March CET

[PhilipEden]

Philip, how do you estimate the Met Office Hadley if you are not using exactly the same station feeds? (I assume you are not!)

Sshh, don't tell anyone, but on BBC shifts I can access the relevant station data. I've also more-or-less sussed out their fudge factor, whoops, sorry, I mean "bias adjustment".

Philip

[SNOW-MAN2006]

only 19 hrs and 6 mins to april

[Metomania]

I've also more-or-less sussed out their [...] "bias adjustment".

Philip

Philip - Are you able to tell us more about the "bias adjustment" they use, and why?

NW tracker up to 4.87C now. 5C looking very likely by midnight.

Edited March 31, 2006 by Metomania

[Optimus Prime]

Sshh, don't tell anyone, but on BBC shifts I can access the relevant station data. I've also more-or-less sussed out their fudge factor, whoops, sorry, I mean "bias adjustment".

Philip

Come on, don't say you've never fiddled with your CET before :lol: I think some of us have sussed that they do fix the CET a little bit. Or do they?

Anyway, I'm actually hoping the net-weather tracker reaches 5.0 or 5.1. That would give me a head start in winning.

[Bottesford]

Well today will certainly pump up that CET! Already over 15C at 1pm (solar maximum of the day). The Sun has some real power in it now as the UV index is now a moderate 3 instead of the measily 1s & 2s of previously. Out of wind & in the Sun it feels very nice indeed.

[Guest Mike W]

Are we looking at a 5.0 or 5.1 now, is 4.9 out of the equation?

[Optimus Prime]

Are we looking at a 5.0 or 5.1 now, is 4.9 out of the equation?

5.1c definetly.

[Metomania]

Are we looking at a 5.0 or 5.1 now, is 4.9 out of the equation?

I don't think 5.1C is likely. But I think, think, 5C will now be reached. It's just gone to 4.92. I laid out a chart of what the temp needs to be at different points today for it to make it to 5C, and so far it's about 40 minutes ahead of schedule! This is great fun and very silly!

5.1c definetly.

But yesterday you said it was impossible to get to 5C :huh:

Seriously cannot see 5.1C very easily. It would take some soaring maxes this afternoon, which could happen. It should just about make 5C though.

Edited March 31, 2006 by Metomania

[kold weather]

It won't reach 5.1c unless we get maxes upto about 17-19c widespread, its possible but it's on the extreme end of possible to be honest.

5c seems to be the probable outcome, though there is a chance that it will make 5.1c IF the number can get rounded up.

[PhilipEden]

Philip - Are you able to tell us more about the "bias adjustment" they use, and why?

NW tracker up to 4.87C now. 5C looking very likely by midnight.

It's simply a normalisation adjustment. If the 1971-2000 mean of the three stations they use to calculate the Hadley CET for, say, April is 7.97, and the 1971-2000 mean of the CET is 8.11, then the adjustment for that month is +0.14. The figure will vary (smoothly, one hopes) from one month to the next. Until two years ago, when they used Ringway and Squires Gate they also applied a slowly growing urbanisation adjustment which had by then reached something like -0.25 + or - 0.05 throughout the year, but of the stations they now use one is entirely rural and the other two minimally urbanised, so the urbanisation factor is now exceedingly small. I think they explain the detailed procedure in a paper which can be accessed on their site (sorry, don't have the URL handy).

If the max of Lancashire and Oxford this afternoon comes out at 13°C, then the Manley CET for March will be exactly 5.00°C (if 14°C then 5.02°C) and the Hadley CET probably 4.85 + or - 0.05 (but don't hold me to that latter figure as I haven't QC-ed all the obs yet). At a local level, it will be variously the coldest March since 2001, 1996 or 1987 ... when I have time I'll try to produce a 'cheimochronic' map for the month.

Philip

[johnholmes]

hi

My March mean almost certain to be 5.4C(5. :huh: , long term average in brackets.

