Veteran trees that make Wanstead Park

April 11, 2015 wansteadmeteo 1 Comment

As the trees in Wanstead Park start bursting into life it is interesting to note that the oaks seem to be beating the ash trees into leaf.

One of the magnificent oaks that provide the backdrop to Music in WansteadPark was in leaf on Friday, April 11th.

After the dry vernal equinox period this could be another sign of a dry summer to come as the saying goes…

If the oak before the ash then we’ll only see a splash.

If the ash before the oak then we’re sure to get a soak.

The story behind the mature trees in Wanstead Park – several of which will turn 200 this year – is a fascinating one.

The park is virtually on my doorstep and it’s like watching a living painting as the trees change from season to season. Spring is my favourite time of year, as the character of the park transforms so quickly. Chalet Wood bursts into colour with a carpet of bluebells, and leaves once again clothe the trees.

Magnificent specimens of oak, horse chestnut, sycamore and holly stand alongside half-rotten victims of gales over the last 200-odd years. But despite storms and floods, the biggest nemesis to these trees was the former owner of the park, William Long-Wellesley. As well as demolishing Wanstead House in 1823 to help clear his debts, Long-Wellesley also sold thousands of mature trees, despite local opposition and a court injunction brought by Sir Edward Sugden, who was seeking to restrain Long-Wellesley’s depredations on his children’s inheritance.

A court report from the time states that Long-Wellesley had marked 2,000 trees for sale, which would have included hardwoods, such as oak, chestnut and elm and perhaps walnut and lime. To quantify that figure, it should be noted that the last full tree survey of the park, not including Bush Wood, in April 1990, listed just over 800 trees.

Richard Arnopp, committee member of the Friends of Wanstead Parklands, said: “There is general agreement that Long-Wellesley left the park more or less devastated, but the wooded areas subsequently regenerated within their former footprints, helped by later planting and management by the Corporation of London.”

It is not clear who bought the trees, though oak was especially valuable at the time for shipbuilding, which was still some decades away from the shift from timber to iron. Britain was at the end of the first Industrial Revolution and timber suitable for making masts, a crucial requirement for any sailing ship, and one that often had to be replaced after storms or wear, was difficult to find.

This graph shows the monthly mean temperature for the periods 1814-1825 (series 1, blue line) and 2004-2015 (series 2, orange line). Notice how much colder most winters were 1814-1825

It was also a cold period. Just over 10 years previous the Thames froze over for the last time and winters were frequently very cold and snowy. Wood was one of the principal methods of keeping warm – house fires would have been burning through the winter – anyone with a wood stove would know just how much wood you can get through, even in an average winter.

As well as selling timber, Long-Wellesley reportedly sold the topsoil of Wanstead Flats to nurseries as potting compost. Most of the mature trees in the park today would have been saplings in the 1820s, thus escaping the attention of Long-Wellesley. According to the Debois survey from 1990, the cedar tree near the Ornamental Water has this year reached its 200th birthday. Also 200 years old this year are the three magnificent oaks next to the Temple, one of which has increased in girth from 319cm to 372cm since 1990.

The trees were protected for future generations when the Epping Forest Act was passed in 1878. Since that time, the Corporation of London has managed their welfare and a new initiative will soon step up this care and reinstate even more of what was lost during Long-Wellesley’s tenure.

* There is much more detail at the site http://www.wansteadpark.org.uk/

** The author has studied forestry and arboriculture at Capel Manor College in Enfield

Weather, weather pattern, weatherlore

Spring signs for a dry summer?

April 3, 2015 wansteadmeteo 1 Comment

What kind of summer is in store this year? According to Richard Kirwan’s weatherlore we’re odds on for a dryer than average season.

Summer overlooking The Temple in Wanstead Park by Wanstead Meteo — Summer overlooking The Temple in Wanstead Park

Kirwan, a Dublin-based chemist with a keen interest in the weather, deduced from observations made from 1677 to 1789 that the weather around the spring equinox provided a very good pointer to what was in store in the months ahead.

The lore, noted in Luke Howard‘s Climate of London, suggests that the probability is five to one in favour of a dry summer.

The detail, however, hinges around key dates.

1/ When there has been no storm before or after the vernal equinox the ensuing summer is generally dry, at least five times in six.

2/ When a storm happens from an easterly point on the 19th, 20th, or 21st of March the succeeding summer is dry, four times in five.

3/ When a storm arises on the 25th, 26th, or 27th of March, and not before, in any point, the succeeding summer is generally dry, four times in five.

4/ If there should be a storm at SW, or WSW, on the 19th, 20th, or 22nd of March, the succeeding summer is generally wet, five times in six.

Howard goes on to say: “Dry summers (this philosopher states) are the consequence of uniform winds, from whatever quarter they may blow; as wet summers are of their variation, particular if in opposite directions.”

Again, “Southerly winds are most frequently accompanied with rain in most parts of Europe at least, and probably in most parts of our hemisphere; but northerly and easterly, with clear dry and serene weather.”

And it seems reasonable to suppose that the wind which is to prevail during the summer, may most frequently set in with the vernal equinox.”

I’ve had a look back through my own records and this theory falls down, when you consider the absolute detail, on notable summers including 1995. But then, just like weather forecasting at short range, it is all about ‘chance’ – five times in six is still only an 83 per cent certainty.

