March CET

[Rollo]

Hi Mr Data,

yes have just been looking at the this Table, although March began cold in 63, it warmed up quite a bit later. I think at this rate and with the current model projections there is a possibility we could see one of the lowest CET's for March this century.

Paul

Actually Paul after the winter of 63' March seemed almost like summer-this year is much much colder,it would be interesting to see the comments should it turn out to be the coldest for a long time.

[Polar Continental]

Actually Paul after the winter of 63' March seemed almost like summer-this year is much much colder,it would be interesting to see the comments should it turn out to be the coldest for a long time.

Hi Rollo,

I was only 10 in 1963, I can remember the winter very well, but not the warm-up afterwards, but with a CET of 6c compared to February 63 which gave –0.7c no wonder it felt like summer, even though it was still a little below the average.

Yes if this March produces a CET under 3c, which is quite possible given the current model projections, there is really going to be some head-scratching going on.

Paul

[Guest Mike W]

I though you might have been referring to March 1962, which was cold at 2.8.

[drfeelgood]

I would presume Hadley. I think Philip would know the answer to that.

In my opinion I don't think they were that accurate. They used generally inaccurate thermometers and apparently they may had been recorded inside houses (obviously people never had Central heating then) I can't say I trust any of the figures before the 1920's roughly as I bet they were fiddled about with and rounded up to the neared decimal place or the Thermometer placed to close to snow cover when it snowed and consequently lowed the readings due to the snow emitting a radiation of cold surface air.

I would say my readings are an awful lot more accurate then them of the olden days but that's my opinion.

I'm wondering when Stevenson screens were first invented and widely used because I know that pre-19th century thermometers were often not screened at all. This had the effect of overestimating maxima and undersestimating minima. And as you were saying, the distortion was often enhanced when there was a lot of snow on the ground. Apparently, some thermometers were simply placed on fences!

My question is if pre-19th century data was so unreliable, doesn't this raise the question of whether the "Little Ice Age" was exaggerated by these distorted readings. There were quite a lot of readings below -20C even in Southern England in the 17th and 18th centuries. If we now say that these are unreliable, then what grounds do we have for saying there was really such a thing as the LIA? Apart from the Thames freezing...etc?

[Snowly does it]

I'm wondering when Stevenson screens were first invented and widely used because I know that pre-19th century thermometers were often not screened at all. This had the effect of overestimating maxima and undersestimating minima. And as you were saying, the distortion was often enhanced when there was a lot of snow on the ground. Apparently, some thermometers were simply placed on fences!

My question is if pre-19th century data was so unreliable, doesn't this raise the question of whether the "Little Ice Age" was exaggerated by these distorted readings. There were quite a lot of readings below -20C even in Southern England in the 17th and 18th centuries. If we now say that these are unreliable, then what grounds do we have for saying there was really such a thing as the LIA? Apart from the Thames freezing...etc?

Historical contemporary accounts are the best guide, and the Thames freezing really is all the evidence needed surely? It may well be an exaggerated figure system, but the contemporary accounts from tis period and say the earlier medieval period (patchy at best) certainly suggest a colder period during what we now call the Little Ice Age. In addition to this there is plenty of evidence from nature, trees etc which show the colder conditions prevalent. Its just hard to be certain of 100% accuracy in the figures. Having said that, scientists and proto-meteorologists were no fools and nothing really suggests that the further back you go the slacker the data gathering.

[reef]

Historical contemporary accounts are the best guide, and the Thames freezing really is all the evidence needed surely? It may well be an exaggerated figure system, but the contemporary accounts from tis period and say the earlier medieval period (patchy at best) certainly suggest a colder period during what we now call the Little Ice Age. In addition to this there is plenty of evidence from nature, trees etc which show the colder conditions prevalent. Its just hard to be certain of 100% accuracy in the figures. Having said that, scientists and proto-meteorologists were no fools and nothing really suggests that the further back you go the slacker the data gathering.

