early, and even though I got him back to sleep, I was too awake to settle down. Eventually, at about 6.00, I gave up, got out of bed and decided to go out on my bicycle. I live in Cookham, close to a picturesque stretch of the River Thames, so I cycled down the lane towards the river. As soon as I left our suburban close behind, my heart leapt. A mist lay over the fields - just a few metres thick, but dense, and tinged magenta by the dawn light. Down by the river the mist hung over the water, and a grebe drifted into view on the mirror flat surface. In the distance I heard an early train clanking along the branch line towards London. A few last stars flickered above me as the sky lightened. And all around there were cobwebs thick with dew. I settled down to take some photos of the cobwebs, happily absorbed in the task of trying to capture their fragile, jewel-like beauty.

    Isolated in my riverside reverie it would be easy to forget that we are hurtling through space, on a planet that is tilted over on its axis, spinning as we go, travelling on an orbit that takes us closer and then further from the Sun. And yet one of the wonderful things about working on 23 degrees is that it has given me a magical new perspective on mornings like this. Intensely local phenomena such as the dawn mist I experienced are also part of a much bigger picture. Dawn mists are a consequence of the longer - and therefore cooler - nights, which in turn relate to our 23 degree tilt and the seasons it creates. 

    But the most revealing insight I've gained from the series is the notion that all our weather is driven by gradients - and by the way the Earth seeks to even them out. Gradients are created whenever two (or more) parcels of air (or water or ground) are next to each other, but with different properties - for example, a hot parcel of air next to a cool parcel of air. This means there is a temperature gradient between them, and the Earth system always seeks to even out these differences. The trouble is, there are constant energy inputs creating (or adding to) these differences. Put another way, the climate system is in a constant search for equilibrium, but our journey around the Sun keeps throwing the system out of kilter.


Gradients exist at every scale of the climate system, and crouched down with my camera in the cool, clammy air, I was experiencing one very directly. As the nights lengthen into Autumn, the ground radiates more and more heat back to space. The land cools down, setting up a temperature gradient between the land and the air above. The ground cools the air - attempting to equalise the gradient - until the air reaches its condensation point, forming mist. But then, as the Sun rose, the ground warmed, the air warmed with it, and within a few minutes the mist vanished - the gradient gone.

When I got home almost an hour after leaving I was relieved to find the house still quiet. Just enough time to download this photograph...

    cob web

    Working on 23 Degrees has given me terrific new insights into how our world works, why it is the way it is, and what makes it change. Hopefully when the series is transmitted early next year, you'll get to enjoy those insights too.

    Day 272: Typhoon Nesat in pictures

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    Aira Idris Aira Idris | 12:30 PM, Thursday, 29 September 2011

    Distance travelled ~ 698'568'800 km

    "These pictures were taken on the Ocampo Street in Malate, Manila Philippines beside Rizal Stadium" by Abby Thompson.
    vehicles left at a standstill in the flooding

    iwitness image captured by Abby Thompson

    heavy rain after typhoon nesat

    iwitness image captured by Abby Thompson, Philippines

    flooding in philippine

    iwitness image captured by Abby Thompson, Philippines

    vehicles struggle in the flooded street

    iwitness image captured by Abby Thompson, Philippines

    Nesat hit China earlier today and continues west:

    satellite image of nesat

    After Typhoon Nesat made landfall near Casiguran on the east coast of the island of Luzon in the Philippines 27 September, earlier today it made landfall in the northeastern part of Hainan island, China. It is moving west towards the far north of Vietnam, where it is predicted to make landfall within the next 12 hours. Nesat is weakening and likely to be categorised as a tropical storm soon.

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