In Depth Model Discussion, Analysis and Summaries

[mushymanrob]

yes a sobering chart Roger

Likewise your comment about the wavelength

Its rather hard to see how this may change, what might be the lever to alter it? Hard to tell. Possibly an active short wave that might just trigger a reset, in a different place, of the major wave length pattern.

Nothing I see at any time scale on the teleconnections suggests this part of the N hemisphere is going to see any marked heat for this month, other than the odd day or two, chiefly for southern areas, or indeed into August really.

Like I say, sobering chart and sobering conclusions!

let's hope I'm wrong.

tbh i think your experience needs to be heeded, and whilst some optimists still bleat on about summer being not half way through, and its daft to 'write it off' (in terms of a decent hot spell)summer, if theres no tangible sign of anything that would lead to the evolution of such an event, then the likelyhood is that this summer isnt going to deliver anything sustained and hot... all we can do is that sometime soon there are signes of a positive evolution towards a hot spell...

ps.... doesnt this chart suggest something better after the 16th?.. (the top chart)

Edited July 8, 2011 by mushymanrob

[johnholmes]

tbh i think your experience needs to be heeded, and whilst some optimists still bleat on about summer being not half way through, and its daft to 'write it off' (in terms of a decent hot spell)summer, if theres no tangible sign of anything that would lead to the evolution of such an event, then the likelyhood is that this summer isnt going to deliver anything sustained and hot... all we can do is that sometime soon there are signes of a positive evolution towards a hot spell...

ps.... doesnt this chart suggest something better after the 16th?.. (the top chart)

hi mushy

Its one chart though, at this time scale we have to look at all available output. The AO and NAO are affected by telec's further out. Indeed they in turn are affected by something further out.Its very very complicated and GP or ch are more 'with it' in this field than me.

No disrespect to GP but his predictions are just as liable, even with the huge amount of time and reflection he puts into the longer forecasts for a season ahead, can and do go wrong.

In what I call the reliable time frame 10-20 days ahead there is really nothing that is giving a strong enough signal over a long enough period to lead me to believe any marked change is going to occur in the time scale just mentioned.

As I've suggested above following the chart Roger showed, even then, unless something starts to show, several telec's, for a week or so, then the outlook beyond 20 days, other than any short spell 1-3 days in length, is not looking very promising.

I hope I'm wrong.

Edited July 8, 2011 by johnholmes

[Roger J Smith]

To my little eye, having that much warm air trapped that far north is like having ten thousand euros in a Greek bank account, it might still be there next month, but it might just all leak out into space somewhere too.

[Duane S.]

Sobering indeed.

Many indicators pre-summer were more than hinting at a very decent summer and we certainly had a great start but so far summer proper has been very UK average and to be honest I see little sign now of that changing for a while

It seems to be as if there are forces at work over-riding those which should have given us a better June and July and (as as been the case for a few years now) dragged the jetstream south. A lag effect from the recent lack of sunspots? Weak gulfstream? Recent volcanic activity?? A combination of them all? All too complicated for anybody, or any computer (now or in the future I suspect), to factor in and come up with a definitive answer but I certainly think solar influences ARE at play here.

That said I would take a punt on an early August 'heatwave' as high pressure forms over Svalbard allowing NE retrogression and a spell of warm settled weather a sinking high sitting perfectly to draw in hot African winds for a few days over the UK before the summer ends in a washout.

Edited July 8, 2011 by s4lancia

[mushymanrob]

hi mushy

Its one chart though, at this time scale we have to look at all available output. The AO and NAO are affected by telec's further out. Indeed they in turn are affected by something further out.Its very very complicated and GP or ch are more 'with it' in this field than me.

No disrespect to GP but his predictions are just as liable, even with the huge amount of time and reflection he puts into the longer forecasts for a season ahead, can and do go wrong.

In what I call the reliable time frame 10-20 days ahead there is really nothing that is giving a strong enough signal over a long enough period to lead me to believe any marked change is going to occur in the time scale just mentioned.

As I've suggested above following the chart Roger showed, even then, unless something starts to show, several telec's, for a week or so, then the outlook beyond 20 days, other than any short spell 1-3 days in length, is not looking very promising.

