Model Output Discussion 18z 30/09/15

[Mark Parsons]

still no zonal onslaught and pocket of heights building all over the place eastern Europe has cold lid holding coldish air in place all the models broadly have heights either to the west of us or over us.

 

settled for sometime really is showing signs of being a blocking atumn so far with a below October cet still up for grabs.

 

ECH1-168.gif.pngECH1-192.gif.png 

 

the 192 ecm looks like it could lead to a win win situation heights trying to build into scandi area or pivot into Greenland area either way slightly below average and pretty settled.

 

the low pressure at the southern point of Greenland its where that goes could be interesting further on.

 

the 216 ecm chart has that little low moving in the right direction but another hot on its tail this is not a bad run as heights to our west is a strong robust high so when the second low pressure moves threw southern Greenland it could make way for heights to build further into Greenland

ECH1-216.gif.png

 

ok so we have our northerly and lower pressure to our east well I cant wait for this evenings ecm 168 to see if we can see this coming into a closer timeframe atleast something to watch.

 

ECH1-240.gif.png

ECH0-240.gif.png

 

09/10 springs to mind although earlier in the season.

most likely change but exciting stuff.

 

lots going on in and around the arctic ive noticed how the heights are much more robust this year not the fleeting visits and retreat like last year.

 

I don't buy into the twitter hype of el nino will bring blow torch sw flow through this winter the early signs are there.

of coarse this could all change but I don't see the vortex being a powerhouse this year,

 

the ecm is the most exciting run but the other top models are not a million miles from he same idea be interesting to see which model will be the closest to the actual outcome

Ridiculous by anyone to suggest an el nino would give us blow torch Sw'lys when the more likely outcome is usually dry and anticyclonic in NW Europe with this phenomenon?

[knocker]

Cold plunge alert.

 

Powerful Arctic cyclone could drive blast of unseasonably cold air across Northeast next weekend

Chart weatherbell

 

[carinthian]

The GEFS anomalies this morning have the Atlantic block in place to just about the end of the run.

http://www.tropicaltidbits.com/

Our own 10 day Central European Model continues to show no dominant wind fields. A continued fall in pressure in Central Europe with block over UK with a gradual retrogression of the block on lines of the latest Euro model. Could allow a Northerly flow into Central Europe. Good news for early snow fields to get established in the Alps.

 C

[bobbydog]

Cold plunge alert.

 

Powerful Arctic cyclone could drive blast of unseasonably cold air across Northeast next weekend

Chart weatherbell

ALERT

james madden has hacked knockers account!

[knocker]

The ecm anomaly showing the amplified pattern with the trough (cold plunge) eastern North America and our own Atlantic block. The ecm is going along with keeping the block until near the end of the ext period. My understanding is the European flower pickers will be arriving here shortly.

Edited October 10, 2015 by knocker

[bobbydog]

The ecm anomaly showing the amplified pattern with the trough (cold plunge) eastern North America and our own Atlantic block. The ecm is going along with keeping the block until near the end of the ext period. My understanding is the European flower pickers will be arriving here shortly.

yes, high pressure dominating our weather for the next couple of weeks. signs of cold plunges into europe though-

the flower pickers better hurry up...

[damianslaw]

The settled theme continues, turning into a notably settled autumn so far, with no sign of any change anytime soon. High pressure ruling the roost, bringing a mostly dry southeasterly airstream coming days with temps slightly below average, the high forecast to move across the country and anchor itself to our west meaning very similar conditions in terms of temps but sunnier in the east and south, with frost and fog in places. Longer term, the atlantic trough will drop across scandi/west Russia, and a NW flow most likely will be felt, and a potentially very chilly one for the time of year..

[nick sussex]

Quite a static picture with the high limpeting itself to the west and weakish low pressure running over the top and into Europe.

 

Whether the high retrogresses more and colder conditions spread in from the north is dependent on the amplification upstream in the eastern USA.

 

Overall  not a bad outlook for the next 10 days with the weather being kind to those who want to get out and enjoy some dry calm conditions.

 

Good consistency between GFS outputs in terms of the overall pattern. The GFS 06hrs illustrates the impact of the jet stream across the eastern seaboard of the USA, here we see a more amplified jet kicking north towards western Greenland and the down stream effect is to pull that colder northerly flow into Scandi. Whether theres enough retrogression to pull that flow into the UK only time will tell.

Edited October 10, 2015 by nick sussex

[Gael_Force]

yes, high pressure dominating our weather for the next couple of weeks. signs of cold plunges into europe though-

gfsnh-0-336.png

the flower pickers better hurry up...

 

They've been beaten to it by the nitpickers.

[Cloud 10]

Cold plunge alert.

 

Powerful Arctic cyclone could drive blast of unseasonably cold air across Northeast

 

 

 

Lets hope your right...

 

[Frosty.]

Whether the high retrogresses more and colder conditions spread in from the north is dependent on the amplification upstream in the eastern USA.