John

ps

just to add to the above, at 5.4C its only the second March since I started recording in my back garden in January 1997, with a mean for March below 7.0C; the coldest being 2001 with 5.1C, so still second coldest in 10 years. Up to 23rd March it was 3.5C.

jh

above data confirmed

jh

Edited March 31, 2006 by johnholmes

[Metomania]

It's simply a normalisation adjustment. If the 1971-2000 mean of the three stations they use to calculate the Hadley CET for, say, April is 7.97, and the 1971-2000 mean of the CET is 8.11, then the adjustment for that month is +0.14.

Excellent, thanks! In theory, by applying the same principle, anyone with access to a handful of stations should be able to produce a CET and over time get very close to knowing the Hadley figure. Which is what you do?! But for all my support of the Met Office there is a case to be made for yours being the 'official' CET anyway, although 'official CET' is arguably a tautology where Gordon Manley was concerned? Your domain, so I put that as a question!

If the max of Lancashire and Oxford this afternoon comes out at 13°C ...

A pretty good bet I would think. There are 12's and 13's up the north-west coast, and Benson and Brize Norton were showing 14C and 15C an hour ago.

A sudden leap of 0.02 on the NW tracker to 4.95C makes 5C a pretty firm bet now on that tracker index.

Edited March 31, 2006 by Metomania

[Polar Continental]

hi,

It looks as though the mean for my small area of the country will come out at 4.77c, amazingly for the first 24 days of the month my mean was standing at 2.7c :huh:

Paul

Edited March 31, 2006 by Paul Carfoot

[reef]

5.2°C is looking like the final value here, a shame really as thats only 1.1°C below average. The last 7 days have seen an average of 11.2°C, increasing the average for the month by a whole 1.6°C and covering up what has otherwise been a very cold month.

[Optimus Prime]

The first 3 weeks were very cold. But the last week very, very warm.

I don't think I'll remember this month as being that cold, much like March 2001, there were some cold periods but I don't think any brought any snow to southern England. The record snowfall in Scotland would go down in history books of course.

It's been more of a typical, cool March. It would had been nice to have a month at least a degree below the 61-90 average, they have become nearly extinct since 1997.

.

[Metomania]

I don't think I'll remember this month as being that cold,

I feel the same as you actually. The mean was pegged back I think in the main by some persistently low night-time minima. It was the persistence of the low temps, rather than the extremity of them, which produced such a low CET for 3/4 of the month. I fyou look at the temperature chart on Philip's site this is borne out:

http://www.climate-uk.com/graphs/0603.htm

Even so, I think I will remember this March as one where for 3 weeks spring just never seemed to want to come. Day after day of ghastly horrible yukky stinking nasty cold weather. Yuk yuk yuk.

[The PIT]

Looking like the champ could well be Shugee

[PhilipEden]

Excellent, thanks! In theory, by applying the same principle, anyone with access to a handful of stations should be able to produce a CET and over time get very close to knowing the Hadley figure. Which is what you do?! But for all my support of the Met Office there is a case to be made for yours being the 'official' CET anyway, although 'official CET' is arguably a tautology where Gordon Manley was concerned? Your domain, so I put that as a question!

A pretty good bet I would think. There are 12's and 13's up the north-west coast, and Benson and Brize Norton were showing 14C and 15C an hour ago.

Exactly right ... and refining one's efforts over twenty years or more leads one to become, setting false modesty aside, something of an expert.

I don't like "official" ... we live in a world where "official" is widely used to attach a false or spurious credibility to an idea, a person, etc. Although GM was my M.Sc supervisor, and I subsequently exchanged letters with him a couple of times, I cannot say that I ever had a proper climatological conversation with him, much to my regret. However, I believe he would have appreciated my attempt to draw back from the three-site index used by the MO and to continue his own series using his own method. Let's just call them the Manley CET and the Hadley CET. That's clear enough.

Philip

I don't like "official" ... we live in a world where "official" is widely used to attach a false or spurious credibility to an idea, a person, etc. Although GM was my M.Sc supervisor, and I subsequently exchanged letters with him a couple of times, I cannot say that I ever had a proper climatological conversation with him, much to my regret.

