Autumn

[BornFromTheVoid]

http://www.wetterzentrale.de/pics/Rtavn662.png

GFS12z has the -20C isotherm forming in 66 hours.

In regards to the Polar Vortex, it is actually well east of the cold pool in this particular case, though i must disagree on the development of a Polar Votrex being a bad thing. A strong polar vortex ensures that there is plenty of cold air to tap into once high pressure does develop oer the pole, it is only a bad thing in +AO conditions.

Actually SB, the 12z has it at t45.

Not much of it, but ya never know!

[SNOW GO]

Foxy On Weather

Cheryl continues to be odd, now now, miaow, enough's enough, truce Cole-girl? Apart from the odd spat or two at PWS Towers, the great debate at present is the banter on the web about winter 2010/11, and how it will turn out. 'Good question' I said to Cheryl, 'Come on then clever!' she said to me. 'My guess is that winter will still fall between December and early March' I replied. Seriously.... As I see it, not PWS, (we'll wait for Mr P to roll out one of his masterpieces at a later date), this winter looks on a par with last year, perhaps not as bad. This is my own research done in my sparetime, (not on company time I promise Mr P), perish the thought! However, I won't be subscribing to the crackpots and their 'frozen stiff for three months under a ton of snow' nonsense, that's highly unlikely, and in the current mix of affairs, the replication of last year's winter doesn't add up either, not from where I'm sitting. A generalised cold theme yes, but similar snowfall amounts, mmm, I don't think so. I will be buying boots for winter, (the footware, not the chain of chemists), but let me tell you it's a fashion thing, just to keep my feet warm. Nothing to do with red berries on trees, or cows pointing one way in a field, although, yes, go on then, add 'Lisa buying boots' as weather folklore for a harsh winter. The projections PWS have at present take us up to the end of February 2011, and they make for interesting reading. If released now, it would be strongly at odds with current thinking, but not totally at odds with the thinking of the past 10 years, when you take a chunk of past data, rather than a thin slice of the present stats to hand. We'll see, but calling it now would be a bit daft, I mean, who'd do that? Old misery won't let me have a 'Twitter' account, ain't he mean? Bet Cheryl gets one! Catch you again, remember our Mr Powell is on twitter - 'nullGuru'

Lisa Fox Chief Assistant Forecaster. Saturday September 4th 2010

A bit off topic here but I have just come across this on the Positive Weather Soloutions website and it suggests in a rather pathetic un professional way that they are already backtracking on this Winters so called bitter cold and snow same as last year forecast there own head forecaster Jon Powell was predicting and reported in the media way back in Spring? Sometimes I dont get this weather organisation as they seem to bring out these sensationalist claims like the BBQ Summer one and then try and either blame it on the Met Office or backtrack and change the original forecast massively. I dont know about anyone else on the forum but I think they just fell lucky last Winter as most of this year the LRFS and even short range forecasts from them have been very poor compared to the likes of Net Weather, The Weather Outlook and even the Met Office month ahead wise! Its probably just me turning grumpy with my old age but is anybody else fed up with the poor forecasting PWS have been giving us this year??

Edited September 4, 2010 by SNOW GO

[Winter Monsoon]

As the Winter 2010/11 area has been closed on here I did not know where to post this link I found via the Daily Mails Winter forum

http://globalcooling...k.blogspot.com/

at times its a bit OTT Ice Age now sort of stuff but does mention about the Jet stream and its possible future effects on the UKs weather.

I would agree that its a bit OTT. Some of this is interesting as im leanring as i go along on here. Further down the page he bemoans the lack of response from the papaers however when you read the actual e-mail he sent to them i can see why they havent replied. You just get the impression that he's trying to big himslef up.

I wouldnt mind if some of what he says does come true though.....who'd have thought 2 snowy winters in a row eh??

[BornFromTheVoid]

A very small -20C 850hPa patch now down to t27, though I imagine it will be gone soon as it's been progressively shrinking on each run!

[summer blizzard]

A very small -20C 850hPa patch now down to t27, though I imagine it will be gone soon as it's been progressively shrinking on each run!

GFS also has one at 48 hours out, not to worry we are still well ahead of recent years.

[Weather-history]

Not sure what the fuss is over this -20C isotherm?

Anyway back on topic, I notice leaf litter before and ivy on a house nearby has turned red in colour.

[summer blizzard]

As promised earlier in the thread, this is my official Autumn forecast. I will update it every month, however this will be my official forecast no matter what changes.

The teleconnection pattern for the Autumn ahead is likely to be dominated by the connection between La Nina and the Arctic Ossilation, as a result of this the effect of the QBO is likely to be weak.

QBO: Unfortunately only weak anologues were available due to the La Nina pattern currently dominating our weather however we are likely to have a strengthening +QBO throughout Autumn, the caveat here being that one anologue did have the +QBO peak occuring in October.

