Model Output Discussions 12z 01/09/2016

[Zakos]

There's that black hole anomaly in FI again, in virtually the same place as yesterday

Although the bigger picture remains unclear, it is clear IMO that the Atlantic is going to become increasingly blocked as we head into November, and there is every reason to be optimistic for cold weather as the month progresses.

Even if this block does not deliver cold to our shores this time around, such a huge block must surely disrupt the formation of the Polar vortex.

 

[Daniel*]

 Knocker should be afraid.  

 

[SMU]

23 minutes ago, Zakos said:

There's that black hole anomaly in FI again, in virtually the same place as yesterday

Although the bigger picture remains unclear, it is clear IMO that the Atlantic is going to become increasingly blocked as we head into November, and there is every reason to be optimistic for cold weather as the month progresses.

Even if this block does not deliver cold to our shores this time around, such a huge block must surely disrupt the formation of the Polar vortex.

 

Yes its not about the UK yet- the expanse of cold air is still growing- so ideally the second week in November is really the main starting point-

anything in the run up to that is a Brucey Bonus-

ATM - its all about the AO

[Scandinavian High.]

What time does ecm run thanks..?

[SMU]

7pm -745 at the moment - then 1 hour earlier as the clocks roll back

[Matthew.]

1 minute ago, abbie123 said:

What time does ecm run thanks..?

The run starts usually about 19:15 and completes by 19.55

[Scandinavian High.]

2 minutes ago, Matthew Wilson said:

The run starts usually about 19:15 and completes by 19.55

Thank you..

[Man With Beard]

It's cropping up in different places but I'm seeing lots of HLB on recent runs - GFS op, 1050mb over Iceland, surely a collector's item!

[Frosty.]

The GEM 12z is less troughy than the 00z and ends on a high note with very warm continental air wafting north towards the uk.

[Frosty.]

The GEFS 12z mean looks very settled / pleasant from next midweek onwards until almost the end of october. Lots of sunshine, temps near average by day but with chilly nights with mist and fog patches which would be slow to clear.

[Ali1977]

Day 10 ECM looks great, low building over Spain and heights building North.  That low to the SW of Greenland has no chance of bowling the block over.

[Matthew.]

5 minutes ago, Ali1977 said:

Day 10 ECM looks great, low building over Spain and heights building North.  That low to the SW of Greenland has no chance of bowling the block over.

That's the real meaning of a meandering Jetstream

[Man With Beard]

1 minute ago, Matthew Wilson said:

That's the real meaning of a meandering Jetstream

Almost very warm for the UK too on that ECM D10, not far off a fetch from N Africa. Colder air gathering around though.

[knocker]

The ecm has a classic example of a negatively tilted trough deconstructing as it orientates under the block. For good measure we can throw in a cut off upper low over Germany once again.

Edited October 14, 2016 by knocker

[Frosty.]

Well I make no apology that I'm seeking our first cold shot of the season and there are a few interesting GEFS 12z perturbations for the end of october with powerful scandi highs and others with potential arctic incursions!

I like P5 best

Edited October 14, 2016 by Frosty.

[bluearmy]

It might be time to start thinking about a sustained spell of southerlies pushing well into the arctic around a Scandinavian block and what that might do for wave breaking and the potential damage to any developing vortex 

forget cold for the uk - it's of no decent wintry potential so early in the season anyway. There is a far bigger prize to fight for longer term. 

