327 replies to this topic

[Mr_Data]

We haven't had a daily CET mean of 5.0C or above since 10th December.

A run of 17 days so far.

27th January -15th February 2009: 20 day run

8th December 2001 - 12th January 2002: 36 day run

[damianslaw]

Mr_Data, on 28 December 2009 - 19:18 , said:

We haven't had a daily CET mean of 5.0C or above since 10th December.

A run of 17 days so far.

27th January -15th February 2009: 20 day run

8th December 2001 - 12th January 2002: 36 day run

Those figures for 2001/2002 are quite noteworthy showing how although never particularly cold that period was generally consistently below average for a long time, an often forgotton half decent sustained cold period. I know the opening days of 2002 brought a number of ice days to the north of the country, the coldest start to a new year since 1997, beating last year. Shame the rest of 2001/2002 was a mild fest much like what eventually happened in winter 96/97.

[kold weather]

I'd suspect as others have said between 3.2-3.3C seems the best call right now, of course much depends on exactly where the front goes with regards to what the temps do in the CET zone...slightly higher mins though I suspect will hold the temps up a touch...but I suspect we wil lbe in for a decent correction, probably down to 3.0C again I reckon!

[noggin]

Are there any ideas yet re the CET for 2009? Are we in the running for a sub 10 degrees? Or did our mild Autumn dash our hopes?

[snowmaiden]

noggin, on 29 December 2009 - 09:44 , said:

Are there any ideas yet re the CET for 2009? Are we in the running for a sub 10 degrees? Or did our mild Autumn dash our hopes?

No chance of sub-10 - it looks like it will end up around 10.1 to 10.15

[Don]

noggin, on 29 December 2009 - 09:44 , said:

Are there any ideas yet re the CET for 2009? Are we in the running for a sub 10 degrees? Or did our mild Autumn dash our hopes?

It looks like we'll finish at 10.1C. So, another warm year but still one of the cooler ones of the noughties!

Edited by Don, 29 December 2009 - 09:56 .

[Mr_Data]

First time since 2001, since we have had two sub 4C CET months within the same year.

The lack of really mild Decembers over the last two decades is notable considering how many notably mild Januarys and Februarys there have been in the same period.

Only 2 Decembers over 6C for the CET (There were 6 in the 1970s and 1980s)

1994 and 2006

Whilst there have been 4 Januarys and 5 Februarys

As a consequence, December has turned out the coldest month of the last 20 years (1990-2009) than either January or February

Edited by Mr_Data, 29 December 2009 - 11:16 .

[Gavin P]

I think the reason for that, however, is that December has tended to get a week or two of cold weather under mid latitude high's. I'm not one of these people that signs up to the whole "faux cold" thing - Cold is cold - But 95 and 96 are the only two months I can think of in the last twenty years where the cold has been delivered by proper cold synoptics (second half of December 2000 as well I suppose) rather than the AH building over us and giving inversion cold as it true of most of those cool Decembers. Until this December of course.

[Mr_Data]

Gavin P, on 29 December 2009 - 10:52 , said:

I think the reason for that, however, is that December has tended to get a week or two of cold weather under mid latitude high's. I'm not one of these people that signs up to the whole "faux cold" thing - Cold is cold - But 95 and 96 are the only two months I can think of in the last twenty years where the cold has been delivered by proper cold synoptics (second half of December 2000 as well I suppose) rather than the AH building over us and giving inversion cold as it true of most of those cool Decembers. Until this December of course.

First half of December 2008 had cold synoptics, back end of December 2001 had cold synoptics as well.

[snowmaiden]

OK Manley at 3.1 to the 28th
Hadley at 3.5 (3.47 rounded up)

Last night down as -1.9 on Hadley so we should be at 3.4 tomorrow

sub 3 and Hadley will require a downward correction, probably in the order of the Dec and Jan 08/09 -0.3 corrections - which means we have about 3 and a half cumulative degrees to play with for the last 3 days of the month (would get us in at 3.24 or thereabouts) - if minima are low we will get this but tonight for example looks above zero.....

Manley should finish 2.9 or 3.0 (maybe 2.8 but that is the lowest it would go I think)

[Gavin P]

Can anybody work out what all of this means for the yearly CET? I assume this cold December won't be enough to off-set April and November and 2009 will still come in +10c?

[snowmaiden]

Gavin P, on 29 December 2009 - 12:01 , said:

Can anybody work out what all of this means for the yearly CET? I assume this cold December won't be enough to off-set April and November and 2009 will still come in +10c?

