## Thursday, May 30, 2013 ... //

### An extremely cloudy Prague in 2013

A Czech Canadian e-pal has complained to me that "the month of May was worth [an excrement]: cold, windy, rainy etc". But that's nothing compared to the first five months as we have experienced them in Czechia.

The Czech media such as The Week (EN) have told us about some cold hard figures describing the weather in Prague between January 1st and May 17th, 2013.

In this 137-day-long period, the number of hours when it was "clear skies" in Prague was just 80. To compare, it was 417 hours in the same period of the year 2011. I kid you not: the total length of the "clear skies" i.e. sunny weather in Prague dropped by a factor greater than five! (The figures refer to the Ruzyně station near the Havel airport.)

The cloudy, rainy weather may be blamed on the frequently low pressure but why the pressure is so low in 2013 isn't being explained by anything more fundamental that the meteorologists would be able to tell us. This lousy weather shouldn't continue indefinitely but the predictions suggest that the cloudy, rainy mess will actually continue for a few more weeks, well beyond the May 17th deadline I have mentioned.

The differences are extreme when we demand the "clear skies" but there are significant gaps even if we compare more inclusive quantities such as "the average percentage of the skies covered by clouds". In 2011, it was 61%; in 2012, it was 65%. In 2013, it was a whopping 82%. And let me remind you: this is not just some day-to-day variation of the weather but a comparison of periods that are almost half a year long!

The meteorologists warn that there could be floods but I don't think that there is such a direct relationship between a persistently lousy weather and floods. Impressive enough floods probably require some accumulation of water in the atmosphere while the persistently bad weather is delivering the precipitation in the form of rather uniform showers. These neverending showers and clouds is what the climate alarmists present as the "nice homogenized weather free of any extremes" but I have called it the "socialist weather" for 30 years (because this is how I remember the early 1980s) and even though farmers may like it, I am confident that most people agree that such a weather simply sucks.

Needless to say, the articles also mention promises of a global warming trend that our weather should eventually return to. Nice.

I want to emphasize how much more important these annoying yet mundane changes of the weather (which self-evidently have natural causes) are relatively to the "marvelous" effects that the promised global warming trends could ever bring us. If your good mood strongly depends on a sunny weather – or even clear skies – your reasons for a good mood were 5 times weaker than 2 years ago. That's a huge difference that may encourage suicides, the folks suggest. And I am not even going to explain what the cloudy weather does to the photovoltaic industry in which Czechia is still a major "power".

On the other hand, even if you adopt the hugely overestimated median predictions by the IPCC, the overall change of the global temperature during the two years that they want to attribute to CO2 is something like 0.03 °C. Imagine that you are a sane person and I ask you: What is the more important change among the following two: the increase of cloud cover from 61% to 82% or an increase of the global mean temperature (that is only very weakly correlated with the local temperature anywhere) by 0.03 °C?

Clearly, no human in the world could possibly detect the latter without special gadgets – and even common thermometers aren't really enough. On the other hand, everyone notices the lousy weather we've had in the Czech Republic since the early 2013 or so. After all, the clouds decide about more than 10 °C changes of the temperature during the daytime, 300 times greater temperature difference than the hypothetically CO2-induced temperature change. It's important to see various events and changes in the proper context and ignore events and changes that are manifestly 100+ times less important than certain other things that we pretty much ignore, too.

#### snail feedback (13) :

reader Brian G Valentine said...

Just be glad you don't have a heat wave - even worse than the heat is the noisy mouths of Global Warmers

The trash from their mouths is worse than being in a prison camp

reader Shannon said...

France is experiencing the same weather as in Tchequie. This is a picture of Le Pic du Midi in Pyrenees, South of France, May 2011 (top) and May 2013 (bottom). However in Ireland we are experiencing 23 C I'm happy to say :-)

reader Luboš Motl said...

What an irony, Dublin and Belfast are the new sunny Monaco and Cannes. ;-)

reader BMWA1 said...

The major differences between stations at different longitudes are typical in periods of low solar influence as predicted by Vaclav Bucha about 4 years ago...this is dependent on stronger relative geomagnetic field that influences electro-magnetis particle flow above the troposphere (jet stream)...the JS 'drags' tropospheric air masses and influences penetration of polar air masses below.

reader woodnfish said...

Those are beautiful pictures of your city, Lubos. The dark clouds add some real drama to the photographs.

reader AJ said...

