Model Output Discussions 12z 01/09/2016

[Ali1977]

Channel lows in East to North East winds then knocker - just what we like. Let's hope the Nov update is still showing this.

[Grimers]

On 10/9/2016 at 12:05, knocker said:

He also mentioned low pressure to the south west so i can envisage some warm south westerly zephyrs. He also added the caveat best wait for the November outputs.

I thought that low pressure to the SW brought SE winds from the continent meaning colder and drier conditions, certainly not winds from the tropical maritime air mass.

Edited October 14, 2016 by Grimers

[summer blizzard]

35 minutes ago, bobbydog said:

i wouldn't worry about short term variations for now, tentative good news is, from ian ferguson, the EC seasonal is showing HP anomalies over Greenland/N-NW of the UK. from november right through to february!

back to now, how will the track of TS Matthew affect the models now it is predicted to travel east into the Atlantic rather than curve back to the Bahamas?

Post-Tropical. Most of the tropical energy is already being siphoned off. 

Nicole is the one to watch.

[swfc]

would seem the winter rutting season is already here amongst a few members!!! anyway looking at the current set up things look calm and very pleasent

high pressure seems in control and typical autmn fair.the nhp and pv look to be going hammer and tongs to dominate but it looks a stand off atm.interesting looking as a novice at the qbo and enso ete and where that will go heading into winter? mild or cold who nos and the struggle the pros are having should be an indicator that its up in the air!!! chill and enjoy,whatever the weather

 

 

 

[phil nw.]

Again a reminder that this the Model discussion thread everyone.There are threads to expand on Winter prospects so please all let's get back on topic.

Thanks.

[legritter]

Its great having this forum gang ,good learning area some very sensible posts etc ,and i would just remind many of us including myself ,10DAYS ahead is a long time in chart forecasting so looking ahead 3/4 months is a minefield ,but still very interesting ,looking at current Data a good week ahead but low pressure moving in i feel ,cheers all 

[Frosty.]

1 hour ago, Grimers said:

I thought that low pressure to the south west brought SE winds from the continent meaning colder and drier conditions, certainly not winds from the tropical maritime air mass.

It can mean both William so you are right.

[knocker]

4 hours ago, Grimers said:

I thought that low pressure to the south west brought SE winds from the continent meaning colder and drier conditions, certainly not winds from the tropical maritime air mass.

Well it all does depend on where the upper low sets up shop and thus the surface low as can be seen on the latest GFS run so as to stay on topic. If that drifts SE then the wind will back SE and be rTm and in this context one must keep in mind sea temps around the UK being above average.

Edited October 9, 2016 by knocker

[Frosty.]

Yes I always look forward to this time of year when the SST's start to slowly fall!

The models show next midweek feeling chillier with strengthening ESEly winds with more showers for the east, some heavy and thundery with sunny spells between but the best of the sunshine and driest weather across the west of the uk but then a change to generally unsettled weather from the southwest by the end of the working week.

[Nick L]

Looking way further ahead, the EC seasonal has updated today. The GH500 anomalies throughout the winter are signalling fairly significant high-lat blocking. What I'm liking about this is that it's reasonably consistent with last month's run. Pinch of salt, definitely, but for coldies there is hope.

[Dancerwithwings]

1 hour ago, Nick L said:

Looking way further ahead, the EC seasonal has updated today. The GH500 anomalies throughout the winter are signalling fairly significant high-lat blocking. What I'm liking about this is that it's reasonably consistent with last month's run. Pinch of salt, definitely, but for coldies there is hope.

'Fergie weather' mentioned it yesterday in the E.N.S,O Thread 

"Indeed it did. Essentially it runs an consistent story through N-D-J-F of +ve GPH/MSLP anomalies to NW/N of UK; -ve ones to S/SW".

  and in he's words he also said (below)

 

Edited October 9, 2016 by Dancerwithwings

[SMU]

1 hour ago, Nick L said:

Looking way further ahead, the EC seasonal has updated today. The GH500 anomalies throughout the winter are signalling fairly significant high-lat blocking. What I'm liking about this is that it's reasonably consistent with last month's run. Pinch of salt, definitely, but for coldies there is hope.

 I think I hinted @ this with the October AO ( thus far ) supporting the follow on through the Winter...

[Captain Shortwave]

Hmm well the models are certainly heading towards a more unsettled mid-range outcome now.

