Model Output Discussion - 17th Oct Onwards

[BLAST FROM THE PAST]

At the present time I'm seeing flooding as the bigger issue rather than the winds this time. It will be windy but I don't think we will see the winds of yesterday.

I know some on the winter thread are looking at the tropospheric vortex splitting at some point. Not sure to be honest, at the moment I'm seeing a mid latitude block near the uk being more likely than one to the north bringing significant cold. The ensembles for example paint a rather north/south split with the south becoming drier than of late with the north remaining wet and windy.

Yes, I'll go for that latter 2/3rds to half, first week, maybe first 10-12 days could be far more interesting though. Agreed the wind may not be th main factor but it will have its part, but flooding looks possibly being the real issue here.

BFTP

Edited October 29, 2013 by BLAST FROM THE PAST

[johnholmes]

The anomaly charts keep the unsettled/disturbed weather pattern throughout the next 15 days or so.

[Newberryone]

This is just one of those things, my opinions were based on this mornings output, not this evenings. Tomorrow will show something else..and so it goes.

In actual fact Karl my weather preferences are very similar if not completely so to yours. So in no way was I attempting to undermine or disregard your well respected output. We are in a very unstable atmosphere right now and a considerable change in model output from each run is only to be expected as your reply points out.

 

Unless my untrained eye is misinterpreting these charts there's very little sign of the Jet Stream migrating north anytime soon.

[Frosty.]

Thanks Newberryone 

[phil nw.]

Some recent posts have been moved here

http://forum.netweather.tv/topic/76235-model-banter-moans-and-ramps/

 

as they were more general comments rather than discussing current models.

 

Please remember folks there are the other threads for talking about preferences/hopes etc.

 

Thanks all.

[Bobby]

That low that comes up from the Azores around Friday is interesting, some models don't develop it much and it gets swallowed by the approaching main low while the GEM blows it up into a vigorous windy system with a lot of rain given the source. GFS is somewhere inbetween. If it does develop then rain will probably be more a issue than wind.

 

GEM   GFS 

 

Though 1 or 2 ensembles do this!

 

Edited October 29, 2013 by Bobby

[phil nw.]

That low that comes up from the Azores around Friday is interesting, some models don't develop it much and it gets swallowed by the approaching main low while the GEM blows it up into a vigorous windy system with a lot of rain given the source. GFS is somewhere inbetween. If it does develop then rain will probably be more a issue than wind.

 

GEM   GFS 

 

Though 1 or 2 ensembles do this!

 

 

 

That low that comes up from the Azores around Friday is interesting, some models don't develop it much and it gets swallowed by the approaching main low while the GEM blows it up into a vigorous windy system with a lot of rain given the source. GFS is somewhere inbetween. If it does develop then rain will probably be more a issue than wind.

 

GEM   GFS 

 

Though 1 or 2 ensembles do this!

 

Yes Bobby that warm air just lurking to our south west looks like a breeding ground for wave development.

Latest UK fax along with the 06GFS run shows it as a bog standard secondary running across the far south on Friday.

 

something to watch though.From this range the prognosis could well change.Looks like the next low you mentioned could be more of a feature as it deepens and runs up the west coast bringing another injection of colder pm air behind the cold front.

 

being on the boundary of the airmasses it looks like a continuing procession of lows and frontal features.

[Chess01]

Yes Bobby that warm air just lurking to our south west looks like a breeding ground for wave development.Latest UK fax along with the 06GFS run shows it as a bog standard secondary running across the far south on Friday.fax84s.gif 850.pngsomething to watch though.From this range the prognosis could well change.Looks like the next low you mentioned could be more of a feature as it deepens and runs up the west coast bringing another injection of colder pm air behind the cold front.111.pngbeing on the boundary of the airmasses it looks like a continuing procession of lows and frontal features.

how many days before the last storm was it picked up and did it develop as we got closer. I remember that there was downgrades about 48 hours before it hit us

[summer blizzard]

Positive indications from the ECWMF with the strongest jet energy moving east over time.

 

[Summer Sun]

Positive indications from the ECWMF with the strongest jet energy moving east over time.

 

 

ECM ensemble looks pretty good as well for high pressure to build just south of the UK

 

[Cheshire Freeze]

ECM ensemble looks pretty good as well for high pressure to build just south of the UK

 

 

Gavin, I don't think he meant positive for a high to build S of the UK. He presumably means the lowest heights are mixing out to the N of us and possibility of a bit more amplification from that point.