Even the Thames freezing in London is not a good guide, as differences in bridge design back then meant that it was much more prone to freezing than it is now. I doubt the Thames would completely freeze over even if the climatic conditions and temperatures matched the coldest winters back in the little ice-age, waterflow is just too great now.

[Guest Mike W]

1895 would have seen a frost fair, but because of the 'new' bridge, it instead resulted in ice floes, block of ice floating around. also 1963 winter would have had conditions for a frost fair, but a better bridge meant that the water flowed fast enough not to freeze, I think thats the way of it anyway, others will the the how it goes.

Edited March 14, 2006 by Mike W

[Scorcher]

Temperatures today are actually not cold at all in a lot of places. It's currently 8C in Manchester which is around average for the time of year and with temperatures set to stay comfortably above freezing tonight I'd expect to see a rise in the CET.

[reef]

Temperatures today are actually not cold at all in a lot of places. It's currently 8C in Manchester which is around average for the time of year and with temperatures set to stay comfortably above freezing tonight I'd expect to see a rise in the CET.

Its only 2.8°C here, quite a temperature gradient for only 90 miles!

It certainly looks like my CET estimate was miles off the mark. This could be quite an interesting year, maybe it will end the torture of year after year of 10.xx annual CETs.

[Snowly does it]

Temperatures today are actually not cold at all in a lot of places. It's currently 8C in Manchester which is around average for the time of year and with temperatures set to stay comfortably above freezing tonight I'd expect to see a rise in the CET.

yeah, a minmal one though, todays CET may come in around the 5 - 5.5 mark, will make little in the way of difference to the average so far, a small rise.

[kold weather]

Yeah a small rise upto 2.7C is likely today (I actually got 2.74c) this is all down to max tyemps being fairly close to average, though the mins were actually fairly low inland typically between 0-2c.

Beyond that and I can't see it getting above 2.8c for at least 7 days, with Thursday at the moment looking like having a daily CET close to 0c with some low mins for the time of year:

http://www.wetterzentrale.de/pics/Rmgfs424.gif

An average CET is still reachable at the moment but I think this cold spell thats upcoming will put the final nail in that idea even if the last 4-5 days are much milder.

[Stratos Ferric]

Even the Thames freezing in London is not a good guide, as differences in bridge design back then meant that it was much more prone to freezing than it is now. I doubt the Thames would completely freeze over even if the climatic conditions and temperatures matched the coldest winters back in the little ice-age, waterflow is just too great now.

...indeed, that and increasing quantities of warm effluent, combined with a much greater UHI effect. As SM suggests, contemporary corroboration (formal and informal e.g. Dickensian and Hardy's accounts of winters) supports the overall outcomes, the variation will be in the margins of preicse numbers.

[Snowly does it]

...indeed, that and increasing quantities of warm effluent, combined with a much greater UHI effect. As SM suggests, contemporary corroboration (formal and informal e.g. Dickensian and Hardy's accounts of winters) supports the overall outcomes, the variation will be in the margins of preicse numbers.

Although having reconsidered somewhat, the lack of transport network at this time would have exacerbated the impression of white out, with little 'traffic', even a small amount of lying snow would have caused havoc in cross-country travel. Certainly though the pictures painted by messrs Dickens, Hardy et al are not the paintings of todays winter.

[acbrixton]

...indeed, that and increasing quantities of warm effluent, combined with a much greater UHI effect. As SM suggests, contemporary corroboration (formal and informal e.g. Dickensian and Hardy's accounts of winters) supports the overall outcomes, the variation will be in the margins of preicse numbers.

I suspect that even more important than bridge design was the embanking of the Thames in central London in the second quarter of the 19c (and later). The paintings of the 18c (Canaletto?) suggest a "lazier" more sluggish flow arising from the higher friction from irregular banks and an irregular/wider river bed adjacent to the banks.

Regards

ACB

[kold weather]

What makes this march even more stunning is if you look at the even larger teapot March CET has a average of 7.1c!!!

