Model Output Discussion - 31/8/14 Onwards.

[ANYWEATHER]

The fine weather continues for most, ecm at the silly time frame at T+240 continues to show settled conditions , gfs as the other idea.! Im not sure any model has got things right in the days ahead....But settled conditions for now looks likely for the next week, some showers for the south, otherwise Bonedry!

[SteveB]

Well I was blessed with fine weather while I was off work for two weeks holiday. Some say I was lucky, I say it was planned as it's usually nice around this time.

 

And it looks like the fine weather continues....

 

 

 

There really doesn't look like any rain to talk off until the far reaches of FI.

 

I think August & September have  got them selves muddled up!

[Frosty.]

Awesome model output, no sign of the block collapsing in the next few weeks, indeed, more chance of the block strengthening, becoming very warm in the south with lots of sunshine and just a few heavy showers. It's a very blocked outlook with predominantly fine and sunny days and light winds with temperatures later this week into the low 80's F but much cooler for the north and NE with patchy rain and mid teens celsius. Looking longer range, just a hint the far NW will become unsettled but for the vast majority it is set to stay fine and warm although after this coming week, temperatures drifting down into the high teens to low 20's c range but very good weather by mid to late september standards. I think the models should be congratulated for frequently suggesting mid september would bring BBQ conditions from several weeks back..well it's now within the reliable timeframe

 

those looking for a general change to cool & unsettled..unlucky guys, just hope the pattern changes in october..for the vast majority..ENJOY the last of the summer wine or a cold beer or 3

[Frosty.]

Interesting different take on TS track and development.

Interesting in what way? can you please elaborate with some kind of description

[Troubleatmill]

Just for Fun if anyone is bored with the current set up....December looks great right the way through if cold and snow is your thing!

 

http://www.meteociel.fr/modeles/cfse_cartes.php?ech=1866&mode=0&carte=0&run=0

[Timmytour]

This time last week it seemed the models were looking at the same warm up they still are but followed by thunderstorms and a breakdown into the weekend with autumn announcing its arrival

Now we've got a small vicious looking little low which  crosses the Atlantic to the south and fades away west of Spain. Is the eventual lack of potency to this what's making the difference now, and how "nailed on" would it be to now fade and die?  Could it in fact invigorate further as it crosses and change the outlook dramatically or would it have needed the PV dropping as once was forecast to "feed2 it? 

[knocker]

This time last week it seemed the models were looking at the same warm up they still are but followed by thunderstorms and a breakdown into the weekend with autumn announcing its arrival

Now we've got a small vicious looking little low which  crosses the Atlantic to the south and fades away west of Spain. Is the eventual lack of potency to this what's making the difference now, and how "nailed on" would it be to now fade and die?  Could it in fact invigorate further as it crosses and change the outlook dramatically or would it have needed the PV dropping as once was forecast to "feed2 it? 

 

 

The vicious looking low is the current tropical storm doing the rounds. It's absolutely nothing to do with the PV. Different models treat it differently but none dirctly affect the UK. I tried posting this earlier but it kept loading in jumbled manner which rather negated the post. Anyway the GFS and Chinese interpretations. If it's jumbled not much I can do. Pain in the rectum but the GFS has combining with the Iberian low and getting a temporary new lease of life.

Edited September 15, 2014 by knocker

[Summer Sun]

UKMO shows high pressure never far away from the UK later this week

 

 

Staying warm with some sunshine but also the risk of some showers developing at times

[knocker]

And the ECM does at the beginning of next week but accompanied by quite chilly temps.

 

[phil nw.]

Modelling continues with a predominantly blocked Atlantic right out into week 2 with a lot of mid-latitude high pressure.

Granted we will see some showers scattered about through this week,first from the current little feature off the north sea and possibly later towards the weekend as the Iberian low edges a little closer,but overall the ensembles go with small amounts of rain until month end.

 

Here the graphs for 3 locations north to south underline this.

 

The main thrust of the jet,what there is, looks like remaining well north for the next 10 days at least.

 

 

Many of us could end up with one of the driest Septembers for some time if this trend continues to month end.  

Edited September 15, 2014 by phil nw.

[Man With Beard]

Just for Fun if anyone is bored with the current set up....December looks great right the way through if cold and snow is your thing!

 

http://www.meteociel.fr/modeles/cfse_cartes.php?ech=1866&mode=0&carte=0&run=0

Ok, appreciate it's just for fun but this really is bonkers, deep blues and purples rushing at a rate of knots from Siberia towards the UK, stupendous northern blocking, has anything like this ever happened before!

