Winter Forecast! - He's At It Again...

[Met4Cast]

The Thames will never freeze over again properly because a bridge that was in place which slowed down the flow of the river is no longer there. It may have frozen over a bit in December 2010 if this was still the case.

I hate the whole "the water moves faster so it can't freeze" theory, if that was the case, how do waterfalls freeze? One month of cold isn't enough to freeze over the Thames, if we had two months of sub zero temperatures, I'd say it could quite easily start to freeze over again.

[johnholmes]

and the probability of 2 months below freezing?

[AWD]

and the probability of 2 months below freezing?

about 1/50000

[Gavin Hannah]

I think ya mean 50000/1 - I would stake a pound on that haha.

Edited September 9, 2012 by IBringTheHammer

[AWD]

I think ya mean 50000/1 - I would stake a pound on that haha.

Yeah, and that! Lol.

[Relativistic]

I hate the whole "the water moves faster so it can't freeze" theory, if that was the case, how do waterfalls freeze? One month of cold isn't enough to freeze over the Thames, if we had two months of sub zero temperatures, I'd say it could quite easily start to freeze over again.

The last time the tidal Thames properly froze over was in 1813-14, just before the Old London Bridge was removed. The CET for that Winter was:

December: 1.7C

January: 1.9C

February: 5.8C

Yet, it couldn't even manage to freeze over in the exceptionally long lasting and cold winter of 1962-1963, when temperatures were much lower, for longer. The closest it got was small lumps of ice. Unless we get a Winter that mops the floor with 1683-84 (just won't happen) then I don't think it will properly freeze over again. Waterfalls only freeze under exceptionally cold temperatures, which due to the urban heat island effect, cannot be achieved in London. I think you are being unrealistically optimistic.

Edited September 9, 2012 by 22nov10blast

[Methuselah]

The last time the tidal Thames properly froze over was in 1813-14, just before the Old London Bridge was removed. The CET for that Winter was:

December: 1.7C

January: 1.9C

February: 5.8C

Yet, it couldn't even manage to freeze over in the exceptionally long lasting and cold winter of 1962-1963, when temperatures were much lower, for longer. The closest it got was small lumps of ice. Unless we get a Winter that mops the floor with 1683-84 (just won't happen) then I don't think it will properly freeze over again. Waterfalls only freeze under exceptionally cold temperatures, which due to the urban heat island effect, cannot be achieved in London. I think you are being unrealistically optimistic.

And, at -10C, fine spray freezes when it impacts any solid surface...

[AderynCoch]

The last time the tidal Thames properly froze over was in 1813-14, just before the Old London Bridge was removed. The CET for that Winter was:

December: 1.7C

January: 1.9C

February: 5.8C

Those figures are a bit off. The actual values are:

December: 2.8C

January: -2.9C

February: 1.4C

March was also very cold with a CET of 2.9C.

[Relativistic]

Those figures are a bit off. The actual values are:

December: 2.8C

January: -2.9C

February: 1.4C

March was also very cold with a CET of 2.9C.

Ah yes, sorry for the mistake. Anyway, we still had a January of well below sub zero temperatures, like that of 1963. The point I was trying to make was that if the Thames were still capable of freezing over, it probably would have done so in 1963.

[Met4Cast]

The last time the tidal Thames properly froze over was in 1813-14, just before the Old London Bridge was removed. The CET for that Winter was:

December: 1.7C

January: 1.9C

February: 5.8C

Yet, it couldn't even manage to freeze over in the exceptionally long lasting and cold winter of 1962-1963, when temperatures were much lower, for longer. The closest it got was small lumps of ice. Unless we get a Winter that mops the floor with 1683-84 (just won't happen) then I don't think it will properly freeze over again. Waterfalls only freeze under exceptionally cold temperatures, which due to the urban heat island effect, cannot be achieved in London. I think you are being unrealistically optimistic.

When I was a kid I lived in London and saw a water fountain frozen twice, can't remember the exact years but it would have been sometime in the mid-late 90's, so it can and does happen, even in London!

[johnholmes]

When I was a kid I lived in London and saw a water fountain frozen twice, can't remember the exact years but it would have been sometime in the mid-late 90's, so it can and does happen, even in London!

of course it does Daniel but a totally different phenomena to the Thames freezing over!

[cheeky_monkey]

Ah yes, sorry for the mistake. Anyway, we still had a January of well below sub zero temperatures, like that of 1963. The point I was trying to make was that if the Thames were still capable of freezing over, it probably would have done so in 1963.

The reason the Thames dosent freeze over is that it constantly dredged to keep in more free flowing and to take traffic further west..also it has power stations on it or did that would pump out warm waste water into the river keeping the temp of the water above freezing point.

Edited September 11, 2012 by cheeky_monkey

[Met4Cast]

of course it does Daniel but a totally different phenomena to the Thames freezing over!

