Post by cuttydyer on Jun 3, 2013 12:05:53 GMT
The BBC reports: Central Europe on alert for flooding
The BBC reports that in Prague the 14th Century Charles Bridge is at risk; the same bridge collapsed as a result of the great flood of September 4th 1890.
The weather around this period of the 1890’s had very similar extremes to those that the Northern Hemisphere has been recently experiencing:
Extreme Winter – TheUK’s winter of 1890/91 was remarkable for its long duration, from 25th November to 22nd January; December 1890 was the coldest such-named month in the CET record (q.v.)
Skating in Regent's Park occurred on 43 days, the thickness of the ice exceeding 9 inches (circa 23cm) but the frost penetrated in the ground to a depth of only about 30cm. At Worcestershire, on the Rivers Severn & Avon, the ice was thick enough to allow ordinary road traffic to pass over the ice-covered river and to permit sheep & pigs to be roasted on the surface. Ice floes were reported in the lower Thames and the Estuary.
December 1890, with a CET value of -0.8degC/~5C below average, is the coldest December in the CET record.
In March Heavy, fine powdery snow and strong easterly winds raged across SW England, southern England and Wales, with over half a million trees being blown down, as well as a number of telegraph poles. On the 9th (and later?), great snowstorm in the west of England, trains buried for days: E-NE gale, shipwrecks, many lives lost. (Eden notes: 220 people dead; 65 ships foundered in the English Channel; 6000 sheep perished; countless trees uprooted; 14 trains stranded in Devon alone.) Although the West Country was the worst affected, southern England, the Midlands, and south Wales also suffered. snowdrifts were 'huge' around some houses in the London - would be accounted a most remarkable sight nowadays! A man was reported found dead at Dorking, Surrey, while snowdrifts of 3.5 metres were recorded at Dulwich, London and Dartmouth, Devon. At Torquay and Sidmouth, Devon over 30 cm of snow fell.
On the 18th May 1891 snow fell over a wide area in the Midlands and East Anglia, to a depth of 15cm.
Major drought – 1893 Spring / early summer some places in SE England had no rain for 60 consecutive days, from mid-March to mid-May with the longest absolute drought of all being at Mile End (London) from 4th March to 15th May. This is thought to be the longest period without measurable rain ever recorded in the British Isles.
Then in August…
Major rains - On the 10th August in 1893, at Preston (Lancashire) a rainfall of 53mm in 35 minutes is thought to have included the highest known 5 minute fall in the United Kingdom - 31.7mm.
Link: booty.org.uk/booty.weather/climate/1850_1899.htm
What could have caused such extremes of violent weather? - an errant Jet Stream.
Solar cycle 13 (started 1890) was similar in strength to that of our current cycle N° 24. As this Met Office presentation demonstrates, weak solar activity results in low levels of UV which is a primary driver for AO/NAO and the strength and position of the Jet Stream.
Link: lasp.colorado.edu/sorce/news/2012ScienceMeeting/docs/presentations/S2-01_Ineson_sorce2012.pdf
A weak Jet Stream results in a "meridional circulation" pattern. The small, weak cells may stagnate over vast areas for many months, bringing unseasonably cold weather on one side and unseasonably warm weather on the other. Droughts and floods become more frequent and may alternate season to season, while the hemisphere as a whole is cooler, individual areas may alternately break temperature and precipitation records at both extremes.
What was the CO2 ppm value in the late 19th Century?
The BBC reports that in Prague the 14th Century Charles Bridge is at risk; the same bridge collapsed as a result of the great flood of September 4th 1890.
The weather around this period of the 1890’s had very similar extremes to those that the Northern Hemisphere has been recently experiencing:
Extreme Winter – TheUK’s winter of 1890/91 was remarkable for its long duration, from 25th November to 22nd January; December 1890 was the coldest such-named month in the CET record (q.v.)
Skating in Regent's Park occurred on 43 days, the thickness of the ice exceeding 9 inches (circa 23cm) but the frost penetrated in the ground to a depth of only about 30cm. At Worcestershire, on the Rivers Severn & Avon, the ice was thick enough to allow ordinary road traffic to pass over the ice-covered river and to permit sheep & pigs to be roasted on the surface. Ice floes were reported in the lower Thames and the Estuary.
December 1890, with a CET value of -0.8degC/~5C below average, is the coldest December in the CET record.
In March Heavy, fine powdery snow and strong easterly winds raged across SW England, southern England and Wales, with over half a million trees being blown down, as well as a number of telegraph poles. On the 9th (and later?), great snowstorm in the west of England, trains buried for days: E-NE gale, shipwrecks, many lives lost. (Eden notes: 220 people dead; 65 ships foundered in the English Channel; 6000 sheep perished; countless trees uprooted; 14 trains stranded in Devon alone.) Although the West Country was the worst affected, southern England, the Midlands, and south Wales also suffered. snowdrifts were 'huge' around some houses in the London - would be accounted a most remarkable sight nowadays! A man was reported found dead at Dorking, Surrey, while snowdrifts of 3.5 metres were recorded at Dulwich, London and Dartmouth, Devon. At Torquay and Sidmouth, Devon over 30 cm of snow fell.
On the 18th May 1891 snow fell over a wide area in the Midlands and East Anglia, to a depth of 15cm.
Major drought – 1893 Spring / early summer some places in SE England had no rain for 60 consecutive days, from mid-March to mid-May with the longest absolute drought of all being at Mile End (London) from 4th March to 15th May. This is thought to be the longest period without measurable rain ever recorded in the British Isles.
Then in August…
Major rains - On the 10th August in 1893, at Preston (Lancashire) a rainfall of 53mm in 35 minutes is thought to have included the highest known 5 minute fall in the United Kingdom - 31.7mm.
Link: booty.org.uk/booty.weather/climate/1850_1899.htm
What could have caused such extremes of violent weather? - an errant Jet Stream.
Solar cycle 13 (started 1890) was similar in strength to that of our current cycle N° 24. As this Met Office presentation demonstrates, weak solar activity results in low levels of UV which is a primary driver for AO/NAO and the strength and position of the Jet Stream.
Link: lasp.colorado.edu/sorce/news/2012ScienceMeeting/docs/presentations/S2-01_Ineson_sorce2012.pdf
A weak Jet Stream results in a "meridional circulation" pattern. The small, weak cells may stagnate over vast areas for many months, bringing unseasonably cold weather on one side and unseasonably warm weather on the other. Droughts and floods become more frequent and may alternate season to season, while the hemisphere as a whole is cooler, individual areas may alternately break temperature and precipitation records at both extremes.
What was the CO2 ppm value in the late 19th Century?