October 2007 CET

[West is Best]

WIb, the 61-90 average is warmer then the 71-000 average. By 0.2c.

Oh yes! I read my figures off too fast and just assumed the 61-90 was colder.

So 0.2C below the old average, and level pegging with the proper one.

This weekend has certainly not shown the slight upward nudge I'd expected,

No, well ...

but next week is undeniably mild,

I'm sorry but I'm not at all sure you are right about that. Once again there look to be some chilly nights.

Edited October 7, 2007 by West is Best

[Stu_London]

This weekend has certainly not shown the slight upward nudge I'd expected, we have for once managed the rare combo of cloudy days and clear nights, but next week is undeniably mild, though depending on the vagueries of cloud it may not move that much from where we are now: even so, still think we'll be 12-12.5C by the end of next Saturday, so around 1C above the norm by then.

If the GFS 12z is to be believed then any mild weather is pushed back again

[kold weather]

Probably hold or slightly drop over the next few days looking at the models, then prehaps a slight upwards rise as the late week/weekend set-up looks fairly warm to me with cloudy nights keeping the mins up, esp as we pick up a SW flow during the weekend.

Edited October 7, 2007 by kold weather

[Stratos Ferric]

If the GFS 12z is to be believed then any mild weather is pushed back again

Well I'm not seeing anything notably below par this week. If anything, the 12h data nudges things up a smidgeon by next week, but it's still around about 12C by my tally.

[Stu_London]

Well I'm not seeing anything notably below par this week. If anything, the 12h data nudges things up a smidgeon by next week, but it's still around about 12C by my tally.

I would agree there is little cold in the reliable timeframe. However the warmth might not be quite as pronounced as was previously progged and looks like being delayed to boot. That said something around 12 by next weekend does look likely.

Some hints of a colder 2nd half (as one would expect). If I had to call this early I would go as follows: -

Sub 10C - 5%

10.1C to 10.6C - 10%

10.7C to 11.0C - 20%

11.1C to 11.5C - 25%

11.6C to 12.0C - 20%

12.1C to 12.5C - 15%

Over 12.5C - 5%

All of which translates to a median average at this stage of 11.3C

[Kentish Man]

No Manley update today but Hadley now stands at 12.1C (Oct 1 - 7)

[Stratos Ferric]

I would agree there is little cold in the reliable timeframe. However the warmth might not be quite as pronounced as was previously progged and looks like being delayed to boot. That said something around 12 by next weekend does look likely.

Some hints of a colder 2nd half (as one would expect). If I had to call this early I would go as follows: -

Sub 10C - 5%

10.1C to 10.6C - 10%

10.7C to 11.0C - 20%

11.1C to 11.5C - 25%

11.6C to 12.0C - 20%

12.1C to 12.5C - 15%

Over 12.5C - 5%

All of which translates to a median average at this stage of 11.3C

I have to agree that it would be quite something for H2 to hold up, and 11-11.5 allows for a reasonable dip second half.

The models are bouncing around a tad but the changes at present tend to net out about neutral, though the FI runs today - for what they're worth - are less insistent regarding a cold plunge. In the short term I suspect the GFS max-mins underplay the maxes a tad, certainly on Thur, but the flip is that clear nights, even in warmish air, could cool of smartly, in which case, with humid air, fog enters into the reckoning.

[Eugene]

Hadley CET provisionally is bang on the 1961-90 average, no significant warmth as of yet though some warmth possible end of the week not for long though if the models are to be believed.

http://hadobs.metoffice.com/hadcet/cet_info_mean.html

[Stratos Ferric]

Hadley CET provisionally is bang on the 1961-90 average, no significant warmth as of yet though some warmth possible end of the week not for long though if the models are to be believed.

http://hadobs.metoffice.com/hadcet/cet_info_mean.html

This evening's models beg to differ, though in FI they've been bouncing around a bit, though not really with any extravagant excess in either direction. A warm back end to the week will nudge the anomaly up neatly given that the baseline trend is obviously downwards at this time of year. Still looking like around 12C by Saturday though, perhaps a notch or two higher.

