March CET

[Metomania]

When was the last time the March CET was at or below this year's value (5.03°C)?

1996 at 4.5C. Before then there were a string of cold Marches in the 1980's. Between 1979 and 1987 there were no fewer than 6 sub 5C March months: quite incredible.

In 2001 it was close at 5.2C

Hadley CET can be viewed here: http://www.meto.gov.uk/research/hadleycent.../HadCET_act.txt

[Thundersquall]

1996 at 4.5C. Before then there were a string of cold Marches in the 1980's. Between 1979 and 1987 there were no fewer than 6 sub 5C March months: quite incredible.

In 2001 it was close at 5.2C

Hadley CET can be viewed here: http://www.meto.gov.uk/research/hadleycent.../HadCET_act.txt

The Met Office were very correct in their seemingly bold statement late last year (coldest Winter since 1995/96)!

[shuggee]

The Met Office were very correct in their seemingly bold statement late last year (coldest Winter since 1995/96)!

But only in terms of the small triangle of central southern England that makers up the CET, TS.

[Thundersquall]

1996 at 4.5C. Before then there were a string of cold Marches in the 1980's. Between 1979 and 1987 there were no fewer than 6 sub 5C March months: quite incredible.

In 2001 it was close at 5.2C

Hadley CET can be viewed here: http://www.meto.gov.uk/research/hadleycent.../HadCET_act.txt

Another very interesting statistic: Between the years 1994 and 2005 there were only two years with a

mean annual Hadley CET below 10°C.

Very much shows the warming trend during the 1990's and 2000's.

Edited April 1, 2006 by Thundersquall

[johnholmes]

But only in terms of the small triangle of central southern England that makers up the CET, TS.

come on Shuggee, be a little more accurate in sweeping statements like that,

this tells the actual story,

http://www.met-office.gov.uk/corporate/pre...r20060303b.html

and shows that most of Wales and England had their coldest winter since 1996/7

England has had a colder-than-average winter - the coldest since 1996/7 <LI>Wales has had a colder-than-average winter - the coldest since 1996/7

John

Edited April 1, 2006 by johnholmes

[shuggee]

come on Shuggee, be a little more accurate in sweeping statements like that,

this tells the actual story,

http://www.met-office.gov.uk/corporate/pre...r20060303b.html

and shows that most of Wales and England had their coldest winter since 1996/7

England has had a colder-than-average winter - the coldest since 1996/7 <LI>Wales has had a colder-than-average winter - the coldest since 1996/7

John

Of course you're right John - just trying to get some discussion going on a day I'm not feeling charitable

And I'm allowed to say that thanks to my miraculous CET crytal ball gazing predictions

[johnholmes]

Of course you're right John - just trying to get some discussion going on a day I'm not feeling charitable

And I'm allowed to say that thanks to my miraculous CET crytal ball gazing predictions

yes I'm sure there is room on the forecast team for you mate.

prps' you would like to say, in detail, what the weather will be like out to next Friday for the Uk, just as a small test??!!

j

[shuggee]

Unfortunately the crystal ball is offline at the moment.

[Weather-history]

Before then there were a string of cold Marches in the 1980's. Between 1979 and 1987 there were no fewer than 6 sub 5C March months: quite incredible.

Pales in comparison to the Marches from 1783 to 1789 where 6 out of the 7 Marches had CETs of less than 4C, including 3 consecutive Marches with a CET less than 3C

The decadal March CET average for the 1780s (1780-89) was a mere 4C

Edited April 1, 2006 by Mr_Data

[PhilipEden]

come on Shuggee, be a little more accurate in sweeping statements like that,

this tells the actual story,

http://www.met-office.gov.uk/corporate/pre...r20060303b.html

and shows that most of Wales and England had their coldest winter since 1996/7

England has had a colder-than-average winter - the coldest since 1996/7 <LI>Wales has had a colder-than-average winter - the coldest since 1996/7

John

Even apparently legitimate statistics can still be used to spin a story:

http://www.climate-uk.com/temp3.htm

You could equally correctly, though even more misleadingly, say that "parts of Britain had their warmest winter this century", because at Stornoway and Kirkwall it was the warmest since 1997-8 and at Lerwick since 1991-92.

Philip

[Metomania]

The decadal March CET average for the 1780s (1780-89) was a mere 4C

Astonishing!

Even apparently legitimate statistics can still be used to spin a story:

http://www.climate-uk.com/temp3.htm

What a great forum this is!

