The Enforcer

I've been busy analysing the SST situation from 1998-2005 for the first week of November. For 1999 I've had to look at a chart from the second week as there is no first week chart archived for that year. I've created a table which shows the relative distances of the limit of the coldest actual SSTs from the UK each year. As the SST maps have no scale, I was unable to use miles or kilometres which would have been the ideal, so instead I've created an arbitary numbering system, which I won't go into, but nonetheless enables easy comparison. the 'best' years are highlighted red. The second point I ought to mention is that I've assigned SST values to colours based on how I interpret the sliding key at the bottom, which appears to show round numbers as lying between two colours. I've assigned a round number to a colour. If I'm out by a degree or so I don't think it matters as any correction would be to the same amount for every year analysed, so the relative differences should remain the same. Anyway here's the table:SST_table_Nov_1.doc The conclusion is that the current SST situation is comparable to the same time of year in 1998 (Closer than 2002, which I have been previously using as a comparison until I discovered the Nov 1998 data this evening). However, 1998/1999 ended up with the highest winter CET of all of the winters featured. This may be because the cold anomalies took a real battering during November (just like 2002): http://weather.unisys.com/archive/sst/sst_anom-981101.gif http://weather.unisys.com/archive/sst/sst_anom-981108.gif http://weather.unisys.com/archive/sst/sst_anom-981122.gif http://weather.unisys.com/archive/sst/sst_anom-981129.gif http://weather.unisys.com/archive/sst/sst_anom-981206.gif Conversely, even though early Nov 2000 doesn't look too promising, winter 2000/2001 had the lowest CET of the data set, maybe because by December 2000, the SST situation had not altered significantly and by that stage was far preferable to 1998/1999: http://weather.unisys.com/archive/sst/sst_anom-001105.gif http://weather.unisys.com/archive/sst/sst_anom-001203.gif I'm going to produce an update to this table in a week's time to see whether 2005 can clearly stand out from the other years.

Time for an SST anomaly progress update over the last month or so: http://weather.unisys.com/archive/sst/sst_anom-051002.gif http://weather.unisys.com/archive/sst/sst_anom-051009.gif http://weather.unisys.com/archive/sst/sst_anom-051016.gif http://weather.unisys.com/archive/sst/sst_anom-051023.gif http://weather.unisys.com/archive/sst/sst_anom-051030.gif http://weather.unisys.com/archive/sst/sst_anom-051106.gif In summary, the cold anomalies are not just holding on to the north and north west of the UK, but have now linked up with the other cold anomaly to the west of Greenland. In addition, the rate of cooling has increased across the North Atlantic, so thatthere are fewer areas of high positive SST anomalies. It is now got to the point where it is worth looking at the SST position with respect to the start of previous Decembers: http://weather.unisys.com/archive/sst/sst_anom-981206.gif http://weather.unisys.com/archive/sst/sst_anom-991205.gif http://weather.unisys.com/archive/sst/sst_anom-001203.gif http://weather.unisys.com/archive/sst/sst_anom-011202.gif http://weather.unisys.com/archive/sst/sst_anom-021201.gif http://weather.unisys.com/archive/sst/sst_anom-031207.gif http://weather.unisys.com/archive/sst/sst_anom-041205.gif The last time there were any sort of reasonable cold anomalies at the beginning of winter (and therefore one could argue that the sea was genuinely cold) was back in Dec 2000. The cold anomalies were not as widespread as they are now, but this may well have had some impact on making that winter 00/01 the coldest of the winters which the dataset covers. Some of the other years have a certain degree of cold anomalies present, but there are also some warm anomalies alongside them in the Iceland area, which leads me to believe it is total absence of any positive areas at that lattitude that is the key factor. If the existing pattern can at least hold in its current form, we should at least be able to see whether cold seas in those areas have any effect on the pattern of mild winters. What happens over the next three weeks is therefore crucial. EDIT: Have just realised that the dataset includes 1998/1999 and 1999/2000 - all the files called 8 Nov 1999 in the archive are different dates and not duplications of 8 Nov 1999. :blink:

.... over Siberia? I presume you mean the UK? Unfortunately our friendly cold anomalies to the north-west are not doing anything to shift this persistant Bartlett-driven southerly flow.

Time to take a step back and look at the SST development for October so far: http://weather.unisys.com/archive/sst/sst_anom-051002.gif http://weather.unisys.com/archive/sst/sst_anom-051009.gif http://weather.unisys.com/archive/sst/sst_anom-051016.gif http://weather.unisys.com/archive/sst/sst_anom-051023.gif The potent cold anomalies are hanging on in there. Also, there is a general acceleration of cooling at northern lattitudes, so that more of the positive anomalies are closer to average now than at the start of the month. It's the next month that's going to be the acid test - here's what happened in 2002: http://weather.unisys.com/archive/sst/sst_anom-021027.gif http://weather.unisys.com/archive/sst/sst_anom-021124.gif .... nice - just in time for winter.

I wonder if it is the colder than average SSTs in the GIN area that are contributing to the expansion of the Greenland High that is forecast for the end of the week:

Time for a general progress update for GIN SSTs for October on a week by week basis: http://weather.unisys.com/archive/sst/sst_anom-051002.gif http://weather.unisys.com/archive/sst/sst_anom-051009.gif http://weather.unisys.com/archive/sst/sst_anom-051016.gif Negative anomalies generally holding position. Positive anomaly also growing between them. Also, trend towards average SSTs to the west of Greenland. The situation in Oct 2002, whilst similar, was a lot more fluid. EDIT: October 2002 not 2003.

