Model Output Discussions 12z 01/09/2016

[Frosty.]

Anyone fancy more high pressure? The Gem 12z certainly does!

Even by T+240 we are in familiar territory...as blocked as ever!

[Barry12]

Some very interesting GEF ensembles at day 10, with WAA moving towards Greenland...

Possibly a trend growing as we head into November, which is what I believe GLOSEA5 and the ECMWF monthly have been hinting at.

Edited October 20, 2016 by Barry95

[Frosty.]

The GEFS 12z mean is anticyclonic for much of the next couple of weeks with the high intensifying and becoming centred over the uk for a time before slowly drifting west into the atlantic but maintaining a strong ridge. There would be plenty of settled and pleasant / sunny days but with chilly nights bringing slight frosts, mist and fog..hints of change during early november.

Edited October 20, 2016 by Frosty.

[SLEETY]

Dont want block sinking south though frosty,look what can happen if it sinks ,record breaking mild weather like last nov dec 

[joggs]

4 minutes ago, SLEETY said:

Dont want block sinking south though frosty,look what can happen if it sinks ,record breaking mild weather like last nov dec 

Personally can't see the block sinking with the background signals,wave activity,further on also slight neg AO NAO and the unusual happenings in the strat.

I think the mods will try to sink the high at times but will correct it.

Not saying a 2010 is on the way but model watching att was similar to the present imo.

[bluearmy]

11 minutes ago, SLEETY said:

Dont want block sinking south though frosty,look what can happen if it sinks ,record breaking mild weather like last nov dec 

Why worry about what might happen early November with a sinking block?  It's events high up in the strat and over the higher latitudes which matters re the start of winter proper. 

[Frosty.]

The Ecm 12z gradually becomes milder and increasingly anticyclonic across southern uk from around next midweek with the highs influence extending further north for a time, the second half of the run looks very pleasant indeed across the southern half of the uk by late october standards but there are signs of unsettled weather towards months end arriving in the northwest but remaining settled further south until the end of the run.

Edited October 20, 2016 by Frosty.

[A.J]

6 minutes ago, joggs said:

Personally can't see the block sinking with the background signals,wave activity,further on also slight neg AO NAO and the unusual happenings in the strat.

I think the mods will try to sink the high at times but will correct it.

Not saying a 2010 is on the way but model watching att was similar to the present imo.

Whilst we do have a little bit of power, I think sinking the High is testing even our limits! 

In the short term the GFS continues a chilly at times easterly feed with showers feeding in to eastern districts becoming breezier over southern parts of the UK as LP to the SW exerts its influence

[joggs]

2 minutes ago, ajpoolshark said:

Whilst we do have a little bit of power, I think sinking the High is testing even our limits! 

In the short term the GFS continues a chilly at times easterly feed with showers feeding in to eastern districts becoming breezier over southern parts of the UK as LP to the SW exerts its influence

Sorry for one liner,lololololok

[Matthew.]

1 hour ago, Frosty. said:

Anyone fancy more high pressure? The Gem 12z certainly does!

Even by T+240 we are in familiar territory...as blocked as ever!

 

Nice chart Frosty. The ECM up to +168 doesn't bring it on top of the Uk but there's always tomorrow

[Frosty.]

2 minutes ago, Matthew Wilson said:

Nice chart Frosty. The ECM up to +168 doesn't bring it on top of the Uk but there's always tomorrow

The Ecm 12z turned out pretty good for central / southern uk according to those charts I posted above.

[damianslaw]

Quite a bit of consistency between the models today, all showing anticyclonic conditions dominating in the main for the foreseeable future. In the short term, its the familiar easterly airstream bringing showers to eastern and perhaps central parts, with the far west seeing the sunniest conditions, temperatures around average, perhaps a tad below in northern parts through the weekend, with the risk of frost in sheltered western districts. 

Into next week, low pressure will attempt to exert a stronger influence on things, but it will be a damp squib affair and deliver light rain in SW parts Monday, but perhaps something heavier for the SE by Tuesday, whilst much of the country remains dry, and turning a little milder. As we move through the week, all models keen to build in ridge from the SW ushering in a milder pattern and feeling quite pleasant in southern parts in particular, frost looking limited thanks to the milder uppers.

Longer term - the theme continues i.e. high pressure ridging out into the mid atlantic and heading northwards, not sinking southwards whilst we see trough action heading into scandanavia, the outcome most likely a cold blast from the north. 

October is looking like it will end up notably dry for many, especially so for the NW, I think we must have had only about a third of the average rain we would normally expect to have seen this month so far here at least, perhaps even less. I'm going to do start a rainfall stat thread to see just how dry things have been so far.

[Frosty.]