I was replying to 22nov10blast who said that it could not be achieved in London due to the urban heating. The orginal point was that the Thames cannot freeze due ti faster flowing water, was it not? My waterfall post was only an exagerated version to make the point that the Thames flow of speed is completely irrelevant, I never stated it was the same phenomena making your point fairly invalid to the discussion at hand

[Interitus]

Rivers can be too fast flowing and turbulent to form a solid sheet ice cover on the surface. This is known as border ice as it starts at the banks and gradually spreads towards the middle.

Instead if cold enough, fast flowing waters can form frazil ice - particles of ice suspended in the water column. These can clump together to form ice pans or pancake ice on the surface, or can gather on the bed of the river and form anchor ice. These ice forms can form ice jams and damage structures whilst submerged ice is hazardous to shipping.

[Liam J]

LOL Why are we talking about the Thames freezing over for anyway, a tad ambitious

I've seen fountains, harbours, lakes, rivers freeze and also waterfalls and streams... A few nights below -10c and sub zero days then things start to freeze over. Obviously not faster flowing waters.

Edited September 11, 2012 by Liam J

[jethro]

Okay, firstly, there is a phenomenon arriving in the UK and Northern Europe soon called Maunder Minimum but it's unknown when this will arrive, hence James Madden's mistakes in his predictions. The last time we had a cold winter which was Winter 10/11 was caused by a warmer Arctic and increased melting which caused a high pressure system to drag cold air down from the Arctic across Russia and Scandinavia which therefore caused the High pressure to sit over Norway as a blocking high. So as I have just mentioned, these cold winters are usually caused by the Ice pack in the Arctic. We have just witnessed recently that the Arctic has had its lowest surface area of ice in the summer ever, this suggests that maybe the winter for this year will be colder than usual.

Also, relating back to Maunder Minimum, we are seeing a decrease in solar activity which is going to cause colder weather anyway, but, it's causing the sun to have 4 poles instead of two, which is similar to that of the period from 1640 to 1710, where the Thames river froze over!

So, in some respects I believe James Madden has a good forecast this year, he's predicted the summer well indeed. But I have spoken to Hannah Bayman from Look North recently on the phone and she also says that there is a period recently where we have had unusual weather, and we don't quite understand what might happen this winter due to the solar cycle being later than usual.

Ask this chap about the 4 poles - I'm pretty certain he's dismissed these claims as nonsense but worth checking all the same.

http://solarcycle24com.proboards.com/index.cgi?board=general&action=display&thread=1587

[Steve C]

LOL Why are we talking about the Thames freezing over for anyway, a tad ambitious

I've seen fountains, harbours, lakes, rivers freeze and also waterfalls and streams... A few nights below -10c and sub zero days then things start to freeze over. Obviously not faster flowing waters.

I think the last time the Thames froze over (in London anyway) was in 1814. I also think the bridges around then were a factor, maybe because they inhibited water flow at the surface?

I could be wrong though. This is something I think I once read.

[Relativistic]

When I was a kid I lived in London and saw a water fountain frozen twice, can't remember the exact years but it would have been sometime in the mid-late 90's, so it can and does happen, even in London!

That is quite cool, and to me actually quite surprising! But the Thames is a very different body of water. Another point to consider is its salt content. I'm sure the Thames in London is saltwater, if not brackish, which I believe lowers the freezing point? If this is true it would mean it would have to be a few degrees C lower than zero to freeze.

Edited September 11, 2012 by 22nov10blast

[Ladyofthestorm]

lol you gotta hand it to him he just loves the attention and limelight.

[Met4Cast]

That is quite cool, and to me actually quite surprising! But the Thames is a very different body of water. Another point to consider is its salt content. I'm sure the Thames in London is saltwater, if not brackish, which I believe lowers the freezing point? If this is true it would mean it would have to be a few degrees C lower than zero to freeze.

Good point, I was completely forgetting/disregarding the salt content, I still think though given the right conditions it could freeze over again, perhaps just not as easily as it did all those years ago

[johnholmes]

Daniel it has less chance of freezing over than the UK having another 1962-63 winter!

It did not freeze then.

The whole situation regarding the Thames is totally different to 1814 regardless of how long a severe cold spell occurred.

[Methuselah]

Good point, I was completely forgetting/disregarding the salt content, I still think though given the right conditions it could freeze over again, perhaps just not as easily as it did all those years ago

Quite right, Daniel. Fortunately, said conditions will almost certainly never occur. What would such a freeze take? -20C for six weeks'?

[Interitus]

Of course the Thames did freeze further upstream in 1963 - people were able to walk across between Molesey and Hampton.

[Mark Neal.]

To get temperatures of -20c for a long period of time (weeks?) would be hard. But to think the best we can usually get is 3/4 nights of temperatures crossing the -10c divide. Its extremely hard to achieve the set conditions for it to freeze over, its not out the question, just seems highly unlikely.

[Gavin Hannah]

If you moved the Thames to Altnaharra (Coldest spot in the UK) then, maybe then, it would freeze over lol.