I'm perfectly happy with my 10.85C prediction. Of course it's still early days yet but there is nothing in any of the output I've seen that suggests anything significantly deviating from an average month. Naturally the figure will be running rather above the monthly average during the 1st half of October but as the LTA falls so quickly during the month then assuming generally average conditions contine that will bring it back in.  I think for October watching the anomaly is a better guide than the actual figure.

Indeed. And that is why I'm nervous that I've gone a bit high this month. Currently, the anomaly is negative. It certainly looks like mild nights will nudge the CET up a bit for a while but anything could still happen later in the month and a cold snap would scupper my prediction.

I notice that the likes of Gusty and MartinG are placed nicely and could easily sneak in and snatch the title!

 

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Just been reading the Climatemps.com website and it has the average maximum temp for London in October as 14c. This seems a tad low to me - I would assume it's more like 15c or even 16c. 

It also states that the ratio of cloudy to sunny conditions in October is 70:30% which makes depressing reading.

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Met Office Hadley             11.4c.         Anomaly      -0.8c. Provisional to 7th.

Metcheck                          11.15c        Anomaly      0.64c

Netweather                       11.59c        Anomaly      1.2c

Peasedown St John   11.9c.        Anomaly      -0.1c.    

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Briggsy your perception perhaps reflects the abundance of very warm Octobers we have had in recent years. Over the last 15 years it has been quite a phenomenal run. Even though a cold October isn't such a pleasabt thing as it will tend to serve to make the winter seem longer... it would make an interesting change to have one now. But as my 11.8c guess shows I have no faith in the weather to do it this year ! I've sweated in Halloween costumes too many times in recent years for that....

Briggsy your perception perhaps reflects the abundance of very warm Octobers we have had in recent years. Over the last 15 years it has been quite a phenomenal run. Even though a cold October isn't such a pleasabt thing as it will tend to serve to make the winter seem longer... it would make an interesting change to have one now. But as my 11.8c guess shows I have no faith in the weather to do it this year ! I've sweated in Halloween costumes too many times in recent years for that....

Yes, we’ve had some mild Octobers in recent years and I remember freezing in Halloween costumes when my kids were young in the nineties.  Mild doesn’t always mean pleasant though.  It often means damp and dull, which I think prolongs winter more than cold clear days and of course, the latter is what gives Autumn leaves their vibrant colour.  

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M et Office Hadley           11.6c.         Anomaly        -0.6 Provisional to 8th.

Metcheck                         11.18c        Anomaly        0.67c

Netweather                      11.74c        Anomaly        1.35c

Peasedown St John         11.17c       Anomaly       -0.83c.

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Met Office Hadley            11.6c.        Anomaly        -0.5c. Provisional to 9th.

Metcheck                         11.09c       Anomaly        0.58c

Netweather                      11.69c       Anomaly        1.29c

Peasedown St John           11.77c       Anomaly        -0.23c.  

 

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Met Office Hadley            11.6c          Anomaly          -0.4c Provisional to 10th.

Metcheck                         11.36c.       Anomaly          0.85c

Netweather                      11.79c        Anomaly          1.14c

Peasedown St John           11.77c        Anomaly          -0.23c.

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It’s holding steady at 11.6c but why is the anomaly falling?  I’d have thought the average temp through October would fall. 

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Nighttime temperatures not falling enough yet. May be the cause.

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It’s holding steady at 11.6c but why is the anomaly falling?  I’d have thought the average temp through October would fall. 

Could be, Caz, a seasonal quirk: look at the LTM at 850- on the rise until 13th. But of course, that doesn't always cascade down to the surface, as we know with the June upper heatwave, but not lower heatwave!

Logic would say that in this half of the year there was a steady downward trend, with no reason not to be maintained. But anomalous numbers of warm, or cold, spells at certain points throughout the month over a period of years can upset the smooth line.

Examples are found at the other side of the solstice too: Aprils in the 40s and in the 00s had mid-month peaks that could potentially (I haven't checked: SC or GW could possibly deliver that information) affect the 30 year mean- one might expect the end of April to be warmer than the middle. 

