Model Output Discussions 12z 30/11/16

[karlos1983]

I quite like the CFS's take on the 7-14 day time frame, not out of the question and i'll take that everyday of the week over an active Atlantic.

And then of course there is January 

If you've got the mental strength to stay the course that is 

[Faronstream]

31 minutes ago, Ed Stone said:

Does the recent loss of any decisive cold signal mean that all the long-range models/forecasts are useless? No. Of course it doesn't! It means that things have changed. That's all.

So, stop whining about it and accept it. It's weather and it's unpredictable...Isn't that the beauty of it?

There are still 89 days of winter to go - if you count today!

I tried to write yesterday to another member that wrote almost the exactly same thing like you did now but my comment was removed so i will try again. Some people in here wants the snow and cold especially around christmas since december is the winter month with most action and heavy snowfalls ( stronger jetstream and humid air), just like some people wants the summer heat before august beacuse it is darker evenings and colder nights in august.

[Man With Beard]

Karlos - that shows perfectly what could happen - such a subtle shift.

Sorry to throw in a T0 chart but when I thought about it, this is a perfect example of how the macro picture was correctly forecast 15 days in advance (east-based vortex, lots of heights to the west), but things just not falling for us in the micro details - we were not far off being affected by the arctic plunge currently over Scandi:

[Weathizard]

10 minutes ago, Ali1977 said:

06z quite different at 144 over America, it still looks brutally cold but it may help with a change for us later in the run.

If anything I would say that chart is worse than the 0z, more pressure systems coming out the eastern seaboard and just a generally flatter pattern.

 

Edited December 2, 2016 by Weathizard

[feb1991blizzard]

Flat again.

[A.J]

10 minutes ago, Faronstream said:

I tried to write yesterday to another member that wrote almost the exactly same thing like you did now but my comment was removed so i will try again. Some people in here wants the snow and cold especially around christmas since december is the winter month with most action and heavy snowfalls ( stronger jetstream and humid air), just like some people wants the summer heat before august beacuse it is darker evenings and colder nights in august.

sorry, but this is not model output discussion.....please stay on topic......yes your post does have a point and is probably quite representative of how a lot of people think, but it simply isn't valid for this particular thread......and back to the model output discussion 

[lorrimor]

37 minutes ago, Nick F said:

I know yesterday I cautioned about posting premium EC charts from subscriptions, there is some EPS available freely if you know where to look, this is the week 3 from the EC46 updated yesterday from an Icelandic Weather Service page and shows, as bluearmy and GP have indicated, +height anomalies to the W and NW. Though looking at the 00z operational GFS - a long way off getting anything like that kind of anomaly going on ... is a change from the last EC46 - which had +ve HGT anomalies more over the Norwegian Sea and Iceland around similar time scale.

Hi Nick do you have a link to these charts on their site? Had a browse around it and can't find them. 

[Ravelin]

7 minutes ago, feb1991blizzard said:

Flat again.

At least the Jetstream is to our South, just about.

[Snowman.]

Peak of interests here on the 6z

The heights north manage to create trough disruption in the Atlantic this could create slow moving pressure systems that head south. 

 

[bobbydog]

Surprised at how many long standing members on here are banging on about how 'useless' long range forecasts are. We know how it works by now. They are estimates subject to change- not promises.

Anyway, the 06z has some quite big differences at 144hrs compared to the 00z

OK, it might not lead to a winter wonderland but it will mean a very different set up much further down the line. If such changes keep happening at relatively short range then just possibly, all the whinging and whining might have been for nothing. Keep watching....

[Ali1977]

I think American frigid cold will once again make the news this year looking at the latest run - proper cold.  Very different FI again this run.

[Man With Beard]

6 minutes ago, bobbydog said:

Surprised at how many long standing members on here are banging on about how 'useless' long range forecasts are. We know how it works by now. They are estimates subject to change- not promises.

