BornFromTheVoid

-0.8C overnight. Yesterday's max was just 4.6C, quite low for November. Quite cloudy so far today, with the occasional sunny spell. Still very cool though, just 4.1C.

Just as most of us believe we are sceptics at heart, I'm sure most also believe we have a moderate and reasonable views too. This includes folk from the "AGW is a great conspiracy" (a few of those here) to the "We'll be like Venus in 100 years" types (oddly missing from here though). We are all biased and polarised, with skewed ways of looking at things (especially from others perspectives). Acknowledging these things in ourselves is as important when forming our own views as it is for fostering fair and useful discussions.

Below is the December CET, with the 10 year average in red and linear trend in black. The correlation between the November and December CET is 0.25, the third lowest of all consecutive monthly pairs. With both detrended, the correlation falls to 0.22, which is still statistically significant and suggests there is a weak positive relationship between Novembers CET and the following December. November looks like finishing between 6.0 and 6.6C, so the mean of all Decembers following Novembers in that range, is 4.2C. A CET of 1.6C or lower is required to drop the 10 year mean below 4.0C for the first time since 1970. Our current run with the 10 year mean above 4C (42 years) is the second longest on record, the longest being 67 years, from 1900 to 1966. Our current run without a December CET higher than 6.5C (24 years) is the 3rd longest on the CET record, after 1869 to 1897 (29 years) and 1734 to 1794 (61 years).

Min today of -1.1C (lowest of the Autumn so far) and maxima reaching the mid 5s (mean around 2.2C), we should see a drop to 6.7 or 6.8C on tomorrows update. After that, the 06z GFS op run has the CET at 6.6C to the 24th (4.1) 6.5C to the 25th (2.6) 6.4C to the 26th (3.0) 6.3C to the 27th (4.9) 6.3C to the 28th (6.9) 6.3C to the 29th (7.1) 6.4C to the 30th (7.0) Odds now in favour of finishing below the 61-90 average. Surprisingly, we're still yet to record a single significantly cold day this month (more than 1 standard deviation below normal). Today does look like the best chance to achieve this, but would require maxima reaching no higher than the low 5s.

4.0C, thanks

Apologies for the delay... Update for the week to November 16th The current 1 day extent is 9,779,690km2, while the 5 day mean is on 9,672,180km2 The daily anomaly (compared to 79-11) is at -949,470km2, an increase from -915,140km2 last week. The anomaly compared to the 07, 11 and 12 average has decreased from +200,693km2 to +145,013km2 this week. We're currently 5th lowest on record, the same as last week. The average daily increase over the last 7 days was +65.0k/day, compared to the long term average of +69.3k/day, and the average of the last 5 years of +78.5k/day. The average long term increase over the next week is +63.6k/day, with the average of the last 5 years being +77.1k/day. The increase so far this November is the 5th smallest on record. To record the largest November gain in total, an average daily increase of 144.4k/day is required for the next 14 days. To record the smallest November gain, an daily average of 30.5k/day is required

