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uk.sci.weather (UK Weather) (uk.sci.weather) For the discussion of daily weather events, chiefly affecting the UK and adjacent parts of Europe, both past and predicted. The discussion is open to all, but contributions on a practical scientific level are encouraged. |
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#1
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For those who like to view Britain's weather through the flawed
prism of the NAO index, that index during March was negative, very very negative, more negative even than any calendar month since Feb 1986. And yet there was much mobility over the Atlantic Ocean and western Europe south of latitude 50 degN, and this mobility penetrated across the whole of the British Isles during the second week of March and again from the 24th onwards, resulting in an outstandingly wet month in many parts of the UK ... exactly what one is supposed to get with a -ve NAOi month, right? More available: Charts: http://www.climate-uk.com/monpre/0603.htm The Monthly Review is already up at: at: http://www.climate-uk.com/monthly/0603.htm Graphs: http://www.climate-uk.com/graphs/0603.htm and http://www.climate-uk.com/graphs/200603.htm Not The Long Range Forecast will be uploaded on Apr 3 to http://www.climate-uk.com/page4.html The mean sea-level chart shows that the Icelandic Low is displaced far to the southwest of its normal position, with the main centre 999mbar just ESE of Newfoundland, but a marked trough extends ENE-wards across the Atlantic and the British Isles to the central North Sea. A weak Azores High (1018mbar) is displaced to Madeira, while abnormally high pressure (1030+ mbar) sits over northern Greenland. The mean flow is SW-ly over England, Wales, both parts of Ireland, and southern Scotland, but E-ly over north Scotland. The main features of the sea-level pressure anomaly field are the big departures over Greenland (+ve) and mid- Atlantic (-ve) and the extensive zone of anomalous E-ly gradient between. The main centres a +13mbar over Greenland -12mbar between the Azores and Newfoundland -7mbar over Romania Over the British Isles pressure anomaly ranges from zero over Shetland and -8mbar at Valentia. The anomalous flow is E-ly over Scotland, Northern Ireland and northern England, but S-ly over the bulk of England and Wales. CET (after Manley) 5.0°C (-1.4 degC wrt 1971-2000) CET (after Hadley) 4.95°C (-1.45 degC) and by this measure it was the coldest March since 1996, although only marginally colder than March 2001. E&W Rain: 87.1mm (119% of 1971-2000 mean) making it the first month with above-average rainfall since November, and also the wettest March since 2001. E&W Sunshine: 106.3 hr (94% of 1971-2000 mean) It was outstandingly dull after the first six days which were exceptionally sunny. CScotT: 4.1°C (-1.7 degC) ScotRain: 98.8mm (141%) ScotSun: 83.6 hr ( 80%) NIT: 5.7°C (-1.1 degC) NI Rain: 91.8mm (147%) NI Sun: 101.2 hr ( 91%) Rainfall totals ranged from 403.0mm at Capel Curig (Snowdonia) to 20.3mm at Southend (Essex). Percentages ranged from 277 at West Freugh (Galloway) to 49 at Hurn (Dorset). Sunshine totals ranged from 156.0hr at St Helier (Jersey) - a CS recorder - to 56.5hr at Kinloss (Moray) - a KZ sensor. Percentages ranged from 109 at Cromer (Norfolk) to 48 at Kinloss. (c) Philip Eden |
#2
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Is that rainfall at Southchurch Park Philip?
Keith (Southend) http://www.southendweather.net Philip Eden wrote: Rainfall totals ranged from 403.0mm at Capel Curig (Snowdonia) to 20.3mm at Southend (Essex). Percentages ranged from 277 at West Freugh (Galloway) to 49 at Hurn (Dorset). (c) Philip Eden |
#3
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![]() "Philip Eden" philipATweatherHYPHENukDOTcom wrote in message ... For those who like to view Britain's weather through the flawed prism of the NAO index, that index during March was negative, very very negative, more negative even than any calendar month since Feb 1986. And yet there was much mobility over the Atlantic Ocean and western Europe south of latitude 50 degN, and this mobility penetrated across the whole of the British Isles during the second week of March and again from the 24th onwards, resulting in an outstandingly wet month in many parts of the UK ... exactly what one is supposed to get with a -ve NAOi month, right? snip The NAO index is useful *if* you know how to use it. There is a misconception that a negative NAO always means a blocked pattern - it doesn't . That can be seen clearly in the mathematics as a negative NAO can arise from a shallower than normal Icelandic low and a less intense Azores high. Even a high over Iceland all month can still mean lows/fronts crossing the UK but further south than normal. The NAO is really only useful for climatologists and possibly for seasonal prediction not for the prediction of individual months and weeks. It is an atmospheric mode of variability ie part of the spectrum that causes variability in the atmospheric flow over the North Atlantic, to understand it properly one needs to go into wave theory, which is involved. Once again we see people dabbling in and using something they don't properly understand (I don't mean you BTW Philip). And you can't understand it properly without many weeks/months of training in mathematics and meteorology. Will. -- " You cannot count your life a success unless you can find one person who says that they are happier because you were born " ------------------------------------------------------------------------------- A COL BH site in East Dartmoor at Haytor, Devon 310m asl (1017 feet). mailto: www: http://www.lyneside.demon.co.uk/Hayt...antage_Pro.htm DISCLAIMER - All views and opinions expressed by myself are personal and do not necessarily represent those of my employer. ------------------------------------------------------------------------------- |
