model discussion Model output discussion 11th July onwards

[Frosty.]

There’s quite a few GEFS 12z members showing improvement from as early as 4th August!...so you never know, we might NOT be writing off the first half of August for anything decent?  

 

[MATTWOLVES 3]

13 minutes ago, Jon Snow said:

There’s quite a few GEFS 12z members showing improvement from as early as 4th August!...so you never know, we might NOT be writing off the first half of August for anything decent?  

 

Karl I will get you a knighthood if you mange to pick up on another fine spell at range..I think you managed it the other year from 2 weeks out.. Its always worth paying attention to those ens,especially when more and more of them start signalling a pattern change! All I can say is whatever your preferences folks I'm sure we will get a little of everything in the coming few weeks.

Enjoy the rest of your Weekends and sorry if I've offended anyone recently with at times...some of my overly bias views...there I admitted it..

Edited July 24, 2021 by MATTWOLVES

[Frosty.]

Looking further ahead between early / mid august, some GEFS 12z members become very interesting if you’re a summer fan!...of course, it may not become interesting, it may be vile but I’m just looking on the potentially bright side!...for sure we are going to pay for this weeks spectacular weather but summer ain’t over yet!! ?  

Edited July 24, 2021 by Jon Snow

[Mike Poole]

The big three at T144:

It is this ridge into Greenland that I think is wrong, it is too much!  I’ve highlighted it on the GFS chart, it is more hassle for some reason to scribble on the other two on an iPad.  The ECM chart is less good than UKMO but both have more of a push from the Azores high than the GFS.  But the NH view is useful now because of what else is going on. 

[MATTWOLVES 3]

UKMO day 7 chart courtesy of Brian's website. Perhaps the trough being pushed that little bit further NE..

[JayAlmeida]

The ECM 12z looks interesting tonight with the low pressure not being as close to us from friday into next weekend. Hope this comes off as I am on staycation in the south east.

 

Probably an outlier but still shows that we are yet to reach a consensus for next weekend.

 

Edited July 24, 2021 by JayAlmeida

[Singularity]

Judging by this, we're getting GFS runs picked out of a hat at the moment.

The 00z and 06z runs didn't take the MJO right across the tropical Pacific, either stalling or decaying it.

The 12z did, with the Azores High showing its hand in the 10-16 day range (albeit intermittently until the final few days) as a result.

EPS seem to have a better agreement on the MJO signal continuing across the Pacific, but are undecided on whether it remains an active event. At least this means we might soon see an ECM run that has a more promising day 9 or 10 chart.

I wonder if they're moving things along a bit quickly, though. Into the Indian Ocean by 7th August seems too early (we'd struggle to reach mid-August before another deterioration in weather pattern)... but time will tell.

[Uncertainty]

8 hours ago, bluearmy said:

And august is more than 4 weeks long ……I’m expecting a similar pattern to July with a warm/hot spell later in the month. 

So are the MO and BBC so yes it’s more than just a punt. The seasonals were pretty determined for HP to sit near us for August and I’d be surprised if they’re completely wrong at this range. That said, they’ve got a way to go to turn over the early August anomaly!

 

Usually there’s at least one cluster I’d settle for, on this occasion I’d demand a re-rack

!

 

Edited July 24, 2021 by Uncertainy

[Methuselah]

Nowt too heinous about today's GEFS 12Z ensembles:

    

[Mike Poole]

6 minutes ago, Ed Stone said:

Nowt too heinous about today's GEFS 12Z ensembles:

    

No, and there won’t be.  The idea that August is going to be a total rain fest, as some are portraying it, is for the birds, in my opinion.  Yes, there is an unsettled spell now, but did anyone ever say that this summer would be wall to wall heat?  I certainly didn’t.  What i do think, is that some credence should be put in the long rangers e.g. GloSea5 - this model has a warm and dry signal.  I see no need to worry because of one or two anomaly charts 14 days hence.  Look hard at the UKMO T144 would be my advice…we will see…

[MATTWOLVES 3]

15 minutes ago, Mike Poole said:

No, and there won’t be.  The idea that August is going to be a total rain fest, as some are portraying it, is for the birds, in my opinion.  Yes, there is an unsettled spell now, but did anyone ever say that this summer would be wall to wall heat?  I certainly didn’t.  What i do think, is that some credence should be put in the long rangers e.g. GloSea5 - this model has a warm and dry signal.  I see no need to worry because of one or two anomaly charts 14 days hence.  Look hard at the UKMO T144 would be my advice…we will see…

It was probably me Mike that forecast wall to wall Heat

Let's just say a SW/NE split could develop for argument sake with time on tonight's mean

[knocker]

23 minutes ago, Mike Poole said:

No, and there won’t be.  The idea that August is going to be a total rain fest, as some are portraying it, is for the birds, in my opinion.  Yes, there is an unsettled spell now, but did anyone ever say that this summer would be wall to wall heat?  I certainly didn’t.  What i do think, is that some credence should be put in the long rangers e.g. GloSea5 - this model has a warm and dry signal.  I see no need to worry because of one or two anomaly charts 14 days hence.  Look hard at the UKMO T144 would be my advice…we will see…

What are they saying?

