Model Output Discussions 12z 01/06/2017

[mushymanrob]

19 hours ago, johnholmes said:

I think an objective acceptance of a fairly unsettled 7-14 days is the most likely outcome. Beyond that I have not enough depth of knowledge to give any guidance.

Yes, the anomaly charts are what I use for the above comment. They can be wrong just as any model output can but not very often and even less so if all 3 are showing a similar outcome and all 3 are doing so consistently over a number of days.

I spend time with each output and make a summary each day and this was my note in the file this morning.

Saturday 24 June and there is no sign of any major change on any of the 3 models=westerly unsettled type in general out day 14 at least!

The links are below

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

Some 'slight' signal for rising heights west of Iberia

http://www.cpc.noaa.gov/products/predictions/610day/500mb.php

again re the above, NOAA is similar, but shows little sign of this on the 8-14 day chart.

Just a very slight idea to watch perhaps?

the last height anomaly build though came overnight, the 8-14 day chart failed to pick it up in that timeframe and this appears to happen quite frequently. it wouldnt surprise me at all if there was a switch in their predictive pattern  as they re-align  when a height rise becomes apparent. it would fit with the general long wave pattern of troughing and ridging too..... im optimistic, but would be happier with a weaker jet.

[Singularity]

Another step forward with Azores High ridging across days 8-10 from both GFS (by day 8 ) and ECM (day 9 ).

As far out as this is, such a trend is significant given the insistence the models had been displaying with respect to maintaining a west-retracted Azores High.

Of course consistency in this trend or at least with something that fits as settled as the GFS 00z is needed before we can really start to breathe sighs of relief and raise the bar of hope.

[Summer Sun]

Looking at the pressure ensemble means we see a rise again in early July no signals yet for a big high but something more what we expect in the UK around 1010mb or a bit higher

[knocker]

48 minutes ago, Singularity said:

Another step forward with Azores High ridging across days 8-10 from both GFS (by day 8 ) and ECM (day 9 ).

As far out as this is, such a trend is significant given the insistence the models had been displaying with respect to maintaining a west-retracted Azores High.

Of course consistency in this trend or at least with something that fits as settled as the GFS 00z is needed before we can really start to breathe sighs of relief and raise the bar of hope.

I think to call a couple of charts in the day 8-10 range a significant trend and another step forward somewhat hasty particularly with little supporting evidence for this conclusion This morning's GEFs and EPS anomalies suggest that ridging in that range into the UK is transient and an indication of what has been noted for a couple of days now. And that is the percentage play is for LP to the NW and HP to the SW and thus a westerly upper flow. This is not an unusual pattern in our neck of the woods and does not preclude transient ridging as the cooler/warmer airmasses phase in the mobile pattern. But at the moment there little indication of any noted amplification. That is not to say that cannot change of course.

The EPS is little different out to day 14

Edited June 25, 2017 by knocker

[Singularity]

That's where the required consistency needs to come from, but we have to start somewhere and at such range ensemble means will inevitably trail operational runs. 

What I've done is essentially point out that an option has emerged against the 'flow' of recent model (including ensemble) guidance - from two major models at once - and this represents a significant possibility of a new path emerging.

I know some won't believe in such a method of interpretation but I have found it to serve me well enough over the years

[FetchCB]

In a sense of what be called IMBYism tainted with wishful thinking I am away on holiday in Cornwall first two weeks in July and have watched the ensembles with a fair degree of interest. 

It does seem to me that they mean pressure has on average (taken over the course of each day) been rising. When the first week came into view on the ensembles the first few days of July the mean was 1000 - 1010mb but now trends 1010 - 1020mb 

[knocker]

36 minutes ago, Singularity said:

That's where the required consistency needs to come from, but we have to start somewhere and at such range ensemble means will inevitably trail operational runs. 

What I've done is essentially point out that an option has emerged against the 'flow' of recent model (including ensemble) guidance - from two major models at once - and this represents a significant possibility of a new path emerging.

I know some won't believe in such a method of interpretation but I have found it to serve me well enough over the years

I'm not sure I quite follow that. Surely at that range the det.runs are becoming increasingly unreliable so that an agreement as to the upper air pattern (anomalies) between the various models is a good start to establish the framework within which the det, runs will operate to establish the detail. Det. can spot trends out in the yonder but then one has to be clever enough to know when this is happening. Working with both in tandem is a reasonable way forward IMO.

Edited June 25, 2017 by knocker

[bluearmy]

Intrigued by the developing Azores ridging in a weeks time. Transient or not ?? The eps ens mean says transient but the extended mean output has looked a bit unconvincing recently with lower height anomalies and higher pressure anomolies existing at the same time period in the 11/15 day timeframe. Beyond better the further se and worse the further nw you are, I wouldn't be calling early July just yet with any confidence. 

[mushymanrob]

27 minutes ago, bluearmy said:

Intrigued by the developing Azores ridging in a weeks time. Transient or not ?? The eps ens mean says transient but the extended mean output has looked a bit unconvincing recently with lower height anomalies and higher pressure anomolies existing at the same time period in the 11/15 day timeframe. Beyond better the further se and worse the further nw you are, I wouldn't be calling early July just yet with any confidence. 

well the current noaa anomaly charts would allow for anything other then transient, ill keep faith in them personally. but will continue to hope for something soon to emerge that will allow for a longer settled spell.

mind you, they arent looking bad at all, theres no monsoon in the offing which for me is most welcome!