#4
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![]() "Keith (Southend)G" wrote in message oups.com... Is that rainfall at Southchurch Park Philip? Keith (Southend) http://www.southendweather.net Yes, Keith ... not terribly reliable, these days, it has to be said. Next lowest I have is 22.2mm at Clacton which is even less reliable, 24.1mm at Herne Bay, 25.7mm at Margate, 26.6mm at Manston and 28.2mm at Shoeburyness (much closer to your figure!) So it's clearly the Thames Estuary which missed out last month. Philip |
#5
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Philip Eden wrote:
For those who like to view Britain's weather through the flawed prism of the NAO index, that index during March was negative, very very negative, more negative even than any calendar month since Feb 1986. And yet there was much mobility over the Atlantic Ocean and western Europe south of latitude 50 degN, and this mobility penetrated across the whole of the British Isles during the second week of March and again from the 24th onwards, resulting in an outstandingly wet month in many parts of the UK ... exactly what one is supposed to get with a -ve NAOi month, right? I can never remember what the southern oscillation is supposed to produce. And I rather think there are 3 or 4 phases to it rather than the simplified el nino/la nina approach.\/ Charts: http://www.climate-uk.com/monpre/0603.htm The Monthly Review at: http://www.climate-uk.com/monthly/0603.htm Graphs: http://www.climate-uk.com/graphs/0603.htm and http://www.climate-uk.com/graphs/200603.htm The Not The Long Range Forecast: http://www.climate-uk.com/page4.html The mean sea-level chart shows that the Icelandic Low is displaced far to the southwest of its normal position, with the main centre 999mbar just ESE of Newfoundland but a marked trough extends ENE-wards across the Atlantic and the British Isles to the central North Sea. A weak Azores High (1018mbar) is displaced to Madeira, while abnormally high pressure (1030+ mbar) sits over northern Greenland. The mean flow is SW-ly over England, Wales, both parts of Ireland, and southern Scotland, but E-ly over north Scotland. The main features of the sea-level pressure anomaly field are the big departures over Greenland (+ve) and mid-Atlantic (-ve) and the extensive zone of anomalous E-ly gradient between. The main centres a +13mbar over Greenland -12mbar between the Azores and Newfoundland -7mbar over Romania Over the British Isles pressure anomaly ranges from zero over Shetland and -8mbar at Valentia. The anomalous flow is E-ly over Scotland, Northern Ireland and northern England, but S-ly over the bulk of England and Wales. CET (after Manley) 5.0°C (-1.4 degC wrt 1971-2000) CET (after Hadley) 4.95°C (-1.45 degC) and by this measure it was the coldest March since 1996, /\ although only marginally colder than March 2001. E&W Rain: 87.1mm (119% of 1971-2000 mean) making it the first month with above-average rainfall since November, and also the wettest March since 2001. E&W Sunshine: 106.3 hr (94% of 1971-2000 mean) It was outstandingly dull after the first six days which were exceptionally sunny. CScotT: 4.1°C (-1.7 degC) ScotRain: 98.8mm (141%) ScotSun: 83.6 hr ( 80%) NIT: 5.7°C (-1.1 degC) NI Rain: 91.8mm (147%) NI Sun: 101.2 hr ( 91%) Rainfall totals ranged from 403.0mm at Capel Curig (Snowdonia) to 20.3mm at Southend (Essex) Percentages ranged from 277 at West Freugh (Galloway) to 49 at Hurn (Dorset). Sunshine totals ranged from 156.0hr at St Helier (Jersey) -a CS recorder - to 56.5hr at Kinloss (Moray) -a KZ sensor. Percentages ranged from 109 at Cromer (Norfolk) to 48 at Kinloss. (c) Philip Eden The NAO index is useful *if* you know how to use it. There is a misconception that a negative NAO always means a blocked pattern - it doesn't.That can be seen clearly in the mathematics as a negative NAO can arise from a shallower than normal Icelandic low and a less intense Azores high. Even a high over Iceland all month can still mean lows/fronts crossing the UK but further south than normal. The NAO is really only useful for climatologists and possibly for seasonal prediction -not for the prediction of individual months and weeks. It is an atmospheric mode of variability ie part of the spectrum that causes variability in the atmospheric flow over the North Atlantic, to understand it properly one needs to go into wave theory, which is involved. Once again we see people dabbling in and using something they don't properly understand (I don't mean you BTW Philip). And you can't understand it properly without many weeks/months of training in mathematics and meteorology. Actually you don't need much more than schoolboy physics to know that there is no way a wave can travel unaided through a gas. Some people still believe that the air around a storm an fill with electricity in order to produce lightning. (Sometime after the first serious research showed it to be too unlikley to be so.) Once a portion of the atmosphere has been compressed or whatever, it would take a force of orders of magnitude greater than that first cause, to pass it on. Without risking further ire from ne'er do anythings like ***: The oceanic oscillations seem to rely on the ice cover of the various seas in them -or in the snow cover of the land-masses surrounding others. Maybe both. (Probably both.) Whether or not this is a cyclical thing that is regulated by the distortion of the planet's orbit or merely by poor land management or (again) both, remains to be seen. It is stupid to actively persuade others to follow know-nothings into ignoring other paths. For there is no other "wave" that can act over a series of years. Is there? |