[Mike Poole]

45 minutes ago, knocker said:

What are they saying?

Well I don’t really care because FI is <T144 at the moment in my opinion.  But these charts have suggested a UK trough for a while, for sure next few days, beyond that I’m questioning it.  

Edited July 24, 2021 by Mike Poole

[stodge]

15 minutes ago, Mike Poole said:

Well I don’t really care because FI is <T144 at the moment in my opinion.  

Well, perhaps, and in truth we can very often say that.

I'm still struggling to see any fundamental pattern change in the "near" future, the T+120 charts look universally unsettled with LP over or close to the British Isles.

ECM 12Z at T+120:

The development of either some form of mid-Atlantic ridging or heights over Greenland dragging the jet south (first indicated by GEM in all fairness) seems set for this coming week and into August.

I do concede cheerfully there are hints of improvement at the far reaches of GFS FI - both OP and Control at T+348 trending to a more settled evolution 

That's only August 8th so your "forecast" of a settled and warm August is obviously more than credible were such charts to verify. To this observer, however, we're entering a 7-10 day period of unsettled conditions - I agree not a complete washout but certainly rain or showers about and average to below average temperatures.

The major change is the return of colder air and lower heights to Greenland which allows the Azores HP to build NE and the jet to return north - a more "normal" summer synoptic pattern. 

We'll see if this verifies - for what little it's worth at this time, I think you're on the right track. I'll be watching GEM in three or four days if it picks up a similar signal.

[Kentspur]

4 hours ago, Uncertainy said:

So are the MO and BBC so yes it’s more than just a punt. The seasonals were pretty determined for HP to sit near us for August and I’d be surprised if they’re completely wrong at this range. That said, they’ve got a way to go to turn over the early August anomaly!

 

Usually there’s at least one cluster I’d settle for, on this occasion I’d demand a re-rack

!

 

Surely cluster 3 no? Makes a change this summer for a model ensembles set to forecast lower heights in the northwest rather than the south

[Methuselah]

Nowt cold in this morning's GFS 00Z run, so I wouldn't call it a 'disaster' by any means:

    

    

    

And, hoping the GEFS ensembles are in the right ballpark, much more comfortable for sleeping/working/thinking?

   

[carinthian]

23 hours ago, carinthian said:

I hope there is nothing definite about this long term chart from GFS. However some consistency in its runs showing a southerly tracking jet. This bodes for a period of unsettled conditions in August, especially in Southern Britain and the continent. Who would bet against early frost in Scotland ?

 C

ECM overview chart continues to show " Cool Scots " to start the new month. If those uppers are correct and with light winds , a first and very early frost of the season is on the cards  ! Crazy.

C

[mushymanrob]

14 hours ago, Mike Poole said:

The big three at T144:

It is this ridge into Greenland that I think is wrong, it is too much! 

But its there, clearly and consistently on the NOAA charts .

These charts are quite clear, there will be a strong Azores high probably just West of the Azores. There will be a strong Greenland high, there will be a connecting ridge between them that will probably give way allowing a succession of shortwave lows to pass. There will be a mean upper trough to our near Northeast and the UK will be under a negative pressure anomaly with a mean upper airflow from the Northwest.

With a pattern like that, there will be no quick route back to anything summery and settled, that pattern is about as far away from a settled warm summery one as you can get. IF these charts are proven to be accurate, then we will be getting cool, fresh, unsettled, showery conditions. Probably no monsoon as the jet stream appears to be heading far South of the UK.

The Azores high will go nowhere fast, the Greenland high will go no where fast, the troughing to our near Northeast has nowhere to go. Personally i absolutely HATE this pattern for this time of the year, but its there. So i think we can in all probabilty write off (for settled summery warmth) most of the first half of August, and possibly beyond, that though is speculation. For now ill back these charts for accuracy in the 6-14 day timeframe...... oh, and im doing a bit of research into their accuracy, ill publish when completed.

Oh, and im not looking for a protracted argument over this, lets just sit back and see whether these charts are proven accurate or not. I guess im in a win win situation, i want them to be wrong! lol

[MATTWOLVES 3]

Personally I think its risky to write of 2-3 or maybe 4 weeks of a season based on current output,thank God Exeter are not going this way currently. I eventually see the troughs lifting with an improving picture towards the South....Hell if we don't see another summery spell next month I will Happily retire to the amateur forecasting home

[Timmytour]

28 minutes ago, MATTWOLVES said:

Personally I think its risky to write of 2-3 or maybe 4 weeks of a season based on current output,thank God Exeter are not going this way currently. I eventually see the troughs lifting with an improving picture towards the South....Hell if we don't see another summery spell next month I will Happily retire to the amateur forecasting home

Matt I'm guessing by the first map that ECM is discounting the possibility suggested by NHC here?