I hope I'm wrong.

understood and thanks!

That said I would take a punt on an early August 'heatwave' as high pressure forms over Svalbard allowing NE retrogression and a spell of warm settled weather a sinking high sitting perfectly to draw in hot African winds for a few days over the UK before the summer ends in a washout.

that would keep me happy! just a week of heat is all i ask!

i note the mjo is predicted to move into phase 8, pass through phase 1 and end up in phase 2 ..... IF that happens wouldnt phase 2 lead to better weather esp in the southeast? (ive viewed the phase 2 mean for july, isnt bad)

Edited July 8, 2011 by mushymanrob

[BLAST FROM THE PAST]

Think if we want the jet stream further north we need higher sunspot activity - this seems to indicate to me that the solar cycle 24 is on the rise but not very much: http://www.solarham.com/

So unless we get higher sunspot activity and higher geomagnetic field we are pretty much stuck with what we have got with a southerly tracking jetstream pattern.

With [iMO] a pending Grand Minima, perturbation cycle of La Nina domination, lunar cycle all pointing to a southward shift of the jetstream [as observed over last 3-4 years] set to continue I wouldn't hold my breath. I believe that we won't as suggested see much change for a wee while yet. This seems to be 'supported' by RJS post and JH thoughts which have come from a different angle.

I have noted Roger's analogy.......that tells a story to me.

BFTP

[mushymanrob]

ok.... heres todays mjo predicted path... i see that by next weekend its predicted to enter phase two, which i believe is better for summery weather then phase one. (although viewing the monthly mean, phase 6 for august looks best! lol).

question... how long, what is the timelapse, between the mjo favourable phase and the unfavourable one... er... if phase 2 is 'better' how long after it enters phase 2 will we see the benefits here?.. i dont understand how the graph works, im assuming that the further from the centre, the stronger the signal...yes?

sorry for all the q's but if i can learn to read these things properly, i wont have to moan and expect others to tell me what they mean! :lol:

[chionomaniac]

ok.... heres todays mjo predicted path... i see that by next weekend its predicted to enter phase two, which i believe is better for summery weather then phase one. (although viewing the monthly mean, phase 6 for august looks best! lol).

question... how long, what is the timelapse, between the mjo favourable phase and the unfavourable one... er... if phase 2 is 'better' how long after it enters phase 2 will we see the benefits here?.. i dont understand how the graph works, im assuming that the further from the centre, the stronger the signal...yes?

sorry for all the q's but if i can learn to read these things properly, i wont have to moan and expect others to tell me what they mean! :lol:

Rob, the 500hPa anomaly charts that have been constructed helpfully by Alan Huffman do not have any timelapse involved at all. What he did was to look at each phase of the MJO that occurred in each month and then constructed the anomaly charts using those correlated dates. So in fact what we see are the anomaly charts for that particular phase derived from a number of dates.

The MJO forecast that you have shown a strong likelihood that The MJO will stay in phase 1 for some time. The phase 2 forecast is less certain (MJO FI if you like). The Phase 2 anomaly chart to me suggests no overall pressure pattern likely. It looks somewhat of an in between phase, with phase 1 having a trough dominating the UK and phase 3 a ridge. I would exercise caution until we see the MJO head towards phase 3. On top of this we need to remember that the MJO is a tropical determinant of longwave patterns and we need to take into consideration the extratropical factors (such as mountain torques) that will also have a bearing on the longwave pattern.

[mushymanrob]

Rob, the 500hPa anomaly charts that have been constructed helpfully by Alan Huffman do not have any timelapse involved at all. What he did was to look at each phase of the MJO that occurred in each month and then constructed the anomaly charts using those correlated dates. So in fact what we see are the anomaly charts for that particular phase derived from a number of dates.