Alternatively to all this waffle I've just Friday-nighted at the thread, it might be an error. 

 

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It’s holding steady at 11.6c but why is the anomaly falling?  I’d have thought the average temp through October would fall. 

Because its negative! The long term mean is falling day by day. As the current year CET is holding steady that must mean the negative anomaly gets smaller each day. If the anomaly was positive it would be increasing.

Here is the latest CET tracker. Not much movement expected in the CET over the next couple of weeks. A mean of 11.27C expected by the 25th.

Worth noting that a significant difference has now opened up between my calculations and the provisional Hadley data. My figures are now 0.35C lower than Hadley so could be a significant month end adjustment.

Chart 1

Chart 2

 

Because its negative! The long term mean is falling day by day. As the current year CET is holding steady that must mean the negative anomaly gets smaller each day. If the anomaly was positive it would be increasing.

Ahh!  Yes, of course, thanks GW!  The penny just dropped!  I knew I wasn’t thinking logically but I just couldn’t get my head round it! Doh!    

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Here is the latest CET tracker. Not much movement expected in the CET over the next couple of weeks. A mean of 11.27C expected by the 25th.

Worth noting that a significant difference has now opened up between my calculations and the provisional Hadley data. My figures are now 0.35C lower than Hadley so could be a significant month end adjustment.

IMAGE. Members enable at bottom of page

Chart 1

IMAGE. Members enable at bottom of page

Chart 2

That gives me a bit of confidence in my guess and it’s good news for Col.  All we need then is a slightly cooler final week, which shouldn’t be a big ask for October!  Oops!  Now I’ve blown it!  

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I must admit, the overall pattern evolution through mid-Oct isn't proving to be as I was anticipating at the end of Sep; the Atlantic troughs are staying further north and west on average than the Nina-like atmospheric state would have one expecting.

I've noticed some internet fingers being pointed at the exceptionally warm NE Pacific as a possible explanation; it may be feeding enough extra warmth & moisture across N. America to give the polar jet an extra kick as it heads out across the North Atlantic, causing troughs to deepen further west than we'd otherwise see. This puts the southward jet loop out in the N. Atlantic rather than down through the UK and into Europe.

 

There are hints in the NWP models that the N. American pattern may amplify this coming week, slowing down the eastward movement of anomalously warm & moist air and causing the favoured location for trough deepening to shift even further west, at least for a time.

If that happens, we may at least get a break from the unsettled regime, with a ridge building across from S or SE of us. In which case, resulting temps could be anything from 'Indian Summer' to chilly with overnight frost and daytime fog (aided by very saturated soils). It'll depend on the exact orientation of the high pressure ridge.

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Met Office Hadley         11.8c       Anomaly      -0.2c Provisional to 11th.

Metcheck                      11.43c     Anomaly      0.92c

Netweather                   12.01c     Anomaly      1.62c

Peasedown St John       12.5c      Anomaly      0.5c.

 

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Met Office Hadley         11.8c       Anomaly      -0.2c Provisional to 11th.

Metcheck                      11.43c     Anomaly      0.92c

Netweather                   12.01c     Anomaly      1.62c

Peasedown St John       12.5c      Anomaly      0.5c.

 

Id expect the CET to hover around the 12c mark for a while now. 

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Ahh!  Yes, of course, thanks GW!  The penny just dropped!  I knew I wasn’t thinking logically but I just couldn’t get my head round it! Doh!    

Worse for me Caz- I didn't look back at Art's 2 posts and misinterpreted 'falling' as 'getting lower' rather than 'reducing'. So it is normal after all. Double duh! That said, the 850s LTM rising slightly is still a bit quirky.

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Here is the latest CET tracker. Not much movement expected in the CET over the next couple of weeks. A mean of 11.27C expected by the 25th.

Worth noting that a significant difference has now opened up between my calculations and the provisional Hadley data. My figures are now 0.35C lower than Hadley so could be a significant month end adjustment.

 

Hoping so!

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