December C.E.T

[Joneseye]

Hi Joneseye,

Yes Kevin called this one earlier yesterday morning. A 0.4 drop yesterday and from what I can see a further 0.4 drop per day for the next 4 or 5 days (depending on cloud cover). I fear my 6.1 and your 5.9 may, just may be a tad on the "high" side.

Rgds, John

I agree that we may have punted too high...I found it very hard to make a sensible guess (within 1.0C) at the start of this month with all the models showing raging zonality, but then again I guess that makes these threads all the more fun!!

[Optimus Prime]

The period 12th-20th looks very ncold indeed averaging +1.1c according to the GFS run.

By the 20th the CET should be around 4.7c, 0.4c below average. If it remains cold thereafter it may well yet get down into the 3s.

That is very unlikely of course, high 5s is still favorable. Either way, it won't be a record warm month.

[JohnAcc]

The period 12th-20th looks very ncold indeed averaging +1.1c according to the GFS run.

By the 20th the CET should be around 4.7c, 0.4c below average. If it remains cold thereafter it may well yet get down into the 3s.

That is very unlikely of course, high 5s is still favorable. Either way, it won't be a record warm month.

I'm not sure high 5's is favourable at the moment. As indicated earlier if the models are picking up correctly on the westward movement of the high then low 5's looks to be favourite. I agree that on current model outputs around 4.7 by the 20th looks about right.

Rgds, John

[eddie]

Finishing below the 71-00 average is certainly looking achievable at this point. Close to the 61-90 average is also within reach.

Below 4C would require the 12th-31st to return a CET value not seen since 1995 (and 1981 before that and 1962 before that).

I still think getting below 4.7C is a very tall order but I guess you should never say never with weather.

Can anyone remember icicles? I seem to remeber there were always huge icicles hanging from roofs when I was a kid.

[The PIT]

Can't see why we need to worry about ground temps although the downward trend is nice. If it snows it may stick a while.

Certainly present air temps are giving a CET a good bashing. You can see the slide here.

http://www.climate-uk.com/graphs/0712.htm

By the end of week Sheffield maybe below average for mins temps and Max's closing onto normal. Chances of a below average month?????

I think I saw one Icicle last year. Very rare site these days.

Edited December 12, 2007 by The PIT

[Polar Continental]

Mean here in Burton now at 6.3c from a high of 7.9c on the 9th, currently +1.2c above the CET average.

Paul

[damianslaw]

The period 12th-20th looks very ncold indeed averaging +1.1c according to the GFS run.

By the 20th the CET should be around 4.7c, 0.4c below average. If it remains cold thereafter it may well yet get down into the 3s.

That is very unlikely of course, high 5s is still favorable. Either way, it won't be a record warm month.

I don't think anyone can write off such a CET value as you state i.e. in the 3s being recorded at this stage, even if the high does collapse into europe in time for christmas there are still 7 days to play with and it would only take a few days of polar maritime air to dent the CET down to such levels.

[Stratos Ferric]

Finishing below the 71-00 average is certainly looking achievable at this point. Close to the 61-90 average is also within reach.

Below 4C would require the 12th-31st to return a CET value not seen since 1995 (and 1981 before that and 1962 before that).

I still think getting below 4.7C is a very tall order but I guess you should never say never with weather.

Can anyone remember icicles? I seem to remeber there were always huge icicles hanging from roofs when I was a kid.

Yes, but icicles generally formed when there was snow on roofs. When was there last significant snow on roofs AND snow that persisted behind the passing front? I don't think it's happened for ten years. Staggering.

[Anti-Mild]

Can anyone remember icicles? I seem to remeber there were always huge icicles hanging from roofs when I was a kid.

I had fairly large icicles hanging from my roof and my car number plate during the very cold spell at the end of December 2005. Not as big as they were in the 80's though.....<sigh>

[damianslaw]

I had fairly large icicles hanging from my roof and my car number plate during the very cold spell at the end of December 2005. Not as big as they were in the 80's though.....<sigh>

I have a photo taken during the snowfall of the 6th february 1996 in Cumbria - plenty of icicles dangling from the porch roof in that photo

More recently I recall seeing quite large icicles during the winter of 2005/2006 more probably in late february- these were dangling from the underside of bridges on the newcastle-sunderland rail line and this wasn't during a particularly harsh spell of weather.

[West is Best]

Yes, but icicles generally formed when there was snow on roofs. When was there last significant snow on roofs AND snow that persisted behind the passing front? I don't think it's happened for ten years. Staggering.

Icicles tend to form I think when there is some snow melt but the drips freeze (usually overnight) so typically they form off a roof which has heated in the daytime sun ... so is the point you are making that thawing just isn't what thawing used to be?!

I notice Hadobs fell 0.5C yesterday and is now slightly below Manley. The CET is taking a hammering at the moment, which is excellent to see!

[West is Best]

CET heading nicely on its way towards eventual below average territory

Tamara

Indeed Tamara! It's taking a plunge at the moment! Down another 0.5C on Manley to 7.2C and at the moment on course to be not far off 4.5C by close of play on 20th: there or thereabouts anyway.

