February CET

[The PIT]

Philip now has a final February CET figure of 6.05C.

It can't be as Feb isn't over as yet and the todays Max should carry through into Tomorrow.

[Snowly does it]

It can't be as Feb isn't over as yet and the todays Max should carry through into Tomorrow.

Todays maxima is the end of the Feb series PIT. The month runs 2100 31 jan - 2100 28 Feb.

Phillip has updated his figure to 6.05 (not sure which way that is rounded) as maxima for today will not now be exceeded before 2100 and the cut off. Hence Feb on Manley is 6.0 or 6.1 depending on the rounding.

Source Phillip Eden

Edited February 28, 2007 by snowmaiden

[North-Easterly Blast]

When you look at Philip's Manley figures for recent Februarys and see how they compare to Hadley:

Manley Hadley

2000 6.3 6.3

2001 4.5 4.4

2002 7.1 7.0

2003 4.1 3.9

2004 5.5 5.4

2005 4.3 4.3

2006 3.9 3.7

Looking at the above figures, Hadley have tended to be 0.1 to 0.2 below Manley for the February CET of recent years. I wonder what figure Hadley will release? I will plump for 6.0.

[summer blizzard]

I'm going to go for 5.8C for the Hadley figure.

[Don]

I'm going for a Hadley CET of 5.9 for February.

[Stratos Ferric]

It might be worth waiting a few days aswell. Especially as we dont know how far from Phillip's value the Hadley will come out at (it was 0.2°C under on the 20th). While on the same subject, the January table was calculated using 7.1°C for January, but the Metoffice later released the value 'officially' as 7.0°C, will that be amended this time?

I might...

[Joneseye]

The Net-Weather tracker came out at 6.07°C..

CET: (Feb 1-28): 6.05°C (+1.85 degC) from Climate-UK, C Philip Eden.

Happy with how it turns out regardless of whether it ends up being 6.0C or 6.1C

Ian

[Thundery wintry showers]

So the triple-6 record goes... by a whisker.

[Joneseye]

So the triple-6 record goes... by a whisker.

Ian - I haven't got to grips with what is seen as the "official" figure. Is this what appears on the Met-Office website?

[Thundery wintry showers]

Technically the "official" figure is the Met Office one that appears on the Met Office website. Philip Eden uses an alternative method which is closer to what Gordon Manley originally used, thus although his isn't the "official" CET there are arguments for its validity, and it usually ends up close to the Met Office value.

Others, such as the N-W Tracker, are not true measures of the CET but give a good approximation to it, so people can use the N-W Tracker to assess roughly how warm or cold a month has been so far. Looks like the N-W tracker did very well this month.

[shuggee]

Why has Philip's site suddenly gone to two decimal places?

And I can't remember which way round it is (odd or even numbers?) - would 6.05ºC be rounded up or rounded down?

[BLAST FROM THE PAST]

Why has Philip's site suddenly gone to two decimal places?

And I can't remember which way round it is (odd or even numbers?) - would 6.05ºC be rounded up or rounded down?

Shuggs

I believe it is rounded down.

BFTP

[Snowly does it]

Shuggs

I believe it is rounded down.

BFTP

On his summary page he has rounded it up to 6.1

[The PIT]

Nope you round up.

[shuggee]

Yep - just been reading through the convention - and it's round to the odd number. So 6.1ºC it is

[WBSH]

I thought I was aiming "high" with 5.5c but even then the sky high figures never cease to amaze me! I actually guessed that it would start of high but get slightly reduced towards the end of the month, instead it was the other way round!!

[VillagePlank]

Yep - just been reading through the convention - and it's round to the odd number. So 6.1ºC it is

Unusual.

Normally if you're rounding like this you normally round to nearest digit that is evenly divisible by two (n mod 2 = 0) ala Gaussian, but also known as Banker's rounding. This is designed to reduce the error of calculations performed on rounded numbers.

I went for 6C, so I hope that Gaussian rounding will be implemented, here!!

***

In-line with requests to fully explain, and detail what is being discussed, please find, below, the Quick Marky guide to Modulo Arithmetic

Consider 21pm. If, using standard arithmetic (as we all learnt at school) and wanted to add 7 hours to this time, we would arrive at 28pm, which, as you know, is utterly ridiculous.

There is a branch of mathematics that deals with numbers that wrap-around; in the above example we want it to wrap around 24 – being the 24hour clock. The function to implement this branch of mathematics, called modulo arithmetic, is the ‘mod’ function. In this case the modulus (the number we want to wrap around) is 24.

Implementing the above function we would perform the arithmetic as ‘(21+7) mod 24’, which can read as ‘Add 7 to 21, and wrap the result around around 24.’ This gives the correct answer which is 4am.

We can also use this for tests. We can, for instance say ‘n mod 2 = 0’; which is a test for whether the number,n, is even. It can be read as ‘if n when wrapped around 2 leaves 0 return true’ You can test for whether a number is odd by saying ‘n mod 2 = 1.’

Another example is that let’s say you are currently in August – the eight month; we need to add 47 months to this month, and we want to know what month of the year that’ll be. Using modulo arithmetic you’d write ‘(8+47) mod 12’ which returns 7 - which, of course, is July.

***

There is no mathematic reason that one should round the CET to n mod 2 = 1 (to odd number) but by convention, historically, is should rounded to nearest even number.

Edited March 2, 2007 by VillagePlank

[Stargazer]

I went for 6.0 too, so I second that! However, I believe we're using the official Met Office Hadley figure, which in recent months has often come in slightly lower than Philip's. I think an outturn of 6.0 is still quite likely, though.

[shuggee]

VP/Stargazer

The context here is that it is a meteorological convention to round to the odd number.

[kold weather]

Ah well I was too high then it looks, still despite this I never thought it'd go so high after that very snowy spell, and I'd love to know the CEt between the 15-th to the 28th, must have been quite impressive, maybe not far of some of the mildest spells in Feb ever.

[Snowly does it]

Ah well I was too high then it looks, still despite this I never thought it'd go so high after that very snowy spell, and I'd love to know the CEt between the 15-th to the 28th, must have been quite impressive, maybe not far of some of the mildest spells in Feb ever.

Somewhere around 8 Kold as we were on or about the long term Feb average on Valentines Day

[Stratos Ferric]

Apologies: the CET trophy update for end Feb has been posted in the march thread. Remarkably enough, if you have "snow" in your name, I wouldn't bother looking...

[Snowly does it]

I keep forgetting, do we use Manley or Hadley for the competition?

[Stratos Ferric]

I keep forgetting, do we use Manley or Hadley for the competition?

That's a good question. I tend to use Philip's figure, which I think is Manley isn't it? In the great scheme of things it probably wouldn't make a big difference come the end of the year.

[Snowly does it]

That's a good question. I tend to use Philip's figure, which I think is Manley isn't it? In the great scheme of things it probably wouldn't make a big difference come the end of the year.

Yes thats Manley. Probably better to use it as it is always available straight away, Hadley often don't update until much later.