January CET

[Snowyowl9]

Not much of a rise on....

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

Edited January 26, 2010 by Snowyowl9

[Weather-history]

I find these monthly benchmarks a little bit pointless when you consider, we had last winter a 11 week period that was sub 3C and a 6 week period this winter that is sub 1.5C

They would have more point if they had not been achieved, well at least the argument whether these can still be achieved is out the window for me.

[Stu_London]

Hadley is 1.4 (1.38 rounded up)

GFS 06z points to a final outcome of 1.3 (1.28 rounded up) before recalabration takes place.

Still in outside chance of sub 1, but we need a big adjustment and the next couple of days to be a bit less mild than progged currently.

[i luv snow]

Hadley is 1.4 (1.38 rounded up)

GFS 06z points to a final outcome of 1.3 (1.28 rounded up) before recalabration takes place.

Still in outside chance of sub 1, but we need a big adjustment and the next couple of days to be a bit less mild than progged currently.

Last few dont day's arent progged to be mild though...so very outside chance of sub 1 as you say! :unsure:

[North-Easterly Blast]

Well, with only five days to go this month now looks highly likely to achieve a CET below 2*C, so certainly an exceptionally cold month by the standards of the last 22 years on all accounts, and the first month since Feb 1991 to achieve the sub 2*C figure, so at long last we are seeing an end to the longest interval on record between sub 3*C months (13 years 0 months), and highly likely an end to the longest interval between sub 2*C months (18 years 11 months), and last January, 2009, ended the longest interval ever between sub 3.5*C months (8 years 0 months). It now looks likely that this month may possibly come in at about 1.5*C, thus matching the CET of Feb 1991, and if so, it will also be the first calendar month of any name to be 2.0*C below the 1961-90 average since May 1996. There must be something to explain why such mild synoptics (Bartlett Highs, Polar Vortex over Greenland) have been so prevalent for so long, as in the last 22 years there have been so few occasions when we have got proper cold synoptics, at least for long enough to deliver a notably cold month. Indeed the vast majority of the generally rare winter cold spells in the 1990s and 2000s have come from mid-latitude Rex blocks and faux surface cold, and the winter of 2008-09 was even no exception to this.

Up until this winter I can only think in the last 20 years of Feb 1991, the middle two weeks of Feb 1994, most or if not all the cold spells in the 95-96 winter, late Dec 96, early Jan 97, late Dec 2000, first half of Feb 2009 when cold weather in the UK was delivered by proper cold synoptics and not faux surface cold (Rex blocking). Although outside the winter there was also March 2006.

Getting a significantly below average month requires a stroke of luck, and always has done, and relies on not even a few days of well above average temps to obliterate extended cold spells. We came close to a well below par month in March 2006. Up to the 23rd of that month the CET was only 3.2*C (2.5 below 61-90), but a very warm spell in the last week added 1.7*C to that month's CET making it far less outstanding and less than 1*C below the 61-90 mean. Had the cold weather of March 2006 lasted a few more days then we could well have had the first March CET below 4*C since 1970! November 2005 would have been a well below par month had it not been for such a mild first half (the second half was only 2.6). Had the first half of Nov 2005 been average, then the CET may well have approached that of Nov 1993 (4.6), and been below 5*C. The first half of February 2009 was also pretty cold (1.1), but if this cold spell wasn't ruined by such a mild second half we could have had a February in the below average category. Feb 1994 was only 2.7 to the 25th, but only three very mild closing days put 0.5 on to the final CET.

Prior to 1988 a number of months came close to being notably cold, but were ruined by short mild spells. A very mild last three days of Jan 1982 added 0.7 to that month's CET. Feb 1978 was cold and had a spell of notably cold easterlies mid-month and the CET was only 1.1 to the 21st, and only due to a very mild last week that month didn't end up severe, and what was a very cold month to the final week only ended a relatively cold one at 2.8. Jan 1955 was also cold (0.8 to the 21st) but milder weather in the last ten days raised that month to 2.6.

The same is true for notably cold winter seasons too. Winter 1995-96 was cold for the most part, with a number of cold snowy spells throughout the season, and would have had a lower overall CET had it not been for a mild first part of January (which despite having much blocking over Scandy it still had a very mild spell in the first half). 1984-85 and 1985-86 were the last winters to achieve an overall CET below 3*C, both of which had extended notable cold spells. These winters (and also 1986-87) would have been colder still if it wasn't that all of them had a mild December. Winter 1981-82 would have been colder if it hadn't have fizzled out with a fairly mild February. Winter 1968-69 had a good cold snowy February and a fairly cold December, and that winter would have easily been much colder than its 3.2 CET had it not been for a mild January (which despite much blocking over Greenland it was mild overall for the UK, in an otherwise cold winter).