Edited October 9, 2007 by Stratos Ferric

[eddie]

18z GFS looking quite warm for October. I wouldn't be suprised if we are 1.5C above average by the 15th if this run come off.

Edited October 9, 2007 by eddie

[West is Best]

This evening's models beg to differ, though in FI they've been bouncing around a bit, though not really with any extravagant excess in either direction. A warm back end to the week will nudge the anomaly up neatly given that the baseline trend is obviously downwards at this time of year. Still looking like around 12C by Saturday though, perhaps a notch or two higher.

It may nudge up later in the week, but once again I think you overlook minima at your peril Stratos. Wednesday night, for instance, looks to be pretty cold with some ground frost around.

This month is relatively cool compared to the first half of September. We are still currently on average.

[Hiya]

Based on research analogues, watch for a strong northerly around 16-20 Oct with retrogression of the current high ... this is when there could be some near-wintry weather and a sharp drop in the CET which I think will remain in the 12 to 12.5 area until mid-month.

I like to keep an eye on your predictions, and the hardest part is over on this one, well done.

[Stratos Ferric]

It may nudge up later in the week, but once again I think you overlook minima at your peril Stratos. Wednesday night, for instance, looks to be pretty cold with some ground frost around.

This month is relatively cool compared to the first half of September. We are still currently on average.

WiB, I have said in various posts that it will bounce around a little, but the upside at the end of the week still looks like more than compensating for a coolish night tonight, and I'm still thinking it's around 12 by the w/e - I do believe that I've not really deviated in this view, and I'm not seeing any impending 'peril'. I guess anyone who has bid for a monthly outturn down in single figures would have to be making claims for a downward movement soon, but I'm certainly not seeing any real correction in the reliable forward view.

I like to keep an eye on your predictions, and the hardest part is over on this one, well done.

Hiya, what 'hardest part' are you referring to? Particularly as I see no 'strong northerly' in the charts at present for the 16-20th.

[West is Best]

I see no 'strong northerly' in the charts at present for the 16-20th.

It's a pretty convincing polar sourced northerly/north-westerly on ECM in that timeframe SF.

As I'm fond of reminding people, this month is currently average.

[Gavin P]

So far, it really seems to be a very unexciting month.

Edited October 10, 2007 by Gavin P

[jemtom]

My pre month call was 11.0c, thinking now I might just be a tad low with this one.

[Stratos Ferric]

It's a pretty convincing polar sourced northerly/north-westerly on ECM in that timeframe SF.

As I'm fond of reminding people, this month is currently average.

Is anyone disagreeing that it's currently average?

So far, it really seems to be a very unexciting month.

Re the weather, yes. WiB's been getting very excited though.

It's a pretty convincing polar sourced northerly/north-westerly on ECM in that timeframe SF.

As I'm fond of reminding people, this month is currently average.

There's a transitory polar burst. Not what would pass in my book for a "strong northerly", but hey, it might introduce a small correction: GFS, by the way, is even less compelling in its support. It's a short cool oasis in what is otherwise an average or higher outlook. You have to remember at this time of year, if the average climbs by around 0.1C per day, then after 4-5 days the mean will be around 1C above par.

It's not presently as big a comeback from midway as September had to achieve to get below par (and of course, as suggested, it didn't happen), but it's headed in that direction. GFS keeps tantalising with cold in FI, but I seem to remember that that has been a recurrent failing in winter GFS runs for 2-3 years now. Maybe Metcheck have taken out shares...

[Nick F]

Hadley creeping every so slightly upwards now (upto the 9th):

http://hadobs.metoffice.com/hadcet/cet_info_mean.html

... perhaps a cool night tonight but nights look like generally warming up thereafter, could be quite warm maxes on friday with rising thicknesses ... GFS has 21C over central areas - so this may translate to 22C perhaps. A mild weekend and Monday as the high shifts East and allows a SWerly flow to develop ahead of the trough arriving to the NW.