The MJO forecast that you have shown a strong likelihood that The MJO will stay in phase 1 for some time. The phase 2 forecast is less certain (MJO FI if you like). The Phase 2 anomaly chart to me suggests no overall pressure pattern likely. It looks somewhat of an in between phase, with phase 1 having a trough dominating the UK and phase 3 a ridge. I would exercise caution until we see the MJO head towards phase 3. On top of this we need to remember that the MJO is a tropical determinant of longwave patterns and we need to take into consideration the extratropical factors (such as mountain torques) that will also have a bearing on the longwave pattern.

not sure i understand that, because as i read it, the index moves into phase 1 tomorrow and stays for about 6 days, if theres no time lapse, that doesnt correspond with the next week of ridging over us... im confused dot com! (thanks anyway)

[UV-RAY]

Rob, the 500hPa anomaly charts that have been constructed helpfully by Alan Huffman do not have any timelapse involved at all. What he did was to look at each phase of the MJO that occurred in each month and then constructed the anomaly charts using those correlated dates. So in fact what we see are the anomaly charts for that particular phase derived from a number of dates.

The MJO forecast that you have shown a strong likelihood that The MJO will stay in phase 1 for some time. The phase 2 forecast is less certain (MJO FI if you like). The Phase 2 anomaly chart to me suggests no overall pressure pattern likely. It looks somewhat of an in between phase, with phase 1 having a trough dominating the UK and phase 3 a ridge. I would exercise caution until we see the MJO head towards phase 3. On top of this we need to remember that the MJO is a tropical determinant of longwave patterns and we need to take into consideration the extratropical factors (such as mountain torques) that will also have a bearing on the longwave pattern.

So a continuation of what we've been use to so far this summer. Oh dear I think mushy might feel a little depressed now you've told him that.

[chionomaniac]

not sure i understand that, because as i read it, the index moves into phase 1 tomorrow and stays for about 6 days, if theres no time lapse, that doesnt correspond with the next week of ridging over us... im confused dot com! (thanks anyway)

Remember to look at the 500hPa level. Whereas the trough may not be as distinct as some others, it is there at the 500hPa level. The 500 hPa anomaly charts should be used as a guide only due to extratropical factors that can modify the strength and positioning of any expected anomaly.

[Roger J Smith]

The high latitude block hasn't shifted appreciably today but if it would weaken and retrogress towards northeast Siberia then most other features might also retrogress which would probably create a more favourable set-up for the Azores high to ridge towards the UK in a week to ten days.

My index method of LRF was showing a heat wave in late July when I ran it in May and otherwise rather normal conditions most of the summer. Although some days in June ran below the index curve, in general it has been verifying fairly well so far. I expect the peak of warmth to occur around 25-30 July.

[mushymanrob]

Remember to look at the 500hPa level. Whereas the trough may not be as distinct as some others, it is there at the 500hPa level. The 500 hPa anomaly charts should be used as a guide only due to extratropical factors that can modify the strength and positioning of any expected anomaly.

oh right... thanks for that..

[BLAST FROM THE PAST]

The high latitude block hasn't shifted appreciably today but if it would weaken and retrogress towards northeast Siberia then most other features might also retrogress which would probably create a more favourable set-up for the Azores high to ridge towards the UK in a week to ten days.

My index method of LRF was showing a heat wave in late July when I ran it in May and otherwise rather normal conditions most of the summer. Although some days in June ran below the index curve, in general it has been verifying fairly well so far. I expect the peak of warmth to occur around 25-30 July.

That's my camp week Roger when I take my little Rhys.....so relying on you!!

BFTP

[La Bise]

Another one cheering on Roger for those dates...

[Downburst]

Is this excellent topic shut down? I know we are the mercy of the intelligent and considered input from GP and others, my own considerations could not in anyway compare. I don't want to be pushy but I miss the analysis. Perhaps there is another thread somehwere?

Many thanks

[The PIT]

I think it died would be nice if GP and others posted in this thread. Gave you good inkling of what to expect in the coming weeks

[davehsug]

I see that GP hasn't actually been active on the site since 5th July. I do hope he hasn't decided to leave us as a result of the summer forecast. It would be very sad indeed.

As he was a member of the site team, maybe someone could tell us?