Tonight's Ecm 12z ensemble mean shows anticyclonic influence becoming significantly stronger across at least the southern half of the uk from the second half of next week onwards, just as the operational earlier.

[Geordiesnow]

7 hours ago, Frosty. said:

Anyone fancy more high pressure? The Gem 12z certainly does!

Even by T+240 we are in familiar territory...as blocked as ever!

Too me, I would not class those as blocking charts really, the real scandinavian block will retreat more towards Russia during next week which will increase the chances of an Westerly influence, the question will be just how much the Euro high will affect the UK and at this stage it looks like quite a large part of the UK will stay under the influence of the Euro high.

Those charts show the jet stream aligning a SW.NE'ly diretion so those type of charts is certainly not what cold lovers want too see in a couple of months time thats for sure..

[bluearmy]

EC 46 mean steady as she goes.  No sign of persistent euro heights to our south. Atlantic high anomoly stays throughout and scandi low anomoly pretty continuous. temps look to be more below average then above pretty much throughout. 

If there is anything significant on the clustering then I'm sure ian will inform us. 

[blizzard81]

35 minutes ago, bluearmy said:

EC 46 mean steady as she goes.  No sign of persistent euro heights to our south. Atlantic high anomoly stays throughout and scandi low anomoly pretty continuous. temps look to be more below average then above pretty much throughout. 

If there is anything significant on the clustering then I'm sure ian will inform us. 

How far ahead does this forecast go? Is it 46 days? 

[fergieweather]

1 hour ago, bluearmy said:

EC 46 mean steady as she goes.  No sign of persistent euro heights to our south. Atlantic high anomoly stays throughout and scandi low anomoly pretty continuous. temps look to be more below average then above pretty much throughout. 

If there is anything significant on the clustering then I'm sure ian will inform us. 

Little useful to add. Akin to the EC update of Monday, there's a signal in the latest run for strong mid-Atlantic ridging during 1st week of Nov, with resultant colder NW flow. This is also favoured in latest GloSea5. Both models suggest a blocked scenario most likely 1st half of Nov, albeit with uncertainty/spread in exactly how this manifests (respective H/L positioning). Either way, zonality looks less likely than average through first half of the month. 

[Summer Sun]

This morning ECM shows high-pressure building next week keeping any rain to the far north and west of the UK with the high pressure we could see frost and fog overnight leading to some very pleasant days providing the fog isn't stubborn to lift

[carinthian]

This latest jet stream forecast chart for early November took my interest this morning. Usually by this time of the year the zonal jet is firing up as the equatorial air mass engages the increasing colder air mass and we see a curved flow in the upper air mass or Rossby Waves formation ( old school name ). However, no sign of this and looks like the mainly blocked pattern stays into the first part of November. Now the blocked pattern shifts around and looks like moving from Scandinavia to Mid Atlantic over the coming 2 weeks or so.

Looking at the pressure pattern charts for next week alone still makes forecasting rather uncertain with-in the 96-144 hour forecast period with what looks like almost a COL chart for Southern Britain.  Fax charts look fascinating watching the shorter term synoptic views.

Over here the snow stopped spot on 4 pm as the Numerical model we used suggested. Colder today in the valley than on the mountain tops. Over the coming days we are going to be on the boundary of the warmer uppers coming up from the south and the colder surface flow further north. Hope the snow holds out for the longer nights and radiation cooling.

 C

[mb018538]

Very quiet in here, much like the model output! Looks like we've got high pressure moving in next week, more uncertain after this though. No signs of zonality just yet.

[Frosty.]

The Ecm 00z op turns into a BEAUTY with high pressure building in from the south and introducing much milder uppers with surface conditions becoming very pleasant for the time of year.

[Ali1977]

Nice charts there Frosty, dry with nice days and chilly nights is what Autumn should be about - not storms and floods.  Save the North and East winds for when they will produce some proper cold air. Things still looking very good for an Autumn without significant Zonel influence. 

Edited October 21, 2016 by Ali1977

[Frosty.]

Just now, Ali1977 said:

Nice charts there Frosty

Yes Ali, the Ecm has been showing this trend for a few runs now, very pleasant autumn weather could be on the way.

[legritter]

Well looking at current Data,  its looking quiet and rather pleasant till Months end ,after that a possibility that we could see some typical november weather ,But although its great looking at GFS throwing some 528 dam at us or close to us i personally wont be getting excited quite yet ,[ bring on the stellas !!!!  Frosty get the crayons out ] i,m looking forward to this upcoming winter ,on the best weather forum on the planet ,catch you all up later 

[jvenge]

I was having a look through the GSF ensembles. Quite a spread of temperatures on offer starting at 144. Nothing above seasonal norms, though.