In Depth Model Discussion, Analysis and Summaries

[Uncle_Barty]

There is a lot of faith being placed in the CFS at ridiculous ranges (20-odd days plus) and is no better than looking at 300+ on GFS.

I am finding that constant reference to it is adding to the 'white noise' in the MO threads. Perhaps we need a separate thread for the very long range models such as CFS because I don't think it adds anything to the day-to-day MO thread....

[phil nw.]

There is a lot of faith being placed in the CFS at ridiculous ranges (20-odd days plus) and is no better than looking at 300+ on GFS.

I am finding that constant reference to it is adding to the 'white noise' in the MO threads. Perhaps we need a separate thread for the very long range models such as CFS because I don't think it adds anything to the day-to-day MO thread....

I tend to agree Jim.

At the moment though we simply have a Model Discussion Thread to cover all outputs so i guess this has to include these long range charts.

Like you though i am sceptical wrt their regular appearances in the thread by some members and would rather see more use of the more immediate outputs.

Edited June 3, 2012 by phil n.warks.

[Methuselah]

I tend to agree Jim.

At the moment though we simply have a Model Discussion Thread to cover all outputs so i guess this has to include these long range charts.

Like you though i am sceptical wrt their regular appearances in the thread by some members and would rather see more use of the more immediate outputs.

That may be something for us to discuss, phil?

[phil nw.]

That may be something for us to discuss, phil?

I have posted a reply in the Hosting Thread mate.

[BLAST FROM THE PAST]

Summer is not all lost, we could have a decent hot spell last week of June, similar to turnaround we had in May?

BFTP

[cooling climate]

There is a lot of faith being placed in the CFS at ridiculous ranges (20-odd days plus) and is no better than looking at 300+ on GFS.

I am finding that constant reference to it is adding to the 'white noise' in the MO threads. Perhaps we need a separate thread for the very long range models such as CFS because I don't think it adds anything to the day-to-day MO thread....

Agreed. I think it is bad enough them being regularly referenced in the model output discussion thread

(J. Holmes must be pulling his hair out), but to have them in the technical discussion thread does the

thread no credit at all. Why would G.P. want to have his posts lost amongst such triviality.

Also one liners such as I think the weather will be this or that in a week or two's time with no explanation

as to why (in other words a hopeful guess) also adds nothing to what should be more knowledgeable

and technical discussion like it says on the tin.

[Glacier Point]

Over the last week, NWP has continued with a general improvement theme. However, this has remained in the realms of extended range, seemingly not moving into a more reliable timeframe.

At the same time, models have begun to pick up the potential for a strong MJO wave to develop in phases 7-8-1. Arguably, the models were too progressive with this signal (I lost count of the number of mornings' updates which seemed to be a carbon copy of the last).

GFS ensemble product:

UKMO ensemble product:

That is something of a pattern changer, hence why met organisations invest so much in the modelling of the MJO.

With angular momentum running close to normal, and the SOI tanking negative,

...we shouldn't see too much interference from these signals so definate prospect for at least a steady improvement in the pattern with our longwave trough finally lifting out and shifting mean position further west allowing much more of a ridge and more settled conditions to take root.

[phil nw.]

Yes i have been following the MJO outputs Stuart and indeed the forecasts to a more active MJO period with movement to those phases you mention have been repeating for a few days now.

I was reluctant to post on those as the daily modelling in the 10day range was giving mixed signals wrt to where Height rises were coming from.

I see this evening the 8-14day 500hPa anomls are at last showing a slow erosion of the UK trough towards the Atlantic, with hts rising from the south east.

with some similarity to 12zECM/GFS mean hts.anomols days 8-10

For the first time for a while the NOAA forecasters have expressed higher confidence in the days 8-14 day forecasts-link to full discussions here.

http://www.cpc.ncep....day/fxus06.html

With the MJO on it`s way towards Phase 8 the composite MJO 500hPa anomols. reflects the later mean outputs

so reasons to be looking at some real change to the wave pattern in the medium term.

We have some unsettled weather still to get through before then but some real hope of something more like Summer towards the last week of June? I really hope so.

