Comparing Novembers And Following Winters

[damianslaw]

Thought this an apt thread to post as we head into November and how many people seem to base there thoughts on the winter ahead based on November conditions.

I do not have any stats to hand and would appreciate if someone could post these. I would like to compare Nov CET values in say the past 30 years or so with the following winter CET values.

I always remember people used to say a mild wet November often signalled a cold winter, whereas a cold dry Nov signalled a mild wet winter. I know you shouldn't pattern match but I would be interested all the same. It is quite noteworthy how our two coldest winters of recent times 78/79 and 09/10 were preceded by two very mild Novembers. However we have had other mild Novembers like 1994 which were followed by wet mild winters but this was during a notably wet period.

[North-Easterly Blast]

Thought this an apt thread to post as we head into November and how many people seem to base there thoughts on the winter ahead based on November conditions.

I do not have any stats to hand and would appreciate if someone could post these. I would like to compare Nov CET values in say the past 30 years or so with the following winter CET values.

I always remember people used to say a mild wet November often signalled a cold winter, whereas a cold dry Nov signalled a mild wet winter. I know you shouldn't pattern match but I would be interested all the same. It is quite noteworthy how our two coldest winters of recent times 78/79 and 09/10 were preceded by two very mild Novembers. However we have had other mild Novembers like 1994 which were followed by wet mild winters but this was during a notably wet period.

November 1984 was also mild overall, and led to a winter that was cold overall. The same was true of November 1981, and November 1995 was largely mild too and this led to the coldest winter in both the 1990s and 2000s.

However, this doesen't always work, as Novembers 1994 and 1997 were very mild and the following winters were also very mild. Novembers 2002 and 2003 were also mild and neither led to a cold winter. Nov 2006 was also a mild month and the winter was very mild.

[Thundery wintry showers]

Just looking through Philip Eden's version of the CET since 1974, the following winters continued on from Novembers with CETs of 8C and above:

1978/79- cold & exceptionally snowy for most

1984/85- cold & snowy

1994/95- mild & very wet

1997/98- exceptionally mild

2002/03- fairly mild

2003/04- mild & wet, though snowy in parts of the NE

2006/07- exceptionally mild, wet

2009/10- cold & snowy, exceptionally so in the north

And the following winters continued on from Novembers with CETs of 6C and below:

1973/74- mild

1985/86- cold, a freeze-up during February

1988/89- exceptionally mild

1993/94- wet, quite mild in the south, cold & snowy in the NE

1996/97- cold and dry till February, then mild and wet

2005/06- mild in the NW, cold in the SE

A mixed bag of winters in both cases.

[johnholmes]

Thought this an apt thread to post as we head into November and how many people seem to base there thoughts on the winter ahead based on November conditions.

I do not have any stats to hand and would appreciate if someone could post these. I would like to compare Nov CET values in say the past 30 years or so with the following winter CET values.

I always remember people used to say a mild wet November often signalled a cold winter, whereas a cold dry Nov signalled a mild wet winter. I know you shouldn't pattern match but I would be interested all the same. It is quite noteworthy how our two coldest winters of recent times 78/79 and 09/10 were preceded by two very mild Novembers. However we have had other mild Novembers like 1994 which were followed by wet mild winters but this was during a notably wet period.

look at temperature data available on the CET site, for all months from 1900 onwards.

precip not sure where you look for data that long.

I stand by my oft repeated comment, no one has yet discovered a link that is statistically significant, neither with temps/precip, or AO/NAO or any other data.

[Guest]

A mixed bag of winters in both cases.

Thank you for the analysis TWS & NEB, this goes a good way to show (not quite proving) that there is no relation between November weather and the rest of the winter!

[stewfox]

Thank you for the analysis TWS & NEB, this goes a good way to show (not quite proving) that there is no relation between November weather and the rest of the winter!

I did look at the coldest 30 Octobers, Novembers last 300+ years re CET and saw no correlation to the following winter on a thread a while back. Obviously if there was I'm sure I wouldn't be the first to find it.

Although the attached is a interesting read

http://hadobs.metoffice.com/hadcet/cetml1659on.dat

Its better of course (if you like snow/cold etc) to have a mild November rather then a mild Dec/Jan

[Thundery wintry showers]

Hadley (as opposed to Philip Eden's version) has the same list of Novembers except for 1982, which came in at 8.0 (7.8 on Philip Eden's version) and 2005, which was just above 6C. Anyway 1982/83 was a mixed winter- December was mild in the south, cold and wintry in the north, January was mild everywhere and February was cold everywhere, with snowfalls from NE winds in the second week, so it makes absolutely no difference to my earlier overall findings!

