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Highest Pressure since March
At long last A High of significance - had a quick look back at my pressure
readings this year and today has seen the highest pressure in Leeds since 17 March. It's now 1038mb and still rising. |
Highest Pressure since March
"Rob Brooks" wrote in message ... At long last A High of significance - had a quick look back at my pressure readings this year and today has seen the highest pressure in Leeds since 17 March. It's now 1038mb and still rising. Is this really surprising, though? In terms of pressure readings isn't a winter anticyclone likely to be more 'intense' than a summer one? -- Col Bolton, Lancashire 160m asl |
Highest Pressure since March
"Col" wrote in message ... "Rob Brooks" wrote in message ... At long last A High of significance - had a quick look back at my pressure readings this year and today has seen the highest pressure in Leeds since 17 March. It's now 1038mb and still rising. Is this really surprising, though? In terms of pressure readings isn't a winter anticyclone likely to be more 'intense' than a summer one? dynamics lesson Why? And don't say because the air is colder as that would not be the right answer, this high has 552DAM air entrained. The reason is all in the dynamics - this high developed at the left entrance of a confluent relaxing upper trough and right exit of an Atlantic jet both regions of upper level convergence due to ageostrophic wind components. Also we had a deep low with a lot of wind and kinetic energy which has been converted to potential energy helping to raise pressure substantially. This is a warm and intense high. /dynamics lesson Will -- |
Highest Pressure since March
"Will Hand" wrote in message ... "Col" wrote in message ... "Rob Brooks" wrote in message ... At long last A High of significance - had a quick look back at my pressure readings this year and today has seen the highest pressure in Leeds since 17 March. It's now 1038mb and still rising. Is this really surprising, though? In terms of pressure readings isn't a winter anticyclone likely to be more 'intense' than a summer one? dynamics lesson Why? And don't say because the air is colder as that would not be the right answer, this high has 552DAM air entrained. The reason is all in the dynamics - this high developed at the left entrance of a confluent relaxing upper trough and right exit of an Atlantic jet both regions of upper level convergence due to ageostrophic wind components. Also we had a deep low with a lot of wind and kinetic energy which has been converted to potential energy helping to raise pressure substantially. This is a warm and intense high. /dynamics lesson Will, I don't understand any of that :) -- Col Bolton, Lancashire 160m asl |
Highest Pressure since March
On Thu, 10 Sep 2009 at 17:07:48, Col wrote
in uk.sci.weather : "Rob Brooks" wrote in message ... At long last A High of significance - had a quick look back at my pressure readings this year and today has seen the highest pressure in Leeds since 17 March. It's now 1038mb and still rising. Is this really surprising, though? In terms of pressure readings isn't a winter anticyclone likely to be more 'intense' than a summer one? I wouldn't quite call this winter yet :) - mind you, the temperature did drop to 4.6C last night... -- Paul Hyett, Cheltenham (change 'invalid83261' to 'blueyonder' to email me) |
Highest Pressure since March
"Col" wrote in message ... "Will Hand" wrote in message ... "Col" wrote in message ... "Rob Brooks" wrote in message ... At long last A High of significance - had a quick look back at my pressure readings this year and today has seen the highest pressure in Leeds since 17 March. It's now 1038mb and still rising. Is this really surprising, though? In terms of pressure readings isn't a winter anticyclone likely to be more 'intense' than a summer one? dynamics lesson Why? And don't say because the air is colder as that would not be the right answer, this high has 552DAM air entrained. The reason is all in the dynamics - this high developed at the left entrance of a confluent relaxing upper trough and right exit of an Atlantic jet both regions of upper level convergence due to ageostrophic wind components. Also we had a deep low with a lot of wind and kinetic energy which has been converted to potential energy helping to raise pressure substantially. This is a warm and intense high. /dynamics lesson Will, I don't understand any of that :) -- Sorry Col, I forgot you hadn't done an advanced forecasting course or the Met. degree at Reading :-) To put it more simply, two upper air flow patterns occurred close together where the wind flows were such that they produced a coming together of air high up in the atmosphere at around 30000 feet. This air was forced to come down as the tropopause higher up was acting as a lid. This downward motion transported masses of air into one place and pressure began to rise at the surface. Meanwhile at the same time a very deep low began to fill up and the kinetic energy of the fast moving air was converting to potential energy (energy is never lost) reinforcing the effect of the coming together of the air flows. Is that better? Will -- |