Edited January 26, 2010 by North-Easterly Blast

[damianslaw]

So much for any mild weather this week in the CET zone, blink and your going to miss the very short lived mild sector that will move through the CET zone tomorrow night, it sums up the month nicely, mild weather has just not been able to take a grip on the country at any stage, when I say mild I mean widespread maxes of 8 degrees or above. Its been a long long time that we have seen a whole month immune from any real mild weather. The past 2 weeks have been average or below average CET wise. Todays CET values will come in low with widespread maxes of 2-3 degrees and mins around the -1 or -2 degree mark.

1.5 Degrees is certainly achieveable as the finishing mark, and with adjustments 1.2 degrees is in with a shout, I can see CET values of just above freezing by the weekend as the polar air beds in.

[Richard Lake]

NetWeather Temperature Tracker in the DataCentre peaked at 1.55, just updated to 1.54; after a small blip tomorrow lunch the only way down now is doowwnn.

[Optimus Prime]

Well the 18z is a massive upgrade in terms of mean temperature for the period 27th-31st

12z 2.1c

18z 1.3c

[reef]

Hadley still on 1.4C to the 26th (1.43C rounded down), yesterday came in at 2.7C.

Today might not be as mild as expected as the min in the zone last night was -0.2C. Something in the 4C range on tomorrow's update looks likely.

[Weather-history]

Well we have had the coldest December since 1996 followed by what looks like the coldest January since 1987.

Has got me wondering when was the last time, we had two consecutive months that were both the coldest for at least 10 years.

July 2007, August 2007?

Edited January 27, 2010 by Mr_Data

[reef]

Well we have had the coldest December since 1996 followed by what looks like the coldest January since 1987.

Has got me wondering when was the last time, we had two consecutive months that were both the coldest for at least 10 years.

July 2007, August 2007?

December 2008 (coldest since 1996) and January 2009 (coldest since 1997) also managed it, as did February and March 2006 (both coldest since 1996).

[SteveB]

Well we have had the coldest December since 1996 followed by what looks like the coldest January since 1987.

Has got me wondering when was the last time, we had two consecutive months that were both the coldest for at least 10 years.

July 2007, August 2007?

It's funny that, when Summer 2007 & 2008 came in overall colder than many if not all in the last 10-15yrs I thought to myself, wonder if we could get the same in the Winter months.

Low & behold 2008/09 & 2009/10 look like bucking that trend too.

[Tom D]

As the last couple of days look cold again, with overnight frosts crucially in the midlands, I think the CET will end up around 1.3/4. I never thought my 1.6c could be about right/too high!

What's everyone thinking for February?

[North-Easterly Blast]

It's funny that, when Summer 2007 & 2008 came in overall colder than many if not all in the last 10-15yrs I thought to myself, wonder if we could get the same in the Winter months.

Low & behold 2008/09 & 2009/10 look like bucking that trend too.

Summers 2007 and 2008 were not cool compared to the long term average (1961-90). Only summer 2007 managed to be fractionally below the 61-90 mean. Summer 2008 didn't manage to be below the 61-90 average at all. However, it is true that summers 2007 and 2008 were two of the cooler summers of the last 20 years. It is many years since we had a proper cooler than average summer (ie below 15C for the CET). 1993 was the last one. There were four cool summers in a row from 1985-88.

[Kentish Man]

Why are we still referring to 1961-90? It has no more relevance than 1941 - 1970 or 1901 - 1930. In fact it won't be long until we should start referring to 1981 - 2010. Once we start doing comparisons to that warmer 30 year mean some of the seasons referred to above would start looking rather cooler.

[Roger J Smith]

I have to agree, the use of any thirty-year period seems a bit arbitrary, why not have the "current climate average" as the latest available 50-year average, which could be updated continuously so that right now we would be judging this winter against 1960-2009. This is the sort of standard that would be applied to economic data, I think, an indication of past performance based on the most up-to-date statistics available.

The 30-year average has a long history in climatology but I'm not sure that it means very much, climate shifts are more on a century to century time scale.

Having said that, all hail the return of the 1.something month to the CET ... or the 0.something if they go nuts with the adjustment.