We were 2.3 degrees above 2008 at end November - hence 3.5 (same as 2008) would give us 10.15
3.0 would be 10.10 or 10.11 depending on roundings

sub 10 requires 1.6 for December or thereabouts (so no chance unfiortuantely)

10.12 seems about the mark

[Mr_Data]

If we don't get a sub 3C calendar month, we are odds on going to have a 30 day period that is sub 3C

11th-28th December CET: 1.8C

And if the the New Year spell has some really sharp frosts well, I wonder how low that 30 day period will be.

[Gavin P]

Thanks Snowmaiden! Lovely as April was, I kinda wish it was more of a cool and dull month now.

[kold weather]

Mr_Data, on 29 December 2009 - 12:05 , said:

If we don't get a sub 3C calendar month, we are odds on going to have a 30 day period that is sub 3C

11th-28th December CET: 1.8C

And if the the New Year spell has some really sharp frosts well, I wonder how low that 30 day period will be.

I'd say a sub 3C 30 day period is certain to be honest Mr.Data given what would required to get to 3C now is out of reach given the model outputs....

Given most of the models are cold out to the 8-9th at least, it will be interesting to see just how low that 30 day period can go, could go sub 1C...

[West is Best]

Although not directly CET related, when was the last time snow fell on 30 consecutive days somewhere in the UK? How many days has this happened so far? Rather a lot I believe ...?

[snowmaiden]

Manley 3.1 to 29th still
Hadley now 3.38 rounded up to 3.4
Last night's minima 1.6, so today may not see enough of a downward movement to get to 3.3
I fancy the finishing number unadjusted for December will be 3.3 and therefore we may see an adjustment to 3.0 or 3.1 (given Manley's current position)
Sub 3 is now the outsider unless a dramatic revision is on the cards.
Manley looks likely to finish 3.0

[karyo]

snowmaiden, on 30 December 2009 - 11:37 , said:

Manley 3.1 to 29th still
Hadley now 3.38 rounded up to 3.4
Last night's minima 1.6, so today may not see enough of a downward movement to get to 3.3
I fancy the finishing number unadjusted for December will be 3.3 and therefore we may see an adjustment to 3.0 or 3.1 (given Manley's current position)
Sub 3 is now the outsider unless a dramatic revision is on the cards.
Manley looks likely to finish 3.0

Yes, it is looking unlikely to go below 3.0 which is unfortunate. If only we could have a clear night tonight rather than the blanket of cloud!

A sub 3.0 month would have shut many (global warming) mouths! Nevertheless, it is a very good result for an el nino December!

Karyo

[Matt12]

karyo, on 30 December 2009 - 12:02 , said:

Yes, it is looking unlikely to go below 3.0 which is unfortunate. If only we could have a clear night tonight rather than the blanket of cloud!

A sub 3.0 month would have shut many (global warming) mouths!
Karyo

I disagree. Just because we have had a rather cold month, it doesn't even go close to disproving GW. In fact, the latest data out suggests that this decade has been by far the warmest on record, with an overall temperature increase of almost 1C! Let's face it - the weather is significantly milder than in even 20 or 30 years ago. A small short-term anomaly, such as that experienced this month, only proves that cold spells are still possible in Britain (and likely), even in this warming climate. Moreover, the climate is still cyclical; hence, our climate is still subject to cyclical changes (i.e. colder years/wamer years) in the same way that it was decades ago. It's just that we are unlikely to ever get winters like those in 60s/70s ever again.

That said, I think the current CET is looking decidedly cold. Perhaps it's a sign of things to come!

Edited by Matt12, 30 December 2009 - 14:45 .

[Boar Wrinklestorm]

karyo, on 30 December 2009 - 12:02 , said:

A sub 3.0 month would have shut many (global warming) mouths! Nevertheless, it is a very good result for an el nino December!

A month of anomaly a theory does not prove.

It will be interesting to see how the planets heat transport mechanisms (Hadley cells) cope with this as we head into spring. The heat is normally transported to the poles, but since it doesn't seem to be getting their this year, then is that heat retained waiting for a chance to move?

If so, record breaking hot spring, anyone?

BOT, still, a 3C, or thereabouts December really does go to show the vagueries and variability of the climate. It was only ten years ago that we were told these sort of synoptics given rise to snow were 'rare and unusual'

We've had them two years on the trot, now.

Edited by VillagePlank, 30 December 2009 - 14:59 .