Highest Pressure since March
On 10 Sep, 21:11, "Will Hand" wrote:
Will, I don't understand any of that :) -- Sorry Col, I forgot you hadn't done an advanced forecasting course or the Met. degree at Reading :-) Is that better? Will What an utterly pretentious response that is, Will. Please grow up and have some respect for the majority on this newsgroup who don't have your background but who are asking perfectly reasonable questions in order to seek greater understanding and not to be used as target practice for patronising statements such as the ones above. I suggest an apology to Col is in order. -- Stephen Burt Stratfield Mortimer, Berkshire |
Highest Pressure since March
"Stephen Burt" wrote in message ... On 10 Sep, 21:11, "Will Hand" wrote: Will, I don't understand any of that :) -- Sorry Col, I forgot you hadn't done an advanced forecasting course or the Met. degree at Reading :-) Is that better? Will What an utterly pretentious response that is, Will. Please grow up and have some respect for the majority on this newsgroup who don't have your background but who are asking perfectly reasonable questions in order to seek greater understanding and not to be used as target practice for patronising statements such as the ones above. I suggest an apology to Col is in order. -- Stephen Burt Stratfield Mortimer, Berkshire I didn't understand too much of that either but as this is the "uk.sci" heirachy of usenet I guess a bit of science is to be expected. Paul |
Highest Pressure since March
Yes Will, that's OK for the dynamics. But the next step is to equate this to
the physical consequence, the thermodynamic effect, of the dynamics you describe. The effect of the upper level convergence is to lift a substantial layer of the upper troposphere and lower stratosphere, which of course results in a cooling of the layer, especially well marked in the stratosphere, where the lapse is zero or negative. It is this cooling that more than compensates for the tropospheric warming due to subsidence and advection, and produces the increase in pressure at the base of the atmosphere. Mass can only increase in an atmospheric column if there is a corresponding decrease in temperature. A map of the pressure or height field at any level in the atmosphere is a direct reflection of the mean temperature field (or thickness) in the atmosphere above that level. A high pressure 'cell' at any level will be a reflection of a cold anomaly above that level, and a warm anomaly will be found above a low pressure area. -- Bernard Burton Wokingham, Berkshire, UK. Satellite images at: www.woksat.info/wwp.html "Will Hand" wrote in message ... "Col" wrote in message ... "Rob Brooks" wrote in message ... At long last A High of significance - had a quick look back at my pressure readings this year and today has seen the highest pressure in Leeds since 17 March. It's now 1038mb and still rising. Is this really surprising, though? In terms of pressure readings isn't a winter anticyclone likely to be more 'intense' than a summer one? dynamics lesson Why? And don't say because the air is colder as that would not be the right answer, this high has 552DAM air entrained. The reason is all in the dynamics - this high developed at the left entrance of a confluent relaxing upper trough and right exit of an Atlantic jet both regions of upper level convergence due to ageostrophic wind components. Also we had a deep low with a lot of wind and kinetic energy which has been converted to potential energy helping to raise pressure substantially. This is a warm and intense high. /dynamics lesson Will -- |
Highest Pressure since March
On Sep 10, 11:28*pm, "Bernard Burton" b.j.burton-