Signs of a possible downturn for the CET mid-next week as a NW-Nerly develops on the latest output behind the long-wave trough moving East, hard to see if it will bring the CET down much atm against the rises likely over the next 4-5 days - back to average than below par most likely, depends how long the Pm air hangs around.

[Glacier Point]

...and nicely picked out by ECM Ensembles...

http://www.knmi.nl/exp/pluim/vijftiendaagse/index.html

If the ensemble mean was taken on trust, we would arrive at the 20th at around 12 C. Winner takes all in that final third I suspect with local factors such as low cloud, fog and patchy frost taking the lead and keeping us on our toes until the end.

[Stratos Ferric]

...and nicely picked out by ECM Ensembles...

http://www.knmi.nl/exp/pluim/vijftiendaagse/index.html

If the ensemble mean was taken on trust, we would arrive at the 20th at around 12 C. Winner takes all in that final third I suspect with local factors such as low cloud, fog and patchy frost taking the lead and keeping us on our toes until the end.

With the obvious mathematical caveat that the further into the month you get, the more likely the outcome is to be close to where you already are. 12C at, say, the 20th, converts far less readily to 10C by month's end than does 12C on the 10th. The former requires the final ten days to average 6C per day; the latter requires only 9C per day.

[ukmoose]

Is anyone disagreeing that it's currently average?

I am - all the sites I have looked at have the current CET at more than 12. The average for October (barrring last year) is 10 point something. October has so far been above average all month and all signs are that it will continue to be so.

I just can't see where WIB's 'average month' comes from.

Moose

[Nick F]

I just can't see where WIB's 'average month' comes from.

Moose

WIB is referring to the CET mean against the rolling average, so he is right to say that it is average. 10.4 is the overall '71-'00 CET mean for October - 10.6C for the '61-90 mean. The daily CET mean figure you see from Manley or Hadley are set against the rolling mean, which is higher in early October (around 12C atm) than late October where the rolling mean drops for the obvious reason of it tending to get cooler in the 2nd half of the month.

[Hiya]

Hiya, what 'hardest part' are you referring to? Particularly as I see no 'strong northerly' in the charts at present for the 16-20th.

But you do see the northerly yes? Just not a strong one. Predicting a northerly in october from 10 days out, thats a hard feat to do. Don't you agree?

[West is Best]

The average issue can be a bit confusing so thank you to Nick for explaining it to UKMoose. I fell into the same state of confusion once a few years back.

It makes sense when you consider that the average max temp drops as much as 4C through October. Stratos I think you need to factor that metereology into your otherwise mathematically correct assertion.

Edited October 10, 2007 by West is Best

[Stratos Ferric]

But you do see the northerly yes? Just not a strong one. Predicting a northerly in october from 10 days out, thats a hard feat to do. Don't you agree?

Predicting is easy...here you go...'northerly in twenty one days' time..and there aren't even any charts to look at yet'. What's hard is predicting accurately.

The average issue can be a bit confusing so thank you to Nick for explaining it to UKMoose. I fell into the same state of confusion once a few years back.

It makes sense when you consider that the average max temp drops as much as 4C through October. Stratos I think you need to factor that metereology into your otherwise mathematically correct assertion.

I don't think I do. It's clearly the case, given your cooling point (you're right, though October doesn't cool by 4C, 3C would be closer to it) that my argument is absolutely correct. 12C on the 10th is marginally above the norm, 12C n the 20th is well above norm. Ipso facto, to get down to any given end point the cooling in the latter case would have be twice as strong as in the former case. Rolling average makes not a jot of difference, nor does the fact that the end of the month is colder: if a larger drop is required then it's going to be harder to achieve.