There is one important aspect of the whole HS2 saga that has
not been properly considered by the politicians, and that is UK WEATHER.
No one seems to have looked at the detailed Met Office weather
maps for the last couple of decades, the conditions and the temperatures
recorded. It is a simple fact that it rains in Manchester and the
proposed route down to Birmingham lies on a mapping grid that seems to
consistently attract the worse possible UK weather, the weatherpeople call it the Atlantic lows ( a big clue we suggest).
The whole point of HS2 is that
it should provide a high speed service, but it will need fair weather to do so. Buried under 4 metres of snow or submerged in floodwater, would tarnish any form of schedule or high speed timetable. And possibly drive customers to the adjacent Manchester Ringway airport. So what is the point of a west coast HS2?
The journey times presented by the supporters of HS2 are
calculated using the best possible weather conditions. Clearly if there are high
winds, driving rain, snow, snow drifts , flooding and hail to contend with, the trains will have to run
at lower non high speed journey times - if at all.. This in turn will impact on the scheduled
HS timetable and possibly have a domino , knock on effect and before you know it the advantages of HS2 are lost.
As the Met Office say:
The Atlantic Lows are more vigorous in autumn and winter and bring most of the rain that falls in these seasons. In summer, convection caused by solar surface heating sometimes forms shower clouds and a large proportion of rain falls from showers and thunderstorms then.
A further factor that greatly affects the rainfall distribution is altitude. Moist air that is forced to ascend hills may be cooled below the dew point to produce cloud and rain. A map of average annual rainfall therefore looks similar to a topographic map.
The exposure of NW England to westerly maritime air masses and the presence of extensive areas of high ground mean that the region has some of the wettest places in the UK. The higher parts of the Lake District are particularly wet, with an average of over 3200mm of rain each year.
In contrast, the reputedly wet city of Manchester averages 860mm and the more sheltered areas of Cheshire and the Eden valley in Cumbria are even drier with less than 800mm per year. These areas benefit from the 'rain shadow' effect of the high ground of N Wales and the Lake District respectively. The annual averages for the Isle of Man range from about 900mm on the coast to 1800mm around Snaefell.
These values can be compared with annual totals of about 500mm in the drier parts of eastern England and over 4000 mm in the western Scottish Highlands.
The course of mean monthly rainfall for 1971 - 2000 for 3 sites is shown below. Whilst rainfall is generally well-distributed through the year, there is a seasonal pattern. The driest season is spring whilst there is an autumn/winter maximum, when the Atlantic depressions are at their most vigorous. This contrast is most pronounced in the wetter upland areas.
Over much of the region, the number of days with rainfall totals of 1 mm or more ('wet days') tends to follow a pattern similar to the monthly rainfall totals. In the higher parts in winter (December-February), 50-60 days is the norm but this decreases to 40-45 days in summer (June-August). In the drier areas of Cheshire and Merseyside, 35-40 days in winter and about 30 days in summer are typical.
Periods of prolonged rainfall can lead to widespread flooding, especially in winter and early spring when soils are usually near saturation. The autumn of 2000 was particularly wet, with over twice the normal rainfall in much of the Pennines, Greater Manchester and Cheshire.
A recent example was the heavy rainfall in early January 2005 that led to widespread and severe flooding in Carlisle, considered to be the worst to affect the city since 1822. During this period, 227 mm of rainfall were recorded at Shap, Cumbria in 72 hours.
Thunderstorms are most likely to occur from May to September, reaching their peak in July and August, In the Isle of Man thunder occurs on about 5 days per year, on average, while on the mainland the number is 8 to 10 days. The heaviest falls of rain in the UK are often associated with summer thunderstorms. An example was the 95.9 mm that fell at Manchester-Ringway in 11 hours on 5/6 August 1981.
Periods of prolonged rainfall can lead to widespread flooding, especially in winter and early spring when soils are usually near saturation. The autumn of 2000 was particularly wet, with over twice the normal rainfall in much of the Pennines, Greater Manchester and Cheshire.