 

But how useful are they if they change so much?

Last night I listed some of the successes that Glossea has had recently (we know thanks to Fergie's updates). But can anyone tell me of a reasonably successful D20-D46 forecast from the ECM 46 in the past year - apart from when it is predicting westerlies?

[bobbydog]

Just now, Man With Beard said:

But how useful are they if they change so much?

Last night I listed some of the successes that Glossea has had recently (we know thanks to Fergie's updates). But can anyone tell me of a reasonably successful D20-D46 forecast from the ECM 46 in the past year - apart from when it is predicting westerlies?

Do they change so much? Or do we only notice when they change when it matters (to our weather preferences)?

[Frosty.]

11 minutes ago, Ali1977 said:

I think American frigid cold will once again make the news this year looking at the latest run - proper cold.  

Plenty more YouTube snow videos to watch then!

This side of the pond the Gfs 6z shows a milder and more changeable southwesterly airflow arriving from next midweek.

 

Edited December 2, 2016 by Frosty.

[Snowman.]

3 minutes ago, Man With Beard said:

But how useful are they if they change so much?

Last night I listed some of the successes that Glossea has had recently (we know thanks to Fergie's updates). But can anyone tell me of a reasonably successful D20-D46 forecast from the ECM 46 in the past year - apart from when it is predicting westerlies?

They provide insight to give us maybe even a small idea of what we can expect, it's to avoid something like 2010 just appearing out of the blue. UKMO still believe that blocked end is probable just considering the range + factors they give caution that it's chances are still low.

 

[Methuselah]

5 minutes ago, Man With Beard said:

But how useful are they if they change so much?

Last night I listed some of the successes that Glossea has had recently (we know thanks to Fergie's updates). But can anyone tell me of a reasonably successful D20-D46 forecast from the ECM 46 in the past year - apart from when it is predicting westerlies?

They'd be a lot less useful if they were to go into Comical Ali Mode, wouldn't they, MWB? How would the doubters see computer models if they (the models, not the doubters) never adapted to ever-changing signals, and kept to a clearly defunct script?

[Man With Beard]

1 minute ago, bobbydog said:

Do they change so much? Or do we only notice when they change when it matters (to our weather preferences)?

Don't know. My gut instinct is that the ECM46 doesn't nail down specifics enough to be useful - for example, a month ago it was predicting northern blocking for right now, well, you could say there is a small positive anomaly to our NW right now but it doesn't seem in keeping with what was predicted, which I think was high pressure centred to our NW or even NE, and not over the UK. But you could be right, it could be selective memory. Perhaps others could add a situation where they remember the ECM46 saying something that turned out pretty accurate at a long range?

[gottolovethisweather]

Hi, all.

 

One thing to keep an eye out for is just how the NH Jet is forecasted to act over the coming days. At present, the start off point is a very blocked Atlantic setup as shown by this GFS 0z t+0 chart.

 

Come D5; we are beginning to witness changes, but they aren't really notable until then, next Wednesday, our weather isn't set to be affected by changes in the Jet beforehand. Before this, it is a case of as you were, dry, on the whole, some frosts and sunnier days, others cloudier, temperatures on the cold side for most.

The highlighted regions in red are ones to keep an open mind about because changes in the Jet profile off the eastern seaboard of the US up to D5 will have large ramifications for our weather into the second half of next week and beyond into the middle part of December. The black arrow doodle shows the probability that the Jet might dig yet further South than the GFS (as with all current modelling) predicts. 

 

 

The final chart I'll put up is from the first day of the newly emerged milder spell (IMHO a 70-80% likelihood of occurring) so still slight potential for things to alter at the surface yet, given the timescales involved. However, what is equally important for coldies is the forecast NH Jet at t+162 doesn't come about as suggested. Again my hashed out area encased in red and the black arrows hint at differing probabilities to those currently expected. 