[bluearmy]

its likely that an addition to the rampling household has taken a fair amount of his time up. stewart is not the type to allow a busted forecast to affect him. sh*t happens. anyway, as we head into autumn, hopefully more varied patterns will come into view and the model threads will get greater interest and input.

[davehsug]

Thanks Blue, I didn't know about that. Thanks

[Downburst]

Just to help others, http://www.cpc.ncep....e/sstanim.shtml

It really helps visualize the ENSO anomalies. However if only it was as simple as just ENSO reading.

Just to help others, http://www.cpc.ncep....e/sstanim.shtml

It really helps visualize the ENSO anomalies. However if only it was as simple as just ENSO reading.

Apologies http://www.cpc.ncep....s-fcsts-web.pdf

Latest update August 29th

Summary

•ENSO-neutral conditions are present across the equatorial Pacific.

•Sea surface temperatures (SST) anomalies are becoming increasingly negative in the east-central equatorial Pacific Ocean.

•Atmospheric circulation anomalies still reflect aspects of La Niña.

•ENSO-neutral is expected to continue into the Northern Hemisphere fall 2011, with ENSO-neutral or La Niña equally likely thereafter.

Update:

NAO http://www.cpc.ncep....a/nao.sprd2.gif

The ENSO pattern is near neutral now and forecast to stay there, which might be good in order to reduce the complexity of looking ahead. The NAO has been negative since early June, the last time I had any sort of summary weather, no suprise there. I think this Winter if ENSO remains very near neutral we can expect the NAO index to be the most useful guide to forecasting our weather, I know folks will say ENSO drives NAO to some degree and I can see that makes some sense, but from what I've read that is not totally proven. Anyway I would not be surpised now looking back at the Index that the previous long run of negative conditions may have come to an end and we go major zonal this winter. Thoughts anyone?

Greenland Blocking from http://www.climatelogic.com/forecasts/winter-2011-forecast-europe.html

"The effect of solar activity is more clearly seen in the Greenland Blocking (GB) index, which represents a high pressure center sitting, as the name suggests, over Greenland. The statistics shows that in 15 out of 18 winters since 1955 when January sunspot numbers were fewer than 25, the GB index was positive. The GB and NAO indices are inversely correlated with r = -0.83 for the period 1949-2010. It is interesting to note that the GB index experiences a strong positive trend since the late 1980s (Fig. 2). In December 2009, the GB index sharply increased and remained positive since then"

Very interesting in bold. Might be incorrect data of course and I know it is not as simple as that, but I'd love to see a map of sun spot activity over NAO index to see if there is any relationship as is suggested above. Anyone?

Edited August 29, 2011 by Downburst

[BLAST FROM THE PAST]

Interesting stuff. I am a believer that the solar perturbation cycle has a direct correlation with the NAO. It snugly fits with the PDO too. The pertubation cycle is approx 36 yrs in length and in Feb 2007 we switched to La Nina 'prevalence' cycle which correlates with a general -ve NAO set up. Since the switch we have certainly seen a -ve NAO and also the jetstream on a more southerly track bringing us winters that many believed only 3-4 years ago were utterly beyond us achieving due to AGW.

I don't think we will enter a horrendous -ve NAO state for months on end, we will experience + ve phases but I think the -ve prevalence will force its hand.

I see no reason to not anticipate at least one 'severe' month in winter.

BFTP

[Roger J Smith]

If you check this recent 500-mb hemispheric map

http://www.weatheroffice.gc.ca/data/analysis/sai_100.gif

the most anomalous warmth is found in eastern Siberia near the Sea of Okhotsk and the most anomalous cold is found over the Baltic regions.

The flow over North America and most of the Atlantic is not very far from normal values especially for a day following a coastal hurricane (which is now moving out of Labrador into the N Atlantic).

There was quite a change in the northeast U.S. from hot/dry to cool/wet from July to August, meanwhile the west coast here changed from cool/cloudy to warm/sunny. There are probably very few analogues for this which will make the long-range forecast interesting.

[The PIT]

Looks like this thread has died again pity.

[TonyH]

Looks like this thread has died again pity.

It will suddenly come to life in December no doubt, shame we don't get the 'expert' input year round though.