Or if  such a system did end up forming, would it  have blown out by 3rd August anyway?

Edited July 25, 2021 by Timmytour
Wrong model originally mentioned!

[MATTWOLVES 3]

26 minutes ago, Timmytour said:

Matt I'm guessing by the first map that ECM is discounting the possibility suggested by NHC here?



Or if  such a system did end up forming, would it  have blown out by 3rd August anyway?

I think the Jet stream is currently way South ! Or heading that way..so its a case of seeing how that feature develops over the coming days,its then a case of a storm moving too Higher Latitudes,with the jet then having a role in where it may end up. I'm not sure of the current La nina or El nino cycles or whether neutral,which tend to be big factors in there development. Obviously one to watch,because can really shake up a pattern. Quite possibly this storm could head to the South if it fully forms and moves with the current Jet profile.. quite possibly,but worth keeping an eye on Tim..Thanks for that update regarding that potential storm though...something of interest

Edited July 25, 2021 by MATTWOLVES

[Methuselah]

25 minutes ago, MATTWOLVES said:

I think the Jet stream is currently way South ! Or heading that way..so its a case of seeing how that feature develops over the coming days,its then a case of a storm moving too Higher Latitudes,with the jet then having a role in where it may end up. I'm not sure of the current La nina or El nino cycles or whether neutral,which tend to be big factors in there development. Obviously one to watch,because can really shake up a pattern. Quite possibly this storm could head to the South if it fully forms and moves with the current Jet profile.. quite possibly,but worth keeping an eye on Tim..Thanks for that update regarding that potential storm though...something of interest

I don't really know what to make of this morning's GFS 06Z, Matt; inasmuch as it shows a slight -ive anomaly over Scandi and a weak +ive anomaly over Greenland, it seems to agree with the Anomalies? But, it also shows weakish ridging from the Azores, across southern areas, at times? Though, of course, each run can flip and flop, without necessarily wandering too far outwith the anomalies' envelope?

    

    

    

There are good reasons why Exeter make little effort at predicting day-to-day 'deviations' past ten days?

[mushymanrob]

NOAA anomaly chart accuracy..

Ok, ive gone back over the last 3 months of my own postings to discover how these charts have performed.

Ive used them 42 times, with the 8-14 day chart being used twice as many times as the 6-10.

They have been accurate or very accurate 70% of the time.
They have been inaccurate 30% of the time with totally wrong 7 out of 12 inaccurate occassions.

Very accurate = 22/42
accurate = 8/42
not very accurate = 5/42
wrong = 7/42

Most of the inaccurate readings came in late June/early July when for some reason there was a cluster of bad predictions.

They are very good at picking up the signals for a high pressure dominated pattern, and these signals are picked up at the 8-11 day range as a rule.

These findings support the findings @johnholmes did when he first researched these charts.

Its true that using the operational runs by themselves anything past around t144 becomes uncertain, but what these charts do do is extend that, so we can see the general pattern with some certainty, most of the time, out to t240, ten days. This is especially true in the 8-10 day timeframe when the two charts share those dates, and the 8-14 day chart follows on from the 6-10 day chart.

No model suite is perfect, these arent, but are, id suggest, the most accurate for the timeframe they cover and the stats suggest this to be true.

[MATTWOLVES 3]

29 minutes ago, mushymanrob said:

NOAA anomaly chart accuracy..

Ok, ive gone back over the last 3 months of my own postings to discover how these charts have performed.

Ive used them 42 times, with the 8-14 day chart being used twice as many times as the 6-10.

They have been accurate or very accurate 70% of the time.
They have been inaccurate 30% of the time with totally wrong 7 out of 12 inaccurate occassions.

Very accurate = 22/42
accurate = 8/42
not very accurate = 5/42
wrong = 7/42

Most of the inaccurate readings came in late June/early July when for some reason there was a cluster of bad predictions.

They are very good at picking up the signals for a high pressure dominated pattern, and these signals are picked up at the 8-11 day range as a rule.

These findings support the findings @johnholmes did when he first researched these charts.

Its true that using the operational runs by themselves anything past around t144 becomes uncertain, but what these charts do do is extend that, so we can see the general pattern with some certainty, most of the time, out to t240, ten days. This is especially true in the 8-10 day timeframe when the two charts share those dates, and the 8-14 day chart follows on from the 6-10 day chart.

No model suite is perfect, these arent, but are, id suggest, the most accurate for the timeframe they cover and the stats suggest this to be true.

Like I've said before Mushy,I don't dispute your independent research into those charts...my point as always been all data beyond that 10 day window becomes very uncertain,and there will always be that element of bias towards climatology the further ahead we go. And this as been the answer I have received from other forecasters in the profession! The noaa charts are know doubt a very useful tool,but certainly not the be all and end all of compiling a forecast.

[Mapantz]

A bunch of posts moved over to here

That's the place for general chit-chat about Summer.