wrote: Yes Will, that's OK for the dynamics. But the next step is to equate this to the physical consequence, the thermodynamic effect, of the dynamics you describe. The effect of the upper level convergence is to lift a substantial layer of the upper troposphere and lower stratosphere, which of course results in a cooling of the layer, especially well marked in the stratosphere, where the lapse is zero or negative. It is this cooling that more than compensates for the tropospheric warming due to subsidence and advection, and produces the increase in pressure at the base of the atmosphere. Mass can only increase in an atmospheric column if there is a corresponding decrease in temperature. A map of the pressure or height field at any level in the atmosphere is a direct reflection of the mean temperature field (or thickness) in the atmosphere above *that level. A high pressure 'cell' at any level will be a reflection of a cold anomaly above that level, and a warm anomaly will be found above a low pressure area. -- Bernard Burton Wokingham, Berkshire, UK. Satellite images at:www.woksat.info/wwp.html "Will Hand" wrote in message ... "Col" wrote in message ... "Rob Brooks" wrote in message ... At long last A High of significance - had a quick look back at my pressure readings this year and today has seen the highest pressure in Leeds since 17 March. It's now 1038mb and still rising. Is this really surprising, though? In terms of pressure readings isn't a winter anticyclone likely to be more 'intense' than a summer one? dynamics lesson Why? And don't say because the air is colder as that would not be the right answer, this high has 552DAM air entrained. The reason is all in the dynamics - this high developed at the left entrance of a confluent relaxing upper trough and right exit of an Atlantic jet both regions of upper level convergence due to ageostrophic wind components. Also we had a deep low with a lot of wind and kinetic energy which has been converted to potential energy helping to raise pressure substantially. This is a warm and intense high. /dynamics lesson Will --- Hide quoted text - - Show quoted text - Thank goodness someone has come up with a lucid explanation of where the extra air is, to put it simply. i used to be a bit puzzled about this. If you go to 30,000 feet in an anticyclone the pressure is still higher than normal for that height so one is still forced to ask oneself where all this "extra air" is. Above 30,000 feet, obviously. I knew it must be in the stratosphere but it is now clear to me how it gets there and why it causes high pressure. One could say that the dynamical processes try to lift the lid and the lid fights back with adiabatic cooling. It's all a bit clearer now. Thanks, Bernard. Tudor Hughes, Warlingham, Surrey. |
Highest Pressure since March
On Thu, 10 Sep 2009 at 17:15:01, Will Hand
wrote in uk.sci.weather : this high has 552DAM air entrained. The reason is all in the dynamics - this high developed at the left entrance of a confluent relaxing upper trough and right exit of an Atlantic jet both regions of upper level convergence due to ageostrophic wind components. Ow - my head hurts. :p -- Paul Hyett, Cheltenham (change 'invalid83261' to 'blueyonder' to email me) |
Highest Pressure since March
"Stephen Burt" wrote in message ... On 10 Sep, 21:11, "Will Hand" wrote: Will, I don't understand any of that :) -- Sorry Col, I forgot you hadn't done an advanced forecasting course or the Met. degree at Reading :-) Is that better? Will What an utterly pretentious response that is, Will. Please grow up and have some respect for the majority on this newsgroup who don't have your background but who are asking perfectly reasonable questions in order to seek greater understanding and not to be used as target practice for patronising statements such as the ones above. I suggest an apology to Col is in order. Eh? I thought that was a perfectly reasonable response, I didn't think it was patronising at all. He used a smiley which to me means that it was a light-hearted comment, nothing to take offence at. -- Col Bolton, Lancashire 160m asl |
Highest Pressure since March
"Will Hand" wrote in message ... "Col" wrote in message ... Sorry Col, I forgot you hadn't done an advanced forecasting course or the Met. degree at Reading :-) To put it more simply, two upper air flow patterns occurred close together where the wind flows were such that they produced a coming together of air high up in the atmosphere at around 30000 feet. This air was forced to come down as the tropopause higher up was acting as a lid. This downward motion transported masses of air into one place and pressure began to rise at the surface. Meanwhile at the same time a very deep low began to fill up and the kinetic energy of the fast moving air was converting to potential energy (energy is never lost) reinforcing the effect of the coming together of the air flows. Is that better? Yes, thanks! -- Col Bolton, Lancashire 160m asl |