[J10]

Yes i have been following the MJO outputs Stuart and indeed the forecasts to a more active MJO period with movement to those phases you mention have been repeating for a few days now.

I was reluctant to post on those as the daily modelling in the 10day range was giving mixed signals wrt to where Height rises were coming from.

I see this evening the 8-14day 500hPa anomls are at last showing a slow erosion of the UK trough towards the Atlantic, with hts rising from the south east.

with some similarity to 12zECM/GFS mean hts.anomols days 8-10

For the first time for a while the NOAA forecasters have expressed higher confidence in the days 8-14 day forecasts-link to full discussions here.

http://www.cpc.ncep....day/fxus06.html

With the MJO on it`s way towards Phase 8 the composite MJO 500hPa anomols. reflects the later mean outputs

so reasons to be looking at some real change to the wave pattern in the medium term.

We have some unsettled weather still to get through before then but some real hope of something more like Summer towards the last week of June? I really hope so.

Fingers Crossed that this comes to fruition, quite often pattern ending June is the one to continue. I seem to recall in recent Junes, the best case scenario painted in the models also panning out, while currently the opposite is seeming to occur, so a role reversal would be more than welcome.

[BLAST FROM THE PAST]

It seems the MJO is in line with my thinking, whether we have main influence from Scandi HP or AZH remains to b seen...maybe a linkage of the two, but settled and warm being theme. How long it lasts.....lets get there first. The very southerly tracking jetstream has been our real problem and I suspect it'll plague us throughotu the summer.

BFTP

[johnholmes]

Agreed. I think it is bad enough them being regularly referenced in the model output discussion thread

(J. Holmes must be pulling his hair out), but to have them in the technical discussion thread does the

thread no credit at all. Why would G.P. want to have his posts lost amongst such triviality.

ta but not a lot to pull out!

[BLAST FROM THE PAST]

Who knows Fred about how things are going to come to fruition? All I know is el niño is coming so he will warm up summers globally. I think it will be an el niño modoki as its developing westwards. GP what are the current diagnostic pressure patterns for July and August?

I think any El Nino will be modified by the strong -ve PDO phase we are in, indeed neutral enso conditions are just as likely? Interesting year ahead.

BFTP

[Methuselah]

Am I wrong, or are the 'predictions' for the QBO, MJO, PDO, NAO etc. just as subject to change as the prognostications that stem from them? And, if so, doesn't that make such prognostications even more inherently unreliable?

[johnholmes]

All outputs based on anything predicted are liable to being wrong from time to time. NOTHING in meteorology , short or at long time scales is infallible. That is why professional and knowledgable amateur forecasters will use as many models and predictions as possible before they make a judgement on what they feel the weather is most likely to do.

There is an interesting article in a recent Weather which I am hoping I am going to be allowed to copy in full about this type of thing. Its not about the lrf type really but it does show just how much of a balancing act the job is.

[Gael_Force]

All outputs based on anything predicted are liable to being wrong from time to time. NOTHING in meteorology , short or at long time scales is infallible. That is why professional and knowledgable amateur forecasters will use as many models and predictions as possible before they make a judgement on what they feel the weather is most likely to do.

There is an interesting article in a recent Weather which I am hoping I am going to be allowed to copy in full about this type of thing. Its not about the lrf type really but it does show just how much of a balancing act the job is.

Thank you. I was feeling quite put-down after Cooling Climate's stiff rebuke for including links to medium and seasonal model output.

[johnholmes]

for what it's worth and not that technical at all this is my take after a couple of days to look at the various ouputs-excuse the short hand

Thur 14 june Ec-gfs

And still some differences, gfs shows more signs of rising heights to south, ec does not and both shows some differences in how they treat the trough although each has 500 flow into uk from s of west –they tend to be similar further west with ridge trough set ups

After now seeing two lots of runs from all 3 I would suggest there is no major long term pattern change. However probably enough to give some break from the present unsettled spell towards end june/early july with some warmth returning for a few days.

There seems to me no really strong signal from any source as to how july might turn out. Yes the mjo is being predicted to show more blocking but it is no more accurate than other trend indicators to me. The ao and nao are both showing signs of less –ve and the overall enso signature is not a strong one either way. Maybe getting it ‘correct’ 10-15 days is the best we can expect with current conditions.