A recent example was the heavy rainfall in early January 2005 that led to widespread and severe flooding in Carlisle, considered to be the worst to affect the city since 1822. During this period, 227 mm of rainfall were recorded at Shap, Cumbria in 72 hours.
Thunderstorms are most likely to occur from May to September, reaching their peak in July and August, In the Isle of Man thunder occurs on about 5 days per year, on average, while on the mainland the number is 8 to 10 days. The heaviest falls of rain in the UK are often associated with summer thunderstorms. An example was the 95.9 mm that fell at Manchester-Ringway in 11 hours on 5/6 August 1981.
Snowfall
The occurrence of snow is linked closely with temperature, with falls rarely occurring if the temperature is higher than 4 °C. For snow to lie for any length of time, the temperature normally has to be lower than this. Over most of the area, snowfall is normally confined to the months from November to April, but upland areas may have occasional falls in October and May. Snow rarely lies on low ground outside the period from November to March but over higher ground lying snow can also occur in October and as late as May.
On average, the number of days with snow falling is about 15-20 per year on the Isle of Man and from 20 to 30 days in lower-lying parts of the mainland but as much as 60 days over the highest ground. An average increase of about 5 days of snow falling per year per 100 m increase in altitude has been found typical.
The number of days with snow lying is also mainly dependent upon altitude but partly upon proximity to the sea. The number therefore varies from less than 5 days per year on the Isle of Man to around 3-7 days on the Cumbrian and Lancashire coasts and over 30 days in upland areas such as the Pennines and Lake District.
These averages can be compared with parts of the Scottish Highlands, which have about 60 days with snow lying on average and with the coasts of SW England, with less than 3 days per year. In most places, January is the month with most days of both snow lying and snow falling closely followed by February.
The monthly averages of days with sleet/snow falling and lying at Ringway are shown below (a day of lying snow is counted if the ground is more than 50 % covered at 0900).
The number of days with snow lying is also mainly dependent upon altitude but partly upon proximity to the sea. The number therefore varies from less than 5 days per year on the Isle of Man to around 3-7 days on the Cumbrian and Lancashire coasts and over 30 days in upland areas such as the Pennines and Lake District.
These averages can be compared with parts of the Scottish Highlands, which have about 60 days with snow lying on average and with the coasts of SW England, with less than 3 days per year. In most places, January is the month with most days of both snow lying and snow falling closely followed by February.
The monthly averages of days with sleet/snow falling and lying at Ringway are shown below (a day of lying snow is counted if the ground is more than 50 % covered at 0900).
So that is the Met Office view. However take
the weather history of the East Coast Main Line and the picture is somewhat
different.
Simply gale and weather systems generally gathers momentum as
they cross the very open Atlantic Ocean. The Atlantic icebergs after all sunk
the Titanic. As the weather fronts hit the west coast they start losing
momentum as they travel from west to east crossing the country, by the time they
reach the North Sea, its all but blown out.
Put another way how many offshore wind farms are located on
the Atlantic side of the country and how many are there off the East Coast?
Upgrading the East Coast Main Line and installing cross east west country
feeder railway lines would give the country all the advantages of HS2 without
major disruption as the land is already in place and the former
railway property board still own much of the land either side of the existing
ECML track. (It was after all the Dr. Beeching plan to just leave a few
'vertical' lines North to South going up and down the country and to rip out all
the 'horizontal' left to right railway lines).
Ike all plans it sound too easy but bear in mind that the
planners of HS2 started out with an agenda to link Manchester with London via
Birmingham, still with the Dr Beeching blinkers on by not considering a simple
cross country connection to the Royal Scot Line the East Coast Main Line.
Conveniently routed and not carving up the centre of this small overcrowded
island and destroying Constables England for evermore.
JULIAN BRAY, broadcaster & Journalist, Media, Aviation, & Travel Expert. Broadcaster & Journalist EQUITY Member NUJ Life Mbr. UK Tel: 01733 345581 (isdn link on application)
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