Highest Pressure since March
"Stephen Burt" wrote in message ... On 10 Sep, 21:11, "Will Hand" wrote: Will, I don't understand any of that :) -- Sorry Col, I forgot you hadn't done an advanced forecasting course or the Met. degree at Reading :-) Is that better? Will What an utterly pretentious response that is, Will. Please grow up and have some respect for the majority on this newsgroup who don't have your background but who are asking perfectly reasonable questions in order to seek greater understanding and not to be used as target practice for patronising statements such as the ones above. I suggest an apology to Col is in order. It was a joke Stephen - a joke. This is not the first time you have had a pop at me in public, and you an ex Met Office person as well, who now works for Dell (at least last time we spoke you did). Also we were friends once and Helen is a godparent to one of my children - remember that? You will notice that I did offer a less technical explanation - I didn't have to do that. Can I suggest you sort yourself out first before making such rash statements in public. Will -- |
Highest Pressure since March
"Col" wrote in message ... "Will Hand" wrote in message ... "Col" wrote in message ... Sorry Col, I forgot you hadn't done an advanced forecasting course or the Met. degree at Reading :-) To put it more simply, two upper air flow patterns occurred close together where the wind flows were such that they produced a coming together of air high up in the atmosphere at around 30000 feet. This air was forced to come down as the tropopause higher up was acting as a lid. This downward motion transported masses of air into one place and pressure began to rise at the surface. Meanwhile at the same time a very deep low began to fill up and the kinetic energy of the fast moving air was converting to potential energy (energy is never lost) reinforcing the effect of the coming together of the air flows. Is that better? Yes, thanks! -- Cheers Col. Will -- |
Highest Pressure since March
Thanks Bernard. I didn't mean to neglect the thermodynamics. I was trying to
illustrate the fact that intense highs are not entirely due to very cold dense air near the surface as a lot of people believe. Will -- "Bernard Burton" wrote in message ... Yes Will, that's OK for the dynamics. But the next step is to equate this to the physical consequence, the thermodynamic effect, of the dynamics you describe. The effect of the upper level convergence is to lift a substantial layer of the upper troposphere and lower stratosphere, which of course results in a cooling of the layer, especially well marked in the stratosphere, where the lapse is zero or negative. It is this cooling that more than compensates for the tropospheric warming due to subsidence and advection, and produces the increase in pressure at the base of the atmosphere. Mass can only increase in an atmospheric column if there is a corresponding decrease in temperature. A map of the pressure or height field at any level in the atmosphere is a direct reflection of the mean temperature field (or thickness) in the atmosphere above that level. A high pressure 'cell' at any level will be a reflection of a cold anomaly above that level, and a warm anomaly will be found above a low pressure area. -- Bernard Burton Wokingham, Berkshire, UK. Satellite images at: www.woksat.info/wwp.html "Will Hand" wrote in message ... "Col" wrote in message ... "Rob Brooks" wrote in message ... At long last A High of significance - had a quick look back at my pressure readings this year and today has seen the highest pressure in Leeds since 17 March. It's now 1038mb and still rising. Is this really surprising, though? In terms of pressure readings isn't a winter anticyclone likely to be more 'intense' than a summer one? dynamics lesson Why? And don't say because the air is colder as that would not be the right answer, this high has 552DAM air entrained. The reason is all in the dynamics - this high developed at the left entrance of a confluent relaxing upper trough and right exit of an Atlantic jet both regions of upper level convergence due to ageostrophic wind components. Also we had a deep low with a lot of wind and kinetic energy which has been converted to potential energy helping to raise pressure substantially. This is a warm and intense high. /dynamics lesson Will -- |
Highest Pressure since March
On Fri, 11 Sep 2009 09:18:02 +0100, Will Hand wrote in
