Arctic ice loss and Weather.....summer forecast for the N.H.?

[Gray-Wolf]

Well we've seen even more evidence of the links and even climate models that appear to ape what is happening today (post 2012 mega melt) so anyone else want to predict the northern Hemisphere summer season?

I'd like to think , purely for selfish reasons, that last years 'extra' melt has lead us into a phase that differs from the past 6 summers here in the UK.

The current cold entry into Spring gives me hope that the change has been great enough to allow this to be the case.

For the rest of the hemisphere I would expect H.P. dominated drought/heatwave for all mid continental areas but with the 'extent' of the influence of the H.P. extended outward. There will be associated wildfires across the U.S. , Russia and Indo China. The 'stalled ' zones of precipitation may well now be shifted across areas that have not yet suffered such (and so spare us here).

Should Mediterranean temps allow I would not be surprised to see mega storms grow in the basin and impact Spain,Italy and Greece ( on the way to temps sustaining re-curve Hurricanes in the basin)

I would expect the Eurasian temps to be top ten through May,June,July, Aug ,Sept and Oct.

I would expect another major melt across Greenland.

I would be surprised for Arctic ice losss to not challenge last years record and , if changed synoptics bring a new kind of 'perfect storm' to the basin, near melt out.

One thing must be certain, it will not be a summer season of calm an no extremes?

[BornFromTheVoid]

One thing I'd suggest GW, is that it may be unlikely that we'll see another melt similar to the last few years in Greenland, and get a good summer here!

A large part of why Greenland has had such a large melt recently is that there has been a strong upper level ridge across the ice sheet (sunshine and warmth), with a corresponding trough in western Europe (mild and wet).

As for what may happen globally... that requires a level of long range forecasting that I certainly struggle to get my head around. It will be interesting to see if the Spring snow cover continues its downward trend. That may influence large scale patterns early on.

[Gray-Wolf]

I think we may need think outside the box?

Last year we saw the Jet 'drop off the maps' across swathes once it's velocity dropped below the key measure. This summer we may see months with no discernable jet across swathes of the N.H. with only the acceleration out of peaks and troughs showing as Jet Streaks?

A Greenie High Joined to a Scandi High joined to a Central Russian High joined to an indo chinese high......

What happens if we extend the inner continental highs? We have the anomalous S. Greenland High, Russian High, Chinese High and U.S, High? Where do they spread?

I reckon the Polar Jet is done for and the Rapid northerly Hike of the sub-Tropical Jet is what we are about to see so how will that mess with our understanding of settled patterns (like the NAO)?

Things are massively altered so why not Northern Hemisphere Circulation?

One thing I am sure I'll see is the same again for Russia (and wildfires) , Greenlands southern high and the U.S. High (I'm not well schooled on the Chinese H.P.?).

In the northern hemisphere we have a lot of land and when that land gets hot it sticks the H.P. in place due to drying of the air masses.

All I want (if we're on our way to Hell in a Handcart) is a nice long, Hot ,Dry Summer to sit and chill???

[knocker]

I

I reckon the Polar Jet is done for and the Rapid northerly Hike of the sub-Tropical Jet is what we are about to see so how will that mess with our understanding of settled patterns (like the NAO)?

Things are massively altered so why not Northern Hemisphere Circulation?

Hi GW. In general I agree with your observations but not sure about the rapid northerly hike of the sub-tropical jet as this involves a slightly different mechanism. In fact the complications are outside my area of expertise. But a few notes.

Figure 6. 7 gives a generalized view of the wind and temperature distribution in the northern hemisphere troposphere in winter. Figure 6.8 shows that there are three westerly jet streams. The more northerly ones, termed the Polar Front and Arctic Front Jet Streams , are associated with the steep temperature gradient where polar and tropical air and polar and arctic air, respectively, interact (see Figure 6.8, but the Subtropical Jet Stream is related to a temperature gradient confined to the upper troposphere.

Complex isn't the word for it.

Edited March 31, 2013 by knocker

[The PIT]

It will all melt this year. Actually I'm surprised there hasn't been an article predicting that in media somewhere. Hopefully it will do better than last year but I'm not predicting any amounts.

[stewfox]

Not 100% certain hit the max yet but would look at a large recovery. Say 5.8m min this year back to 2000's average

[BornFromTheVoid]

Not 100% certain hit the max yet but would look at a large recovery. Say 5.8m min this year back to 2000's average

Hi Stew.

I'm gonna set up a minimum poll later this evening, but any reasons why you think the minimum will be so high?