CORRECTION: not my supervisor, my external examiner

Philip

[Thundery wintry showers]

The mean sea-level pressure chart for March is likely to show an anomalous east or south-easterly flow over Britain I reckon, with lowest pressure to the W and NW, at least according to the NOAA maps. It'll be interesting to see what Philip's pressure map for March looks like.

Although March 2006 won't come out as an exceptionally cold month it's worth noting that once again, the mild end is insufficient to raise the temperature above the 1961-90 average, let alone 1971-2000- whereas before we would take it as read that this would happen. There has certainly been more incidence of cold weather synoptics since November.

I will remember this March as a month with persistent cold until the last week, partially offset by the very mild end. However, I will remember the cold in three segments- the bright snowy weather of the first six days, the snowfalls around the 12th, and the persistent cold cloudy weather from after then until the 21st.

Interesting insights into how the Manley/Hadley CETs are calculated. I certainly think of them these days as the Hadley as opposed to Manley (or Manley emulation) CETs, and to be honest, I don't really rate either of them as "official"- just as two valid measures of the CET.

[PhilipEden]

The mean sea-level pressure chart for March is likely to show an anomalous east or south-easterly flow over Britain I reckon, with lowest pressure to the W and NW, at least according to the NOAA maps. It'll be interesting to see what Philip's pressure map for March looks like.

Low 999 just east of Newfoundland with marked trough extending across Atlantic, Br.Isles to Denmark. High 1018 Madeira and High 1030 northern Greenland. Cyclonic/southerly gradient across the UK.

Anomalies: -13mbar between Azores and Newfie, +13mbar east Greenland, -7mbar Romania. Strong easterly anomalous flow over northern and central parts of the UK but cyclonic/variable southern regions.

Manley CET is 5.01, Hadley likely to be 4.96.

Philip

[Terminal Moraine]

The March mean here ended up at 3.0c, the coldest only since 2001 and 1.3c below the 1971-2000 March average. It was also the greatest negative anomaly for any month since March 2001.

The mean for the first 22 days of the month was 1.2c and had this been maintained throughout the month it would have been about equal with 1970 but not quite as cold as 1969.

The mean temp' for the final 9 days was 7.3c, a quite remarkable turn around.

T.M

[Metomania]

Manley CET is 5.01, Hadley likely to be 4.96.

Philip

NW tracker 5.02 but may nudge another 0.01 before close of play. One interesting feature of this is how close Manley-Hadley-NW are to one another. The first two is not so surprising, but well done to this site. I cannot say that all weather fora manage quite so well ... cough cough.

So 5C it looks like being for Hadley (rounded up) and 5C with Philip's Manley. Although this will disappoint some of the diehard cold lovers, it is still a well below average month against the 1971-2000 mean. It is variously the coldest since March 1996 or March 2001. In terms of 'meaning' it continues the sequence of average-ish/below average months since November which saw the end of the long above average run.

Edited March 31, 2006 by Metomania

[Optimus Prime]

Tallyed up my stats. While minima was well below average (nearly 1.6c below) maxima was well above average (around 1.1c above) overall therefore the average temperature came out at 5.74c (0.26c below average) last time I recorded a below average month was December 2005 and November 2005 (november was about 0.6c below average)

A disappointingly average month. Yet again maxima has put the average up massively on what has been a very cold month minima wise.

March_CET.rtf

[Shiny_Bottom_1]

Hi OP.

Theres likely to be some regional variations, but the Net-Wx CET for March came in at 5.03oC.

Thats 1.27oC below average

[Metomania]

I thought some of you might be interested in the following:

March 2006: 5.0C

1971-2000 mean: 6.3C Anomaly -1.3C

1961-1990 mean: 5.7C Anomaly -0.7C

1906-2005 mean (100 year rolling average): 5.9C Anomaly -0.9C

I keep a rolling 100 year average because it can sometimes iron out the arguments over which benchmark to use. The 100 year average up to 2005 is a good test, and against it March 2006 was 0.9C below average. In anyone's analysis of that raw statistic it must be considered a cold month.

(I will post the 100 year rolling average for April in that thread.)