I think we can all agree there is very good agreement at southwesterly or westerly winds in the run up and probably over the xmas Period.

Charts are now consistently showing some intense features clipping, hitting, or scurrying over the UK. It looks very wet. over 100mm of rainfall for the 2 week period of GFS.... like i said before, this has a very 2014 look about it

Very unsettled with little chance of frost

Slightest chances of breaking out to a colder regime are possible... but realistically this seems no different to any other year in the UK...

If there was a serious chance of maybe something colder, we would have seen some evolutions to that idea... but theres literally been nothing for days now

I would love to be wrong...

I think at the moment all hopes hinge on this maybe?

Originally Posted by: Russwirral 

Now here is a theory and it might be (and probably is) complete codswallop but here goes.



I believe in winters we are going to see less of the PV influencing the weather

The PV exists because it sits above a pool of very cold air which is sinking, think of taking the plug out of the bath and the water going down the hole, it creates a whirlpool and the PV is basically an atmospheric version of that.

Now add to the mix that the polar regions due to Climate Change are around 7-8c above average this year, as is Greenland (When cold this is why the PV often sits over Greenland), so there is less forcing or downwelling of air over the pole so less force creating the whirlpool. Hence we have a weak and disorganised PV. I believe this will become a feature of winter going forward because of said climate change. The Pole heats faster basically because there is no land mass, just ocean. The reason for the PV shifting toward Greenland over the past 2 decades, is because of this as Greenland was the nearest landmass for the cold air to pool over.



Now the bad news for us is that High pressure likes cold pools and when the PV is disorganised this allows the cold air to fall into the mid latitudes, and where there is a landmass it will cool more and more, and produce a high pressure cells. So the high pressure over Europe/Siberia is displaced south as the cold air is leaking further south due to lack of PV. The bad news for us is that this would mean that we would have a semi permanent high over central Europe in winter, with strong temperature contrast between land and sea (remember the seas are warming), low pressures will dominate the Atlantic and Pacific basins.

Originally Posted by: warrenb 

I think we can all agree there is very good agreement at southwesterly or westerly winds in the run up and probably over the xmas Period.

Originally Posted by: Russwirral 

On the subject of temperatures in the Northern Hemisphere I will make the following very simple observations:

1) The evidence I've seen suggests the Azores / Bores / Euro HP belt has strengthened in the last 70 years

2) We are having month after month of above CET in the UK. The frequency of colder months has decreased

3) Arctic ice levels more often than not are below the mean both when measured by extent and thickness

4) The NH appears to be warmer at most levels in the troposphere than it was several decades ago

Now I couldn't give a monkey's whether you ascribe those changes to the magic tooth fairy or global warming. However, to deny them is utterly crazy.

Originally Posted by: Brian Gaze 

Now here is a theory and it might be (and probably is) complete codswallop but here goes.



I believe in winters we are going to see less of the PV influencing the weather

The PV exists because it sits above a pool of very cold air which is sinking, think of taking the plug out of the bath and the water going down the hole, it creates a whirlpool and the PV is basically an atmospheric version of that.

Now add to the mix that the polar regions due to Climate Change are around 7-8c above average this year, as is Greenland (When cold this is why the PV often sits over Greenland), so there is less forcing or downwelling of air over the pole so less force creating the whirlpool. Hence we have a weak and disorganised PV. I believe this will become a feature of winter going forward because of said climate change. The Pole heats faster basically because there is no land mass, just ocean. The reason for the PV shifting toward Greenland over the past 2 decades, is because of this as Greenland was the nearest landmass for the cold air to pool over.



Now the bad news for us is that High pressure likes cold pools and when the PV is disorganised this allows the cold air to fall into the mid latitudes, and where there is a landmass it will cool more and more, and produce a high pressure cells. So the high pressure over Europe/Siberia is displaced south as the cold air is leaking further south due to lack of PV. The bad news for us is that this would mean that we would have a semi permanent high over central Europe in winter, with strong temperature contrast between land and sea (remember the seas are warming), low pressures will dominate the Atlantic and Pacific basins.

Originally Posted by: warrenb 

Definitely trending towards colder for Xmas week, hopefully that continues

Originally Posted by: ballamar 

The jet streams (the polar jet particularly) is fundamentally caused by the difference in temperature between the Poles and the Equator. Rapid warming at the Poles compared to the Equator would weaken the jetstream? 

Originally Posted by: Perthite1 

I'll add that in terms of impact for the UK, it seems over the past 20 years that...

1) Springs are getting more volatile (this last decade we've had both extreme cold and extreme warm spells)

2) Augusts have got more rubbish

3) Octobers and Novembers have got warmer

Originally Posted by: Saint Snow 

One of the biggest changes in our climate is how commonplace uncomfortable heat is down here in summer. We run the gauntlet of oppressive conditions June through September seemingly every year.

Not a good trend.

Originally Posted by: Downpour 

Yes, we are looking at getting a form of Air Con installed down here, as this year was the last straw.

Originally Posted by: warrenb 

Rubbish meaning horribly hot for point 2?

Last August was defined by another unbearable heatwave.

Originally Posted by: Downpour