There's a useful Jet Stream forecast at www.westweather.co.uk/jetstream that goes up to ten days forward.

Equally interesting is the description below of the mechanics of a Jet Stream, and especially how Rossby waves can result in e.g prolonged wet summers whilst people are dying of heat just...There's a useful Jet Stream forecast at www.westweather.co.uk/jetstream that goes up to ten days forward.

Equally interesting is the description below of the mechanics of a Jet Stream, and especially how Rossby waves can result in e.g prolonged wet summers whilst people are dying of heat just across the Channel in usually nice-to-go-places like Spain and Italy. And also France.

In a nutshell - the Jet Stream is a band of fast moving air that blows from west to east - it separates the cold grey miserable polar air from the warm, continental 'just baked croissant'-flavoured stuff.

The stream itself wanders slowly north and south across the UK - when it's south of us we are stuck in miserable grey days of Old London Town, when its to the north we get our flipflops out. So far so simple.

But it's not the kind of steady stream that your Doctor asks for - ripples move from the east to the west that force it up and down the country temporarily - these are called Rossby Waves and they are independent of the speed of the oncoming stream..

If the Rossby wave speed matches the opposite-flowing Jet Stream speed then conditions become static and we may see either a prolonged heatwave or wet season.

A useful example is tomorrow 9pm's Jet Stream forecast (second image) vs XC Weather forecast (third image). The Jet Stream has completely looped south around the bottom of the country, leaving us in a pool of unsettled 'Polar' weather which persists until Thursday.

As to how accurate the predictions are I have no idea, though most likely the further out they get the less accurate they become.

Understanding the mechanics of UK weather may not make you feel any happier about our stolen summer, but it is some comfort to know what to blame.

.. Show more

For anyone interested in watching the Blood Moon Eclipse today (visible in the Southern hemisphere), The Griffith Observatory has a live stream on YouTube here

m.youtube.com/watch

Streaming starts at 09:44 BST, the Moon moves into the Earth’s penumbra at 10:45am BST, and moves into the Earth’s...For anyone interested in watching the Blood Moon Eclipse today (visible in the Southern hemisphere), The Griffith Observatory has a live stream on YouTube here

m.youtube.com/watch

Streaming starts at 09:44 BST, the Moon moves into the Earth’s penumbra at 10:45am BST, and moves into the Earth’s umbra at 12:11 BST. Show more

theconversation.com/supermoon-how-an-illusion-make…

weather.mailasail.com/Franks-Weather/How-Waves-And…

Frank's Weather has some useful background on waves

"There are requests from time to time for more detailed forecasts of sea conditions. I have been asked why the UK does not include swell height in its marine forecasts.

Here, I try to explain...weather.mailasail.com/Franks-Weather/How-Waves-And…

Frank's Weather has some useful background on waves

"There are requests from time to time for more detailed forecasts of sea conditions. I have been asked why the UK does not include swell height in its marine forecasts.

Here, I try to explain how waves and swell are formed and why sea state can be so variable in space and time.

Sea state depends on wind, current, coastal topography, the depth and nature of the sea bed. A sailor should be able to predict, qualitatively, how rough the sea is likely to be using a local wind forecast, tidal atlas and charted warnings of overfills and eddies. As in all of sailing, predictions will improve with experience gained and lessons learned. It is my belief that sea state near the coast cannot usefully be predicted on the space/time scales of an inshore waters or offshore forecast.

Swell originates beyond the areas of local forecasts and varies depending on its source, so it is hard for a sailor to predict. It can be a hazard at some harbour entrances and, in those cases, swell forecasts for the coasts affected are valuable. " Show more

royalsocietypublishing.org/doi/10.1098/rsta.2017.0…

Particles in the water actually drift towards the waves, called Stokes Drift, discovered in 1847.

This paper discusses the physics behind the phenomenon

www.ranker.com/list/10-biggest-deadliest-most-dest…

Hard to a hurricane called Fifi seriously - perhaps that was a factor in the number of lives lost..

www.theguardian.com/world/2020/dec/18/cyclone-yasa…

"The government had estimated that 850,000 people – 95% of Fiji’s population – would be directly affected by the cyclone."

"The cyclone is another blow to the country’s tourism-reliant economy, already devastated by pandemic shutdowns which have...www.theguardian.com/world/2020/dec/18/cyclone-yasa…

"The government had estimated that 850,000 people – 95% of Fiji’s population – would be directly affected by the cyclone."

"The cyclone is another blow to the country’s tourism-reliant economy, already devastated by pandemic shutdowns which have caused tens of thousands of job losses. Fiji’s economy has shrunk more than 20% this year due to the pandemic." Show more

www.theguardian.com/world/2020/dec/16/cyclone-yasa…

Even if the two storms don't combine Yasa alone is devastatingly powerful - the Guardian seems remarkably sanguine about it given the wind speeds and its slow moving nature (which means inundation for towns by cobtinual heavy rainfall).

www.theguardian.com/world/2020/nov/10/devastating-…

"The annual record for the number of major storms forming in the Atlantic has been shattered, with Subtropical Storm Theta becoming the 29th named event in a hyperactive hurricane season.

The US National Hurricane Center said the development of...www.theguardian.com/world/2020/nov/10/devastating-…

"The annual record for the number of major storms forming in the Atlantic has been shattered, with Subtropical Storm Theta becoming the 29th named event in a hyperactive hurricane season.

The US National Hurricane Center said the development of Theta, currently churning through the heart of the Atlantic, had broken a record that stood since 2005, when there were 28 named storms. " Show more