Model Output Discussion - September Onwards

[Mark Neal.]

What happened to our so called ' sunny settled september', its been common in recent years, Merh -_-

[Thundery wintry showers]

I don't think we were ever promised a sunny settled September by the model outputs- the problem is that MOD effectively serves as a High Pressure/Settled Watch thread in the summer, so thoughts always focused on the next potential high pressure, just as it focuses on the next cold snowy outbreak in winter, and thus we always seem to be promised "settled" weather at some stage. I don't like such one-sided discussions, but it was how this thread went for most of the summer.

At present, though, conditions do look turning quieter in the south in the near term. Thursday looks like it will be a dry sunny day for most, then Friday will have a breakdown initiate from the west, and there is still a slight chance of some thundery activity. After that, GFS and UKMO place the Azores High quite far north, which would bring relatively "settled" weather to the south though probably quite cloudy at times due to the tropical maritime flow. ECMWF however places the jet further south. NOAA's longer-term 8-14 day outlook appears to side more with the ECM solution.

[Methuselah]

What happened to our so called ' sunny settled september', its been common in recent years, Merh

What 'sunny settled september'?

[Aaron]

I think he's referring to the fact that September's since 2002 in general have been pretty warm and settled for the most part.

[Mark Neal.]

I think he's referring to the fact that September's since 2002 in general have been pretty warm and settled for the most part.

Yes thats what i was reffering to, as in last 4/5 years Septembers have been mainly settled,dry and quite warm, quite different this year.

[Summer Sun]

Yes thats what i was reffering to, as in last 4/5 years Septembers have been mainly settled,dry and quite warm, quite different this year.

Maybe October will make up for it.

GFS still offers hope from next Tuesday onwards with plenty of settled weather around apart from 1 day.

[Frosty.]

A bit of respite from this unsettled weather in the next few days with a ridge covering the uk on thursday but low pressure then arriving by friday and the weekend looks unsettled and into next week but at least the gfs hints at a blocking scandi high later in FI with warm continental air for the uk but until then it looks fairly zonal with the north being most unsettled and the south having the longer dry spells with high pressure south of the BI. The Ecm 00z shows some very cold pooling across greenland and eastern canada which is a nice reminder that winter is not far away.

[ribster]

Maybe October will make up for it.

GFS still offers hope from next Tuesday onwards with plenty of settled weather around apart from 1 day.

I think you are possibly becoming obsessed with 'settled' weather. Not sure it's all that likely at the moment anyway, Atlantic seems to be very active, think the charts will look different in 8 days time. Still, if October does deliver some settled weather, would likely deliver some frosts which would be great.

[Gibby]

Good evening.

GFS tonight shows the current deep low north of Scotland moving away NE leaving the UK in a strong westerly flow for a day or so with further showers at times. By Wednesday the showers should of died out as a ridge crosses from the west through Thursday. By Friday though Low pressure moves back into the UK with some rain for many by the weekend. Later in the weekend and into the start of next week Low pressure well to the NW drives an actice cold front across the UK. Once the associated rain passes the weather improves for the south with dry and brighter skies while the North stays breezy and unsettled. This unsettled and changeable theme continues right out to the end of the run with rain at times for all but some lengthy drier spells in the south.

UKMO also shows the storm system currently to the North moving away over the next few days with the weather improving slowly with most places dry by late Wednesday. With a ridge crossing the UK on Thursday the best day of the week weatherwise looks likely then. However, in the days that follow Low pressure returns slowly from the west with rain, perhaps thundery for a while in the South replace the fine weather with the Atlantic looking set to dominate in the days that follow the termination of the run.

ECM shows a close resemblance to UKMO up until Saturday with the sequence of events as already described. Then over the weekend and into the following week the weather remains very changeable with rain at times with winds continuing to blow mainly from the west or southwest.

The weather continues to show an unsettled look about it tonight. This weeks best day shown by all models will be Thursday with a few cool nights for the North just after midweek before a return of unsettled weather is shown by both the longer term models although GFS does show some respite at times for the south. Temperatures will be mostly near to normal for most of the time though it will feel chilly at times in the wind.

[Turnedoutniceagain]

Just can't see that first N'ly incursion yet - it's all Atlantic, Atlantic, Atlantic *yawn*

[mushymanrob]

The only fishy thing from that chart is that you don't want too see that pattern dominating in the winter months with the jet stream to the North of Scotland and the weather coming from the Atlantic.

speak for yourself mate, id be most happy if winter was mild..

What happened to our so called ' sunny settled september', its been common in recent years, Merh

thankfully we are having a more normal september, thus going some way to confirming why meterologically september is autumn!

[Gibby]

Good morning. Here's the morning look at the latest output from GFS, UKMO and ECM.

