November CET

[Stu_London]

Slow and steady, with forecasts currently, I'm expecting around 6C or over for the 20th here, and around 8C for the CET. Currently, I think anyone between 7C and 7.5C has the best chance, but if the cold spells towards the end occur, 6.5C to 7C is very much possible.

I think 7.5C is way too high. Looking at the way the models are shaping up, it's likely that most days from here to the month end will have downward pressure. I think 6.5C is plausible, but wouldn't be suprised if it dips a little further down than that. Although not that common, November is the most likely month of the year to shed a whole degree or so in the last week, like 2005.

It's funny how the last three months have all started mild and then the CET has collapsed in each month. I suppose more likely to happen in Autumn than any other season, but each has been spectacular in it's own way.

[Gavin P]

How does the CET now compare to this point in 1996 and 2005?

[Weather-history]

How does the CET now compare to this point in 1996 and 2005?

8.8 up to 12th November 1996

10.6 up to 12th November 2005

[Isolated Frost]

8.8 up to 12th November 1996

10.6 up to 12th November 2005

I'll have a drop like that please :o

[Gavin P]

8.8 up to 12th November 1996

10.6 up to 12th November 2005

Thanks Mr D.

[North-Easterly Blast]

November 1996 was overall a cold cyclonic north to north-westerly month, almost identical in synoptics and character to November 1969 or even 1965. Nov 1996 was really a notably cold month from the 8th onwards; take the first week of that month out of the equation and then you have a CET of 4.1, the same as that for the entire month of Nov 1985. It was down to only a very mild first week that obliterated much of the negative anomaly for Nov 1996 and added 1.8*C to the overall CET for the month, in only a week!

Nov 1996 is a bit like March 2006 in opposite fashion. March 2006 had a CET of only about 3.2 to the 24th I believe, matching the overall CET for the likes of notably cold Marches 1969, 1955 etc, but a very mild final week to the month obliterated much of this low CET and meant that the month finished less than 1*C below the older long term averages despite being well below average until the last week; in Nov 1996 it was the opposite, that a very mild first week obliterated a cold month and prevented the CET from ending that low.

The second half of November 2005 was also one of the coldest since World War 2; only 1952 and 1993 had colder second halves of November, and again similar to months like the above, a very mild first half to the month prevented a CET much below average.

All this goes to show how difficult it has been in the last two decades or so to record a month significantly below average, although last winter did far better than has been the case for many years, January recorded a CET well down into the 1s, December was quite a bit below average and Feb just managed a CET in the 2s. Since then during this year we have managed a cooler than average May and August although neither by a long way.

By the way the models are now shaping up we may well see a Nov 2010 CET in the 6s. To get as low as Nov 2005 is a long shot now but if we can beat the 7.0 CET of Nov 2008 we can achieve only the second sub 7*C November in 12 years!

[damianslaw]

November 1996 was overall a cold cyclonic north to north-westerly month, almost identical in synoptics and character to November 1969 or even 1965. Nov 1996 was really a notably cold month from the 8th onwards; take the first week of that month out of the equation and then you have a CET of 4.1, the same as that for the entire month of Nov 1985. It was down to only a very mild first week that obliterated much of the negative anomaly for Nov 1996 and added 1.8*C to the overall CET for the month, in only a week!

Nov 1996 is a bit like March 2006 in opposite fashion. March 2006 had a CET of only about 3.2 to the 24th I believe, matching the overall CET for the likes of notably cold Marches 1969, 1955 etc, but a very mild final week to the month obliterated much of this low CET and meant that the month finished less than 1*C below the older long term averages despite being well below average until the last week; in Nov 1996 it was the opposite, that a very mild first week obliterated a cold month and prevented the CET from ending that low.

The second half of November 2005 was also one of the coldest since World War 2; only 1952 and 1993 had colder second halves of November, and again similar to months like the above, a very mild first half to the month prevented a CET much below average.