[knocker]

The 06z gfs det. output is a classic example of the interplay (phasing) between the energy/troughs/cooler air emitted upstream and the warmer anticyclonic airmass to the SW/S.Thus you tend to get the switching between trough/HP influence with a N/S bias. Very much as the anomaly indicates. This does not rule out the possibility that more persistent amplification could occur but to my ageing eyes there is no discernible trend to indicate this at present. Care must be taken not to let 'winter syndrome'  infiltrate the summer thread when a snowflake spotted in downtown Leighton Buzzard in day 12 of the det run often initiates severe palpitations.

Edited June 25, 2017 by knocker

[knocker]

59 minutes ago, mushymanrob said:

mind you, they arent looking bad at all, theres no monsoon in the offing which for me is most welcome!

This should be kept in mind. Changeable weather is not all doom and gloom although if the prognostics come to pass, Scotland inevitable comes off the worst.

[DTHFCJ]

all looking fairly average which wont feel too bad...a bit on the damp side though,good growing weather as some might say

 

[Frosty.]

1 hour ago, DTHFCJ said:

all looking fairly average which wont feel too bad...a bit on the damp side though,good growing weather as some might say

 

Yes it's not too bad, pretty normal summer fayre during the week ahead with some warm sunshine but also spells of heavy rain / showers with a good chance of thunder.

[Summer Sun]

Improving slightly for the start of next weekend?

[CK1981]

45 minutes ago, Summer Sun said:

Improving slightly for the start of next weekend?

I hope it continues to improve. I'm having a BBQ on Saturday!

[I remember Atlantic 252]

1 minute ago, CK1981 said:

I hope it continues to improve. I'm having a BBQ on Saturday!

2 days later, opening day of Wimbledon 2017! where weather is a key thing, latest GFS shows, as a guess dry, mostly sunny, with temps of 25° and no covers needed

 

[Singularity]

You know, I'm making so much of this rather wobbly trend because of my knowledge of background drivers etc. - I am playing the 'spot the trend spotter' game that to be honest is the main reason why I follow the models with such enthusiasm.

GFS 12z is mighty close to a settled outcome next week but a particularly deep Atlantic trough (for the time of year) to the northwest keeps it changeable in the end, though with plenty of dry spells to be made the most of so... half-decent might be the summary unless of course you're looking for some proper warmth to return.

Speaking of which, the ensembles do now contain a few runs that develop a breakaway ridge into Europe, reminiscent of how the last fine and very warm/hot spell (for much of England and Wales) began but without such extreme heat lurking to the south, and funnily enough GEM has gone all slack and ponderous-looking for early-mid-next week which is also similar to before the aforementioned spell of weather.

Now I'm not saying that much should be made of this at this stage, but it is along the lines of what GP put across the idea of about a week ago, and something I've also been considering given the behaviour of certain teleconnections (on which I can't give away the details, sorry).

So it seems a lot of options are now on the table, albeit some of them just barely, with the ensemble mean starting to be more a reflection of wide spread among the ensembles leading to a mean signal that resembles climatology quite well, but with distortion due to numerous ensemble members producing particularly deep lows in the N. Atlantic - these being features that may help us or hinder us depending on the orientation of the jet stream, a detail that remains very unclear indeed but with a slight overall shift in the emphasis away from flat west-east (or even WNW to ESE), which offers some encouragement  .

[mushymanrob]

6 hours ago, mushymanrob said:

well the current noaa anomaly charts would allow for anything other then transient, ill keep faith in them personally. but will continue to hope for something soon to emerge that will allow for a longer settled spell.

mind you, they arent looking bad at all, theres no monsoon in the offing which for me is most welcome!

ive done it AGAIN.... that should read WOULDNT ..... i really must pay more attention..

[Summer Sun]

2 hours ago, Summer Sun said:

Improving slightly for the start of next weekend?

We can add ECM to the above as well

[Summer Sun]

A bit more positive from ECM tonight

[Frosty.]

13 minutes ago, Summer Sun said:

A bit more positive from ECM tonight

Yes it's always nice to see the azores high ridging in during summer..hope it keeps doing it for the rest of this summer into early autumn..things don't look as bad as recent model output suggested!

 

 

[knocker]

ecm 850mb temps and contours

[ANYWEATHER]

Evening All ,Hope you have had a good weekend. Outlook uninspiring at the ten day range from  Gfs and Ecm if you like High Summer weather . We have had a BIG  bite of the cherry this year with a hot spell the last week in May and another hot spell just last week the 3rd week in June. . Normal British weather resuming . Looks a 1975ish summer .intence downpours in some places .Bone dry in others

[knocker]

The EPS and NOAA this evening. Not much to add to my previous witterings except the rather intense upper low N.canada/Greenland is becoming a bit of a nuisance. So westerly upper flow portending a N/S split as systems tend to track ENE.

[Snowy L]

7 hours ago, Frosty. said:

Yes it's not too bad, pretty normal summer fayre during the week ahead with some warm sunshine but also spells of heavy rain / showers with a good chance of thunder.

I appreciate you being optimistic, but 14^oC (the forecast for Wednesday) is not normal summer fayre, it's standard early Spring fayre. That's 6 degrees below average. Friday/Saturday was typical summer weather: a bit of rain, some sun and feeling comfortable with temperatures of around 20^oC. Monday aside, there's no point beating around the bush, it looks terrible and it's weather typical of October, not late June.