GFS this morning shows rising pressure as the recent storm system moves away NE from northern Scotland. A ridge of high pressure crosses east by Thursday with further Low pressure returning from the SW by the weekend. So after a showery day today with rather less tomorrow Thursday will become dry and bright with much lighter winds than of late. This won't last though as cloud and rain move in from the SW overnight into Friday and continues through the weekend although the strong winds look unlikely to return. Temperatures would be near normal and it could feel cool in the wind and rain. Into FI and the changeable pattern continues with Low pressure dominant near Iceland for much of the time pushing rain bearing troughs across the UK although some drier spells remain likely in the South while a strong rise of pressure at the end of FI brings dry, Autumnal weather nationally then.

UKMO today shows rising pressure too in response to the moving away of Low pressure to the North with a ridge of high pressure developing by Thursday and lasting into Friday in the east before Low pressure returns from the SW and NW over the late week and the weekend. So a showery day today and tomorrow too in the North before Thursday offers a dry, bright and pleasant day with light winds before cloud and quite heavy rain move in from the SW and extends to all areas over the weekend clearing later on Sunday.

The Fax Charts shows a complex synoptic situation over the next 5 days with occlusions giving rise to occasional rain and showers today and tomorrow before a temporary ridge brings drier weather for a while on Thursday before further Low pressure and troughs dliver rain late in the week and over the weekend.

ECM finally follows a similarly unsettled route with the synoptics for this repeated as per GFS and UKMO. In the longer term ECM keeps deep Low pressure close to Iceland with a broad westerly flow from the Atlantic blowing over the UK with troughs embedded in the Flow. All this would mean rain at times, heaviest and most prolonged in the North where it remains rather windy at times. There would be less rain in the south but there would be some with some longer drier, brighter but rather cloudy conditions too.

The charts look very Autumnal this morning with Low pressure never far away from the UK. With the winds blowing from the west for most of the time all areas can expect some rain at times with the best of any drier and brighter weather reserved for the South though even here this could not be relied on. With the said westerly wind temperatures would be close to normal and with the exception of Wednesday and Thursday night when a touch of frost is possible in sheltered Northern valleys night time temperatures shouldn't cause too many problems of yet with too much wind and cloud for any significant frost worries.

[Frosty.]

Thursday looks the best day this week with a ridge across all of the uk for a change! After a mellow misty start it will become fairly sunny with light winds and temps will be around or slightly above the seasonal average but by friday we will see low pressure moving in from the west with a deterioration in the weather from the west by the end of friday and an unsettled weekend to follow. Next week also looks unsettled, probably best described as changeable further south with more in the way of sunshine and longer dry spells between the spells of rain but a typically mobile autumn pattern becoming established according to the 00z models this morning.

[Thundery wintry showers]

I think you are possibly becoming obsessed with 'settled' weather. Not sure it's all that likely at the moment anyway, Atlantic seems to be very active, think the charts will look different in 8 days time. Still, if October does deliver some settled weather, would likely deliver some frosts which would be great.

My main objection with the constant talk of "settled" weather is that it doesn't give enough information- in summer we can go pages on end without any information other than when the next "settled" spell might be. I understand that some people are happy if the weather is dry and unchanging irrespective of cloud, wind and temperature, but this thread should cater for more than that (I never get particularly thrilled by stratocumulus sheets, cool days and warm nights for instance). I get a sense, though, that by "settled" most people really mean "warm, dry and sunny", and wrongly assume that if it's settled we can take it for granted that it will be warm, dry and sunny, which often leads to disappointment.

In the meantime I think the high pressure ridge on Thursday will bring dry sunny weather, though not particularly warm. The night of Wednesday/Thursday is projected to be notably cool for mid-September, and ground frosts may occur widely in sheltered spots with an air frost locally in Scotland. Friday still looks like it has some potential for thundery activity, with moderately high convective available potential energy coinciding with an area of heavy rain. After that, it's a couple of days of sunshine and showers over the weekend.

Next week will see high pressure close by to the south, and some parts will end up dry and sunny, but there will be a slow-moving weak front associated with that regime. Places trapped under the front will end up grey and drizzly, while to the north of the front conditions will end up sunny and dry, bar a few showers in western and northern Scotland, and all depends on where the front ends up.

[Backtrack]

I think you are possibly becoming obsessed with 'settled' weather. Not sure it's all that likely at the moment anyway, Atlantic seems to be very active, think the charts will look different in 8 days time. Still, if October does deliver some settled weather, would likely deliver some frosts which would be great.

Save the pattern change for late October.

I just pray to God it does change in time for Winter, or it will be very mild indeed.

[Frosty.]

Next week looks ok for the south with some warm sunny weather and lighter sw'ly winds, more mixed across central britain and then more unsettled across scotland & n.ireland with strong sw'ly winds at times and some spells of rain but with drier and brighter intervals too. This weekend looks like turning unsettled from the west although it now looks as though some rain will spill across northern britain on friday so a very brief respite from the unsettled weather.