There is also the matter of how Kirwan and Howard defined a “storm”. What we would call a storm now would be very rare in the second half of March anywhere around London, possibly less rare in the Dublin area. I am also assuming that Kirwan remembered to take into account the switch from the Julian to the Gregorian calendar in 1752.

What is notable, however, is how far ahead of their time Kirwan, Howard and other scientists were in having the thought to notice these patterns – something that continues to fascinate amateur and professional meteorologists alike today.

month ahead forecast, monthly summary, Weather

March 2015: dry and sunny with av temps

April 1, 2015 wansteadmeteo 3 Comments

The saying March: in like a lion, out like a lamb and vice versa is frequently wrong. This March saw it windy at the beginning, end and middle of the month.

This graph shows the 'wind run' of every day in March. Notice how the peaks are at the beginning, middle and end of the month — This graph shows the ‘wind run’ of every day in March. Notice how the peaks are at the beginning, middle and end of the month

Mean temperature for the month was 7.6C, 0.1C below the 1981-2010 mean, over 1C cooler than March last year. Rainfall of 17.9mm was 44% of average – four of the last five Marches have been notably dry.

There were 131.5 hours of sunshine recorded in this area which is precisely 121% of what we can expect to see during an average March. The wettest day occurred on the 29th with 4.2mm. Hail fell on 1 day. Air frosts: 5 Ground frosts: 13

So what has april got in store weatherwise? The models this morning (April 1st) suggest a dominance of high pressure though there’s lots of uncertainty as to where this will drift once it has formed over the Easter weekend. If it moves north there is a risk of chilly easterly winds at times that will take the edge off temperatures.

Rainfall amounts will be small after the next couple of days though sunshine amounts will be reduced if we get the cold easterly feed off the continent. Beyond that the outlook, as ever, is uncertain.

My long range method suggests the month will be average in terms of temperature: 43% probability. The next highest chance is for rather mild at 29% probability. Rainfall is looking greater than average, though at 57% probability.

My March outlook was good in that it ruled out any chance of a very mild month. Though the signal was for a cold month overall I think the fact that Scandinavia and Russia had a relatively mild winter meant that the resulting overall temperature was far milder than it normally would have been, given the air flow.

Full stats for the month here: http://1drv.ms/1rSfT7Y

Here follows the full weather diary for March…

1st: Sunny start with more cloud afternoon and a rain squall sweeping through at 5.30pm. Cold wind.
2nd: Sunny start though cold wind. Odd shower.
3rd: Sunny start but with cloudier periods and odd spot of rain up to 2pm. Skies turned really dark to the north but no reports of heavy rain. Cold overnight but no air frost due to the wind.
4th: Sunny spells with cloudier intervals.
5th: Sunny, frosty start. Cloud bubbling up with sun becoming scarcer.
6th: Sunny and clear with just a few cirrus.
7th: Sunny start, just a few cirrus though more breeze
8th: Sunny start though more clouds bubbling up than yesterday.
9th: Sunny start was quickly replaced by overcast conditions. Spots of rain on way into work – signs of something heavier when left work at midnight. Clear again by morning.
10th Sunny start with some cirrus type haze. Cloud bubbled up but sunnier than yesterday.
11th: Sunny start, cloud growing thicker through the day before a pink sunset. Some light rain before a clear night.
12th Sunny start and just a few clouds around. Cloud thicker in afternoon.
13th Hazy bright start though cloud thickened.
14th: Sunny start quickly turned cloudy and dull. More brightness in afternoon though cold wind. Early shower at 6.30am.
15th: Dull start into the morning. Some light rain late morning and during the afternoon. More rain after midnight and just beofre dawn.
16th: Cloudy start though with bright intervals in the afternoon. Area of light rain around 4am.
17th: Cloudy start with light rain spreading in. Brighter by 1pm though very misty on ride in to work. Misty again overnight.
18th: Cloudy, misty start though much more sunshine than yesterday on ride to Lea Valley. Cloudier overnight.
19th: Cloudy and dull all day, feeling cold – the cloud persisting into the evening.
20th; Cloudy start for the eclipse. The sky cleared about 12.30pm to leave bright sunshine and a pleasant, springlike afternoon. Early ground frost before sky clouded over.
21st: Cloudy but some spots of drizzle mid-morning. Dry and cloudy afternoon.
22nd: Sunny start though cloud increased through the day. Felt cold in the wind.
23rd: Bright start with lots of sunshine through the morning. Gradually filling in though feeling much milder than of late. Some light rain in the evening, heaviest between 3.30am and 5am.
24th: Cloudy start though with some bright spells. A short shower at 3ish.
25th: Sunny, cloudy start though with lots of high cloud filling in. Brief ground frost moved in just before midnight before rain moved in just before 4.30am.
26th: Drizzly light rain to start – felt cold. Not a nice day.
27th: Bright start with lots of watery sunshine through the day. Spits and spots of rain later as walked home from Wanstead.
28th: Cloudy start and mild with some brightness. Feeling mild. Some rain overnnight.
29th: Drizzly start with heavier bursts of rain, these fell through the day, drying up in the evening.
30th: Bright start with some sunny spells. Wind increased in strength through the day and was very strong overnight.
31st: Bright start after a stormy overnight that prompted a tug rescue that overturned in the Solent. Dartford Bridge was also closed. Showers surrounding Wanstead but only trace here – hail seen in City. Cold and windy overnight.