[Gray-Wolf]

So , have we fallen prey to the first major 'weather departure ' of the year? Should this type of blocking continue then heatwave and drought masy well replace our recent 'flood' years as our norm (until the next major ice loss)?

[Gray-Wolf]

Would anyone h an opinion on what the shift of the 'Cold Pole' to Greenland could have on the weather of the N.Hemisphere? I understand over summer this was always the case but now over winter Greenland is more often the coldest place?

Or will we see 2 cold poles develop? One over Siberia and one over Greenland?

[Gray-Wolf]

Are we beggining to see thngs trending the way I envisaged?

 

As summer heat builds into the continental highs they will provide impressive blocking meanwhile the jet speeds (as we measure them today) drop so low as to leave little but jet streaks on the plots allowing the azores high to block out our european weather (and advect heat into the Arctic).

 

Eventually the Arctic will provide it's own heat further lessening energy for the Jet so lessing polar jet Activity.

 

Could we even see the sub-tropical Jet swing north enough to add some very interesting heatr our way this summer???

[gagerg]

Are we beggining to see thngs trending the way I envisaged?

 

As summer heat builds into the continental highs they will provide impressive blocking meanwhile the jet speeds (as we measure them today) drop so low as to leave little but jet streaks on the plots allowing the azores high to block out our european weather (and advect heat into the Arctic).

 

Eventually the Arctic will provide it's own heat further lessening energy for the Jet so lessing polar jet Activity.

 

Could we even see the sub-tropical Jet swing north enough to add some very interesting heatr our way this summer???

 

Are you referring to a possible heatwave similar that that of the one that occurred in America last year occurring in our neck of the woods?

[Gray-Wolf]

Hi gagerg!

 

This is only my own thinking on the matter and , probably far ,far to 'outside the box' for many member to credit .......but then they are schooled in the 'old Meteorology' of our neck of the woods?

 

The Albedo flip/redistribution of energy is already placing a lot of energy into the north. A weaker pack ,earlier in the year, leads to far more of the equatorial insulation ,that the june/july Arctic recieves, being absorbed by open water at higher latitudes. This leaves less and less potential differnce between either side of the air masses causing the jet. Less potential difference and so less vigurous exchange (i.e. slow, more convoluted jet). at some point the system falls and air masses are close enough mixes to 'mix' without event. this leads to less L.P. systems and more periods of higher pressure.

 

The inner continents have already been in drought episode since 07' with this being the 4th coming 'Russian heatwave' and rampant wildfires we have seen inconsecutive seasons, NOAA forecast a continuation of the U.S. drough afflicted regions. China, drought and wildfires (again). With less of a jet influence the continental 'home grown' highs expand ever further crimping Jet action into 'streaks' stuck over certain geographical regionswhose 'positioning' will make perfect sense once we see this occuring (God not here please!!!). Should the Azores High extend into the continental high we could see nothing but southern weather reaching us (plumes and dust laden heat surges).

 

Should we see the Jet Fail then the odds are the sub-tropical Jet will quickly shift north dragging the hadlet Cell with them ,extending the tropics rapidly and allowing more 'tropical' exchanges in our mid-latitude's weather.

 

None of these changes give a chance for the ice or any thoughts of recovery, in fact the only thing they could bring would be further re-inforcing mechanisms meaning open water from July onwards and a retreat in winter ice comparable with the noughties collapse of summer ice.

 

This will be fast. It will be a mini 'rapid climate shift' with global temps able to climb a couple of degrees in a decade (making all bet's 'off' about limiting change and signing the death warrent for the Permafrosts of the north.

 

We all know where 50yrs from that takes us.

 

Better not to dwell on this though as a matter of years stand between everyone having to accept the changes are with us or me looking a total Loon!

 

Watch for the H.P. dominance of the N.Hemisphere's summer and the fall off of Jet speeds until the only things plotted are the sub-T. Jet and odd Jet Streaks around the northern hemisphere where once the Polar jet ran?

 

As for solar remember we are at high levels and so should not 'enhance' northern blocking as we saw in 2009/10 (at solar min.)

[Gray-Wolf]

So? 

 

Has anyone noticed a different 'trend' to recent springs thus far?

 

I do not know whether I have convinced myself or whether my observations are 'true' (you can help me here!) but I think I am seeing far more H.P. Influence since March and a reluctance for any L.P. events to 'linger' over us leading to prolonged rainfall and over-saturation of the earth (not our Moors at least!).

 

When we look further afield we see the continental H.P. systems beginning to impact with Siberia now rapidly losing it's excess snow cover (and then the impacts this snow loss has on coastal sea ice will begin) but we appear to has mislaid the 'novel' H.P. from over Southern Greenland (keeping cool temps across W.Greenland at odds with recent summers).

