Autumn/Winter 2011-2012

[Wildswimmer]

Well, the sun is weakening and nights drawing in, and still no sign of a decent summer heatwave. The chances are now rapidly diminishing day by day. It looks as though the unlamented "summer" of 2011 is crawling to an unlamented end. The signs of Autumn are already here, grey skies, cold nights and daytime maxes only around 16-20C. Indeed Northern Ireland saw ground temps of just 2C last night - well below normal for August.

It's now late August with no sign of any pattern change so the present autumnal weather seems set to continue for the foreseeable future.

The problem is the same old as with the last four summers: very little in the way of any southerlies or southwesterlies bringing in warm air. The jet stream has been over or even slightly to the south of the UK, some 500 miles south of where it should be during summer, with predominantly polar or polar maritime air affecting the UK. This year the poor summer weather has even blighted the south. Sort of reminds me of the Moody Blues track: "Forever Autumn".

Are things going to improve? I doubt it. As mentioned elsewhere it looks as though the Sun has entered a period of low activity, a Grand Minimum. Although the reduction in sun's heat output is a fraction of one percent, previous Grand Minima have affected weather patterns in the N. Atlantic and NW Europe increasing the frequency of Arctic air incursions, exactly as we have seen over the past few years. The Maunder Minimum was partly responsible for the Little Ice Age (which only affected Europe) while the later Dalton Minimum resulted in a period of unusually cold winters in the early 1800s. December '10 is probably a foretaste of what's to come.

Oddly enough the Little Ice Age may have seen very cold winters but summers were mostly unaffected. Not this time. The current Grand Minimum looks as though it's also affecting our summer weather.

As far as the coming open water season is concerned I suspect it's going to be challenging, with depressed water temperatures falling off rapidly as autumn proceeds.

Wildswimmer Pete

[swimslikeabrick]

Originally Posted by Wildswimmer

Well, the sun is weakening and nights drawing in, and still no sign of a decent summer heatwave. The chances are now rapidly diminishing day by day. It looks as though the unlamented "summer" of 2011 is crawling to an unlamented end. The signs of Autumn are already here, grey skies, cold nights and daytime maxes only around 16-20C. Indeed Northern Ireland saw ground temps of just 2C last night - well below normal for August.

It's now late August with no sign of any pattern change so the present autumnal weather seems set to continue for the foreseeable future.

The problem is the same old as with the last four summers: very little in the way of any southerlies or southwesterlies bringing in warm air. The jet stream has been over or even slightly to the south of the UK, some 500 miles south of where it should be during summer, with predominantly polar or polar maritime air affecting the UK. This year the poor summer weather has even blighted the south. Sort of reminds me of the Moody Blues track: "Forever Autumn".

Are things going to improve? I doubt it. As mentioned elsewhere it looks as though the Sun has entered a period of low activity, a Grand Minimum. Although the reduction in sun's heat output is a fraction of one percent, previous Grand Minima have affected weather patterns in the N. Atlantic and NW Europe increasing the frequency of Arctic air incursions, exactly as we have seen over the past few years. The Maunder Minimum was partly responsible for the Little Ice Age (which only affected Europe) while the later Dalton Minimum resulted in a period of unusually cold winters in the early 1800s. December '10 is probably a foretaste of what's to come.

Oddly enough the Little Ice Age may have seen very cold winters but summers were mostly unaffected. Not this time. The current Grand Minimum looks as though it's also affecting our summer weather.

As far as the coming open water season is concerned I suspect it's going to be challenging, with depressed water temperatures falling off rapidly as autumn proceeds.

Wildswimmer Pete

Are you joking? I've been out for a walk this afternoon, T shirt and Shorts and sweating like the proverbial pig.

[Spidey]

Very hot today, hopefully warmed up Dorney Lake for tomorrow.

[Wildswimmer]

Originally Posted by swimslikeabrick

Are you joking? I've been out for a walk this afternoon, T shirt and Shorts and sweating like the proverbial pig.

Originally Posted by Spidey

Very hot today, hopefully warmed up Dorney Lake for tomorrow.

My post is a long view, not a day-to-day forecast. For what it's worth up here today has been wall-to-wall cloud with the max a miserable 18C.

At my latitude and longitude (53N -3W) on June 21st maximum posssible insolation (ie completely clear sky) at 1pm was 1192W/m2. Today if it hadn't been so bloody cloudy it would have been 1059W/m2 @ 1pm. Bear in mind that with summer time in force the sun is at its highest around 1pm.

At the autumnal equinox (Sept 23) the figure is 840W/m2 which goes to show how rapidly the sun's power will be waning during the next four weeks. Just out of interest the sun's power at the winter solstice (21st Dec) at mid-day is 325W/m2. Again these figures are for my location.

Wildswimmer Pete

[Wildswimmer]

Oh well, despite the weather forecast for sunny, warm weather, up here another grey, sunless, chilly Autumn day with a max of just 19C. Yesterday I saw confirmation that Autumn has already arrived with trees already showing Autumn tints.

Wildswimmer Pete

[Spidey]

Most of the Horse Chestnuts show the tinge because of the leaf miner. I know that the forestry commission have this to look at as well as Dutch Elm desease.

With the clear days following rain, and whilst the light stays fairly late, the autumn colours are something to behold.

[MadHighroller]

I love Autumn, It's my Favourite time of year. All those gold and warm colours, fresh frosty mornings, crispy frosted grass.

Indian summer days.......

[KatieBun]

Yesterday was a proper summer's day here and today looks like following its example, although we had both commented recently that all we were getting was grey cloud, no sun and no rain for the garden. No chance of an Indian summer, Pete?

More and more grateful that I have a three week South African sojourn booked for November.

[Wildswimmer]

Originally Posted by KatieBun

No chance of an Indian summer, Pete?

Technically, Indian Summers occur in October. Is the present moribund "summer" going to expire in a blaze of glory? Not much sign of that and given next weekend is a Bank Holiday the weather looks as though it will be traditionally crap.

No sign yet in patterning but in the past many lousy summers have seen a couple of weeks of high pressure in September although with the rapidly waning sun it's very unlikely we'll see anything like a heatwave. In fact the last really hot spell I remember in September (right at the start) was in 1961 so I wouldn't hold your breath.

Wildswimmer Pete

[MadHighroller]

Originally Posted by Wildswimmer

Technically, Indian Summers occur in October. Is the present moribund "summer" going to expire in a blaze of glory? Not much sign of that and given next weekend is a Bank Holiday the weather looks as though it will be traditionally crap.

No sign yet in patterning but in the past many lousy summers have seen a couple of weeks of high pressure in September although with the rapidly waning sun it's very unlikely we'll see anything like a heatwave. In fact the last really hot spell I remember in September (right at the start) was in 1961 so I wouldn't hold your breath.

Wildswimmer Pete

Surely that depends on what part of the country you're in ?

[Wildswimmer]

Originally Posted by MadHighroller

Surely that depends on what part of the country you're in ?

Partly, but also down to basic physics. The sun's power is now down some 20% on what it is at the summer solstice, and is rapidly reducing as each day passes. At this time of the year hot weather now depends on wind direction and type of airmass. Over the weekend the far south had just a flirt with some really hot continental air but the rest of us were stuck under the cold polar maritime air that's been our lot not only for this summer, but over the past four.

During the past four lousy summers the south-east has been alone in experiencing anything like proper summer weather. The further north and west, the worse.

Wildswimmer Pete

[e-fitz]

..Glorious summer weather in these parts yesterday and today...long sea swim in 18/19 degree water followed by a BBQ on the beach with the sun setting over the water..the only slight concern is whether the warm water will tempt any aggressive sea life from their usual haunts further south. Thankfully the jellies seem to prefer colder water...

[Wildswimmer]

If any confirmation was needed that autumn has well and truly arrived it was today's weather forecast - snow on the Scottish mountain tops. Here the sky is currently black with the imminence of yet another heavy, cold shower. Meanwhile more trees have begun showing their autumn colours.

I suspect that in NW England at least, "summer" 2011 has fallen off the perch, if it ever arrived in the first place.

Wildswimmer Pete

[Wildswimmer]

Well, it's official. The non-summer of 2011 has been the "coolest" (or as I would put it, coldest) since 1993. Meanwhile the possibility of a warm spell later in the week seems to be evaporating faster than a salesman's smile. Some really cold nights are in the offing with even ground frosts possible.

Yes - autumn's here.

Wildswimmer Pete

[Pandi]

Originally Posted by Wildswimmer

Well, it's official. The non-summer of 2011 has been the "coolest" (or as I would put it, coldest) since 1993. Meanwhile the possibility of a warm spell later in the week seems to be evaporating faster than a salesman's smile. Some really cold nights are in the offing with even ground frosts possible.

Yes - autumn's here.

Wildswimmer Pete

Serves you right Pete.Cannot vouch for tother "members" on here,-T-shirt and shorts again at work.Swallows and Swifts still flying around.Summers not over.Yet.