The Gfs 6z shows the high retrogressing to the NW through low res and the uk turns colder from the north with a strengthening Arctic Northerly flow, especially down the eastern side of the uk for a time with showers in the east turning wintry on high ground as a cold plunge sweeps south through scandinavia. For the uk this would also mean night frosts becoming more widespread and some snow across high ground in scotland. In the meantime it looks anticyclonic and feeling chilly, especially across the south with an Easterly flow for a while, then winds become lighter so the days should feel more pleasant but with colder nights and more in the way of overnight mist and fog with slight frosts...and then that change I mentioned at the beginning.

Edited October 10, 2015 by Frosty.

[knocker]

My point being that many people see the EC32 as too significant - whereas in fact the EC32 is frequently off target.

I thought my point was therefore pretty clear - I'll try and spell it out for you more obviously next time.

I'm quite intrigued as to how you know that many people see the EC32 as too significant It strikes me as quite a pointless comment. And in any case it is as relevant as any other posts on here.

My point being that people are quite entitled to decide for themselves the significance and interest of any post and sure don't need any guidance from you on the matter.

Edited October 10, 2015 by knocker
To move discussion on..

[Captain Shortwave]

Good agreement today from the model in the development of a cut-off low near the Azores, shown nicely on the 06z GFS run

This allows a mid-latitude block to develop from the corresponding bridging of the Atlantic ridge and the Iberian ridge. This eventually creates a high situation just west of Ireland, the GFS again is representative of this.

 

From this point the question is, where will the high go, there is always the risk that the ridge could get eroded towards the cold pool and hence allow the movement of the high, if this happens upstream we could see the high drift eastwards, or from the other direction to allow cold air to dig strongly south/south east into Europe. At the moment the latter is favoured, though for the UK conditions look to be set fair going by the ens.

Day 8 and 10 from the ECM

 

Perhaps a few light showers down eastern coasts if pressure and 850s fall enough, otherwise the quiet autumn spell looks set to continue with the increasing risk of frosts, especially in central/northern and western areas.

A more potent Arctic plunge over the UK looks an outside bet at the moment, that said it is an option further down the line and it is quite an obvious evolution given the set up we will see develop next week. No real sign of westerlies gaining the upper hand at the moment.

[IDO]

Levi Cowan is suggesting the MJO will amplify again at the end of the month. The end of the ecm ext hinting at a return to zonality as the block weakens and drifts west and a possibility of a trough just to the east of the UK.

 

Yes I agree, as the GFS shows more amplified forecast for the MJO:

 

 

So October and November for phase 1 & 2:

 

 

 

This ties in with the JMA for the last week of October-first week November: 

 

So looking like over the next two weeks the highs sinking and by late October the jet should be running close to Northern areas, and further south as we enter November. Some settled cool to average weather in the interim. 

[knocker]

The GEFS (P) showing some nice WAA east of the trough over Greenland and then maintaining the block until the end of the run

Charts courtesy weatherbell

 

[Yarmy]

Joaquin uncertainties aside (which show up clearly in the stats below), the big hitter models are all verifying at almost record levels day-to-day.

 

[Summer Sun]

Its looking like another settled week coming up next week with high pressure back in charge cloud levels as ever are going to be crucial to the feel of the days if it stays cloudy all day temps will struggle but where its sunny it will be feeling pleasant enough in the sunshine if skies are clear overnight frosts are likely and fog could become a problem in the valleys

 

[Frosty.]

The Gfs 12z op is another amazingly anticyclonic run from start to finish despite lots of action around the top of the high, it's looking fine for the next few weeks at least, indeed, even by the end of the run the high is still going strong. We can expect day to day variations with cloud cover but we would all see our fair share of sunshine but with frost and fog at night and the fog slow to clear during the morning's. It's great weather for the autumn colours though.

[knocker]

Nothing much to add regarding the GEFS anomalies tonight except perhaps no indication of any retrogressing of the HP.

http://www.tropicaltidbits.com/

 

[knocker]

 High pressure just to the west is certainly the percentage play for the next couple of weeks.

Edited October 10, 2015 by knocker

[Mucka]

 High pressure just to the west is certainly the percentage play for the next couple of weeks.

 

Certainly agree for out 10 days but I wonder if the 14 day anomaly charts aren't a tad misleading in that there should be more variable charts around by then to weaken any  mean anomaly but the anomaly remains very strong and doesn't move SW as one might expect?

 

either way, that is a very strong signal for that range and the longer we keep a mid latitude block the greater the chance of getting some heights build into the higher latitudes and specifically toward Greenland.

I'm just saying that obviously the favourite is for the pattern to flatten out but that is not currently what the anomaly charts are favouring.

[Mucka]

GFS 00z

Hardly an atlantic onslaught is it?

 

[knocker]

An overview of this morning’s GFS run.

 

It continues the theme of high pressure centred just to the west but from the 23^rd change starts occurring  It starts to flatten out the HP and bring LP systems around the north into the Iceland area.

 

It then proceeds to retrogress the high cell to the western Atlantic and connects it to the Greenland HP whilst at the same time developing the low pressure to the east .  All this has the effect of dropping some cold air into the UK from the north.

Chart courtesy weatherbell

 

[Mucka]

Greenland high?

 

 

Now, that's a Greenland high!

[Frosty.]

The Gfs 00z op run shows a wintry spell in the making towards the end of october...great way to start sunday!