2121 replies to this topic

[Sprites]

Temp. dropped to 30f in the garden at 6am today, a slight frost on the car roof too, could be a re-run tonight.

[damianslaw]

sebastiaan1973, on 15 October 2011 - 19:05 , said:

A nice forecast of the winter 2012.

http://www.lightinth...om/archives/420
E.g.
Putting it all together
The dominant factors at play for the winter of 2011-12 should be a weak geomagnetic field, weak electric field strength of the solar wind, a negative NAO, AO, PNA, PDO, and ENSO (moderate La Nina). In addition, a factor not mentioned in the discussion is the QBO, which measures variations in the equatorial stratospheric wind, will be near neutral to slightly negative. Data for winters with this modality in conjunction with the solar external forcing noted already support negative NAO winters with plentiful blocking. Notice that all the indices mentioned above will be in a negative state, suggesting that the middle latitudes of the northern hemisphere are in for a colder than normal winter overall. However, that does not mean everyone will be cold. Notable pockets of warmer than normal temperature departures will exist this winter, one such location over much of the Southern United States. Coupling the conditions expected with analogs (years with similar regimes to this one) suggest an overall warm winter (DJF) from the Southwestern US eastward through the central/southern Plains, and the Southeastern US. The DJF departure map for the Northeast of slightly below average temperatures is a bit deceiving, as I believe there will be periods of extreme cold and extreme warmth spattering the winter in the Northeast. The northern Rockies into the Mid-western US and Great Lakes should have a more predominately colder than average winter.
My analogs for this winter: 1954-55, 1955-56, and 2008-09.

Important for us -on the others ite of the Ocean- is in my opinion the predicted negative NAO.

Interesting read. I would be happy with a winter similiar to 2008-2009 which also delivered a cold start especially for northern parts, the coldest start to Dec since 1978 - though things did unfortunatel become much milder in the run up to christmas. If we can see a winter very similiar to 08/09 but a bit colder, in my opinion I would end up rating it far higher than last year, but not quite as good as 09/10. My early inklings are for a colder version of 08/09 with cold snowy spells interespersed with shortlived milder wet atlantic outbreaks - but these are just my current thoughts and I won't be confirming them until much later in November. Also a Nov like 2008 would be good, no significant cold like last year but it was on the cool side with a notable cold frosty period mid-late month and a very cold end.

[vortex_liam]

I will say Thursday over the higher ground in Scotland could be interesting.

[Geordiesnow]

wimblettben, on 15 October 2011 - 17:35 , said:

It's hardly going to be very noteworthy is it!

Some temperatures on or below freezing only on the highest parts of Scotland. Wow.

Looks like an Air frost in Northern parts of England too, city centre temps being around 3C potentially? Quite noticetably for October considering in recent times its been a mild month generally. Also it could be the first proper widespread frost of the season also so something to look forward too I suppose.

[Snowstorm1]

Bit chilly as you say Geordiesnow will certainly give me a cold head after my haircut today

[Gavin D]

Currently 8.5°C in Darlington under clear sky's and no wind so a chilly night tonight for many yes.

Edited by Gavin D, 15 October 2011 - 20:42 .

[Daniel AKA WMD]

Incredibly cold 850hPa air being projected across Greenland next week


Astonishing!

[A Scottish Winter's Tale]

Daniel AKA WMD, on 15 October 2011 - 20:46 , said:

Incredibly cold 850hPa air being projected across Greenland next week
Cold!.png

Astonishing!

I would imagine that would be quite good for us for the long term with such a decent cold pool over Greenland.

I see that you have found yourself on that [errr] "interesting" discussion of the Daily Mail site.

Edited by A Winter's Tale, 15 October 2011 - 20:53 .

[kold weather]

Actually not sure having very cold air over Greenland is a great thing, though at this stage its probably not super important either. In theory though a stronger thermal gradient is going to add to a greater chance of a strong jet and an organised PV, if we just take a basic view.

[summer blizzard]

sebastiaan1973, on 15 October 2011 - 19:05 , said:

A nice forecast of the winter 2012.

http://www.lightinth...om/archives/420
E.g.
Putting it all together
The dominant factors at play for the winter of 2011-12 should be a weak geomagnetic field, weak electric field strength of the solar wind, a negative NAO, AO, PNA, PDO, and ENSO (moderate La Nina). In addition, a factor not mentioned in the discussion is the QBO, which measures variations in the equatorial stratospheric wind, will be near neutral to slightly negative. Data for winters with this modality in conjunction with the solar external forcing noted already support negative NAO winters with plentiful blocking. Notice that all the indices mentioned above will be in a negative state, suggesting that the middle latitudes of the northern hemisphere are in for a colder than normal winter overall. However, that does not mean everyone will be cold. Notable pockets of warmer than normal temperature departures will exist this winter, one such location over much of the Southern United States. Coupling the conditions expected with analogs (years with similar regimes to this one) suggest an overall warm winter (DJF) from the Southwestern US eastward through the central/southern Plains, and the Southeastern US. The DJF departure map for the Northeast of slightly below average temperatures is a bit deceiving, as I believe there will be periods of extreme cold and extreme warmth spattering the winter in the Northeast. The northern Rockies into the Mid-western US and Great Lakes should have a more predominately colder than average winter.
My analogs for this winter: 1954-55, 1955-56, and 2008-09.