 

As the inner continents now heat up I wonder if we will see a very hot summer developing for the majority of N.Hemisphere land masses?

[stewfox]

So? 

 

Has anyone noticed a different 'trend' to recent springs thus far?

 

I do not know whether I have convinced myself or whether my observations are 'true' (you can help me here!) but I think I am seeing far more H.P. Influence since March and a reluctance for any L.P. events to 'linger' over us leading to prolonged rainfall and over-saturation of the earth (not our Moors at least!).

 

 

 

I see a IJIS figure half a million above a few years ago and trending back to the 1990s ? Does that help ?

 

http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm

[Gray-Wolf]

No stew but the reason the AO was different might? The late SSW/Final warming? may have played a part in this and the Jet's position is key for the 'jump off' of the warm air (over the tibetan plataeu?) so it's positioning also comes into play.

I do not think we can deny that the year so far is not a re-run of the old 07' ice low synoptics?

[Gray-Wolf]

I'm surprised that so few folk are noting the different year we are having so far??? Not just here but across many parts of the N.Hemisphere?

 

Was last years record low not the 'start' of this new chain of events (as 07' was to the previous 'stuck' weather types areas had been plagued with?)

[Methuselah]

I'm surprised that so few folk are noting the different year we are having so far??? Not just here but across many parts of the N.Hemisphere?

 

Was last years record low not the 'start' of this new chain of events (as 07' was to the previous 'stuck' weather types areas had been plagued with?)

Well it might be. But then, it might not...Anyway, 'different year' to what? 1976? 2012?

[Gray-Wolf]

Now , now my little pedant Pete! The pattern of errant Jet stream that has lead to the 'washout' summers here (and flooding) and the U.S. East coast/Greenland High that impacted the rainfall/temps there?

 

At the start of the thread I suggested that last year low ice must have placed an added jolt into the mechanics that brought us the post 07' patterns (if you credit low ice with impacts on the N.Hemisphere circulation?) and that impact will have had 'knock on' effects since (as that 'Jolt/perturbation' subsides).

 

Should last years low ice also lead to an earlier drop in ice cover/snow cover this summer then those impacts will ramp up further?

 

As it is I'm seeing a lot more H.P. across the Atlantic and NW Europe than I've been used to seeing this past 6 years?

 

Have you noted anything similar?

[Methuselah]

Maybe yes; maybe no? But nobody has ever been able to reliably predict any season, as far as I am aware. So, why should this summer be any different? It is only 1 day old... 

[Gray-Wolf]

We used to be able to predict the season Pete? In winter..Cold, in summer... hot.

 

Did we not see one eastern Scottish town match winter solstice temps with summer solstice temps two or three years ago???

 

If you note Corrinth posts you'll know how Austria was over Chrimbo and such temps would suit me for June in my local???

 

Anyhow what I was 'angling' at with the thread is that the likes of prof Francis see the low ice impacting N.Hemisphere Jet patterns esp. after 07's low. From then up until last year ice was at a similar level come Sept but last summer saw a similar scale of a drop that Ms Francis sees as a drop off for recent Jet 'meanderings'.

 

With such a large drop off last Sept I thought any impacts that appear to 'intensify' those patterns might go some way to proving her findings? 

 

As it is I am seeing marked differences (though very early days yet) in the Jet's distribution so far this year?

 

We know things are far more complex than this in the 'weather system' but anything further agreeing with what Jennifer postulates must make it easier to short term plan seasons (even if it is to expect 1 of 2 extremes?)

 

The 'dropping off' of the Jet , across the Atlantic, is now becoming apparent with periods of wind speed so low as to not appear on the plots with only 'streaks' at ridge/trough portions of the river of air? This in turn must lead to more settled conditions below (doesn't it?) with a drop off in the number of depressions crossing over us (and duration of stay) that we have become accustomed to over the last 6 summers?

 

Again I'd say the loss of ice last year will lead to an even lower temp/pressure grad once the snow/ice responds to summer warmth so the back end of last years perturbations will be impacted by a stronger (earlier?) impact this summer/Autumn?

 

Imagine a swing in motion. Last years 'push' is still swinging the thing so how much energy , this year, is needed to have the swing at the same height a last years peak? I'd suggest less energy is needed so that if we end up with more we stand to see even more extreme reactions to this 'energy'. The same will then apply to next year with even less energy needed to hit the same height?

 

The comes a point that ice is so impacted that by late July we see ice levels similar to last summers min.