[PhilipEden]

The sequence of monthly CETs so far this year confirm what we all know anyway, and that is what a late spring it is. Another technique is to use aggregate degree-days on a 6°C base (i.e. add up each daily mean temperature [mean of max and min is near enough] and then subtract 6) because plants don't grow much at all if the temperature is below 6.

Round these parts 50 deg-days usually produces the first daffodil, 100 deg-days plum blossom, 200 deg-days laburnum:

Year 50dd 100dd 200dd

1983 26Feb 17Apr 14May

1984 11Apr 24Apr 22May

1985 02Apr 17Apr 19May

1986 24Apr 06May 25May

1987 27Mar 17Apr 01May

1988 15Feb 02Apr 04May

1989 28Jan 09Mar 02May

1990 04Feb 05Mar 02Apr

1991 11Mar 29Mar 12May

1992 27Feb 20Mar 28Apr

1993 17Feb 22Mar 27Apr

1994 08Mar 31Mar 03May

1995 12Mar 31Mar 25Apr

1996 11Apr 23Apr 27May

1997 08Mar 23Mar 29Apr

1998 10Feb 23Feb 07Apr

1999 04Feb 18Mar 12Apr

2000 27Feb 21Mar 03May

2001 16Mar 10Apr 13May

2002 02Feb 05Mar 13Apr

2003 09Feb 23Mar 21Apr

2004 04Feb 20Mar 25Apr

2005 11Feb 23Mar 25Apr

2006 26Mar

also

1969 09Apr 27Apr 14May

1962 11Apr 04May 22May

That shows just how late the spring of 1996 was, thanks to consistent cold from March to May. How welcome that early-June heatwave was, even to those of us who don't enjoy high temperatures.

Philip

[Metomania]

Just wanted to pick up on one other statistical point that was put around. It was suggested that March has a greater temperature variation than any other. I cannot at the moment judge that, but in terms of the warmest and coldest examples of months in the last 100 years, March is nowhere near the most variable month. That honour belongs to January, closely followed by February. May and June are the months with the least statistical deviation from the mean. Here are the greatest variations over the past 100 years between the warmest and coldest of any given month:

January: 9.6C

February: 9.2C

March: 6.5C

April: 5.1C

May: 4.4C

June: 4.3C

July: 5.8C

Aug: 6.3C

Sep 4.9

Oct: 6.5C

Nov: 7.3C

Dec: 7.8C

This may be a game with statistics, but it does suggest that historically there is less 'to play for' between April and September. It suggests that English summers are relatively consistent. English winters are not. (But we probably all knew that!)

Sorry Philip - I was typing this up whilst you posted your infinitely more important post. Didn't mean to steal your thunder (or daffodils).

Edited April 1, 2006 by Metomania

[reef]

This may be a game with statistics, but it does suggest that historically there is less 'to play for' between April and September. It suggests that English summers are relatively consistent. English winters are not. (But we probably all knew that!)

I imagine this is due to the strength of the sun and its affect on temperatures. In winter the temperature is more dependent on the temperature of the airmass, i.e in 5°C 850hPa air certain areas may reach roughly 10-13°C during December/January. However, in summer, that same 5°C 850hPa air can allow a temperature in the 20°C range due to surface heating (if sunny). Generally for a summer month to be quite a way below average it needs to be relatively cyclonic (though there are probably exceptions), as this helps keep maxima down. The cold spell at the beginning of July 2004 is a good example, where areas in central England were below 10°C at midday. The only anomoly in the pattern is September, though I expect this is more due to higher minimas as the seas around the UK are at their warmest then.

[Terminal Moraine]

The CET is, fundamentally, a tool for comparing the temperature of one month with another and for gaining some sort of perspective of where any one month stands in relation to its peers throughout the history of the record.

Whichever period of comparison is used depends on what information is desired, each has its merits or drawbacks.

For instance if a particular month is 0.1c cooler than the average obtained over the period 1971-2000 but the 1971-2000 period is 0.6c warmer than the average from 1871-2000 it tells us only that the month has been marginally cooler than a run of recent warm months, not that it was a cool month.

This may seem like stating the obvious but it's amazing how many people confuse the two, or cross interpret the statistics.

I think it was Noggin who said he didn't like statistics, it was only observations that mattered. Observations do matter of course, it is accumulated observations that give statistics, but it's not statistics themselves that are at fault, just the way they are interpreted.

Personally I'm in favour of using as long a period of averages as possible as this smooths out any short term variations, warm or cold, and enables each month/season etc to be directly compared with those from the past. This however does not preclude using a shorter period from the recent past, say 30 or 40 years, as this period is a fair proportion of a human lifespan and gives perspective as to how any one month/season etc compares to those within memory.