[noggin]

Why are we still referring to 1961-90? It has no more relevance than 1941 - 1970 or 1901 - 1930. In fact it won't be long until we should start referring to 1981 - 2010. Once we start doing comparisons to that warmer 30 year mean some of the seasons referred to above would start looking rather cooler.

I agree. It seems totally pointless to be comparing NOW to the period 50-20 years ago. It doesn't have any meaningful meaning.

A 25 rolling previous years period for comparison would be good.

[Nick L]

It's the Met Office that use the 1961-90 mean though isn't it? It is quite bizarre. Next year will be the arrival of the 1981-2010 average, it's ridiculous.

[jy]

Just a quick question over on TWO they show Jan CETas0.45 whereas on here general opinion is that its about 1.5 both low but why such a difference?

[Thundery wintry showers]

Why are we still referring to 1961-90? It has no more relevance than 1941 - 1970 or 1901 - 1930. In fact it won't be long until we should start referring to 1981 - 2010. Once we start doing comparisons to that warmer 30 year mean some of the seasons referred to above would start looking rather cooler.

It depends on what sort of comparison we're doing. If we're simply comparing with the most recent "average" that we're used to, measuring differential from the present-day mean, then it makes sense to keep shifting the period forwards, though in that case there is, indeed, a strong argument that a running mean updated each year would be most useful.

However, if we're looking at how the climate has changed over a much longer time span- say the 20th/early 21st century- then shifting the period continuously can mislead as it masks the very climate change that we are meant to be looking into. For example, there is a risk of cold (or anti-AGW) bias leading to presumptions like "this season was very cold relative to 1981-2010 so this shows our climate is cooling", when in reality a season could be very cold relative to 1981-2010 but pretty normal relative to the whole 20th century.

As an example, I compare my weather records for Cleadon with estimated 1971-2000 averages, but I don't see the benefit in moving to 1981-2010 starting next year, because part of the idea is to illustrate any climate change that has occurred at the location, be it warming or cooling.

For the longer-term time span I agree with suggestions that a longer reference period may be more useful.

1961-90 is often used, as it happens, because the WMO only updates its reference period every 30 years, therefore the next period after 1961-90 would be 1991-2020.

[The PIT]

Hadley seems to have got stuck on the 24th. Two average to mild days will have pushed it up a bit and temperatures likely to drop tomorrow again. So overall can't see changing much from the last figure.

[Snowly does it]

Hadley is a rounded down 1.5 (1.52) last night was 2.4 and todays maxima ca 7 so we will be at 1.6 or possibly a rounded up 1.7 tomorrow.

Tonight looks average as does tomorrow and may be enough for a further 0.1 increase depending where roundings end so perhaps 1.8 with Saturday and Sunday looking like drops or static.

I can't see the adjusted number being much below 1.5, and I can't see it ending above 1.8 now

Certainly the coldest month since Feb 91, possibly since Jan 87 but I think Feb 91 will just eclipse it

[Kentish Man]

1961-90 is often used, as it happens, because the WMO only updates its reference period every 30 years, therefore the next period after 1961-90 would be 1991-2020.

Thanks for the explanation.

As regards this month if GFS are to be believed Sat and Sun would probably shave off 0.2C from the CET mean. However you have to suspect their maximas are somewhat understated ie 3C or 4C is perhaps more likely than 1C or 2C. Even if we get to 1.8C by the 29th there's a reasonable likelihood we'll be back to 1.7C or even 1.6C by the end of the month. The landing zone after month end adjustment is probably between 1.4C and 1.6C. Feb 1991 was 1.5C and I think we still have a chance of matching that.

[nick sussex]

It's the Met Office that use the 1961-90 mean though isn't it? It is quite bizarre. Next year will be the arrival of the 1981-2010 average, it's ridiculous.

Yes IMO this is to fit their agenda in pushing GW. By keeping that outdated period which had more cold winters then it's harder for the UK to get colder than average months. Why can't they just include the last 50 years and include the entire period which means this takes into account recent milder winters aswell as those colder ones from the past. The obvious reason is that it doesn't allow them the opportunity to push Global Warming, I would like to know from them their justification in using that time period.

Regarding the WMO, the Met Office still have figures for the UK so why can't they use them, we're talking about the CET series which is UK not the world, if thats the reason then its obvious they're using that lame excuse to further their GW obsession.

Edited January 28, 2010 by nick sussex

[Optimus Prime]

They use the 61-90 series because they reckon it's more reflective of the British climate.

If that's the case then wouldn't it be better to use the 300 odd year series? 1695-2009 say