Anyway, back to the present and indeed reality... D9-D12 might be renewed Atlantic activity to the NW but I think D8 is as far as we can reasonably see right now, and the mean charts still have some sort of heights towards Scandi:

So lots of dry weather abounding ... but as Knocker alluded above, the continued presence of a Scandi High could eventually mean dropping temperatures as we get to the other side of the Autumn equinox and daytime warming decreases over the continent, where we would be drawing our weather from. In such a set-up, we'd need to continue under the influence of a trough over Biscay or west of Portugal if temps are to keep reaching 20C for much longer, let alone the 25Cs which could occur later this week.

 

Some sort of cool-down next week looks almost inevitable - I think it's 75% likely that this week will be the last of what could loosely be termed "hot" until next year. Hopefully for summer lovers it will hold on until the weekend.

[Timmytour]

The vicious looking low is the current tropical storm doing the rounds. It's absolutely nothing to do with the PV. Different models treat it differently but none dirctly affect the UK. I tried posting this earlier but it kept loading in jumbled manner which rather negated the post. Anyway the GFS and Chinese interpretations. If it's jumbled not much I can do. Pain in the rectum but the GFS has combining with the Iberian low and getting a temporary new lease of life.

Hi Knocker....wasn't suggesting the tropical storm has anything to do with the PV except to wonder if the course further north I think it was suggested it would take this time last week, has now changed because the PV is not dropping into the Atlantic as was modelled last week?

Eg   early in the month we were seeing this modelled for later this week.... the tropical storm which was going to eventually impact us now disappears south and west...

 

Edited September 15, 2014 by Timmytour

[Bobby]

Ok, appreciate it's just for fun but this really is bonkers, deep blues and purples rushing at a rate of knots from Siberia towards the UK, stupendous northern blocking, has anything like this ever happened before!

 

That chart reminds me of December 2009, we had a fair bit of snow from that I think

 

[Polar Maritime]

I have just deleted a whole bunch of off topic nit/picky posts, Please can we only discuss Model Output in here.

Many Thanks, PM

[Frosty.]

The most sustained very warm spell since late july / early august is just around the corner according to the Gfs 06z op run, becoming very warm and more humid, locally hot across the south later this week as we begin to import continental air northwards, even the north of scotland reaches 21 c at times which would be incredible by mid / late september standards, the south could hit 80F (26 / 27 celsius) and even by next week, low to mid 20's c is shown. The main theme is for the block to hold, indeed strengthen at times and we should all get plenty of sunshine and just isolated heavy showers, most of those across the south and SW but also a chance of thundery rain spreading up across southern / se england by the end of the week. Later on in low res the gfs decides enough is enough and brings a marked change to much cooler, windier and unsettled weather with the polar front jet ending up in a much more typical position by the end of september..but for most areas, the next 7-10 days look more like high summer than well into early autumn..Let's make the most of it

Edited September 15, 2014 by Frosty.

[tempestwatch]

The most sustained very warm spell since late july / early august is just around the corner according to the Gfs 06z op run, becoming very warm and more humid, locally hot across the south later this week as we begin to import continental air northwards, even the north of scotland reaches 21 c at times which would be incredible by mid / late september standards, the south could hit 80F (26 / 27 celsius) and even by next week, low to mid 20's c is shown. The main theme is for the block to hold, indeed strengthen at times and we should all get plenty of sunshine and just isolated heavy showers, most of those across the south and SW but also a chance of thundery rain spreading up across southern / se england by the end of the week. Later on in low res the gfs decides enough is enough and brings a marked change to much cooler, windier and unsettled weather with the polar front jet ending up in a much more typical position by the end of september..but for most areas, the next 7-10 days look more like high summer than well into early autumn..Let's make the most of it

Hi Frosty, to your knowledge, have you seen charts like this before in September with such a prolonged and blocked pattern?

[Frosty.]

Hi Frosty, to your knowledge, have you seen charts like this before in September with such a prolonged and blocked pattern?

Hi tempestwatch, from memory, the first ½ of last autumn was generally blocked, warm and benign, so in many ways, this looks similar to a year ago, previous to last year, i'm not sure but it could be several years. I think it's a noteworthy spell of summery weather for this time of the year, especially considering how abysmal most of august was thanks to Hurricane Bertha.

[knocker]

Hi Knocker....wasn't suggesting the tropical storm has anything to do with the PV except to wonder if the course further north I think it was suggested it would take this time last week, has now changed because the PV is not dropping into the Atlantic as was modelled last week?

Eg   early in the month we were seeing this modelled for later this week.... the tropical storm which was going to eventually impact us now disappears south and west...

 

Hi Timmytour

 

I should be very wary of saying "has now changed because the PV is not dropping into the Atlantic" as the term is often used incorrectly these days. In IMHO that is of course.