I posted this in a few other threads just now, so here's the (slightly modified) Irish version! Here's my winter 2013/2014 forecast. For this forecast, I looked at 10 different teleconnections for their trends and averages in the last 6 to 9 months (and forecasts for MEI), and then compared those criteria with previous years, mostly back to 1951, and created a list of the years with the most similar teleconnections to this year. Below are the 10 teleconnections and the criteria used with them. Teleconnections ...................... ................... Criteria Arctic Oscillation (AO): Mean of the last 6 months (May to October) close to 0, and little month to month variation. North Atlantic Oscillation (NAO): Mean of the last 9 months (February to October) close to 0, and a moderate to large amount of month to month variation. Multivariate ENSO Index (MEI): Winters averaging between -0.5 and +0.5 for the October to February period. Eurasian Snow Cover: Years that show an above average increase from September to October Eurasian snow extent. Quasi Biennial Oscillation (QBO): Positive in Autumn and falling through Winter. Solar Activity: An 11 year monthly sunspot mean of below 70 Atlantic Multidecadal Oscillation (AMO): Mean above average over the last 9 months. Pacific Decadal Oscillation (PDO): Mean moderately below average over the last 9 months Arctic Sea Ice: A September sea ice area minimum of less than 4 million km2 Globally Averaged Angular Momentum (GLAAM): Mean of the last 9 months close to 0, with moderate month to month variation. After going through the data, these were the most closely matched years Year ... Criteria Matches out of 10 2010/11 = 7* 2009/10 = 6 2006/07 = 6 2004/05 = 7 2003/04 = 6 2002/03 = 6 1985/86 = 6 1978/79 = 6 1976/77 = 6 1973/74 = 6 So using this, each of the years with 6 matches would get 1 place in the composite maps, and 7 matches would get 2. *An exception here is 2010/11, which had a moderate El Nino, so that will only be included once. So based on the above, here's the winter forecast. --------------------- ------------------------------------- ------------------------------ ------------------------------------ ----------------------- DECEMBER A strong Atlantic ridge stretching into southern Greenland, coupled with low heights stretching from Scandinavia to the Iberian Peninsula, look to be the main features for December. An increase in northerly orientated winds could be expected with this set up, but, if the trough moves much further west, the is a chance of some milder southerly winds occurring, sourced from the western Mediterranean. Precipitation is likely to be close to average in general, but with a slightly higher chance of below rather than above average monthly totals. Temperatures are more likely to be below average, perhaps 0.5-1.0C below the 81-10 mean. JANUARY Northern blocking, a west based -ve NAO and a large trough across central Europe are the main features for January. Northerly and northeasterly winds are likely to be more common during the month. Precipitation is likely to be below average again, especially in the west. Temperatures are likely to be below average once more, with the coldest conditions further east. Temperatures around 0.7 to 1.5C below the 81-10 mean. FEBRUARY While confidence is lower this far out, February looks like featuring some very strong northern blocking, centred toward Greenland, with low heights across our south and into Europe. The set up should produce much more easterly winds than normal, maintaining the cold theme and enhancing the snow risk for eastern counties. Precipitation is likely to be close to or above average in the south and east, and below average further north and west Temperatures are likely to be below average everywhere, around 0.8C to 1.8C below the 81-10 average. OVERALL Strong heights over southern Greenland should be a recurring feature of the first 2 months of winter, bring plenty of northerly airflows, before more general blocking takes hold, carrying more easterly winds during February. With low heights nearby and plenty of cold sourced airflows, each month has the potential for spells of cold and snow. So while precip looks like being below average overall, snowfall totals may well end up above average. The coming winter seems quite likely to be below average temperature-wise, with a good chance of all 3 winter months being below the 81-10 average. If I was to guess at a period with the highest risk of severe cold, I'd say late January and early February, as northern blocking strengthens eastward and brings a more easterly flow across the country

I just posted this in the seasonal forecast thread, I thought some here might appreciate it. Here's my winter 2013/2014 forecast. For this forecast, I looked at 10 different teleconnections for their trends and averages in the last 6 to 9 months (and forecasts for MEI), and then compared those criteria with previous years, mostly back to 1951, and created a list of the years with the most similar teleconnections to this year. Below are the 10 teleconnections and the criteria used with them. Teleconnections ...................... ................... Criteria Arctic Oscillation (AO): Mean of the last 6 months (May to October) close to 0, and little month to month variation. North Atlantic Oscillation (NAO): Mean of the last 9 months (February to October) close to 0, and a moderate to large amount of month to month variation. Multivariate ENSO Index (MEI): Winters averaging between -0.5 and +0.5 for the October to February period. Eurasian Snow Cover: Years that show an above average increase from September to October Eurasian snow extent. Quasi Biennial Oscillation (QBO): Positive in Autumn and falling through Winter. Solar Activity: An 11 year monthly sunspot mean of below 70 Atlantic Multidecadal Oscillation (AMO): Mean above average over the last 9 months. Pacific Decadal Oscillation (PDO): Mean moderately below average over the last 9 months Arctic Sea Ice: A September sea ice area minimum of less than 4 million km2 Globally Averaged Angular Momentum (GLAAM): Mean of the last 9 months close to 0, with moderate month to month variation. After going through the data, these were the most closely matched years Year ... Criteria Matches out of 10 2010/11 = 7* 2009/10 = 6 2006/07 = 6 2004/05 = 7 2003/04 = 6 2002/03 = 6 1985/86 = 6 1978/79 = 6 1976/77 = 6 1973/74 = 6 So using this, each of the years with 6 matches would get 1 place in the composite maps, and 7 matches would get 2. *An exception here is 2010/11, which had a moderate El Nino, so that will only be included once. So based on the above, here's the winter forecast. --------------------- ------------------------------------- ------------------------------ ------------------------------------ ----------------------- DECEMBER A strong Atlantic ridge stretching into southern Greenland, coupled with low heights stretching from Scandinavia to the Iberian Peninsula, look to be the main features for December. An increase in northerly orientated winds could be expected with this set up, but, if the trough moves much further west, the is a chance of some milder southerly winds occurring, sourced from the western Mediterranean. Precip is likely to be close to average, with a slightly higher chance of above rather than below average monthly totals. Temperatures are more likely to be below average, with a CET estimate of close to 4C JANUARY Northern blocking, a west based -ve NAO and a large trough across central Europe are the main features for January. Northerly and northeasterly winds are likely to be more common during the month. Rainfall is likely to be average or slightly above, with the driest weather to the south and west. Temperatures are likely to be below average once again, with the coldest conditions further east. The CET estimate is 3.0C. FEBRUARY At this stage, February looks like featuring some very strong northern blocking, centred toward Greenland, with low heights across our south and into Europe. The set should produce much more easterly winds than normal. Precip is likely to be close to or above average in the south and east, and below average further north and west Temperatures are likely to be below average everywhere, with a CET estimate of 2.8C OVERALL Strong heights over southern Greenland should be a recurring feature of the first 2 months of winter, bring plenty of northerly airflows, before more general blocking takes hold, carrying more easterly winds during February. With low heights nearby and plenty of cold sourced airflows, each month has the potential for spells of cold and snow. While precip looks like being near average overall, snowfall totals may well end up above average. The coming winter seems quite likely to be below average temperature-wise, with a good chance of all 3 winter months being below the 81-10 average. If I was to guess at a period with the highest risk of severe cold, I'd say late January and early February, as northern blocking strengthens eastward and brings a more easterly flow across the British Isles