   

Low pressure to our north west gets squeezed between heights to our north east and rising pressure in the Atlantic resulting in a trough developing close to the UK. There are differences in the location of this low, the UKMO has it over the UK, the GFS develops this over central/southern Europe before drifting it slowly towards us. Not a usual pattern again for October and certainly not the increasing westerly influence we would usually expect.

[knocker]

Cool and chance of heavy showers in the easterly midweek with England under the influence of the trough to the south and south east. Then the conduit from Canada comes into play with active troughs running around the Atlantic HP down over the UK portending an unsettled and quite wet weekend.

And right at the end of the run there is an Arctic plunge with a deep trough over the Baltic.

Edited October 9, 2016 by knocker

[TomDav]

Quite strong Greenland blocking at the end of the run

[Frosty.]

Although the form horse is for an unsettled end to the week ahead with a trough either over or close to the uk, I found a couple of GEFS 12z perturbations which show high pressure and there were others with HP close by so it won't necessarily be wet next weekend.

[Matthew.]

1 hour ago, Captain Shortwave said:

Hmm well the models are certainly heading towards a more unsettled mid-range outcome now.

   

Low pressure to our north west gets squeezed between heights to our north east and rising pressure in the Atlantic resulting in a trough developing close to the UK. There are differences in the location of this low, the UKMO has it over the UK, the GFS develops this over central/southern Europe before drifting it slowly towards us. Not a usual pattern again for October and certainly not the increasing westerly influence we would usually expect.

I think there's been a number of unusual patterns this year and still no sign of depressions sweeping through the UK for the 2nd half October. This will be interesting for developments longer term.

[SMU]

Well well - an interesting 48 period of model watching -

24 hours ago the models moved away from the retrograde scenario & replaced it with hope of a warm southerly -

Now just 24 hours later thats been shunted away east as the Upper trough repositions to the south / south west of the UK - delivering cool ENE winds..

interesting...

[Frosty.]

I'm changing gear into cold ramper mode

The GEFS 12z perturbations show some chilly scenarios during late october and these indicate possible arctic maritime airmass heading our way.

[Matthew.]

The Jet Stream seems to have stopped for the weekend on the ECM as the Low hardly moves:

[Frosty.]

A chilly feeling Ecm 12z this evening with a nagging Easterly flow for most of the week ahead and the other feature is the trough later in the week that sticks over the uk for several days..so, in the days ahead its cooler than average with sunshine and showers, the showers especially in the east with the best of the dry and sunny weather further west and then becoming more generally unsettled...certainly seasonal!

[NorthYorksWeather]

43 minutes ago, Matthew Wilson said:

The Jet Stream seems to have stopped for the weekend on the ECM as the Low hardly moves:

Quite like the look of those charts, sunshine and showers during the day and then the possibility for some cold night time minima under slack winds. 

[Mark wheeler]

Now if this chart come off and it was 31st October Halloween is would certainly be spooky .

 

its so interesting this year as since I joined I can not recall such conditions at this time of year with regards to the big picture . Good or bad a great learning curve for me as a novice trying to understand everything.

Edited October 9, 2016 by Mark wheeler

[damianslaw]

Models flip flopping a bit over the last 24 hours with regard to the medium timeframe i.e. 120-168 hrs. UKMO, GFS and ECM all showing trough development over the country by the end of next week, its trajectory determined by heights to our NE and SW paving a direct hit for the UK. So a possible 'cyclonic' interlude by next weekend, bringing the first proper bout of precipitation all month for many, perhaps something quite heavy and long lasting and it would feel cool.

I'm not looking beyond next weekend, as the longer range outlook will hinge on how the trough develops.

Still very interesting charts for October, far from the default westerly zonal onslaught, with quite anomlous high heights to our north.

[knocker]

Today and the next couple of days.

It can be summed up quite succinctly as by HP to the NE maintaining an easterly flow over the UK and thus very much an east/west split with showers along the ara bordering the North Sea, perhaps heavy and thundery in places, and feeling quite cool. Less cloud and drier further west.

According to this morning's GFS the above scenario should last until the end of the week when the upper lows to the SW and SE are augmented by some energy transfer from the NW resulting in a large surface low pressure area which slowly pushes north over the weekend as the Scandinavian HP slides away NE. Ergo quite an unsettled and cool weekend for most of the UK

What happens after this is anyone's guess at this stage with one possibility being the Azores ridging NE but best keep a watching brief for the time being.

And just to note en passant Sidney has had a tail makeover ready for the warm December zephyrs.

 

Edited October 10, 2016 by knocker