All this goes to show how difficult it has been in the last two decades or so to record a month significantly below average, although last winter did far better than has been the case for many years, January recorded a CET well down into the 1s, December was quite a bit below average and Feb just managed a CET in the 2s. Since then during this year we have managed a cooler than average May and August although neither by a long way.

By the way the models are now shaping up we may well see a Nov 2010 CET in the 6s. To get as low as Nov 2005 is a long shot now but if we can beat the 7.0 CET of Nov 2008 we can achieve only the second sub 7*C November in 12 years!

Yes your observations about March 06 and Nov 96 illustrate how sustained cold coinciding with an exact 30 day calandar month period has been a rare event in recent years. We have also had many months where one very cold half has been cancelled out by a mild or very mild other half, Nov 05 being a case in point. Whilst I don't believe the second half of Nov 10 will be as cold as either Nov 93, 96 or 05 largely because the cold will come too late, I do think when it does arrive it will be very potent and help bring the CET down so we are not far off 7 degrees. I said the second half of this month would be much colder than the first half, but due to the very mild first half it would be a tall order for anything lower than a at or slightly above CET being recorded. Still a long way to go yet, we could still end up with a below average month especially if we see foggy conditions develop combined with sub zero nights..

[Isolated Frost]

9.1C to the 12th

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

7.0C to the 13th here at Washington, and projected to be at 6.8C to the 14th. Below Average month looks certain here, I'm expecting 6C to the 20th, and then the cold spell...

My guess is 7.2C for the CET, and 5.1C here, which would be 1C below average, and the first below average November of the millennium (2005 was slightly above here).

[Cymro]

This month could turn around quite drastically IMO if we have a week of sustained cool it won't tale much say day time temps of 2-3 and night time temps of -3/-4 that will erode the cet away and with low sunlight its much mor lightly in November than february!>

[Snowyowl9]

Wheres SF and Snowmaiden these day West is best is back

9.1c well 7c was 2008 which had a very cold end to recent years.

2005 was 6.2c who knows what this will end up up yet,a colder N/NE 2nd half,east wind in a weeks time.

[West is Best]

Certainly could see the CET continue to be chipped away I think. A below average month still looks a distinct possibility to me from here.

[Optimus Prime]

November 2005 was an interesting month when you compared the CET of Manley and Hadley and how different they were;

Hadley;

Mean Max 9.7c (-0.2c)

Mean Min 2.7c (-1.3c)

Mean 6.2c (-0.7c)

Manley;

Mean Min 2.2c (-1.8c)

Mean Max 9.2c (-0.7c)

Mean 5.7c (-1.2c)

0.5c difference between the two standards!

[Stu_London]

CET to the 14th is 8.7C (anomoly +1.1C)

The next 6 days look like averaging around 5.5C, so something in the order of 7.7C to 7.9C looks likely by the 20th.

What the final third of the month holds in store is anyones guess at this stage, however unless we really do get something like last nights ECM, then 6.5C to 7.0C looks the most likely, although confidence is lower than normal at this stage given the quite large spread of possible scenarios

[BornFromTheVoid]

Going by the GFS 06z we'll be at 8.2C to the 16th, 8.0C to the 18th, 7.9C to the 20th and 7.9C to the 22nd.

[Isolated Frost]

Going by the GFS 06z we'll be at 8.2C to the 16th, 8.0C to the 18th, 7.9C to the 20th and 7.9C to the 22nd.

And then 6.6C by the 30th?

[summer blizzard]

Going by the GFS 06z we'll be at 8.2C to the 16th, 8.0C to the 18th, 7.9C to the 20th and 7.9C to the 22nd.

Looking at the output from the long range models (ECWMF, GEM and GFS), i certainly think that my prediction of 7.6C will be far too high, with a likely finishing point between 5.5C and 6.5C, so pretty comfortably below average.