[Guest]

I did look at the coldest 30 Octobers, Novembers last 300+ years re CET and saw no correlation to the following winter on a thread a while back. Obviously if there was I'm sure I wouldn't be the first to find it.

Although the attached is a interesting read

http://hadobs.metoffice.com/hadcet/cetml1659on.dat

Its better of course (if you like snow/cold etc) to have a mild November rather then a mild Dec/Jan

A "mild" month in Dec or Jan doesn't necessarily mean a snowless month. Jan 1993 is a perfect example, the 13th "mildest" month in terms of maximum temperatures in the 1959-2010 period at my local Met-O station yet there were still a few snowy periods, not least the huge blizzard across most of Scotland on the 10th.

[Weather-history]

Thought this an apt thread to post as we head into November and how many people seem to base there thoughts on the winter ahead based on November conditions.

I do not have any stats to hand and would appreciate if someone could post these. I would like to compare Nov CET values in say the past 30 years or so with the following winter CET values.

I always remember people used to say a mild wet November often signalled a cold winter, whereas a cold dry Nov signalled a mild wet winter. I know you shouldn't pattern match but I would be interested all the same. It is quite noteworthy how our two coldest winters of recent times 78/79 and 09/10 were preceded by two very mild Novembers. However we have had other mild Novembers like 1994 which were followed by wet mild winters but this was during a notably wet period.

I posted this 5 years ago, crikey where has the time gone?!

Lets see how true this old weather lore is

"Ice in November to bear a duck, the rest of the winter will be slush and muck."

Here's Novembers with a CET of <3.5 and the following winter CETs

1782 Nov 2.3 Winter 3.2

1915 Nov 2.8 Winter 5.5

1807 Nov 2.9 Winter 2.4

1684 Nov 3.0 Winter 2.7

1851 Nov 3.1 Winter 4.8

1862 Nov 3.2 Winter 5.7

1910 Nov 3.2 Winter 5.0

1740 Nov 3.3 Winter 2.8

1746 Nov 3.3 Winter 4.8

1786 Nov 3.3 Winter 4.1

1919 Nov 3.3 Winter 5.6

1923 Nov 3.3 Winter 3.9

1815 Nov 3.4 Winter 2.4

1871 Nov 3.4 Winter 5.2

Mixed results to be honest

-------------------------------------------------------------------------------------------------------

"Flowers bloomin' in late Autumn

A sure sign of bad winter comin'

Here's very mild Novembers with a CET of 8.5 and > and the following winters

1994 Nov 10.1 Winter 5.9

1818 Nov 9.5 Winter 4.1

1938 Nov 9.4 Winter 4.7

1743 Nov 9.3 Winter 3.1

1730 Nov 9.2 Winter 2.5

1817 Nov 9.1 Winter 3.2

1881 Nov 8.9 Winter 5.1

1939 Nov 8.7 Winter 1.5

1821 Nov 8.6 Winter 5.8

1899 Nov 8.5 Winter 3.1

1951 Nov 8.5 Winter 3.9

1953 Nov 8.5 Winter 4.1

1978 Nov 8.5 Winter 1.6

2002 Nov 8.5 Winter 4.7

Again mixed results

[VillagePlank]

look at temperature data available on the CET site, for all months from 1900 onwards.

precip not sure where you look for data that long.

I stand by my oft repeated comment, no one has yet discovered a link that is statistically significant, neither with temps/precip, or AO/NAO or any other data.

Quite true, John, and verifiably so.

If you take the data from the HadObs site for the CET, and run a correlation check between various CET factors, the correlations come up something like:

The best month for predicting the forthcoming winter is the first winter month, December, that follows the winter average 69% of the time (which is to be expected, really) - but using that's a bit naughty; although it does imply that a large proportion of the variance in winter temperatures happens in December.

Apart from that the best indicator, by quite some margin, is the spring CET which follows the forthcoming winter some 38% time - which, statistically speaking, is meaningless.

As for November? It follows the forthcoming winter trend only some 19% of the time which is, however, the best score for a month.

On the measures used here, forecasting the forthcoming winter from either any of the preceding year's month or seasons CET score or aggregate is essentially an excercise in rolling the dice.

[VillagePlank]

Using last year's Winter as an indicator is essentially useless, too: