Autumn 2013: thoughts, prospects and forecasts.

[Yarmy]

He's done pretty well for this summer though with the exception of June

 

I will say that June, July and August will each average 1.2 degrees above long-term normals

 

June came in at 13.6 -0.6c below average

 

July came in at 18.3 +2.3c above average

 

And August is running at 17.1c currently which is 1.2c above average

 

His overall headline for this sunner was warm, dry, sunny with brief interruptions - that's pretty much what its been for many

 

Have you got a link, Gavin? Like I say, I just picked the most recent Winter forecast I could find on NW.

[Summer Sun]

But it was also pretty obvious how this summer would pan out IMO. I even managed to pinpoint when the less settled spell would occur i.e end of July/beginning of August.......and I don't claim to be an expert at constructing an LRF. I know you saw my posts RE this summer Gavin as you liked a lot of the ones where I was suggesting a good one and that '2/3rds of the summer would be very useable'.

 

Yeah you also called it pretty much bang on as well its just going to be a case of wait and see now the UK weather will do what it wants as always given our location

 

The latest Anomaly for October is suggesting a return to northern blocking with high pressure to the north and low pressure across northern Europe

 

 

Temperatures look below normal

 

 

November also looks unsettled with high pressure continuing to the north and low pressure anchored to our west

 

 

Temperatures again look average to slightly below normal

 

 

An early look to December and we see a change in the pattern with high pressure building to the SE allowing temperatures to come in at normal or maybe slightly above

 

 

Taking a quick look at next month and northern blocking is shown to re-establish which is something we haven't saw for a while it will be interesting to see if it does (GFS isn't going this way at the moment for the first 12 days of September)

 

 

Temperature wise we look average

 

Have you got a link, Gavin? Like I say, I just picked the most recent Winter forecast I could find on NW.

 

Yes I have  - http://forum.netweather.tv/topic/72635-the-seasonal-forecast-thread/?p=2702070

[Yarmy]

This Summer's forecast was pretty close, last Summer's not so...

 

http://forum.netweather.tv/topic/72635-the-seasonal-forecast-thread/page-2#entry2306875

 

Again, I'm not criticising him. I applaud anyone who attempts an LRF.

[Summer Sun]

Here is the latest met office probability maps for Autumn

 

2m temperature

 

 

850hpa temperature

 

 

Precipitation

 

 

So looking at those there is a very good change we'll see a fairly warm / mild autumn overall as roger has already suggested in his seasonal outlook rainfall looks mixed from average to slightly above

 

Taking a quick peak into winter the first 2 months of winter and it looks fairly average temperature wise with a slight chance of above normal in north west Scotland.

 

Eastern and North eastern Europe also looks quite mild for the first 2 months of winter

 

No where is shown to be below normal during the shortest days of winter December and January

 

Edited August 27, 2013 by Summer Sun

[feb1991blizzard]

Serious cold pooling not a million miles away by October standards (536 dam H500 with high pressure), a bit of tweaking and bingo - Snow in London in October.

 

 

 

Then.  BANG!

 

Edited August 27, 2013 by feb1991blizzard

[feb1991blizzard]

A +QBO and solar minimum is the state most likely not to see a SSW - during solar max, a SSW can occur in either phase of the QBO. Question is, would the current very low cycle max be construed as equivalent to a normal cycle minimum.

 

Have a read of this paper on the subject.

 

http://journals.ametsoc.org/doi/full/10.1175/JAS3883.1

 

 

Cheers.

[Weather-history]

A sign autumn is on the way, when you see the Pleiades rising in the night sky.

[StretfordEnd1996]

Serious cold pooling not a million miles away by October standards (536 dam H500 with high pressure), a bit of tweaking and bingo - Snow in London in October.

 

 

 

Then.  BANG!

 

 

Hehe, shades of 2008? Once in a life time stuff, all for fun but I'd put £20 on at the bookies for that scenario to come off. 

 

 

 

Having said that, I do see some decent support and encouragement for a cooler that average end to October; perhaps after the mild and settled spell(s) have finished from mid-Setember onwards*** until mid October. There is support from the models for this too, although let's not forget a cool end to October will only mean chilly days of around 10'C and nights of below 5'C. Anything Wintry is extremely rare stuff! 

*** I mention this next mild/settled spell from Mid-September onwards, this seems to be verrryy up in the air judging by tonights charts! Starting to look much more unsettled especially late on next week. This could last some time. 

 

 

Let's have some proper good Autumn discussion now instead of users just bantering about odd stupid Winter charts ... It's 4 months away, just leave it alone or set up a new thread for Winter instead of all this childish arguing! Everyone's made their point about Winter for now, let's leave it alone. 

Edited August 27, 2013 by SnowySouthPennines

[feb1991blizzard]

A sign autumn is on the way, when you see the Pleiades rising in the night sky.

 

Another sign autumn is on the way is snow geeks like me talking about how we might get an early blast of winter or how good winter is going to be and clutching every straw in the run up, hanging on every little 1%er even though we wont really know what will happen in the run up to xmas until the stratosphere has cooled to its winter level and we know what the PV profile is like, ie - the 50%er!.

[cooling climate]

I still believe to this day that the SSW last winter lead to that exceptionally cold March I hope we don't get a March like that again in a long time as a Gardener it caused me a lot of problems

 

March this year had just ONE day when a temperature of over 10c (11.8c) was recorded here normally we hit the mid to high teens frequently here with the extra day light and occasionally we get a 20c+ (2011 - 21.4c, 2012 - 21.6c)

 

The northerly blocking and exceptionally cold March of this year was without question a result of

the SSW and a further asian mountain torque and warming that took place in the third week of

February.

As for the QBO this winter it will be solidly positive according to this zonal wind anomaly time series

chart

As for the state of the QBO 60n-90n in the lowest part of the stratosphere we may see a lingering

-QBO but I would not hold my breath.

Positive QBO normally means a stronger colder vortex but during the summer the stratosphere

has been running a little warmer than normal due in part to a strong warming during April and May which is one of the reasons we have seen a colder  troposphere and summer in the Arctic I think.

Ozone levels seem to be higher over the northern hemisphere than last year and previous years.

Therefore I would not be at all surprised to see northern blocking and a -AO and -NAO develope

during the winter.

The question is where will the vortices set up shop. I am hopeful that the atmosphere has a memory and the blocking and western american ridging we have seen during the last few months

will be repeated throughout the winter with a vortex setting up shot somewhere between the Hudsons bay and eastern canada  with another piece over central western Russia.

If right and acompanied by what I believe will be a dominant negative AO and NAO then a bitter

winter for the USA and Europe and the UK awaits.

[laserguy]

Definitely autumn, regardless of what the calendar sez.... just got in from work and the missus must have had the door open cos' the place is crawling with daddy long legs.

[Tamara]

The northerly blocking and exceptionally cold March of this year was without question a result of

the SSW and a further asian mountain torque and warming that took place in the third week of

February.

As for the QBO this winter it will be solidly positive according to this zonal wind anomaly time series

chart

strat 2.gif

As for the state of the QBO 60n-90n in the lowest part of the stratosphere we may see a lingering

-QBO but I would not hold my breath.

stratosphere.gif

Positive QBO normally means a stronger colder vortex but during the summer the stratosphere

has been running a little warmer than normal due in part to a strong warming during April and May which is one of the reasons we have seen a colder  troposphere and summer in the Arctic I think.

Ozone levels seem to be higher over the northern hemisphere than last year and previous years.

strat 3.gif

Therefore I would not be at all surprised to see northern blocking and a -AO and -NAO develope

during the winter.

The question is where will the vortices set up shop. I am hopeful that the atmosphere has a memory and the blocking and western american ridging we have seen during the last few months

will be repeated throughout the winter with a vortex setting up shot somewhere between the Hudsons bay and eastern canada  with another piece over central western Russia.

If right and acompanied by what I believe will be a dominant negative AO and NAO then a bitter

winter for the USA and Europe and the UK awaits.

Your technical analysis is really good there and well explained - it made sense and was a help to me for sure

[Andy_]

Just had amazing two clear blue sky warm days, but very much looking forward to Autumn and things getting colder towards Winter. I am most definitely a coldie, and the most anticipating times are coming up in the transitionary season of Autumn, I have no prospects or forecasts at the moment, but I am wishful of an active season, which is traditionally autumnal. 

[Summer Sun]

Vantage Weather Services autumn forecast from Jonathan Powell

 

Autumn 2013: Largely typical autumn, but risk of extremes.

 

September 2013

 

September may offer up some fair runs of weather, chiefly to the south and east during the month, but the most part, expect a seasonal mix.  The north and west of the country are likely to see a lean towards wetter, windier, and cooler conditions, with southern and eastern parts probably receiving the best of September, although not completely avoiding the inevitable onset of change that the season brings.  Therefore, an unstable month, with the best of any conditions anywhere reserved for the opening week or so.  Above average rainfall for the north and west is expected, with the further north and west heightening the percentages.  Most of the UK will return the average for temperature, perhaps a touch above to the south and east.

 

October 2013

 

October looks likely to see a continuation of the north-west, south-east divide, although the Atlantic will probably make more inroads into the drier weather across the south and east than it did in September.  To the north and west, rather damp, with cooler and cloudier weather tending to dominate from a chiefly westerly flow.  Furthermore, expect gales or severe gales; perhaps at times flooding issues as well.  To  the south and east, the best that October has to offer in the way of drier and brighter conditions, although sporadically, and especially along the English Channel, some rather turbulent weather.  Rainfall may see a more even spread of normal or slightly above normal readings UK wide, with temperatures on the average for all areas.

 

November 2013

 

November looks to see more evenly balanced weather across the country, with a lessening degree of rainfall nationwide.  Apart perhaps from the far north west, most areas should see a mix of dry, bright, and sunny weather, with a decreased amount of wet and windy conditions.  Temperatures late month may well induce some early snow across the hills of Scotland and to the north of England.  Towards the middle and latter part of the month under clear skies, frost activity can be expected, leading to chilly, bright, and crisp autumnal days.  On balance, rainfall is expected to come in below the average for the majority of areas, with temperatures reflecting the norm.

 

http://vantageweatherservices.co.uk/3.html

[Severe Siberian icy blast]

Vantage Weather Services autumn forecast from Jonathan Powell

 

Autumn 2013: Largely typical autumn, but risk of extremes.

 

September 2013

 

September may offer up some fair runs of weather, chiefly to the south and east during the month, but the most part, expect a seasonal mix.  The north and west of the country are likely to see a lean towards wetter, windier, and cooler conditions, with southern and eastern parts probably receiving the best of September, although not completely avoiding the inevitable onset of change that the season brings.  Therefore, an unstable month, with the best of any conditions anywhere reserved for the opening week or so.  Above average rainfall for the north and west is expected, with the further north and west heightening the percentages.  Most of the UK will return the average for temperature, perhaps a touch above to the south and east.

 

October 2013

 

October looks likely to see a continuation of the north-west, south-east divide, although the Atlantic will probably make more inroads into the drier weather across the south and east than it did in September.  To the north and west, rather damp, with cooler and cloudier weather tending to dominate from a chiefly westerly flow.  Furthermore, expect gales or severe gales; perhaps at times flooding issues as well.  To  the south and east, the best that October has to offer in the way of drier and brighter conditions, although sporadically, and especially along the English Channel, some rather turbulent weather.  Rainfall may see a more even spread of normal or slightly above normal readings UK wide, with temperatures on the average for all areas.

 

November 2013

 

November looks to see more evenly balanced weather across the country, with a lessening degree of rainfall nationwide.  Apart perhaps from the far north west, most areas should see a mix of dry, bright, and sunny weather, with a decreased amount of wet and windy conditions.  Temperatures late month may well induce some early snow across the hills of Scotland and to the north of England.  Towards the middle and latter part of the month under clear skies, frost activity can be expected, leading to chilly, bright, and crisp autumnal days.  On balance, rainfall is expected to come in below the average for the majority of areas, with temperatures reflecting the norm.

 

http://vantageweatherservices.co.uk/3.html

The thing with this forecast although it will most likely be right , absolutely anybody could of wrote it . Why? Because there is absolutely nothing in it to suggest its a forecast for this year , or any other year imparticularler , a north south split , with the best weather in the south east , with snow on Scottish mountains , with air frosts later on in the season , is something that anyone of us could of wrote . I'm not put anyone down hear I'm just been honest.

[Jax]

Vantage Weather Services autumn forecast from Jonathan Powell

 

Autumn 2013: Largely typical autumn, but risk of extremes.

 

September 2013

 

September may offer up some fair runs of weather, chiefly to the south and east during the month, but the most part, expect a seasonal mix.  The north and west of the country are likely to see a lean towards wetter, windier, and cooler conditions, with southern and eastern parts probably receiving the best of September, although not completely avoiding the inevitable onset of change that the season brings.  Therefore, an unstable month, with the best of any conditions anywhere reserved for the opening week or so.  Above average rainfall for the north and west is expected, with the further north and west heightening the percentages.  Most of the UK will return the average for temperature, perhaps a touch above to the south and east.

 

October 2013

 

October looks likely to see a continuation of the north-west, south-east divide, although the Atlantic will probably make more inroads into the drier weather across the south and east than it did in September.  To the north and west, rather damp, with cooler and cloudier weather tending to dominate from a chiefly westerly flow.  Furthermore, expect gales or severe gales; perhaps at times flooding issues as well.  To  the south and east, the best that October has to offer in the way of drier and brighter conditions, although sporadically, and especially along the English Channel, some rather turbulent weather.  Rainfall may see a more even spread of normal or slightly above normal readings UK wide, with temperatures on the average for all areas.

 

November 2013

 

November looks to see more evenly balanced weather across the country, with a lessening degree of rainfall nationwide.  Apart perhaps from the far north west, most areas should see a mix of dry, bright, and sunny weather, with a decreased amount of wet and windy conditions.  Temperatures late month may well induce some early snow across the hills of Scotland and to the north of England.  Towards the middle and latter part of the month under clear skies, frost activity can be expected, leading to chilly, bright, and crisp autumnal days.  On balance, rainfall is expected to come in below the average for the majority of areas, with temperatures reflecting the norm.

 

http://vantageweatherservices.co.uk/3.html

normal service then?

[feb1991blizzard]

Scandi high throughout much of October on the latest CFS run, not until late October that well below average air gets advected around it though.

 

 

 

 

 

 

 

 

 

 

 

 

 

Low level snow possible.

[feb1991blizzard]

Nice Ridging into Greenland.

 

 

 

Is that a nice little blue streak creeping ever further Southwards?

 

 

 

[Cheshire Freeze]

 

Nice Ridging into Greenland.

 

 

 

Is that a nice little blue streak creeping ever further Southwards?

 

 

 

 

Yeah, that blue streak is a right skinny runt at the minute. Give it 8 weeks and hopefully that skinny runt will have been hitting the gym hard and will be turning into a blue beast.

[Alex]

My 2013 Autumn Forecast by Alex B

@alexbweather

I am sure most will agree that Summer 2013 will go down as a good one however I doubt it will be said in the same breath as 76 or 2006, but it has been a big improvement on recent summers!

How is Autumn going to shape up? Lets look at some of the upstream patterns first - tropical activity has been weak during August and this has kept us in a very typically average August pattern. However during the last few days we are starting to get an eastward propagation - this is important as enhanced activity in the Western Hemisphere at this time of the year equates to some cooler weather down the line.

Sea state temperatures are generally average to above normal around our shores this could enhance rainfall and help keep temperatures slightly above normal.

Sunspot activity has been more active this summer and I expect this to continue into the autumn, although not proven - reduced activity correlates well to a southerly tracking jet.

ENSO forecasts favour a continuation of neutral conditions - therefore la nina / el nino anomalies are not evident enough to discuss in any detail.

For seasonal forecasting I use a model called CFS v2 - it did a very good job in helping me to predict the very decent July just gone! Tracking it over a period of time can indicate what it's favoured direction is! One of it's strongest trends for this Autumn has been for a drier/warmer October than normal.

There are other longer term variables that come into play, PDO (pacific decadal oscillation) is one such variable and this is like a longer term el nino or la nina phase. We are currently in a cool cycle.

So in summary of above

* Tropical activity indicates a gradual cooling of our temperatures into September with pressure likely to be low to the east of us.

* Sea state temperatures around the UK are average or even above normal.

* Sunspot activity although still relatively weak, it has been more active than some recent years.

* CFS v2 - strongly supporting a good October in terms of warmth and reduced rainfall.

* -PDO autumns have been generally warmer and drier than normal, 2011 is one example.

What do I expect.

September - The NW/SE split is likely to continue at first but gradually becoming cooler and more unsettled everywhere with probably the best weather in the west midmonth and rather cool everywhere. The end of the month is likely to see a return to more settled conditions and perhaps slightly above normal temperatures as a result.

October - Becoming increasingly settled with some reasonable days, however with the longer nights comes the threat of fog and maybe frost at times especially in northern areas. An easterly flow is likely for the first half of the month but it is likely to be relatively warm air. During the latter half it may become more changeable in the west, the southeast could hold onto more fine weather though.

November - Becoming unsettled at first but temperatures will hold up well with some mild nights at first, during the second half there is a small signal for a colder drier regime with some frosty nights likely.

Summary - I expect rainfall will stay slightly below normal but there will be some local differences. Temperatures likely to be near or above normal.

For stats I am predicting

Rainfall - 90%

CET Temperatures of - +0.5c

Sunshine - 105%

@alexbweather

[Relativistic]

The acorns have started cascading off of the oak tree now, although none of them are full in size. The conkers have been bulging on the horse-chestnuts for at least a week now too, and plenty of people are picking blackberries.

[Summer Sun]

Sounds good to me Alex

 

[MidAtlanticob]

Autumn is my favorite time of year. I have never been to England , but the promise a stormy winter is what a meteorologist desires.

Autumn in the mid Atlantic or New England is special . Unlike the old country Summer can be brutal. The three H's are Hot, Hazy, Humid. This year has been 5 degrees below normal. Because the last few summers have been 5 degrees above, its been a relief, Temps are Fahrenheit.

I have never been to England so I would ask. Do the trees change to a brilliant orange from green? Do they fall and crunch beneath your feet? Is there frost on the pumpkin?

MAO

[MidAtlanticob]

The cool summer and advance of cooling in the North East or New England is theorized as a response to fresh water melt in the Arctic. Anybody got any data???

Frost on the pumpkin is a local thing they sing about....

 

[Tim Bland]

The cool summer and advance of cooling in the North East or New England is theorized as a response to fresh water melt in the Arctic. Anybody got any data???

Frost on the pumpkin is a local thing they sing about....

Arctic ice level is around 60% higher than this time last year. As such this should have less affect this year