Compare that to the 71-00 average of 6.3c and the increase is clear to see, nearly 1c!!!

So if you use the even larger teapot base then we are amazingly below average at the moment, by 4.5c infact!

Looking at the models, they are still giving me the impression of about 4.5c as the eventual outcome, allowing for the last 5-7 days to be much milder while taking into account the next 7-10 days are likely to be cold-very cold for the time of year, infact I can't see us getting above 3c till about the 25th and even that might be a push.

[Thundersquall]

"The current N-W UK tracker figure for March 2006 is: 2.97°C

(difference from average March CET is -3.33°C)"

http://www.net-weather.co.uk/index.cgi?action=cet;sess=

Edited March 14, 2006 by Thundersquall

[kold weather]

Well the cet has gone up slightly as was expected to 2.7c, and will probably go up to 2.8c today considering maxes going to probably get upto 7-8c fairly widespread today.

Beyond that and I can see the CET fall again slightly as we pick up a fairly cold easterly for the time of year over the next two days.

It's really madness though to think we are half-way through the month now and we've still got a CET thats sub-3c!!!!

In March, heck even in winter nowdays, that wouldn't be a bad CET to have but in March, thats quite stunning.

Models stil lforecasting a milder last 5 days to the month, but even this has a fair amount of uncertainty to it and is far from certain.

[Weather-history]

Here's the daily CET mean that is needed in bold to get to predicted values

Button 04 - 7.7 11.8

Westerly Gales - 7.7 11.8

Catchmydrift - 7.6 11.6

Reef - 7.3 11.1

Stephen Prudence - 7.1 10.7

Mike W - 7.0 10.5

PersianPaladin - 7.0 10.5

Bottesford - 6.7 10.0

Magpie - 6.7 10.0

Peter Tattum - 6.7 10.0

Dave J - 6.6 9.8

ThunderyWintryShowers - 6.6 9.8

Fordy - 6.5 9.6

Great Plum - 6.5 9.6

Roger J Smith - 6.5 9.6

Joneseye - 6.4 9.4

Kold Weather - 6.3 9.3

Mark - 6.3 9.3

Snow-Man2006 - 6.3 9.3

The Pit - 6.3 9.3

Evo - 6.2 9.1

Noggin - 6.2 9.1

Rikki - 6.1 8.9

SteveB - 6.1 8.9

Anti-Mild - 6.0 8.7

SnowmanReturns - 5.9 8.5

Stratos Ferric - 5.8 8.4

Paul Carfoot - 5.5 7.8

Thundersquall - 5.5 7.8

Optimus Prime - 5.1 7.1

Shuggee - 4.9 6.7

Snowmaiden - 4.8 6.5

Summer Blizzard - 4.8 6.5

Helly Hanson - 4.6 6.2

Snooz - 4.3 5.6

Tinybill - 4.0 5.1

Drfeelgood - 3.8 4.7

Nick Sussex -2.0 1.4

[Shiny_Bottom_1]

Thanks Mr D.

It wouldnt surprise me if the CET ends up between Drfeelgood and Nick Sussex...the largest gap that wasnt used for an estimate.

[Weather-history]

For Spring 2006 to reach a CET of 9C, the rest of Spring has to have a daily average of 10.1C

Spring 1945 had a CET of 10.1 and that was the second warmest Spring on record.

Edited March 15, 2006 by Mr_Data

[Westerly Gales]

I'm a wee alarmed by the Net Weather home page since yesterday. Of all the calendrical months March is the one with the greatest potential contrast. Not even October can compare. This is a scientific fact & can be seen more prosaically by the 3 seasons-in-1 month that March can throw (not autumn!).

This has been a brilliant cold start for you coldies (hell for the rest of us!). Thing is that many people will miss the "if the current synoptics stay like this" and rush off to the "coldest March in decades" on the home page. Given what March can produce from cold to hot it is just way too early to start pitching those sorts of ramps.