The main reason for thinking this pattern will last is that over the next week we see a fall due to low pressure tracking across the south of the UK supressing maxima, however over next weekend and next week, models are agreed on a northerly shot which will lead to low minima. The key to how cold November 2010 will be to me is the last five days of November, after the initial northerly, because if the Atlantic High collapses we will see a close to average outcome, but if the high settles over or just west of the UK, we could see very low minima (November 2005 saw this senario with -10C across England).

Sadly not a snowy pattern away from Scotland, however it is certainly a cold one, and i would say the odds of a below average month are 80/20 in favour.

[Isolated Frost]

Looking at the output from the long range models (ECWMF, GEM and GFS), i certainly think that my prediction of 7.6C will be far too high, with a likely finishing point between 5.5C and 6.5C, so pretty comfortably below average.

The main reason for thinking this pattern will last is that over the next week we see a fall due to low pressure tracking across the south of the UK supressing maxima, however over next weekend and next week, models are agreed on a northerly shot which will lead to low minima. The key to how cold November 2010 will be to me is the last five days of November, after the initial northerly, because if the Atlantic High collapses we will see a close to average outcome, but if the high settles over or just west of the UK, we could see very low minima (November 2005 saw this senario with -10C across England).

Sadly not a snowy pattern away from Scotland, however it is certainly a cold one, and i would say the odds of a below average month are 80/20 in favour.

Here at Washington, we're at 6.8C (6.6C) after today, which would be +0.5C of the Durham average, usually Durham is 0.2-0.5C cooler than here, do you think Durham could get sub 4C?

[BornFromTheVoid]

And then 6.6C by the 30th?

Nah, 6.8C!

Looking at the output from the long range models (ECWMF, GEM and GFS), i certainly think that my prediction of 7.6C will be far too high, with a likely finishing point between 5.5C and 6.5C, so pretty comfortably below average.

Provided we do reach 7.9C by the 22nd, to reach the 61-90 figure we'd need to average 2.65C for the remainder of the month.

The reach 6.0C we'd have to average 0.78C, and to reach 5.5C we'd need -1.1C. I think <6.0C would require a really exceptional spell of cold weather...

[Isolated Frost]

Nah, 6.8C!

Provided we do reach 7.9C by the 22nd, to reach the 61-90 figure we'd need to average 2.65C for the remainder of the month.

The reach 6.0C we'd have to average 0.78C, and to reach 5.5C we'd need -1.1C. I think <6.0C would require a really exceptional spell of cold weather...

Hehe, 6.6C was my guess, so lower that 6.8C, or face the consequences.

LOL.

I wouldn't mind an exceptional spell of cold weather, AccuWeather are giving me heavy snow showers on the 22nd and 24th, and temperatures not passing 5C for a long 10 day period here in Durham, and AccuWeather were very accurate () during the winter (of course I hadn't discovered NW at that time)!

Edited November 15, 2010 by Isolated Frost

[Typhoon John]

Hehe, 6.6C was my guess, so lower that 6.8C, or face the consequences.

LOL.

I wouldn't mind an exceptional spell of cold weather, AccuWeather are giving me heavy snow showers on the 22nd and 24th, and temperatures not passing 5C for a long 10 day period here in Durham, and AccuWeather were very accurate () during the winter (of course I hadn't discovered NW at that time)!

I like the fact your tracking the Durham City temperature. It's handy for me as I live about 5 mins walk from the Stevenson Screen.Keep up the good work!

Edited November 15, 2010 by Jonathan F.

[Isolated Frost]

I like the fact your tracking the Durham City temperature. It's handy for me as I live about 5 mins walk from the Stevenson Screen.Keep up the good work!

No problem, it's interesting comparing it too the actual Observatory temperature, and the fact that the City altitude (for the station I'm using) is 19m lower than the Observatory. You can see the details in my signature.