#6
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Philip
Don't believe the Hurn figure is accurate. I have recorded 60mm here about 3miles from Hurn and nearer to 95% of average. For several days at the end of the month, Hurn was reporting a "Trace" of rain when i have reported Several mm from Frontal Rain Bands. Believe the Hurn AutoStation has inaccurately reported rainfall too low. Believe the MetOffice should investigate. Kind Regards Paul pblightukATyahooDOTcoDOTuk "Philip Eden" philipATweatherHYPHENukDOTcom wrote in message ... For those who like to view Britain's weather through the flawed prism of the NAO index, that index during March was negative, very very negative, more negative even than any calendar month since Feb 1986. And yet there was much mobility over the Atlantic Ocean and western Europe south of latitude 50 degN, and this mobility penetrated across the whole of the British Isles during the second week of March and again from the 24th onwards, resulting in an outstandingly wet month in many parts of the UK ... exactly what one is supposed to get with a -ve NAOi month, right? More available: Charts: http://www.climate-uk.com/monpre/0603.htm The Monthly Review is already up at: at: http://www.climate-uk.com/monthly/0603.htm Graphs: http://www.climate-uk.com/graphs/0603.htm and http://www.climate-uk.com/graphs/200603.htm Not The Long Range Forecast will be uploaded on Apr 3 to http://www.climate-uk.com/page4.html The mean sea-level chart shows that the Icelandic Low is displaced far to the southwest of its normal position, with the main centre 999mbar just ESE of Newfoundland, but a marked trough extends ENE-wards across the Atlantic and the British Isles to the central North Sea. A weak Azores High (1018mbar) is displaced to Madeira, while abnormally high pressure (1030+ mbar) sits over northern Greenland. The mean flow is SW-ly over England, Wales, both parts of Ireland, and southern Scotland, but E-ly over north Scotland. The main features of the sea-level pressure anomaly field are the big departures over Greenland (+ve) and mid- Atlantic (-ve) and the extensive zone of anomalous E-ly gradient between. The main centres a +13mbar over Greenland -12mbar between the Azores and Newfoundland -7mbar over Romania Over the British Isles pressure anomaly ranges from zero over Shetland and -8mbar at Valentia. The anomalous flow is E-ly over Scotland, Northern Ireland and northern England, but S-ly over the bulk of England and Wales. CET (after Manley) 5.0°C (-1.4 degC wrt 1971-2000) CET (after Hadley) 4.95°C (-1.45 degC) and by this measure it was the coldest March since 1996, although only marginally colder than March 2001. E&W Rain: 87.1mm (119% of 1971-2000 mean) making it the first month with above-average rainfall since November, and also the wettest March since 2001. E&W Sunshine: 106.3 hr (94% of 1971-2000 mean) It was outstandingly dull after the first six days which were exceptionally sunny. CScotT: 4.1°C (-1.7 degC) ScotRain: 98.8mm (141%) ScotSun: 83.6 hr ( 80%) NIT: 5.7°C (-1.1 degC) NI Rain: 91.8mm (147%) NI Sun: 101.2 hr ( 91%) Rainfall totals ranged from 403.0mm at Capel Curig (Snowdonia) to 20.3mm at Southend (Essex). Percentages ranged from 277 at West Freugh (Galloway) to 49 at Hurn (Dorset). Sunshine totals ranged from 156.0hr at St Helier (Jersey) - a CS recorder - to 56.5hr at Kinloss (Moray) - a KZ sensor. Percentages ranged from 109 at Cromer (Norfolk) to 48 at Kinloss. (c) Philip Eden |
#7
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![]() Philip Eden wrote: For those who like to view Britain's weather through the flawed prism of the NAO index, that index during March was negative, very very negative, more negative even than any calendar month since Feb 1986. And yet there was much mobility over the Atlantic Ocean and western Europe south of latitude 50 degN, and this mobility penetrated across the whole of the British Isles during the second week of March and again from the 24th onwards, resulting in an outstandingly wet month in many parts of the UK ... exactly what one is supposed to get with a -ve NAOi month, right? http://www.cpc.ncep.noaa.gov/product..._nh_anim.shtml a 30 day animation of NH 500 hPa GPH makes interesting viewing -showing the migration of an anomaly to settle over Greenland. Looking at animations of tropopause maps available at- http://www.pa.op.dlr.de/arctic/ show a distinctly warm and weak, highly disorganised polar vortex at least in the later half of the month with a great glob of sub tropical air entering right onto the pole, regards, david |
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