 

How much more energy gets harvested at that point?

 

Anyhow. More dry , settled conditions here (hosepipe bans by Aug anyone??) as the continental H.P.'s interact with the 'standard' H.P. locations in the rest of the N.Hemisphere and an alteration to the areas 'creating' low pressure. More of the Jet not being on the plots and higher ridges where we see it (inside the Arctic Basin?).

[BornFromTheVoid]

Whatever the hemispheric pattern, it doesn't seem to matter.

Snow cover is back down close to lowest on record, just as it has done for 23 out of the last 25 Mays. It seems we haven't had an above average summer snow cover since 1987

 

http://climate.rutgers.edu/snowcover/chart_anom.php?ui_set=1&ui_region=nhland&ui_month=6

 

To go from about 1.5 million km2 above average to almost 4 million km2 below average over 8 weeks will surely influence our weather in some way?

[Gray-Wolf]

 

 

http://climate.rutgers.edu/snowcover/chart_anom.php?ui_set=1&ui_region=nhland&ui_month=6

 

To go from about 1.5 million km2 above average to almost 4 million km2 below average over 8 weeks will surely influence our weather in some way?

 

I have to wonder why it didn't used to do similar before? If it didn't then it has to point toward more energy in the system being there to melt it all out???

 

EDIT: i think the guys crowing about how well the ice is doing have about 2 days left before we hit 2012's melt line (and follow it???). Better make the most of it guys! last chance 'till re-freeze.

Edited June 5, 2013 by Gray-Wolf

[Gray-Wolf]

Though very sad to see I have to wonder if the central European areas blighted by flooding will continue to see the trough stuck over then as we have this past 6 summers? If we do not see that anomalous S.Greenland high set up I have to wonder if that area has shunted to us ( giving us a run of HP dominated weather) whilst central Europe has 'our' Lows??

 

Has last years 'extra energy' persuaded the Jet pattern to shift round a bit shunting the weather types along with it?? If so we will have a splendid summer of frequent HP dominated weather and the chance of Spanish/N.African plumes to give us some fireworks once in a while? Perfect for me if that should occur!!!

[BornFromTheVoid]

The main proposed reason why extra energy in the north is impacting the jet stream, is it's reducing the energy or temperature gradient to the lower latitudes, meaning there is less energy in the jet stream, so it meanders around more. It's not a case of the extra energy in the north is invigorating the jet stream and sending the troughs further south and the ridges further north.

 

The work by Francis and Vavrus showed that the changes in the jet stream only start developing to a statistically significant level during summer, as the areas once cooled by snow cover are warming due to the sun heating the land. Blaming changes in the Arctic for the recent goings on in central Europe really has no physical basis to it. That's not to say it's impossible, but that there is no evidence for it yet.

 

We have a +ve AO, which is preventing any lasting -ve NAO from setting up. We still have a slow and meandering jet stream. As things aren't conducive for blocking over Greenland (-ve NAO) the blocking is setting up elsewhere, this time to our north and north east. Explain why the AO has gone +ve and you'll have a better explanation for why we've seen a shift in patterns this year. But for the recent unusual weather, we may not require looking at changes in the Arctic albedo for the main cause

[Gray-Wolf]

Hi BFTV!

 

I understand the role of the reduction in temp Grad ( and thickness) twixt pole and equator impacts the Jet over the period of low ice/greatest heating but the impacts, further on down the line, from 'tweaking' the system are what I'm cogitating over? 

 

Come Aug/Sept/Oct I will be looking to see if there are changes to the pattern that i can ascribe to the ice loss/snow loss but for now it is more how I imagine those impacts of late last year could still be resonating in the system? If there is a 'carry over' of the greater, more immediate impact, then I have to also wonder as to the effect this then brings into play over the next 'low ice' period? I used the analogy of a swing with 'low ice' being the shoves we give it. The slow wind down from this energy keeps the motion going and if this lasts until the next 'Push' then it would take less energy to reach the same height, or, to put it another way, a similar push this time would lead to the swing getting higher than last time?

 

If this is so then the weather patterns we witness would become more 'extreme' even with no 'extra energy' becoming available? Should more energy be available ( as seems likely to me as the remnant pack dwindles to 'seasonal'......and then that 'season' becomes longer under the sun) then we could see the perturbations to the systems appear greater than we might expect due to this 'remainder' from the previous year? A kind of feedback loop setting up that feeds itself and eventually provides a way of heating the far north even faster as the Jet 'peaks' push deep into the Arctic Circle pulling sub-tropical air with it?