Here's my winter 2013/2014 forecast. For this forecast, I looked at 10 different teleconnections for their trends and averages in the last 6 to 9 months (and forecasts for MEI), and then compared those criteria with previous years, mostly back to 1951, and created a list of the years with the most similar teleconnections to this year. Below are the 10 teleconnections and the criteria used with them. Teleconnections ...................... ................... Criteria Arctic Oscillation (AO): Mean of the last 6 months (May to October) close to 0, and little month to month variation. North Atlantic Oscillation (NAO): Mean of the last 9 months (February to October) close to 0, and a moderate to large amount of month to month variation. Multivariate ENSO Index (MEI): Winters averaging between -0.5 and +0.5 for the October to February period. Eurasian Snow Cover: Years that show an above average increase from September to October Eurasian snow extent. Quasi Biennial Oscillation (QBO): Positive in Autumn and falling through Winter. Solar Activity: An 11 year monthly sunspot mean of below 70 Atlantic Multidecadal Oscillation (AMO): Mean above average over the last 9 months. Pacific Decadal Oscillation (PDO): Mean moderately below average over the last 9 months Arctic Sea Ice: A September sea ice area minimum of less than 4 million km2 Globally Averaged Angular Momentum (GLAAM): Mean of the last 9 months close to 0, with moderate month to month variation. After going through the data, these were the most closely matched years Year ... Criteria Matches out of 10 2010/11 = 7* 2009/10 = 6 2006/07 = 6 2004/05 = 7 2003/04 = 6 2002/03 = 6 1985/86 = 6 1978/79 = 6 1976/77 = 6 1973/74 = 6 So using this, each of the years with 6 matches would get 1 place in the composite maps, and 7 matches would get 2. *An exception here is 2010/11, which had a moderate El Nino, so that will only be included once. So based on the above, here's the winter forecast. --------------------- ------------------------------------- ------------------------------ ------------------------------------ ----------------------- DECEMBER A strong Atlantic ridge stretching into southern Greenland, coupled with low heights stretching from Scandinavia to the Iberian Peninsula, look to be the main features for December. An increase in northerly orientated winds could be expected with this set up, but, if the trough moves much further west, the is a chance of some milder southerly winds occurring, sourced from the western Mediterranean. Precip is likely to be close to average, with a slightly higher chance of above rather than below average monthly totals. Temperatures are more likely to be below average, with a CET estimate of close to 4C JANUARY Northern blocking, a west based -ve NAO and a large trough across central Europe are the main features for January. Northerly and northeasterly winds are likely to be more common during the month. Rainfall is likely to be average or slightly above, with the driest weather to the south and west. Temperatures are likely to be below average once again, with the coldest conditions further east. The CET estimate is 3.0C. FEBRUARY At this stage, February looks like featuring some very strong northern blocking, centred toward Greenland, with low heights across our south and into Europe. The set should produce much more easterly winds than normal. Precip is likely to be close to or above average in the south and east, and below average further north and west Temperatures are likely to be below average everywhere, with a CET estimate of 2.8C OVERALL Strong heights over southern Greenland should be a recurring feature of the first 2 months of winter, bring plenty of northerly airflows, before more general blocking takes hold, carrying more easterly winds during February. With low heights nearby and plenty of cold sourced airflows, each month has the potential for spells of cold and snow. While precip looks like being near average overall, snowfall totals may well end up above average. The coming winter seems quite likely to be below average temperature-wise, with a good chance of all 3 winter months being below the 81-10 average. If I was to guess at a period with the highest risk of severe cold, I'd say late January and early February, as northern blocking strengthens eastward and brings a more easterly flow across the British Isles

