PowerSwitch

http://www.channel4.com/programmes/is-o ... -worse/4od

Are the strange events of 2012 a one-off or an ominous sign of climate change in action? How does the changing global climate affect the British weather and what can we expect in the future? Is our weather getting worse?

Met Office - "Yes!"

Our weather has always been bad...now it's just bad in a different way. And more unreliable, which is definitely bad if you want to do something outrageous, like, grow some food

I feel a right twazzock having fallen for the "Mediterranean conditions" thing a few years back and rushed out and bought a lemon plant (RIP) and a grapevine (not very well at the moment).

Here's the forecast chart for saturday - note the pressure of 948mb around Iceland. That is seriously low!

Not quite a record - that's either 1986 or the 'Braer Storm' of 1993:

NORTHERN HEMISPHERE: There are apparently two contenders for the record lowest pressure established in the northern hemisphere. 1) Storm of January 10, 1993 deepened to a central pressure of 912-915 mb (26.93”-27.02”) between Iceland and Scotland near 62°N 15°W and, 2) Storm of December 15-16, 1986 deepened to at least 916 mb south-east of Greenland near 62°N 32°W. A ship in the vicinity actually made a measurement of 920.2 mb on December 15th while still some distance from the center of the storm. The British Meteorological Office assessed the central pressure of the storm at this time as being 916 mb (27.05”) but the West German meteorological service proposed a pressure possibly as low as 912-913 mb (see Stephen Burt article in Weather magazine Vol. 42 pp. 53-56, February 1987).

http://www.wunderground.com/blog/weathe ... 1&month=11

What might it mean, Biff? For Iceland and these islands?

I have borrowed 20 years'-worth of Met data from a family friend, and am (slowly) getting it onto a spreadsheet. He says he has noticed the present-day lack of those High pressures we used to have a while ago: I've noticed 1030 wasn't that uncommon (winter and summer alike) in the late 90s, for example.

I wonder if that means that pressures are getting lower, or perhaps they're varying less.

emordnilap wrote:What might it mean, Biff? For Iceland and these islands?

Windy in Iceland but they are used to it and are mostly indoors at this time of year.

More flooding in Britain, which can make staying indoors tricky.

RenewableCandy wrote: I wonder

Top dozen pressures:
1 mb = 100 Pa = 1 hPa = 33.864 inches.
Month Value Location Date
January 1053.6 hPa Aberdeen Observatory (Aberdeenshire) 31 January 1902
February 1052.9 hPa Aberdeen Observatory (Aberdeenshire) 1 February 1902
March 1047.9 hPa St Mary’s Airport (Isles of Scilly) 9 March 1953
April 1044.5 hPa Eskdalemuir (Dumfriesshire) 11 April 1938
May 1042.2 hPa Dublin Airport (Ireland) 16 May 1943
June 1043.1 hPa Clones (Co. Monaghan) 14 June 1959
July 1039.2 hPa Aboyne (Aberdeenshire) 16 July 1996
August 1037.4 hPa Kirkwall (Orkney) 25 August 1968
September 1042.0 hPa Ballykelly (Co. Londonderry) 11 September 2009
October 1045.6 hPa Dyce (Aberdeenshire) 31 October 1956
November 1046.7 hPa Aviemore (Inverness-shire) 10 November 1999
December 1051.9 hPa Wick (Caithness) 24 December 1926
Table 35. Highest recorded atmospheric pressure values across the British Isles.

http://www.metoffice.gov.uk/media/pdf/c ... _No._9.pdf

If a handful of percentage points is 'seriously low', then a question: at what level - high or low - is atmospheric pressure a danger to human health? I don't mean weather-wise, I mean health-wise, bodily integrity-wise.

emordnilap wrote:If a handful of percentage points is 'seriously low', then a question: at what level - high or low - is atmospheric pressure a danger to human health? I don't mean weather-wise, I mean health-wise, bodily integrity-wise.

From what I have just read, I think 360 mb may be the point at which the human body can no longer acclimatize to the atmospheric pressure conditions and where, if any significant time is spent under such conditions, permanent damage to the body will be incurred.

It equates to 26,000 feet above sea level. Climbers call it the "death zone".

http://meteorologytraining.tpub.com/142 ... 269_75.htm

stevecook172001 wrote:

emordnilap wrote:If a handful of percentage points is 'seriously low', then a question: at what level - high or low - is atmospheric pressure a danger to human health? I don't mean weather-wise, I mean health-wise, bodily integrity-wise.

360 mb is the point at which the human body can no longer acclimatize to the atmospheric pressure conditions and where, if any significant time is spent under such conditions, permanent damage to the body will be incurred.

It equates to 26,000 feet above sea level. Climbers call it the "death zone".

http://meteorologytraining.tpub.com/142 ... 269_75.htm

Ah, I get it now; didn't think that one through but it's pretty obvious put in those terms. What about the other way, high pressure?

Prof Palmer explains: "I think it is a bit unwise, and possibly even a bit dangerous, to think that the climate of the UK will just gradually warm and we'll transition to a more balmy southern European climate.

"If the ideas about a more fluctuating jet stream are correct, then in fact what we will be seeing is a climate with many more extremes: both extremes of wetness and flooding on the one hand, and extremes and dryness and possibly even coldness on the other."

More here.

emordnilap wrote:What about the other way, high pressure?

The all time record high was in Canada at about 1080mb. I don't think you'd notice the pressure - you'd just say "Turned out nice again then".

emordnilap wrote:

stevecook172001 wrote:

emordnilap wrote:If a handful of percentage points is 'seriously low', then a question: at what level - high or low - is atmospheric pressure a danger to human health? I don't mean weather-wise, I mean health-wise, bodily integrity-wise.

360 mb is the point at which the human body can no longer acclimatize to the atmospheric pressure conditions and where, if any significant time is spent under such conditions, permanent damage to the body will be incurred.

It equates to 26,000 feet above sea level. Climbers call it the "death zone".

http://meteorologytraining.tpub.com/142 ... 269_75.htm

Ah, I get it now; didn't think that one through but it's pretty obvious put in those terms. What about the other way, high pressure?

Think about under water swimming; the body can tolerate several atmosphere's in those conditions. Free divers can get down several hundred feet without any problems so the pressure that can be exerted by air shouldn't be a problem. The air pressure disperses through the body quite quickly, equalising internal and external pressure.