OP, I take your point, hence the use of the word 'may'. It does seem to be exceptionally mild air though and the situation up there is rather precarious, with a positive anomaly lurking amongst the negative areas.

Yes you are right, but it's still significantly better than last year. How does it compare with the other winters of the 00's though? When was the last time a year was above the 1979-1990 average? Unfortunately, it looks like mild air heading that way via the UK until Wednesday, which may cause the anomaly to drop further, until the air source turns Arctic once more, until saturday, according to the latest UKMO.

This is an example of what I was harping on about in one of the other threads. If cold air is channeled in our direction, there is a risk that the mild air that we're currently getting would surge up over Greenland instead. This would slow down sea ice development and undermine the persistance of negative SST anomalies in that area, thus hindering the long-term prospects for Greenland High south-eastward expansion later in the winter (not ignoring importance of Polar Jet strength/PNA/PDO/NAO/AO etc).

That graph clearly shows a positive anomaly. Unlike SM to make a mistake (he suggested it was spot on average in another thread), unless he was referring to a alternative data set as the average.

There's a pattern in the Mid-Atlantic though. The positive anomalies form of the eastern coast of America, before spreading/drifting across, by the time they have diminished, a new set are forming, which can be seen at the end of that run.

I have picked out the 'troublemaker' as Dan Corbett would say on today's SST anomaly chart:

Hello Joy. The reason for this is that in previous Octobers, particularly 2002, negative anomalies of this ilk have been prevalent only to be replaced by positive anomalies on almost exactly the same spot within about a month. As far as I can tell, these changes have been brought about by the fairly swift conversion of -ve to +ve rather than a warm anomaly barging a cold anomaly out of the way. Here's the 2002 example: http://weather.unisys.com/archive/sst/sst_anom-020929.gif http://weather.unisys.com/archive/sst/sst_anom-021006.gif http://weather.unisys.com/archive/sst/sst_anom-021013.gif http://weather.unisys.com/archive/sst/sst_anom-021020.gif http://weather.unisys.com/archive/sst/sst_anom-021027.gif http://weather.unisys.com/archive/sst/sst_anom-021103.gif http://weather.unisys.com/archive/sst/sst_anom-021110.gif http://weather.unisys.com/archive/sst/sst_anom-021117.gif http://weather.unisys.com/archive/sst/sst_anom-021124.gif http://weather.unisys.com/archive/sst/sst_anom-021201.gif http://weather.unisys.com/archive/sst/sst_anom-021208.gif Even though the cold tries to fight back in November, it ultimately loses out big time. You will notice that the positive anomaly gains a grip from splitting the negative anomaly in two and this is what I believe is starting to happen now. I think other area you have highlighted may also be important, but recent winters have seen low pressure dominant over Iceland. Cold anomalies around there would tip the balance slightly more in favour of high pressure, in the form of an extension of the Greenland High south-eastwards. This would be a difficult block for any low pressures coming off the north-east American coast or developing around southern Greenland to break through. Instead, these systems would be diverted further south, which in turn lowers the boundary between cold and mild. A rather simplistic theory, I admit, but this is academic as it ain't gonna happen in practice.

It's more likely that the anomalies develop in situ rather than float around. The thing to watch is the bit of dark green between the dark blue core areas adjacent to Greenland and Iceland.

Anything to do with woozey Woozley?

I wonder how many people lived within easy walking distance of their workplace in 1946/7 and in 1962/3 relative to now?

Good man.

roger = someone you don't know Normally used in the context of causing a nuisance or getting in the way, thus: "I almost got knocked off my scooter this morning when roger didn't indicate at a roundabout"; or "I'm sorry I'm late for work, but roger was ahead of me in the queue at the petrol station and took over 10 minutes to pay for his petrol"; and "I can't put out the recycling, because roger has stolen our green bin" It is particularly useful in explaining a frustrating situation where the use of stronger language might lead to problems (parents/boss etc) and in connection with sites like this where, arguably, a more appropriate swear word would either get edited out or lead to a ban.

You probably get more in one november fall than i've seen cumulatively in 9 years.

This is dragging it further off topic, but what the hell. If the UK had a genuine big freeze this winter, it would really ram home the shortcomings of the selfish society we live in. Technology should enable us to cope better, but in reality it's reserved for the privelidged few, but we've been resting on our laurels for too long. The big freeze would expose: - the inadequacy of the public transport system; - the overstretched road network; - the inability of roger to adapt to the road conditions; - the lack of care for one's fellow human being; - the lack of financial support for the emergency services and healthcare; - the lack of forward planning by utility companies with privatisation allowing fatcats to swallow up all the profits that would previously have been available to the public purse/enable sufficient forward emergency planning; and - the unsustainable work-dominated lifestyles that many people are coerced into (epitomised by having to travel miles to get to the workplace) would grind to a halt.

Agreed. It's all relative. a -0.5C anomaly in an area that has been +5C for many years is a more significant development than a +4C anomaly in an area that is traditionally +3C.

But weren't there a lot of mild winters in the 1970's? The 1980's were colder on average?

Is anyone on here old enough to remember when they started putting them up? Surely there must have been outrage at the time?

The obvious answer is to have your own power/heating source. I'm surprised in this day and age that this country hasn't become more self-sufficient. I guess it's to do with Mr Fatcat keeping control over the population. As a side point, what a mess the national grid has made of the UK countryside. National Parks, AONBs, Green Belts - nowhere is sacred. They even invade residential areas. We could do with some of those ice storms they had in Canada a few years ago that destroyed their network. Hopefully they'll then put the grid underground and start setting up more sustainable forms of electricity supply.

All that means is where the average is 4.5C, this winter might be 4.4C.