What the hell is going on with the weather?

Leighb said:
Interesting memories. I was also abroad in 1959, but in North Germany for 3/12, they had no rain at all for many months, the drought was so severe that many hundreds of cattle had to be slaughtered due to failure of their water supply. It was amazingly hot, but very very low humidity so actually quite comfortable.
In 75 and 76 we were in Newmarket, one year, can’t remember which, it snowed on about 6th June, and then the temperature shot up and we had no rain until October!
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In '75 I went to Germany for a long weekend, returning in the first few days of June. It was cold when I left on the Friday and scorching when I returned on the Monday. I had thought that it included the last day or two of May, but maybe it was the week later. '75 did actually get higher temperatures than the famous summer of '76 but the latter started earlier in early May. Aerial pictures showed the countryside as a uniform brown, punctuated by vivid green duckweed on all the remaining water. The canal outside a pub in Surrey we visited with my in-laws was completely covered with duckweed. This fooled their Labrador into thinking it was solid ground, leading him to try to walk across it. I expect he wondered why we were laughing our heads off.
 
johnalison said:
In '75 I went to Germany for a long weekend, returning in the first few days of June. It was cold when I left on the Friday and scorching when I returned on the Monday. I had thought that it included the last day or two of May, but maybe it was the week later. '75 did actually get higher temperatures than the famous summer of '76 but the latter started earlier in early May. Aerial pictures showed the countryside as a uniform brown, punctuated by vivid green duckweed on all the remaining water. The canal outside a pub in Surrey we visited with my in-laws was completely covered with duckweed. This fooled their Labrador into thinking it was solid ground, leading him to try to walk across it. I expect he wondered why we were laughing our heads off.
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The 1976 drought resulted in me being on a Church Council that had to decide to demolish a church. It was a Victorian church in London (Holy Trinity Sydenham), of no great architectural merit, and one end had been built on an infilled pond. It had been fine for the preceding 100 or so years, but the 1976 drought resulted in the clay filling of the pond shrinking. The wall above it developed a large and active crack, and the local authority condemned the building as unsafe. Repairs were going to cost a sum in the region of a quarter of a million pounds (getting on for £2million these days) and the church council decided that they couldn't justify the expenditure, and the church moved to the well-built church hall! There were the usual complaints from people who never darkened the door of the church, but it was demolished and the land used for housing.
 
There was a vast industry developed after '76 selling underpinning to houses across the land. I dare say that some of them needed it, but not all. Our house had a fine crack up the centre thought to have come from a V1 that landed nearby. In '76 this opened up to about 1/3" in places. When the rain came it closed up again and was no worse when we sold the house a year or two later.
 
johnalison said:
There was a vast industry developed after '76 selling underpinning to houses across the land. I dare say that some of them needed it, but not all. Our house had a fine crack up the centre thought to have come from a V1 that landed nearby. In '76 this opened up to about 1/3" in places. When the rain came it closed up again and was no worse when we sold the house a year or two later.
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It's fairly common to see glass slides stuck across cracks in churches, to see if the crack is mobile or not. Mostly they aren't. Of course. most older churches have very shallow foundations and are particularly susceptible to ground movement.
 
There was one in our school chapel, a substantial modernist building from the '30s. I used to stare at the glass tell-tale for hours during sermons. It never moved.
 
Fanny Haddock said:
Actually I really was genuinely interested to know what was happening with the weather. Don't have a TV to explain it to me.
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This site is a good overview.
Click on the word 'Earth' at the bottom left for the options menu.

It shows the jet stream at around 250 hPa. Notice how the stream drops south, dragging polar air down and over the UK - or preventing warmer air from moving up.
 
Greemble said:
This site is a good overview.
Click on the word 'Earth' at the bottom left for the options menu.

It shows the jet stream at around 250 hPa. Notice how the stream drops south, dragging polar air down and over the UK - or preventing warmer air from moving up.
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yes i use that one myself, i find it quite good
 
Greemble said:
This site is a good overview.
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Fascinating & beautiful. I've seen similar but not that particular version, it's enough to make me want to fix a second charging system & get another battery to run on a tablet. Need to study it more. I have explored it fully yet but I guess if it does water temperatures, we could make even more sense of what is going on & why.

How cheap/easy is it the data costs to run at sea?

It's certain a good time to think of sailing to Sweden or Norway.
 
Capt Popeye said:
Might help on tv if the weather forcasts with maps show the jet Stream over the GB/UK as i understand that it has a greater influence than many of us understand, might mean us genning up on the Jet Stream thought to understand it, but it then might help us understand why the weather does not allways do as thought or predicted by the Weather Forcasters

I have noticed that the ITV weather forcast sometimes appear to show the Jet Stream over the GB/U K but never the BBC

Guess that we really appreciate our variable weather in this country really, it affords us unpredictability plus change, plus plus the very best growing seasons for Fruit, Veg, Flowers etc etc
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You are absolutely correct! The reason there is a jet stream at about the 40-60 deg latitude is basically due to the way the convection starts the weather. Just past the solstice, the sun is overhead at noon roughly at the tropics. Obviously the heating effect of the sun is greatest when the sun is vertically overhead. So, that heats the air at the surface, which becomes less dense and rises , meaning that atmospheric pressure at the surface reduces ( so there are areas of low pressure between the equator and the tropics) and with air further north being less warm, the wind commences to flow at the surface to the south. If the earth wasn't a sphere, that would be a straight northerly but, if you consider the West to east rotation, the circle of latitude a few degrees north is smaller circumference. This means that at the equator, a spot on the earth's surface is moving at about 950 mph. At 60 North the similar speed is 475 mph. (Coriolis effect)

Back to the convection circulation... you will all have heard of the Azores High. So the air that was rising at the equator, gets to a height and has lost some energy, and starts to drop down, and so causes High Pressure - in the N.Atlantic, the Azores High... We now proceed North again and we get another area of heating (albeit less than at the Equator) and we get another area of low pressure.

The north bound high level transfer of air (about 5000 metres up) started off at the surface travelling at 950 mph to the east... It's North bound component is about 40 mph, but by the time it gets several degrees north, the part of earth's surface it's over is a couple of hundred miles to the east of the longitude it started at... so the Coriolis effect makes it seem that the high level wind is blowing nearly Westerly at 200 MPH... (the Jet Stream).

The thing that means is that the Jet stream marks the boundary between the High (the Azores High) and the low north of it... ANd hence is a very good predictor of where the low pressure systems spin up. Now how do we know where that is? Some so called "expert forecasts" will produce a forecast of the height of the 500millibar (actually hPa) level

Below is a screen snip of the GFS forecast for this from WeatherOnline Expert Charts (a subscription service - £20 a year)

The Heavy line shown is that level, and shows the northern limit of the Jet stream, and lows generally spin up on the northern side of that line... You will also notice that there are numbers in the grey boxes, this is the forecast for that number of hours ahead - up to 384 hours ahead- 16 days

Sorry for the long post, but it does help to understand... Ona longer cruise I used this forecast extensively to see the likelihood of when lows would be coming our way (deep North Atlantic lows that is). There are many other factors involved, but as a basic principle of how the weather systems at our Latitude work out...Screenshot 2021-07-08 103702.jpg
 
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