[ANYWEATHER]

Hello Folks! Not a lot to say, but the ecm and gfs differ so greatly as usual at a week away given the ops output. The  turbulent waters to the Western Atlantic Basin are certainly causing trouble for model output;  One thing to clarify the ops and ensembles are really clueless in this scenario ,and about as helpful as a Chocolate Teapot! Its certainly interesting viewing though

[damianslaw]

All eyes on hurricane Nicole and how it interacts with the jetstream, models showing a very similiar set up as we had with hurricane matthew, throwing up another strong ridge across the country and then into scandinavia - so almost a carbon copy of developments early this month. In the short term - an unsettled spell, but no strong winds or particularly heavy rain, it is turning into a very 'quiet' autumn in many respects. The influence of ex tropical storms systems as ever being crucial, this year they have helped to build in strong ridges. However, we are nearing the end of the hurricane season and the real test will come in about 2 weeks, when traditionally the PV ramps into full gear and the atlantic gains the upper hand, a strong ridge /high lattitude blocking scenario as being shown by the models today for later in the month, would do significant damage to the Polar Vortex and we could be starting November on a very different note to many recent years, similiar to 2009 and 2010 in some respects.. lets see. 

If the models verify as shown today, a very dry October is on the cards for western districts, we've had barely a few mms so far.. October is normally one of our wetter months.

[Blessed Weather]

I'm finding it very interesting to watch the sustained attack on the fledgling Vortex courtesy of the Scandi block deflecting Low after Low straight into where the Vortex likes to set up residence - Greenland. This afternoon's GFS 12z run suggesting the attack finally sends the Vortex packing towards Siberia at the 3rd attempt:

ex TS Nicole enters and meets the Vortex:

The follow-on Low to ex Nicole has a go:

Block deflects a 3rd Low into the Vortex:

And bingo! Vortex finally gives way:

Output will change of course, but whatever comes in the next run, I'm finding this is terrific model watching at the moment!

[Grimers]

The GFS model and the ECMWF model show a low over SW Ireland bringing light S winds and cool temperatures to W parts of the UK tomorrow and a low to the W of Ireland bringing moderate SW winds and cool temperatures to all parts of the UK on Sunday.

       

 

Edited October 16, 2016 by Grimers

[knocker]

In the ext period he EPS keeps the HP to the east as the main player and with the trough weakening the upper flow will veer to the SW/W

Edited October 14, 2016 by knocker

[bluearmy]

15 minutes ago, knocker said:

In the ext period he EPS keeps the HP to the east as the main player and with the trough weakening the upper flow will veer to the SW/W

Not sure that's so clear kocks. What is though is the continuation on all the extended ens data of the -AO/NAO combo. If anything, it seems to be getting a tad larger through week 2 as each run comes out! 

[Singularity]

2 hours ago, bluearmy said:

It might be time to start thinking about a sustained spell of southerlies pushing well into the arctic around a Scandinavian block and what that might do for wave breaking and the potential damage to any developing vortex 

forget cold for the uk - it's of no decent wintry potential so early in the season anyway. There is a far bigger prize to fight for longer term. 

Are you thinking along the lines of 'bottom up' forcing on the vortex, which I seem to recall is what happened six years ago?

There does seem to be a lot of 'situational intertia' associated with the extreme weather patterns emerging these days. It will be fascinating and very educational to see how well this can hold its own against tropical-derived forcing in particular as we head through the next couple of months.

[East_England_Stormchaser91]

These are very unusual Synoptics and outputs occurring on the latest runs! Normally we would be seeing the Atlantic really ramping up by now. This is definitely not the case. 

All im seeing is potential building blocks for a real cold output to be shown come November. A scandi high and northern heights with a southerly tracking jet stream way down over the Azores is nothing but good signs in my eyes. 

[bluearmy]

18 minutes ago, Singularity said:

Are you thinking along the lines of 'bottom up' forcing on the vortex, which I seem to recall is what happened six years ago?

There does seem to be a lot of 'situational intertia' associated with the extreme weather patterns emerging these days. It will be fascinating and very educational to see how well this can hold its own against tropical-derived forcing in particular as we head through the next couple of months.

I think so. given that we have repeating WAA over the other side of the NH, this two pronged attack of warmth into the arctic could have some interesting ramifications .

  I do recall that Stewart used to be greatly encouraged by such a pattern at this time of year in respect of wintry potential down the line.