The first benchmark is the 4.5C of March 1996. That's the one to beat really. Cos it only takes 5 warm days in March to raise the overall by 1C. Looking at the midnight runs we should end up somewhere around 4.7C at this present stage. Thing is it could go anywhich way from here: below 4C is definitely possible, but so is above 5C.

[Optimus Prime]

I agree Westerly Gales to a degree but the cold spell forecast for this week and the potential for a real plunge of cold air from the North/North east it would easily send the CET below 3c by the 26th which is when it's expected to get warmer. In fact there is a chance that I could be below 2c by the 27th. At that stage it would take a real heat wave to get it above 4.0c. A rise of 2c in 4 days is literally unheard off.

It's felt very warm today despite temperatures around 8c which is still 2c below normal. temperatures tonight will get as low as -2c. 8 plus -2 divided by 2 equals 3.0c. So actually the 24 hour mean is still below the reading by the net-weather tracker of 3.05 so it's likely to drop to 3.02 by tomorrow morning.

Minima potentially as low as -4 during the northerly spell and maxima of 5c. That averages just 0.5c! Watch that CET drop like a stone once we get real cold nights.

And heat waves rarely occur in March. 25c+ is considered hot and I don't think that's ever been recorded at this time of the year. 20c doesn't happen that often.

I expect the Minima to be around 4c below average by the end of the month

I expect Maxima to be around 2c below average.

So IMO either 2.8c or 3.3c looks favourable as the final CET.

[boro_dave]

Here's the daily CET mean that is needed in bold to get to predicted values

Button 04 - 7.7 11.8

Westerly Gales - 7.7 11.8

Catchmydrift - 7.6 11.6

Reef - 7.3 11.1

Stephen Prudence - 7.1 10.7

Mike W - 7.0 10.5

PersianPaladin - 7.0 10.5

Bottesford - 6.7 10.0

Magpie - 6.7 10.0

Peter Tattum - 6.7 10.0

Dave J - 6.6 9.8

ThunderyWintryShowers - 6.6 9.8

Fordy - 6.5 9.6

Great Plum - 6.5 9.6

Roger J Smith - 6.5 9.6

Joneseye - 6.4 9.4

Kold Weather - 6.3 9.3

Mark - 6.3 9.3

Snow-Man2006 - 6.3 9.3

The Pit - 6.3 9.3

Evo - 6.2 9.1

Noggin - 6.2 9.1

Rikki - 6.1 8.9

SteveB - 6.1 8.9

Anti-Mild - 6.0 8.7

SnowmanReturns - 5.9 8.5

Stratos Ferric - 5.8 8.4

Paul Carfoot - 5.5 7.8

Thundersquall - 5.5 7.8

Optimus Prime - 5.1 7.1

Shuggee - 4.9 6.7

Snowmaiden - 4.8 6.5

Summer Blizzard - 4.8 6.5

Helly Hanson - 4.6 6.2

Snooz - 4.3 5.6

Tinybill - 4.0 5.1

Drfeelgood - 3.8 4.7

Nick Sussex -2.0 1.4

I see that nobody had the balls to predict a CET of below 0 :wacko:

:blush:

[Weather-history]

Cos it only takes 5 warm days in March to raise the overall by 1C.

Its not as simple as that for instance say the CET is 5C by the 25th, to get it to 6C by the 30th the next 5 days would need to average 11C

However if it was 5C by the 15th, to get to 6C by the 20th the next 5 days would need to average only 9C

So the later a warm spell is in the month, the less impact it will have or to raise the CET by 1C, the later in the month it is the greater the intensity of the warm spell has to be. :lol:

Edited March 15, 2006 by Mr_Data

[summer blizzard]

Having just looked at the GFS6z ensembles, they would give a CET of around 4.5C from now until the end of the month, so as the CET is currently 2.7C, which is 3.6C below average, the final CET according to the GFS6z, would be around 3.7C, which is 2.6C below average.