 

 

 

Beyond this, I'm not endeavouring to suggest what might happen, synoptically, although I do currently believe down in my region (central southern England) not much will have changed, yes it might be milder by day with fewer frosts around, but there won't be much rain around again if any. The period up to Mid-December (8th through to 15th), therefore, is STILL very much up for grabs in my opinion.

Edited December 2, 2016 by gottolovethisweather

[Snowman.]

6 minutes ago, Man With Beard said:

Don't know. My gut instinct is that the ECM46 doesn't nail down specifics enough to be useful - for example, a month ago it was predicting northern blocking for right now, well, you could say there is a small positive anomaly to our NW right now but it doesn't seem in keeping with what was predicted, which I think was high pressure centred to our NW or even NE, and not over the UK. But you could be right, it could be selective memory. Perhaps others could add a situation where they remember the ECM46 saying something that turned out pretty accurate at a long range?

 

Literally right now. Blocking NW and a trough NE what was expected so I'm failing to see what the issue is. 

[Summer Sun]

48 minutes ago, feb1991blizzard said:

Flat again.

Any chance you could post a chart or charts to show what you mean?

Any newbies not familiar with these sort of terms could be rather confused

[bobbydog]

6 minutes ago, Man With Beard said:

Don't know. My gut instinct is that the ECM46 doesn't nail down specifics enough to be useful - for example, a month ago it was predicting northern blocking for right now, well, you could say there is a small positive anomaly to our NW right now but it doesn't seem in keeping with what was predicted, which I think was high pressure centred to our NW or even NE, and not over the UK. But you could be right, it could be selective memory. Perhaps others could add a situation where they remember the ECM46 saying something that turned out pretty accurate at a long range?

The long range models are subject to same issues as the shorter range ones, they rely on a huge amount of factors- each of which has to be individually forecast to collectively produce a weather forecast. As we well know, small changes to any factor can make huge differences down the line. With LRF's they can only ever be used to estimate broad-scale patterns, based on ensemble clusters. If a major influencing factor changes ( such as the MJO ) then so does the LRF. Like I said earlier, forecasts are predictions not promises.

[Frosty.]

5 minutes ago, Summer Sun said:

Any chance you could post a chart or charts to show what you mean?

Any newbies not familiar with these sort of terms could be rather confused

Just to add a bit more meat to the bone, high pressure to the south, low pressure to the north, westerly flow = flat..positive NAO.

[booferking]

A few ENS show a slight glimmer of hope around 8th 9th Dec, fingers crossed this trend can pick up

[feb1991blizzard]

Just now, Summer Sun said:

Any chance you could post a chart or charts to show what you mean?

Any newbies not familiar with these sort of terms could be rather confused

 

See how its a straight westerly coming right at us with now kinks in the flow, its not the worst ive ever seen because it is far south enough to not be outrageously mild and its west rather than SW flow, but theres no Northward meandering a way up stream, which if thers was could put us into cold down stream so with this set up, with these tyoe of setups your unlikely to get temps much below average and more likely above average.

[Man With Beard]

7 minutes ago, SN0WM4N said:

 

Literally right now. Blocking NW and a trough NE what was expected so I'm failing to see what the issue is. 

With respect that's exactly what I said above and I did actually check the very chart you're showing before I posted - there is a height anomaly to the NW and so I accept the ECM46 was right to a degree on a macro-scale, but I believe we were expecting high pressure to the NW - I mean, much further NW than what we see below - and because the ECM46 didn't get the micro-scale right, conditions ended up extremely differently to the general interpretation people were making in early November, and so to the man on the street it would be seen as being wrong.

Now the argument will be "Why are people expecting a D30/D40 forecast to predict the micro-scale details so precisely in the first place?" But that's the whole point. If it can't, then more caution is needed. I know some show caution already, but I think it is not enough. Just how many times has "Wait until mid-December" been mentioned on here this week - giving a rather stronger impression of certainty than is helpful???