[johnholmes]

Hi Timmytour

 

I should be very wary of saying "has now changed because the PV is not dropping into the Atlantic" as the term is often used incorrectly these days. In IMHO that is of course.

 

I would tend to back knocker up about the frequent use of the term PV and it is quite often not used correctly, again in my view.

Using a term like a deep vortex over the N Atlantic, even perhaps with words like, seeming to be linked back to the main PV, would be better. A bit pedantic perhaps but it is very easy for specific terms in meteorology to get mis used, again in my view, others may of course disagree.

[Frosty.]

I would tend to back knocker up about the frequent use of the term PV and it is quite often not used correctly, again in my view.

Using a term like a deep vortex over the N Atlantic, even perhaps with words like, seeming to be linked back to the main PV, would be better. A bit pedantic perhaps but it is very easy for specific terms in meteorology to get mis used, again in my view, others may of course disagree.

I use the words polar front jet a lot, the Gfs 6z shows it paying a visit to the uk later in the month, much cooler / colder, windier and unsettled if it occurs....Brrrrr, this would make it feel like autumn to be sure.and would blow away some cobwebs

[Nick F]

The jet looks to stay rather convoluted and sluggish over the E Atlantic/Wern Europe over the coming week or so, so no real impetus for big changes really - just subtle changes in pressure i.e. a slight drop in geopotential heights and surface pressure from the southwest through the week as that low tries to move E/NE off NW Iberia - could bring a risk of a few thundery showers across SW UK later in the week as it warms up too and perhaps other southern counties over the weekend, but other than rain in the northeast next few days, no widespread meaningful rain on the cards.

 

GFS and EC both show a marked shortwave trough and stronger jet behind it coming out of NE Canada late w/e early next week, which could mark a change if it digs far enough south over the Atlantic towards the UK, though 00z EC suggests it doesn't dig far south rather high pressure rebuilds from the west. So no certain change from the sluggish pattern of recent few weeks for now.

[Timmytour]

haha....     you're right....i should ask are the atmospheric conditions now being modelled over the North Atlantic  not as condusive as they seemed to be last week to pulling the tropical low up enough to affect us?  I shouldn't really state anything as I haven't anywhere near the knowledge of you guys!

EDIT....this was going to be a direct response to Knocker when originally typed!  I see others agree with him so I just want to add that I'm completely in agreement with you JH and Frosty as well!  :-)

Edited September 15, 2014 by Timmytour

[Summer Sun]

UKMO continues to show high pressure re-building during the weekend

 

 

The weather is doing its best to make up for that disappointingly cool and wet August

Edited September 15, 2014 by Summer Sun

[Frosty.]

The Gfs 12z op run shows the block being strengthened by the weekend as an atlantic high pressure cell drifts eastwards to the north of the uk which bolsters the scandi high and helps to prolong the generally calm settled spell until very late next week, I say generally settled because there will be a few heavy showers dotted around this week, mostly across the southwest of england but a few elsewhere, however, even those die out through the weekend and during the first ½ of next week as pressure rises further. This run, as with previous output shows a very warm or hot spell for the south of the uk with warmer air pushing north to all areas, temperatures should reach 26 / 27 celsius.. around 80 F through thursday / friday & saturday.

 

Looking further ahead, as with the 6z we see a marked change in the weather with the block eventually replaced through low res by much more autumnal charts bringing an increasingly unsettled and much cooler oceanic pattern with spells of wet and windy weather interspersed with sunshine and showers, the jet becomes aligned nw / se and by the end of september / early october it's well and truly autumn weather.

[damianslaw]

Whilst the reliable timeframe offers more the same i.e. settled in the main and warm/very warm for the time of year, with heights to the NE ruling the roost blocking out the atlantic, the models today longer term are for the first time showing a more likely robust change as we had through next week, thanks to energy off the NE USA Seaboard, E Canada being thrown into the mix with some real gusto, dropping down a marked trough and much cooler conditions behind.

 

Its a very plausible set up - now is the time of year we start to see a marked temperature gradient develop in the NW Atlantic thanks to an increasingly colder arctic.

 

My own thoughts were for a change to unsettled conditions occurring this week, with trough action from the NW thereafter, alas the behaviour of ex tropical storm activity combined with robust heights to the NE has put pay to that. Interestingly the models are showing emergence of retrogression of heights in the days ahead, but they don't get a foothold thanks to the position of ex hurricane Edouard getting in the way of things. With heights going nowhere fast to the NE it seems and heights building to the west, the trough will most likely find the weakest point and that will be the UK putting pay to any joining quite swiftly.. this isn't early summer..

 

Its an interesting synoptical set up - far from your average mid-late September standard fayre.

Edited September 15, 2014 by damianslaw