MEI: The current La Nina has developed rapidly and is now the strongest La Nina since 1975, anologues suggest that La Nina should have peaked now, however given the pace of development i would suggest that La Nina will continue to strengthen throughout Autumn.

AO: Anologues suggest a strong signal for La Nina to drive the Arctic Ossilation this Autumn, anologues suggest that September and November will record -AO readings while October will record a +AO.

Temperature: The temperature forecast for the Autumn is based upon the anologues of 1954, 1964 and 1981 however there is very low confidence given the signal from the MEI and QBO.

September: 13.6C, 0.1C below average

October: 10.3C, 0.1C below average

November: 7.3C, 0.4C above average

Autumn Temperature: Close to average

Autumn Precipitation: Below average

ftp://ftp.cpc.ncep.n...s/qbo.u30.index

http://www.esrl.noaa.../MEI/table.html

http://www.cpc.noaa....ent.ascii.table

Edited September 5, 2010 by summer blizzard

[BornFromTheVoid]

Not sure what the fuss is over this -20C isotherm?

Anyway back on topic, I notice leaf litter before and ivy on a house nearby has turned red in colour.

Just interesting to watch, like many thing weather...

The -15C isotherm formed a few weeks early this year and the -20C now looks like doing similar. The earlier cold uppers form the better as far as I'm concerned. Certainly can't hurt!

[Optimus Prime]

That is a very small portion of the Arctic. -20c 850s there usually means the cold is absent from somewhere else.

[damianslaw]

As promised earlier in the thread, this is my official Autumn forecast. I will update it every month, however this will be my official forecast no matter what changes.

The teleconnection pattern for the Autumn ahead is likely to be dominated by the connection between La Nina and the Arctic Ossilation, as a result of this the effect of the QBO is likely to be weak.

QBO: Unfortunately only weak anologues were available due to the La Nina pattern currently dominating our weather however we are likely to have a strengthening +QBO throughout Autumn, the caveat here being that one anologue did have the +QBO peak occuring in October.

MEI: The current La Nina has developed rapidly and is now the strongest La Nina since 1975, anologues suggest that La Nina should have peaked now, however given the pace of development i would suggest that La Nina will continue to strengthen throughout Autumn.

AO: Anologues suggest a strong signal for La Nina to drive the Arctic Ossilation this Autumn, anologues suggest that September and November will record -AO readings while October will record a +AO.

Temperature: The temperature forecast for the Autumn is based upon the anologues of 1954, 1964 and 1981 however there is very low confidence given the signal from the MEI and QBO.

September: 13.6C, 0.1C below average

October: 10.3C, 0.1C below average

November: 7.3C, 0.4C above average

Autumn Temperature: Close to average

Autumn Precipitation: Below average

ftp://ftp.cpc.ncep.n...s/qbo.u30.index

http://www.esrl.noaa.../MEI/table.html

http://www.cpc.noaa....ent.ascii.table

Interesting post - your predicted near average CET values for the autumn as a whole is yet another forecast which doesn't foresee a particularly mild autumn.

[BornFromTheVoid]

There aren't supposed to be any -20C uppers yet, but 80N has been hogging much of the cold air lately. Saying that, the Bering side of the Arctic has seemed swamped with relatively warm upper temperatures most of this summer and what little we've had of Autumn so far.

[summer blizzard]

http://www.wetterzentrale.de/pics/Rtavn422.png

-20C in 42 hours.

[arcticadventurer]

Looks more like mid October than the beginning of September..A lot of trees have changed colour and some trees have even shed their leaves. This Autumn seems to be more pronounced than previous autumns

[conor123]

Looks more like mid October than the beginning of September..A lot of trees have changed colour and some trees have even shed their leaves. This Autumn seems to be more pronounced than previous autumns

It's probably just to do with the incredibly low figures of sunshine in July & August, this past week here even with the generally cloudy weekend has very almost hit July's sunshine hours which is ridiculous considering how much shorter the days are now!

[summer blizzard]

http://www.wetterzentrale.de/pics/Rtavn422.png

-20C in 42 hours.

http://www.wetterzentrale.de/pics/Rtavn662.png

GFS6z has pushed it back to 66 hours out as far as i can tell.

[Thundery wintry showers]

Not sure what the fuss is over this -20C isotherm?

I agree. Remember how the -10C line appeared unusually early in 2006, resulting in a much cooler than average August near the pole, and then we had that exceptionally warm westerly-dominated winter? Still, as long as people aren't misled into thinking that early appearances of the -20 isotherm mean increased chance of a cold and/or snowy winter, it can be interesting to watch out for.

In Norwich some leaves are already starting to fall off the trees, which is a good 2-3 weeks earlier than the last three years. It isn't really that much of a surprise because temperatures for January-August 2010 have been very close to the 1961-90 average, and therefore somewhat down on 1971-2000 and recent rolling averages.

