Model Output Discussions 12z 01/09/2016

[Frosty.]

The GEM 00z is also shaping up nicely next week with high pressure building in from the SW and slowly migrating across the uk to scandinavia but with a ridge still covering the uk by day 10..so it's looking more and more like a pleasant spell is on the way from around next midweek onwards.

Edited October 13, 2016 by Frosty.

[Grimers]

2 hours ago, Frosty. said:

I can't believe I missed the 18z last night, what a cracker of a Northerly..it just shows what could happen with a direct hit, even in October!

This is something else! I'm not sure how often this setup occurs at this time of year, but it's obviously possible!

Edited October 13, 2016 by Grimers

[Frosty.]

The Ecm 00z ensemble mean also shows an improving picture next week with the trough soon shunted out of the way as high pressure ridges in from the southwest and really its a very pleasant outlook from the second half of next week onwards..very similar to the operational..looking very good.

[Man With Beard]

Been here before this month, but I thought these T360 mean charts were notable on both ECM and GEFS:

  

quite strong indications for such a distant timeframe - heights stronger to the west of the UK and dropping to the east (Denmark through Germany and Poland)

You'd imagine therefore that, again, a number of ensembles would be going for a northerly/north-easterly around that timeframe.

You sense the models are trying to get there!

[legritter]

Good morning ,it does seem that high pressure in the outlook wants to be in a more northerly position ,to our west or to our north east ,The Atlantic breaking through this week end giving us some rain and showers then later next week it dies a death ,any further than 7 days i feel would be hard to call and of course at this time of year any positioning of high pressure could be very crucial to the weather at the surface , at least we have a different set up to previouse years  and who knows !! could go in coldies favour ,but we are talking about weather ,certainly many months of interesting twists and turns ,cheers .

[knocker]

43 minutes ago, Man With Beard said:

Been here before this month, but I thought these T360 mean charts were notable on both ECM and GEFS:

  

quite strong indications for such a distant timeframe - heights stronger to the west of the UK and dropping to the east (Denmark through Germany and Poland)

You'd imagine therefore that, again, a number of ensembles would be going for a northerly/north-easterly around that timeframe.

You sense the models are trying to get there!

Yes the EPS has been pushing this for a number of runs MWB and of course much will depend of the precise orientation of the upper ridge and thus the surface HP which is obviously yet to be finalised considering the time scale. But as of this morning in the final stages of the run around the 26th the surface high is centred to the SW of the UK ridging NE thus the streamlines will be westerly veering NW as one moves south and the 850mb temps possibly a little above average

[Frosty.]

The Gfs 6z shows temperatures recovering well by the weekend, especially further south where 17/19c around 65f is probable as the winds will have swung around to more of a southerly point and although it looks unsettled, those temps indicate there will be some sunshine too. The first half of next week also looks unsettled and becoming cooler from the NW after a mild start across the s / e but then the trough fills and is shunted away eastwards by high pressure ridging in from the southwest which briefly becomes centred over the uk before migrating ENE to scandinavia but leaving a strong ridge over the uk with fine pleasantly mild days and cool nights bringing the perfect recipe for mist and fog patches which could be slow to burn off. Further ahead, another showery trough arrives from the northwest but then pressure rises once again from the s / se with very mild conditions, particularly for the south. 

[Mucka]

3 hours ago, Man With Beard said:

Been here before this month, but I thought these T360 mean charts were notable on both ECM and GEFS:

  

quite strong indications for such a distant timeframe - heights stronger to the west of the UK and dropping to the east (Denmark through Germany and Poland)

You'd imagine therefore that, again, a number of ensembles would be going for a northerly/north-easterly around that timeframe.

You sense the models are trying to get there!

 

I just came to post a similar observation.

Looking at GFS 06z ensembles out into la la land there is a consistency about the output which I don't ever recall seeing before. Something that is doubly conspicuous given that consistency goes largely against the climatic norm and shows large anomalous blocking, especially int he Atlantic sector.

http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=384

Although detail is impossible at that range I am still interpreting that (likely foolishly) as increased likelihood of an Arctic outbreak toward the back end of October. 

It may be that blocking doesn't quite align right for us to tap into cold Arctic air but the signal is very strong at those sort of ranges that conditions will be ripe for a prominent Atlantic block to set up.

The only other possibility is that the models are way off and missing an important background signal and so will flip to a more zonal pattern over the coming days. 

 

Edited October 13, 2016 by Mucka

[phil nw.]

Quite a few comments already on the forecasted weakness in the mean Atlantic jet stream over the next couple of weeks.

A look at the 500hPa ens graphs for Iceland and the Azores show the relatively small mean temperature gradient indicating a nearly neutral NAO index(right hand image).

In addition the ongoing positive height anomalies to our north continue to be shown in the ens.- day 10

 

 

-and a quite remarkable chart for so far out

showing such a solid Icelandic/Greenland height forecast.The AO graph is certainly showing a negative trend as a weaker polar vortex continues to be modeled.

Currently with such a weak Atlantic modeled overall the favoured evolution is to develop mid-latitude heights, but it's certainly worth keeping an eye on those easing north towards month end with lower pressure to our south.

Could we really enter November with such a pattern i wonder?-it would be something different for sure.