Using calendar months to calculate any sort of meteorological averages is certainly the most logical time period as the vast majority of us live our lives by the calendar and everyone understands where one month ends and the next begins.

This does not mean that it's not interesting to calculate averages using two weeks data from the end of one month and two at the beginning of the next ( or any other contiguous combination) as a calendar month is after all only an arbitrary period by which we all live; it also give some indication as to the possible range of extreme average values over a month which may not necessarily have coincided with a calendar month but which may do in the future and which would then exceed the current documented extremes.

So, no hard and fast rules for using statistics but it is imperative to be absolutely clear why you're using one particular set and what conclusions you're hoping to draw from them.

T.M

[kold weather]

Here's an intresting stat. The first three months of this year (assuming March comes out at 5c) have been a shocking 1.4c colder then 2005.

It's been the coldest start to a year since 2001 with 2005 missing out by just 0.1c on that.

So what we've now got is a good base for hopefully getting a sub-10c year, though that depends alot on what June-September do.

[Bottesford]

Here's an intresting stat. The first three months of this year (assuming March comes out at 5c) have been a shocking 1.4c colder then 2005.

It's been the coldest start to a year since 2001 with 2005 missing out by just 0.1c on that.

So what we've now got is a good base for hopefully getting a sub-10c year, though that depends alot on what June-September do.

Lets have that sub 10C year achieved with a freezing Nov/Dec and not a rubbish June-Sept! That'd be 'orrid like

[kold weather]

Quite agree with you Bottesford, yesterday for some reasion I got a strong urge to want very hot weather again.

Also I worked out that for the first 10 days of august 2003 London had a average temp at 25c!!!!

though the rest of the month was much cooler which stopped it from being a record August.

[Weather-history]

Assuming that the Hadley CET values for Feb and Mar '06 were the same as Phil's, the period April-December would need to average 11.8C at most for 2006 to have an annual average of 9.99C

28 years out of the entire CET list have had an April-December period that averaged over 11.8 and the last 5 years, 2001, 2002, 2003, 2004 and 2005 have achieved this.

[SNOW-MAN2006]

does anyone know when the final c.e.t will be produced?

[Optimus Prime]

does anyone know when the final c.e.t will be produced?

Middle of next year. Initial one will be released tomorrow or day after.

[Nick F]

Met Office have still to release their February Hadley CET figure (and even then it may be provisional), so their (provisional) March CET will be well over a month away until it appears on their Hadley CET list. However the England and Wales temp/rainfall/sunshine for March will no doubt be updated in the next few days.

[Optimus Prime]

Review for March 2006 has come out on the britweather years site;

http://www.personal.dundee.ac.uk/~taharley/2006_weather.htm

March. Cold and wet. Northerly winds in the first week, prolonged easterlies in the middle, but a mild end with southerly winds in the final week brought the average temperature. A cold start with snow showers in the east. The minimum at Altnaharra on the 2nd was -16.3C. Several places remained beneath freezing for more than 24 hours in the first four days and midmonth. The maximum at Fylingdales (North Yorks.) on the 4th was only -1.3C. More heavy snow in central Scotland on the 11th and 12th. The highest temperature of the month was 17.8C on the 25th. The final week was particularly wet: 240 mm of rain fell at Capel Curig in the final week of the month alone. It was quite dull in the north.

[Optimus Prime]

Metoffice have released their update;

England and Wales;

It was a cold month with spells of wintry weather and below-average temperatures. However, this was partially offset by warmer conditions during the final week of the month as winds turned south-westerly.

England & Wales Mean Temperature Series (series began in 1914).

The initial value for the month was 4.6 °C, which is 0.6 °C below the 1961-1990 average, which is in the below average category. Coldest since 1996.

Scotland;

Cold with significant snow in many places. The last week was milder but very wet.

Scotland Mean Temperature Series (series began in 1914).

The initial value for the month was 2.5 °C, which is 1.0 °C below the 1961-1990 average, which is in the below average category.

N.Ireland;

Very wet with temperatures slightly below average.

Northern Ireland Mean Temperature Series (series began in 1914).

The initial value for the month was 4.8 °C, which is 0.4 °C below the 1961-1990 average, which is in the close to average category.

http://www.metoffice.com/climate/uk/2006/march.html

[summer blizzard]

As the England and Wales series has a defecit of 0.6C from average, we should expect the CET to have the same defecit from average resulting in a CET of 5.1C.