I've got a document for the Temperature I'm following, I'll PM you the details for October and November

Edited November 15, 2010 by Isolated Frost

[damianslaw]

The next 24 hours are looking cold in the CET zone, mins tonight between 0-2 degrees and maxes tomorrow of 4-6 degrees, many parts struggling to get above 4 degrees in low cloud, suspect we will see 0.2 degrees knocked off the current value this time tomorrow possibly even 0.3 degrees.

Thereafter Wed- Fri look preety average with maxes in the region of 7-10 degrees and mins around 4-7 degree mark, by Saturday a marked downturn looks like setting in..

[BornFromTheVoid]

8.4C to the 15th

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

Yesterday was 3.9C. Minimum for today is -0.5C and maxima will probably be around around 7.0C, so we will most likely be at 8.1C by tomorrow.

Going by the GFS 06z we'll be at 7.9C to the 17th, 7.8C to the 19th, 7.7C to the 21st and 7.5C to the 23rd.

[AderynCoch]

November 1996 was overall a cold cyclonic north to north-westerly month, almost identical in synoptics and character to November 1969 or even 1965. Nov 1996 was really a notably cold month from the 8th onwards; take the first week of that month out of the equation and then you have a CET of 4.1, the same as that for the entire month of Nov 1985. It was down to only a very mild first week that obliterated much of the negative anomaly for Nov 1996 and added 1.8*C to the overall CET for the month, in only a week!

Nov 1996 is a bit like March 2006 in opposite fashion. March 2006 had a CET of only about 3.2 to the 24th I believe, matching the overall CET for the likes of notably cold Marches 1969, 1955 etc, but a very mild final week to the month obliterated much of this low CET and meant that the month finished less than 1*C below the older long term averages despite being well below average until the last week; in Nov 1996 it was the opposite, that a very mild first week obliterated a cold month and prevented the CET from ending that low.

The second half of November 2005 was also one of the coldest since World War 2; only 1952 and 1993 had colder second halves of November, and again similar to months like the above, a very mild first half to the month prevented a CET much below average.

All this goes to show how difficult it has been in the last two decades or so to record a month significantly below average, although last winter did far better than has been the case for many years, January recorded a CET well down into the 1s, December was quite a bit below average and Feb just managed a CET in the 2s. Since then during this year we have managed a cooler than average May and August although neither by a long way.

Even last winter fell foul of the calendar curse: the coldest spell lasted from mid-December to mid-January and averaged pretty much bang on 0C (rounding up to 0C rather than down I think, which would make it a sub-zero month-long spell - I can't be bothered rechecking right now). Had December started 11 days later, we would have been looking at a sub-2C winter (by the very slightest of margins mind - again, I can't be bothered rechecking right now!). At least last winter when it wasn't very cold it wasn't very mild either, so the monthly CETs didn't "suffer" that much (unlike in 2008/9, when all three winter months had their cold starts quickly wiped out by mild intrusions).

As for this month, those very mild days early on should also prove sufficient enough to make a significant difference to the CET. It will take a very notable cold snap (at least on a par with November 1993) to cancel them out.

Edited November 16, 2010 by AderynCoch

[Cymro]

Even last winter fell foul of the calendar curse: the coldest spell lasted from mid-December to mid-January and averaged pretty much bang on 0C (rounding up to 0C rather than down I think, which would make it a sub-zero month-long spell - I can't be bothered rechecking right now). Had December started 11 days later, we would have been looking at a sub-2C winter (by the very slightest of margins mind - again, I can't be bothered rechecking right now!). At least last winter when it wasn't very cold it wasn't very mild either, so the monthly CETs didn't "suffer" that much (unlike in 2008/9, when all three winter months had their cold starts quickly wiped out by mild intrusions).

As for this month, those very mild days early on should also prove sufficient enough to make a significant difference to the CET. It will take a very notable cold snap (at least on a par with November 1993) to cancel them out.

What's apparent though those mild shots at the beginning of the month were only really apparent in southern England and rarely affected Wales, Scotland, Northern Ireland and most of middle/north England. It hasn't been overly mild here in Wales and with this cold snap coming up I think below average is odds on.