 

[johnholmes]

What a good post above from phil. Using charts to illustrate his view and a convincing view it is based on the data we have. For sure this October is, so far, not too much like many I can remember. I wonder how things will shape up once the Tropics stops throwing spanners in the works for the models with tropical storms/hurricanes?

[Cheshire Freeze]

2 hours ago, Mucka said:

 

I just came to post a similar observation.

Looking at GFS 06z ensembles out into la la land there is a consistency about the output which I don't ever recall seeing before. Something that is doubly conspicuous given that consistency goes largely against the climatic norm and shows large anomalous blocking, especially int he Atlantic sector.

http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=384

Although detail is impossible at that range I am still interpreting that (likely foolishly) as increased likelihood of an Arctic outbreak toward the back end of October. 

It may be that blocking doesn't quite align right for us to tap into cold Arctic air but the signal is very strong at those sort of ranges that conditions will be ripe for a prominent Atlantic block to set up.

The only other possibility is that the models are way off and missing an important background signal and so will flip to a more zonal pattern over the coming days. 

 

N Atlantic blocking is a huge historical autumnal analogue for the strong Nino- la Nina switch and up until the mid 1900s this type of scenario correlated well to very cold/blocked proceeding winters. We can only hope that the cycle has come around once again...

Edited October 13, 2016 by CreweCold

[Frosty.]

There is plenty of support for high pressure or at least strong ridging to be in control from later next week across most or all of the uk according to the GEFS 6z mean, lots of pleasant options looking ahead. It's a very slow moving pattern with high pressure generally having the upper hand with occasional shallow troughs drifting around but generally it looks like a largely settled extended outlook, especially across the southern half of the uk.

Edited October 13, 2016 by Frosty.

[swfc]

great 12z. look at the strat profile at 200 hrs"be it fi" screams neg nao -no .

[knocker]

Nicole enters stage left and consolidates the HP

 

 

 

Edited October 13, 2016 by knocker

[Summer Sun]

High pressure builds mid week with Nicole staying well away from the UK

[bluearmy]

18 minutes ago, swfc said:

great 12z. look at the strat profile at 200 hrs"be it fi" screams neg nao -no .

Mirrored on the recent gefs runs aswell

the noise on a mid Atlantic ridge as we head towards the end of the month (could be west of the U.K.,, could end up Greenland, could be griceland is getting louder and louder on the gefs. The eps not as loud but certainly not discouraging such a development. 

unlikely to bring anything notably wintry but some frost and freezing fog would be a nice change to what has become standard autumnal fare for this country over the past decade.  

[Mucka]

GFS 12z FI same old same old.

None shall pass! 

Edited October 13, 2016 by Mucka

[Zakos]

Wow...

The chart is for t+348 hours so is to be taken with a pinch of salt of course.

Still, the anomaly forecast is remarkable, is the GFS picking up on a signal for a increasingly blocked Atlantic perhaps?

Edited October 13, 2016 by Zakos

[Grimers]

16 minutes ago, Zakos said:

Wow...

The chart is for t+348 hours so is to to be taken with a pinch of salt of course.

Still, the anomaly forecast is remarkable, is the GFS picking up on a signal for a increasingly blocked Atlantic perhaps?

WOW, that's a stunning chart from the GFS model! Cold sums it up!

Edited October 13, 2016 by Grimers

[cyclonic happiness]

25 minutes ago, Zakos said:

Wow...

The chart is for t+348 hours so is to be taken with a pinch of salt of course.

Still, the anomaly forecast is remarkable, is the GFS picking up on a signal for a increasingly blocked Atlantic perhaps?

give it a month and it'll be raging south-westerlies :-(

[Grimers]

Both the GFS model and the ECMWF model show a high over the E Atlantic on Tuesday and Wednesday bringing light SE winds and cool temperatures to all parts of the UK.

             

 

 

 

Edited October 16, 2016 by Grimers

[Captain Shortwave]

Hmm a lot of interest, again the potential develop an area of high pressure close to or perhaps to the north of us with cold air cutting underneath.

The big three at day 6

      

All three show a similar idea of a shallow trough to our east with high pressure building in from the west. Beyond this a lot of options, some warm and some cold but until we get the picture for the end of next week sorted then it is all conjecture but I don't see a strong zonal signal at this present time.

[Matthew.]

Warm air blasted into the arctic by the ECM by ex hurricane Nicole. Hopefully this isn't the joker in the pack when the hurricane season ends.

Edited October 13, 2016 by Matthew Wilson

[Ali1977]

NH sea and land temps dramatically cool down over the next few weeks so N/NE'lys Mid Nov will have a much colder sting than when they happen now and into late Oct. They are nice to see but no real sustained "big freeze" can really offer , even the cold of Nov 2010 was extremely rare and that was the last week of Nov.  

Lets hope the next EC and GLOSEA seasonal are singing off the same song sheet with lots of NH blocking looking good for winter 

[ANYWEATHER]

Hello Everyone! A general consensus from the ecm and gfs  from now to Tuesday is for unsettled conditions . A ridge builds ahead of ex hurricane Matthew and with cold air in situ a real mix of frost mist and fog  After that some wild swings thanks to Matthew !!! The black arrow shows ex Hurricane Matthew