Important for us -on the others ite of the Ocean- is in my opinion the predicted negative NAO.

I highlighted the analogues at the bottom.

He is backing the PDO analogues as dominant minus 1954 which is an AO anologue.

kold weather, on 15 October 2011 - 21:51 , said:

Actually not sure having very cold air over Greenland is a great thing, though at this stage its probably not super important either. In theory though a stronger thermal gradient is going to add to a greater chance of a strong jet and an organised PV, if we just take a basic view.

I suppose it depends on how much of that cold air is poured out to the mid-latitudes (not much given that the coming high is mainly at the surface). As it is October though, i would actually prefer a strong cold pool.

Edited by summer blizzard, 16 October 2011 - 01:07 .

[kold weather]

The only other thing is if all the cold air is being bottled up in the northern Arctic reaches that isn't going to help with regards to the snow-growth in the 50-60N range and that is fairly important at this time of year. I've noticed that the snow/ice recovery tends to give a very good hint of what the winter is going to be like, a fast recovery tends to highlight a better chance of below average winter (though there are obviously better factors to use to determine a winter...)

[Craig Evans]

Seven of Nine, on 14 October 2011 - 15:45 , said:

Strange temp profiles for the globe.

Indeed it looks like a cool summer over most of the southern hemisphere. Also Tibet looks warm in winter whilst India looks cool at the same time. Very strange. Since Tibet is the source of the cool, dry winter monsoon logically both India and Tibet should be cooler than average.

[cyclonic happiness]

kold weather, on 16 October 2011 - 08:01 , said:

The only other thing is if all the cold air is being bottled up in the northern Arctic reaches that isn't going to help with regards to the snow-growth in the 50-60N range and that is fairly important at this time of year. I've noticed that the snow/ice recovery tends to give a very good hint of what the winter is going to be like, a fast recovery tends to highlight a better chance of below average winter (though there are obviously better factors to use to determine a winter...)

I'm with you on that theory, I think that snowcover is extremely important to what the winter will do, that's why I started my thread.
The snow cover this year is a little down on last year, but it's falling in much the same pattern.
Central/nrothern Russia has alot less atm, which leads me to think that the coldest of the winter will be at around christmas time as it stands.
I WILL find the holy grail of winter forecasts and the answer lies in the snow!

[bluearmy]

apparently the latest ecm look ahead to the winter period (issued 15/10) has a positive pressure anomoly in our part of nw europe with a negative anomoly to our north. whilst the blocking over us is good news for those chasing a cold winter, the negative anomoly to our north is not as it makes it less likely that the block will be able to migrate to positions to deliver a cold flow in general. all in all, better to have a block than not.

[Backtrack]

Good to see you back Winter. *Salutes*

Attached Thumbnails

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Edited by Backtrack, 16 October 2011 - 13:36 .

[Interitus]

Daniel AKA WMD, on 15 October 2011 - 20:46 , said:

Incredibly cold 850hPa air being projected across Greenland next week
Cold!.png

Astonishing!

Of course these are theoretical 850hPa values as the majority of Greenland is above the 850hPa level in altitude.

[karyo]

bluearmy, on 16 October 2011 - 10:47 , said:

apparently the latest ecm look ahead to the winter period (issued 15/10) has a positive pressure anomoly in our part of nw europe with a negative anomoly to our north. whilst the blocking over us is good news for those chasing a cold winter, the negative anomoly to our north is not as it makes it less likely that the block will be able to migrate to positions to deliver a cold flow in general. all in all, better to have a block than not.

Can you please post the link?

Karyo

[kilmannan27]

Brian Gaze has just posted his early thoughts for the upcoming winter (2011/12) over on TWO.

Discuss his thoughts below.

Here's the link:

http://theweatherout...type=bg&id=1821

[Paul-Michael]

So in laymans terms that reads...... 50/50?

Signals are pointing at this stage to a possibly milder winter than the previous two, but then don't discount the possibility of it being another cold one? That would suggest at this rate that pretty much anything is on the cards...

[lloydyd]

So its going to be mild but also cant rule out cold...... Basically the same as everyone else then. We all know snow isnt the easiest thing to predict, but it does make good reading....Only time will tell