What an utterly pretentious response that is, Will. Please grow up and have some respect for the majority on this newsgroup who don't have your background but who are asking perfectly reasonable questions in order to seek greater understanding and not to be used as target practice for patronising statements such as the ones above. I suggest an apology to Col is in order. It was a joke Stephen - a joke. That's exactly how I read it and you then took the time to simplify the dynamics of the process in the subsequent explanation. I think this shows how the meaning of our words here in print can sometimes be misconstrued - more so than in an real conversation. -- Mike Tullett - Coleraine 55.13°N 6.69°W posted 9/11/2009 8:29:43 AM GMT |
Highest Pressure since March
On Fri, 11 Sep 2009 09:32:36 +0100, "Will Hand"
wrote: I would do it more now but I'm afraid of accused of being patronising because of my writing style, so I don't bother much - it is all very sad. Don't take it to heart. It was your comment that was thought patronising not the main content of your post so carry on. Some 'heavy' science would do this group a power of good at the moment. -- Alan White Mozilla Firefox and Forte Agent. Twenty-eight miles NW of Glasgow, overlooking Lochs Long and Goil in Argyll, Scotland. Webcam and weather:- http://windycroft.gt-britain.co.uk/weather |
Highest Pressure since March
Paul Hyett wrote:
On Thu, 10 Sep 2009 at 17:07:48, Col wrote in uk.sci.weather : "Rob Brooks" wrote in message ... At long last A High of significance - had a quick look back at my pressure readings this year and today has seen the highest pressure in Leeds since 17 March. It's now 1038mb and still rising. Is this really surprising, though? In terms of pressure readings isn't a winter anticyclone likely to be more 'intense' than a summer one? I wouldn't quite call this winter yet :) - mind you, the temperature did drop to 4.6C last night... I would have said 17 March is more likely a "winter" anticyclone - only 17 days away from meteorological winter whereas we're about 80 days from it. -- Graham P Davis, Bracknell, Berks., UK. E-mail: newsman not newsboy "I wear the cheese. It does not wear me." |
Highest Pressure since March
Will Hand wrote: "Col" wrote in message ... "Will Hand" wrote in message ... "Col" wrote in message ... Sorry Col, I forgot you hadn't done an advanced forecasting course or the Met. degree at Reading :-) To put it more simply, two upper air flow patterns occurred close together where the wind flows were such that they produced a coming together of air high up in the atmosphere at around 30000 feet. This air was forced to come down as the tropopause higher up was acting as a lid. This downward motion transported masses of air into one place and pressure began to rise at the surface. Meanwhile at the same time a very deep low began to fill up and the kinetic energy of the fast moving air was converting to potential energy (energy is never lost) reinforcing the effect of the coming together of the air flows. Is that better? Yes, thanks! -- Cheers Col. Will The response was very good. More importantly, if anyone was to complain, it would be Col himself, not anyone else. However, as I never saw the complainant's post, I can only assume he was in my kill file. If he hadn't been, he would now. I really hate bullies who think they should tell everyone else how they should act. You carry on, Will. -- Howard Neil |
Highest Pressure since March
"Howard Neil" wrote in message o.uk... The response was very good. More importantly, if anyone was to complain, it would be Col himself, not anyone else. However, as I never saw the complainant's post, I can only assume he was in my kill file. If he hadn't been, he would now. I really hate bullies who think they should tell everyone else how they should act. You carry on, Will. Well exactly. I wasn't offended and found it rather presumptious for somebody to take it upon themselves to be offended on my behalf, without even botherthing to wait to see if*I* said anything about it! -- Col Bolton, Lancashire 160m asl |
Highest Pressure since March
On Sun, 13 Sep 2009 at 20:25:49, Col wrote
in uk.sci.weather : I wasn't offended and found it rather presumptious for somebody to take it upon themselves to be offended on my behalf, without even botherthing to wait to see if*I* said anything about it! Presumably he works for the 'diversity' department of some local council... :p -- Paul Hyett, Cheltenham (change 'invalid83261' to 'blueyonder' to email me) |
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