http://www.pnas.org/content/early/2013/11/13/1313775110

Just 0.8C the minimum here. Plenty of frost about this morning anyway, and beautiful clear skies. Yesterday's max of 5.6C was the lowest of Autumn/Winter so far.

Considering that the seas are still quite mild, and this northerly air stream will bring about quite marginal conditions for snow, I'd say many coastal area may well end up with sleety rain, with showers turning more to snow further inland, especially at night. Of course, every little bit of elevation will count in these situations. This will very much be a nowcasting situation, plenty of radar, local conditions and lamp post watching ahead! The models at this stage will cause more confusion than anything.

For mid-November, I'll certainly take this! Followed by cold, settled and possibly foggy conditions.... sounds good to me!

We're all sceptics SI, some are purely AGW sceptics, others have a more general sceptical approach to things. Whatever the case, you'll find nobody that thinks climate scientists have all the answers, that kind of broad and false generalisation isn't befitting of a sceptical inquirer!

You're right, I need to label my rows better!

Agree with dropping back to 7.5C tomorrow. After that, the 06z GFS op run has the CET at 7.5C to the 16th (7.6) 7.5C to the 17th (7.1) 7.4C to the 18th (6.8] 7.2C to the 19th (3.1) 6.9C to the 20th (0.5) 6.7C to the 21st (2.4) 6.5C to the 22nd (4.0) Could have the first day more than 1 standard deviation below the daily mean since September soon. Despite a significant cold spell coming up, no record low daily mean temps look under threat. Would probably need a good covering of snow first.

The biggest October to November CET drop, 8.5C, occurred in 1807, with a drop from 11.4C to 2.9C. To make the top 10 largest drops, a November CET of 5.4C or lower is required (6.1C or lower for the top 20).

All works fine for me Phil. Cheers for all the work!

I can agree that we may be entering a more LIA-like period (greater variability in our weather), but our climate will continue be quite different to the 1600s, with the global climate even more different. There was more going on in the LIA than just a lack of sunspots too.

EDIT: Deleted

Don't appear to have permission for the PDF either? EDIT: decided pm was better for the question.

I've incorporated MEI and GLAAM into the latest composites for my winter forecast. Just waiting on the October PDO data to be released, and a little analysis on the snow cover, and the forecast will be ready. The signal for northern blocking does appear to have increased significantly since last month.

Sounds good to me! What can we prove with regard the potential LIA if we use 1999 as our starting point?

Slightly delayed update... Below is the latest CFS 12z blocking trends for December The 10 day average remain close to 1, or weak +ve SLP anomalies to our north, with the downward trend remaining quite strong. The last 7 days have averaged 1.7 (moderate blocking), with 1 run having -ve SLP anomalies to our north, and 6 with +ve (previous week averaged 1.3, with 1 -ve, 2 neutral and 4 +ve runs) Below is the latest January graph The 10 day mean was close to 2 for most of the time, but dropped close to 1 over the last 2 days. The trend remains close to neutral though. The last week has averaged 1.1, with 2 -ve runs and 5 +ve (previous week averaged 2.0, with 6 +ve and 1 neutral run). Some highlights from the last week Best January 2014 from November 6th Worst March 2014 from November 10th

Who's been slapping linear trends on the hockey stick graph? My thinking is that the linear trend for the 20th/21st century is simply a help see pass the noise. Perhaps some kind of rolling average would be more suitable?