It's wonderful to have such seasonal weather back!

[Weather-history]

If the daily CET mean for today is 6.0 then the CET will be 7.1 tomorrow

If 5.0, then it will be 7.03

If 4.0, then it will be 6.95

If 3.0, then it will be 6.87

If 2.0, then it will be 6.8

If 1.0, then it will be 6.72

[Stratos Ferric]

Icicles tend to form I think when there is some snow melt but the drips freeze (usually overnight) so typically they form off a roof which has heated in the daytime sun ... so is the point you are making that thawing just isn't what thawing used to be?!

I notice Hadobs fell 0.5C yesterday and is now slightly below Manley. The CET is taking a hammering at the moment, which is excellent to see!

I think the point was exactly as stated. Unless there is snow on a roof to melt, and air cold enough to freeze, then icicles won't form. If thawing isn't what it used to be it's a symptom of there tending to be nothing but no to thaw.

[Optimus Prime]

We have Icicles in January 2003, Couple of times in 2004 and again in January and February 2007.

Biggest ones were in 2003. 3 or 4 inches long.

[Matty M]

There was icicles here in the great winter of 2001!!

[JohnAcc]

Another big 0.5c drop yesterday with further drops to come over the next few days. I'll keep this graph updated to see how close the GFS has called this one.

Rgds, John

[North-Easterly Blast]

The CET should fall to around 6.8 today or even 6.7. The landing zone for the first half of December now looks set to be around 6*C, or possibly 5.8 depending on how cold Friday and Saturday are.

For the final December CET, anything below 4*C is out of the question, unless the second half mirrorred that of 1995 or even the second half of the early 60s Dec's, which looks highly unlikely. Getting even much below 4.5*C looks a tall order now, which would require something akin to the second half of Dec 1996.

If this current UK high does not sink into a Bartlett and we do not get anything too mild in the second half, sub 5*C is a realistic possibility, and if a cold spell does come off late in the month, a below 61-90 December is a distinct possibility, and possibly as low as 2005.

4.4 - 6.0 looks the likely landing zone at present for December's CET. If we can get down into the 4s, then we will manage a sub 10.5 annual CET, which would be great. If we can get some northern blocking and a cold N'ly or E'ly spell before this month is out, then I would say that the chances are there of further cold spells during the rest of winter.

[The PIT]

For once we're well below CET at 5.9C rounded up. Nice change.

I can see this spell lasting to Tuesday Wednesday at least at the present time.

[West is Best]

The CET should fall to around 6.8 today or even 6.7. The landing zone for the first half of December now looks set to be around 6*C, or possibly 5.8 depending on how cold Friday and Saturday are.

For the final December CET, anything below 4*C is out of the question, unless the second half mirrorred that of 1995 or even the second half of the early 60s Dec's, which looks highly unlikely. Getting even much below 4.5*C looks a tall order now, which would require something akin to the second half of Dec 1996.

Hi N-EB. As the CET will be not far from 4.5C by the 20th this is an unusual line of argument.

From 4.5C on 21st anything's possible, even in the 2's. You don't know. I don't know.

p.s. do you remember the last time you used the 'out of the question' phrase? Clue: September ...

Agree with you about the sub 10.5C. Would be great. We're heading for a cold second half of the year.

Edited December 13, 2007 by La Nina

[Optimus Prime]

Looks like it'll be around 4.9c by the 20th. Looking further ahead will be pointless.

These are what I think the percentage ratings should be.

7.0c-8.0c 10%

6.0-6.9c 30%

5.0c-5.9c 35%

3.9c-4.9c 25%

Edited December 13, 2007 by Optimus Prime

[kold weather]

I still think something close to the average is the most likely outcome, which funnily enough is just about where all strong la nina December's ended up!

[summer blizzard]

I still think something close to the average is the most likely outcome, which funnily enough is just about where all strong la nina December's ended up!

MEI values have been at -1.1 all Autumn, the atmosphere is responding to a moderate La Nina, not a strong one.

As for the CET, the 1st-15th looks to record a CET between 6C and 6.5C, to get down to average by the end of the month, we will need to record a CET between 3C and 4C, given the trends of recent months, it is possible we can maintain 4C, but likly, not 3C, so close to average, probably slightly below, looks probable.

[kold weather]

Yeah its a mod right now SB it was just an interesting point of contact esp as the monthly SST data has been fairly close to the strong category.

[West is Best]

Looks like it'll be around 4.9c by the 20th. Looking further ahead will be pointless.

These are what I think the percentage ratings should be.

7.0c-8.0c 10%

6.0-6.9c 30%

5.0c-5.9c 35%

3.9c-4.9c 25%

Wth yet another cold surface run out to T168+ you need to offer odds below 3.9C, and to make them generous.

There are some low low maxima followed by low low minima in the offing. So sub-5C after 20th is looking very likely. Then it all depends on patterns. If Stratos Ferric's 10 days on-10 days off idea comes right then it'll be back to mild, but who knows. If it goes cold again then sub-4C is possible, and something in the 4's probable.