February 2013 CET (2012/13 Competition)

[BornFromTheVoid]

This may have been asked before, but does anyone know why there is such a downward correction every month between the estimated CET and finalised value? Looking at the previous data it is over 1ºC out on some days - a remarkable difference considering that my own weather station is calibrated to 0.055ºC and that we live in a day and age where the 100m can be run and official time is known almost instantly.

Adjustments are made mainly to account for the UHI effect, but also for station location changes. All to keep the record homogeneous.

http://badc.nerc.ac.uk/view/badc.nerc.ac.uk__ATOM__dataent_CET

[Weather-history]

Hadley also adjusts to stay in line with Manley.

Not convinced by that, if that was the case then logic would say just use Manley.

[chionomaniac]

Adjustments are made mainly to account for the UHI effect, but also for station location changes. All to keep the record homogeneous.

http://badc.nerc.ac....OM__dataent_CET

Thanks. Do you know if the adjustments are made because urbanization has occurred around the recording sites or is it that the whole CET zone has increased in temperatures due to urbanization? If it is the former, then the answer should be to relocate the recording sites to a close proximity not affected by the UHI effect. And if it is the latter then that value imo shouldn't be altered as it is a true reflection of the CET and how UHI effect has changed the CET.

Edited March 1, 2013 by chionomaniac

[reef]

Hadley is confirmed as 3.2C:

http://www.metoffice.gov.uk/hadobs/hadcet/cetml1659on.dat

The adjustment was just 0.1C this month.

1.2C below the 1981-2010 average, 1.0C below the 1971-2000 average and 0.6C below the 1961-1990 average. A pretty cold month really and not far off 2010.

[Don]

Hadley is confirmed as 3.2C:

http://www.metoffice...cetml1659on.dat

The adjustment was just 0.1C this month.

1.2C below the 1981-2010 average, 1.0C below the 1971-2000 average and 0.6C below the 1961-1990 average. A pretty cold month really and not far off 2010.

The same as Manley. I was only 0.6C out with my guess, so not bad.

[Midlands Ice Age]

Not convinced by that, if that was the case then logic would say just use Manley.

Not convinced by the above either Chiro

.

Hadley (Met Office) would not agree to using the Manley figures as it is outside of their control.

Philip Eden (who is running the Manley extension figures) specifically decided to continue the work of Manley, and has even backtracked to complete missing years. On his website you can see how the Metoffice variant of the CET has moved away from the figures that Manley would have produced (guess which direction!). The figures are genuine that the Metoffice (Hadley) produces, but it has now been admitted they have moved away from the original stations and included coastal as well as more urban stations in their figures.

The way I see it Philip Eden and his extension of the Manley dataset has meant that we still have a realistic assessment of the historical CET series produced by the Met Office

.MIA .

[Guest pjl20101]

Yes I've won a CET guess for once. Was only a matter of time that I nailed it, I did get the rain part wrong, but you can never tell really just how much rain is going to fall.

[North-Easterly Blast]

Hadley is confirmed as 3.2C:

http://www.metoffice...cetml1659on.dat

The adjustment was just 0.1C this month.

1.2C below the 1981-2010 average, 1.0C below the 1971-2000 average and 0.6C below the 1961-1990 average. A pretty cold month really and not far off 2010.

February comes in at 3.2*C, equal to Feb 1994, and there were 26 colder Februarys in the last 100 years, and one with an equal CET. Highlighting the absence of cold Februarys in recent years was the fact that it was actually the second coldest February for 17 years, even though the CET was only somewhat below the long term mean; the only one with a lower CET since 1996 was 2010.

A feature of Feb 2013 was that it was a generally below average month with few mild days but saw no big freeze. The month also didn't bring much in the way of widespread snowfall. It was really a relatively cold February / winter month that won't be remembered by many people as anything special, as it didn't see any notable freezing spells or significant snowfall - unlike Feb 1994, which had an identical CET to Feb 2013, but saw a much more pronounced cold spell from the 12th to 25th and significant snowfall at times, albeit most of the snow on Feb 15th 1994 thawed over low ground by the 17th before the next snowfall on the 23rd.

Winter 2012-13 ends with a CET of 3.83*C, to be precise, which makes it overall a near to slightly below average winter - certainly no 2009-10 or 1995-96, but colder than most winters in the last 25 years. By pre 1988 standards, winter 2012-13 would have been seen as a near average winter. In actual fact looking at historical standards, it was almost exactly in the middle of the rankings in the whole CET record. Certainly given how most winters since 1988 have been, this winter just ended has been something I have been happy with.

Winter 2012-13 has overall been a good match to 1983-84 - this winter was slightly milder but the overall patterns between the two are strikingly similar. A rather cold or cold early part of December, mild second half of December / Xmas / New Year, a cold snowy middle to latter half of January, then a relatively cold February but little in the way of snow. Winters 1983-84 and 2012-13 have featured very similar patterns in all three months - although the snowy spell in Jan 2013 was due to a battle between a Scandinavian High and Atlantic lows attempting to push in, whereas in Jan 1984 it was cold polar maritime zonality which showed that a positive NAO and zonal pattern can deliver cold and snow to the UK if the orientation sets up favourably and is NW-SE tracking with the Azores High well to the SW of the UK.

[Summer Sun]

The final figure for February was 3.19c

[BornFromTheVoid]

Thanks. Do you know if the adjustments are made because urbanization has occurred around the recording sites or is it that the whole CET zone has increased in temperatures due to urbanization? If it is the former, then the answer should be to relocate the recording sites to a close proximity not affected by the UHI effect. And if it is the latter then that value imo shouldn't be altered as it is a true reflection of the CET and how UHI effect has changed the CET.

It's mostly due to urbanisation near to the sites I would imagine. The UHI effect isn't enough to cause a general warming of central England.

I'd say the issue with moving sites is the difficulty in maintaining a consistent temperature record while keeping the CET stations as close to the historical record as possible.

They do move stations every now and then but I'd say is a pile of work to get right.

I haven't read it, but I think this paper discusses some of the UHI adjustment that the MO make http://www.metoffice.gov.uk/hadobs/hadcet/Parker_etalIJOC1992_dailyCET.pdf

[J10]

The scores have been updated and are as follows.

Monthly Comp

2 people got it spot on [3.2c] pjl20101 and Stormyking

Yearly Comp

The Top 3 is TomSE20, chionomaniac and Stormyking

Winter Comp

Final Results are in and the winner was chionomania, with mulzy in 2nd and seabreeze86 in 3rd.

Spreadsheet / PDF

Feb 2013 CET.xls

Feb 2013 CET.pdf

Edited March 3, 2013 by Jackone

[summer blizzard]

Darn the tight field, my errors would normally lend themselves to a fair few points still but the field is so tight,

[chionomaniac]

The scores have been updated and are as follows.

Monthly Comp

2 people got it spot on [3.2c] pjl20101 and Stormyking

Yearly Comp

The Top 3 is TomSE20, chionomaniac and Stormyking

Winter Comp

Final Results are in and the winner was chionomania, with mulzy in 2nd and seabreeze86 in 3rd.

Spreadsheet / PDF

Feb 2013 CET.xls

Feb 2013 CET.pdf

Blimey! How exciting to have come top of the pile for winter! I think that getting within 0.5ºC of a month is an achievement in itself, so I am very pleased to have guessed two months very close.

Thanks for your time and effort Julian.

[alexisj9]

Well done to all winners in the, Feb, winter and year Cet comps.