[bluearmy]

if any posters are looking for cold as we head into november, i wouldnt 'hold your breath'. however, beyond mid november, anything is possible (as usual) and those looking for clues in this regard would do well to ignore the atlantic charts and follow the NH profile instead.  look for possible vortex disruption. at this time of year, we would expect those purples to be getting darker and spreading out across the polar area. generally n greenland/n siberia is a favoured place for the darkest purple to reside. as the vortex is still to become strongly established, we should see some disruption showing in the fi output. that would be expected to be 'mixed out' as the runs come closer. i would be looking at op/control runs where the vortex strengthens and then begins to show signs of splitting/displacing/weakening (not just one run, but judge over a period of output). that illustrates all may not be well with it. you will only get a feel for this by looking at the NH profile, run after run.

 

just to iterate, forget whats happening this side of the hemisphere. it isnt important at the moment. get the vortex to weaken and colder conditions will probably get here in the end.

Edited October 29, 2013 by bluearmy

[summer blizzard]

Gavin, I don't think he meant positive for a high to build S of the UK. He presumably means the lowest heights are mixing out to the N of us and possibility of a bit more amplification from that point.

 

Yes, the normal response there would be for the high west of the Azores to amplify which would likely result in a north westerly for the UK.

[ChartViewer]

AO & NAO mean still positive as we look at 14 day forecast. Brings us to Mid November......Would hope both would start to go neutral/negative with hopefully a weaker jet/southerly tracking/split vortex and signs of colder weather as we head into latter stages of November....ready for Winter proper. Lovely HLB please as we enter early December.

 

 

 

[johnholmes]

how many days before the last storm was it picked up and did it develop as we got closer. I remember that there was downgrades about 48 hours before it hit us

 

I ran the Fax charts from Wednesday onwards with its origin pinpointed and checks done on each 00 and 12z run for positions predicted on Wednesday for 12z sat, 12 Sun and 12z Monday, the first two were spot on throughout down to the actual, the Monday 12z was obviously wrong and only began to be picked out late Saturday evening, first of all from the 18z GFS.

[Chess01]

I ran the Fax charts from Wednesday onwards with its origin pinpointed and checks done on each 00 and 12z run for positions predicted on Wednesday for 12z sat, 12 Sun and 12z Monday, the first two were spot on throughout down to the actual, the Monday 12z was obviously wrong and only began to be picked out late Saturday evening, first of all from the 18z GFS.

ok thanks by this post we should wait until Tommorow or Thursday to get a real picture of what's going to develop

[Panayiotis]

Haha, this is for my area. Will be interesting to see what the 12z shows!...

[Captain Shortwave]

Not much to report so far on the models, except the coming weekend looks like potentially being a washout

 

[Snowman.]

 

 

Its been a few runs and the GFS FI is still going with disruption over the pole with heights heading into the pole with a chunk of the Vortex over the Scandinavian area.

 

Plenty of time to change but its looking like we will see a pattern change during the second half of November but first we must deal with some significantly stormy weather and with calm periods inbetween.

[Matty M]

Does anybody have any experience of the accuracy of the NASA GOES5 model run at 0.25 degrees?

 

Is there statistics online?

[Panayiotis]

 

 

Its been a few runs and the GFS FI is still going with disruption over the pole with heights heading into the pole with a chunk of the Vortex over the Scandinavian area.

 

Plenty of time to change but its looking like we will see a pattern change during the second half of November but first we must deal with some significantly stormy weather and with calm periods inbetween.

Thats the 06z...

Does anybody have any experience of the accuracy of the NASA GOES5 model run at 0.25 degrees?

 

Is there statistics online?

If I remember correctly it didnt really perform well last year during the winter. It currently doesnt work atm though..

Edited October 29, 2013 by Panayiotis

[Captain Shortwave]

If I remember correctly it didnt really perform well last year during the winter. It currently doesnt work atm though..

It's back up and running now. It stopped during the US government shutdown.

[Snowman.]

Thats the 06z...

If I remember correctly it didnt really perform well last year during the winter. It currently doesnt work atm though..

I wrote it for the 6z

 

not sure what happened.

[Matty M]

Thanks, this chart caught my eye!

 

[snowking]

Does anybody have any experience of the accuracy of the NASA GOES5 model run at 0.25 degrees?

 

Is there statistics online?

I haven't seen any statistics online from the usual places, so I can't quantify it with numbers, but from experience of monitoring it I could possibly sum it up in one rude word...

 

GFS, GEM and UKMO all so far, whilst varying slightly in the track, are giving the same general idea of any low pressure weakening significantly just to the West of the UK before making landfall - UKMO demonstrates this best:

 

 

This has been a pretty consistent theme during today, with the exception of the 0z GEM and about 25% of the ECMWF and GEFS ensemble members.

 

So at the moment the most likely scenario is a pretty standard autumnal low. Probably enough to create some warnings closer to the time, but I suspect, as has been commented on through today already, that it is the rainfall that may be more headline-worthy than the winds this time around. And for anyone who lives in the areas most affected yesterday, I'm sure they would be rather more relieved at that for now. Of course though to those in Western parts of the UK, the potential for some concern by the end of this week.

 

SK