Your friend must live in or around Nova Scotia. May's been a biatch. Look's good this weekend though... 25-30C and sun!

On a side note, you've made Scott Aaronson's blog. He states:

"Well, if someone thought something was too obvious to be worth their time, then—with the single, notable exception of Lubos Motl—they wouldn’t write long disquisitions about why it wasn’t worth their time, would they?"

Context: Feasibility of quantum computing. Is it mere engineering?

http://www.scottaaronson.com/blog/?p=1400#comment-77856

reader Luboš Motl said...

Dear woodnfish, I live 60 miles Southwest from the capital - Pilsen, not Prague, is my city (the weather has been the same - makes no sense to distinguish them) although I've lived in Prague for 5 years and I am there roughly "dozen of times" per year.

Yes, the pictures were meant to be frustrating but this atmosphere makes them exciting at the same moment. ;-) In general, however, I have always loved pictures of places in the sunny weather. The colors are not just prettier but convey more information about the color of things etc.

But realism isn't the best path towards art, of course...

reader Ondra said...

Hi Lubos, on another weather, climate note. Have you read this

Cosmic-Ray-Driven Reaction and Greenhouse Effect of
Halogenated Molecules: Culprits for Atmospheric Ozone Depletion and
Global Climate Change , http://arxiv.org/abs/1210.6844

Ondra

reader woodnfish said...

Yes, I knew it might be Prague rather than Pilsen, but the photos weren't labelled so I was not sure.

That is a lot of dark dreary days though and it is the kind of thing that drives up the suicide rate. I know in far north places like Alaska and Northern Canada some people sit in front of lamps in the winter to get vitamin D that helps them get through the depression.

reader Luboš Motl said...

Dear woodnfish, lamps are great but for vitamin D, they probably have to emit some UV rays. ;-)

I didn't want to be cryptic about the pictures so I picked two most characteristic places of our capital city which was evaluated as the #9 in a top tourist list: the Prague Castle

http://en.wikipedia.org/wiki/Prague_Castle

which is where the Czech presidents (and previously kings) reside - according to the Guinness Book, the largest ancient castle in the world. It's St Vitus Cathedral in the middle.

And the Old Town Square

http://en.wikipedia.org/wiki/Old_Town_Square

which has the city hall and the old Astronomical Clock (Orloj), among other things.

reader Tim Cullen said...

Please excuse my ignorance [and lack of language skills] but I am wondering if you might be able to point me in the right direction regarding the famous ponds of South Bohemia.

For example:

Rožmberk is large fish pond in South Bohemian Region of the Czech Republic, next to the town Třeboň.
Its area is 4.89 square kilometres, and maximum depth is 12.3 m, making it the largest pond of Central Europe.
The pond was designed and built under guidance of Jakub Krčín, working for Bohemian aristocratic family House of Rožmberk and it is named after that family. The work was finished in 1590.
At this time many fish ponds were established throughout South Bohemia.
Water from river Lužnice flows into the pond.

Although Wikipedia states the “pond was designed and built under guidance of Jakub Krčín” it seems rather labour intensive to dig out a pond of that size in the 1580s.

However, channelling water from the river Lužnice into a natural [pre-existing] depression would seem more practical [and more likely].

Therefore, I am wondering whether the ponds of South Bohemia really represent a large area of natural depressions [say similar to the Carolina Bays] that have been converted into ponds by man… or were the aristocracy really so obsessed with ponds [and fish] that they initiated such massive earth moving undertakings?

Many thanks - Tim Cullen [Malagabay.wordpress.com]

reader Luboš Motl said...

Yes, you're right! The old builders of the ponds were using preexisting natural basins from which water was going out and the construction of a new pond effectively meant the construction of the dam/barrage/embarkment/dike/dyke, whatever is the right word here. ;-)

However, the number of ponds used to be (much?) higher than today - it was apparently easy enough. We also have many reservoirs - just in Pilsen, I recently visited several of them - that were created at places where something was being mined.

https://maps.google.cz/maps?q=Ejpovick%C3%A9+jezero

https://maps.google.cz/maps?q=Hromnick%C3%A9+jez%C3%ADrko

but these things are more recent, 19th century or newer.

reader Tim Cullen said...

THANK YOU very much for your help… absolutely amazed… 21,000 ponds… that’s a lot of natural basins…

add in some Moldavite tektites… and it is a fascinating subject to research… Thank you – very much appreciated :-)

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