[Cheese Rice]

The leaves are definatley turning earlier this year, usually around mid-late September we start to see the leaves turn, not Late August on-wards. Interesting really as we were late with the leaves coming out by about 3 weeks, and now they are turning all-ready, shows how cool this year has been compared to recent. 

[ZONE 51]

As their are no replies(why not?) and the topics not locked i thought it would be good to start it off.

Its a strong la-nina developing now and this has and is helping many tropical storms to develop, maybe to end up as the most active season since 98? all these ex-hurricanes and tropical storms a filling the atlantic.

i think these playing an affect on the uk through sept-end oct, with maybe a potent low, and thundery at times, a low moving to our east in november bringing cold weather, high building into december, with a nel'y end of decmb. i cant go any further.

if blocking of the atlantic develops then dry cold and cloudy oct/nov with a n/nw'ly ?

Edited September 7, 2010 by nimbilus

[Weather-history]

Some real natural pruning yesterday due to the gusty wind. Leaves, branches etc on the streets, pavements, parks.

I agree. Remember how the -10C line appeared unusually early in 2006, resulting in a much cooler than average August near the pole, and then we had that exceptionally warm westerly-dominated winter? Still, as long as people aren't misled into thinking that early appearances of the -20 isotherm mean increased chance of a cold and/or snowy winter, it can be interesting to watch out for.

.

Yes and if one wants to be pedantic, its strictly model chat/discussion and not really to do with autumn in general. Its gettting a bit silly now with these comments "it disappears after 72hrs, its pushed back to 66hrs" IMO

Edited September 7, 2010 by Mr_Data

[BornFromTheVoid]

Some real natural pruning yesterday due to the gusty wind. Leaves, branches etc on the streets, pavements, parks.

Yes and if one wants to be pedantic, its strictly model chat/discussion and not really to do with autumn in general. Its gettting a bit silly now with these comments "it disappears after 72hrs, its pushed back to 66hrs" IMO

The arrival of cold upper temperatures is as much a part of Autumn as leaves changing colour and falling off trees... IMO.

Anyway, -20C isotherm down to t27. All the rain and wind really makes it feel like Autumn has arrived, I for one will be glad to see the back of summer, don't enjoy the warmth much!

[laserguy]

. All the rain and wind really makes it feel like Autumn has arrived, I for one will be glad to see the back of summer, don't enjoy the warmth much!

Not as glad as me,I hate everything "summer". Autumn proper has started in earnest now,there's no missing it. Fruits ripe everywhere,leaves obviously turning,my nipper's first day back at school! The air has a smell and feeling that is Autumn's preserve. Last night it absolutely "siled it down" (as they say up here!) and it was..... beautiful. Ain't life sweet?

[Bottesford]

Not as glad as me,I hate everything "summer". Autumn proper has started in earnest now,there's no missing it. Fruits ripe everywhere,leaves obviously turning,my nipper's first day back at school! The air has a smell and feeling that is Autumn's preserve. Last night it absolutely "siled it down" (as they say up here!) and it was..... beautiful. Ain't life sweet?

It certainly has started in earnest! The traffic is back in full force along with an accident that grid locked a large area last night canceling my missus' driving lesson, it was dark by 7:30pm so needing lights on from around 6:30pm and the wind knocked over one of my lanky tomato plants breaking a large branch off it.

Who needs quiet roads & having your dinner outside in the sun when you can queue in traffic inhaling fumes in the rain and sit in dull artificial light for your tea?

[Geordiesnow]

The leaves are definatley turning earlier this year, usually around mid-late September we start to see the leaves turn, not Late August on-wards. Interesting really as we were late with the leaves coming out by about 3 weeks, and now they are turning all-ready, shows how cool this year has been compared to recent. 

I notice leaf change here too but its not that unusual for some trees too start having there leaves changing colour in early September. I don't really have any knowledge about trees but more often than not, the leaves on the trees outside my house start changing around early too mid October time so be interesting if they turn early or late.

[Turnedoutniceagain]

I notice leaf change here too but its not that unusual for some trees too start having there leaves changing colour in early September. I don't really have any knowledge about trees but more often than not, the leaves on the trees outside my house start changing around early too mid October time so be interesting if they turn early or late.

I'm with you on that. I have a giant Lime tree over our entrance gates and it's virtually all yellow/brown !! The laburnam in the kids' garden is orange and the beeches in the bottom paddocks are well into their autumn colours and have been for about 10 days.

It seems really early to me !

[summer blizzard]

Up here, its a mixed picture. One of the trees in my garden had all its leaves turn about two weeks ago, the drough stress and near instantanious to cool weather was too much for it, most are still green but beggining to turn with the odd coulered leaf however one spesious is really yellowy/reddy.