Edited June 14, 2012 by johnholmes

[johnholmes]

re post 1562

Sadly after reading my exchange of e mails with Paul Hardaker, retiring CE of R Met Soc, I feel I cannot do what I wished to do. When I get time I may copy by hand some sections which may give a better understanding of the decision making by a professional forecaster using all the available output-not now not enough time.

Edited June 14, 2012 by johnholmes

[lorenzo]

Spent a wee bit of time this afternoon looking at the El Nino bulletin and trawling back for similar analog years in order to play around in the map room. Fed up of this Autumnal weather and looking for a way out !!

One of the ideas from the latest update is that Nino conditions will develop from August.

Animation http://policlimate.com/weather/SST/tcheat_globe.html

ASO Nino Years were 1976 and 1977. For reference JJA Years were 1951, 2002, 2009. JAS Years 1968 and 1986, so used these in the map room and then factored in this years 2 memorable anomalies, the March and May HP cells, no other reason than curiosity..

Years with similar March anomaly and transition to El Nino provide this for July and August.

Years with similar May anomaly and transition provide the following.

Then all analog years with late summer transition to Nino conditions, showing July then August.

1977 really stuck out when trawling the archives very similar for the May anomaly.

Had a peak at the ppn charts on CFS regarding our recent deluge and an interesting anomaly showing for November..

Hoping for the July analog to come up trumps and everything crossed for that month.. Feels like Autumn today.

[phil nw.]

Wait a minute, now October looks like when version 1 will discontinue.

It would be good if you would post some links/images and perhaps some explanation on what this means to our weather Ledders.

It`s seems like you are thinking aloud and it`s hard to understand what you mean.

It would certainly help people viewing this thread looking for some guidance on the weather prospects beyond the nearterm.

Edited June 15, 2012 by phil n.warks.

[lorenzo]

GP, what do you make of the potential impact of this latest GFS MJO prediction?

[phil nw.]

For phils request I have decided to provide some links to the ENSO from CFS version 2.

Here is the monthly version:

http://www.cpc.ncep....3/nino34Mon.gif

Here is the seasonal version:

http://www.cpc.ncep....3/nino34Sea.gif

Both indicate el niño and now to the z700 which gives us a rough idea of height anamolies.

The monthly version:

http://www.cpc.ncep....bz700e3Mon.html

This to me indicates near average heights towards britain and Ireland for July whereas August looks a bit more dicey with northern blocking. It could all change but that is the current state of play.

Thanks for that ledders-it does help us to see what you are commenting on.

From those 500hPa anomls from the CFS it does look like we are forecasted a mean Westerly flow with a suppressed Azores High for July.

Of course they are very broadly based charts and i am always sceptical of CFS outputs beyond around 2 weeks as there are so many background influences that can change those forecasts as we get nearer.

Still thanks for those.

[lorenzo]

Re MJO and the 10 to 14 day out looks, quite a difference in forecast from GFS to ECM.

ECM quicker to phase 2, may change the pattern sooner than expected...?

[summer blizzard]

Am I wrong, or are the 'predictions' for the QBO, MJO, PDO, NAO etc. just as subject to change as the prognostications that stem from them? And, if so, doesn't that make such prognostications even more inherently unreliable?

Nope, the QBO and PDO are very predictable as they move in phases over several months, NAO and AO are difficult however.

[summer blizzard]

Personally i go by the MEI for El Nino/La Nina, i find the forecast models far too limited.

Going by the MEI i suspect that we may just see moderate strength in early Autumn before a slow decline afterward, it looks strongly like we will see a neutral QBO trending positive.

[cooling climate]

Nope, the QBO and PDO are very predictable as they move in phases over several months, NAO and AO are difficult however.

Could you elaborate on the PDO phases as I have never read any literature about this.

Sure the PDO can fiip one way or another for a short period opposite to whatever

long term phase it is in but to say it has phases of several months is inaccurate I believe.

As for the QBO you may well be right but at the moment I would put my money on a

negative phase in the lower stratosphere this winter which would leave the troposphere

more susceptible to blocking episodes possibly.