.

[summer blizzard]

My main objection with the constant talk of "settled" weather is that it doesn't give enough information- in summer we can go pages on end without any information other than when the next "settled" spell might be. I understand that some people are happy if the weather is dry and unchanging irrespective of cloud, wind and temperature, but this thread should cater for more than that (I never get particularly thrilled by stratocumulus sheets, cool days and warm nights for instance). I get a sense, though, that by "settled" most people really mean "warm, dry and sunny", and wrongly assume that if it's settled we can take it for granted that it will be warm, dry and sunny, which often leads to disappointment.

In the meantime I think the high pressure ridge on Thursday will bring dry sunny weather, though not particularly warm. The night of Wednesday/Thursday is projected to be notably cool for mid-September, and ground frosts may occur widely in sheltered spots with an air frost locally in Scotland. Friday still looks like it has some potential for thundery activity, with moderately high convective available potential energy coinciding with an area of heavy rain. After that, it's a couple of days of sunshine and showers over the weekend.

Next week will see high pressure close by to the south, and some parts will end up dry and sunny, but there will be a slow-moving weak front associated with that regime. Places trapped under the front will end up grey and drizzly, while to the north of the front conditions will end up sunny and dry, bar a few showers in western and northern Scotland, and all depends on where the front ends up.

I agree although 80% of posters seem to want an all out ice age in winter and an African climate in summer so i don't think there is anything that can be done really.

What people need to remember at this time of year is that unless the high makes it east of us, temperatures are unlikely to pass 25C and there is no guarantee thatthe sun will burn it off. In two months if we get a high over us, we are talking about inversions.

Looking at the models this morning, cool and wet sums it up although the east may be be quite sunny as there is a strong westerly component so showers may remain in the west.

[William of Walworth]

80% of posters seem to want an all out ice age in winter and an African climate in summer so i don't think there is anything that can be done really.

I'm a settled weather preferer and post actively about trying to read the best into output during the summer proper (ie usually up to the end of August). Even by my standards though it's been very hard for me to push optimism and hopecasting very far since June at the latest ...

What you say there though is an outrageous distortion of the REAL preferences of many of us 'settledists' or 'anticyclonists' if you like.

My expectations of the UK summer, generally, and particularly this one, have IN FACT been quite low most of the time, and I've often been happy with crumbs of sunny comfort occasionally interrupting the frequent domination of LP systems and Antlantic driven conditions

I certainly don't expect (or even want!) wall to wall sunshine and week after week of 30C all the time, that would be stupid.

Perhaps remarking on the utter transcience of this small, weak apology for a ridge upcoming, and its probable refusal to last even until the weekend, might be forgiven on my part however -- even by unsettled lovers and coldists?

Apologies for offtopicness here. I've contributed plenty of ontopic posts over these threads. But this summertime accusation, often levelled, that there's almost anyone on here who expects and ramps hot hot hot sunny sunny sunny conditions in defiance of evidence and common sense is a canard. It's not just summer blizzard who distorts the real position of summer lovers either.

After all, It's not as if there's been any absence of 'writing off' the entire summer since well before it became clear that it was going to contiue so indifferently /////

(As for winter, you're unlikely to see much if anything of me on here between October and March!)

Edited September 13, 2011 by William of Walworth

[J10]

To be honest I am also one who likes settled conditions in summer with High Pressure. Why because largely it means dry warm weather and quite often sunny weather. Of course wind direction as very important under High Pressure conditions.

Of course it depends where the core of the High pressure is based. NW winds are generally OK here, as we tend to get a lot of shelter especially if the air originates from the North West , however this is offset if the the air type is Tropical Maritime, but even then we can do better than other parts.

Winds from a SW direction are generally not that good. However winds from a Northerly, NE or SE direction which High pressure often provides tends to mean we get the best of any sunny weather. Generally in summer as well, under light winds, any sunshine even 20s tends to feel very pleasant as often we had many summer days like this this year, even with the absence of any real warmth.

Of course there is IMBYism in my post, but that can also be applies to most other posters to some extent.

[Gibby]

Hi folks.

Tonight GFS looks very changeable between now and the weekend. Tomorrow sees Low pressure moving away tomorrow with drier and increasingly bright weather developing through the day. Winds fall light/variable on Thursday as the weather becomes dry nationwide with some sunny spells and variable amounts of cloud with temperatures fairly close to normal. Unsettled weather then returns Friday as Low pressure moves in off the Atlantic though this may not reach the far SE until late Friday. This would mean outbreaks of rain would move slowly east across all parts by the end of the week. The weekend sees a return to a mobile Atlantic style setup with Low pressure to the North and a broad westerly flow over the UK bringing bands of rain and showers east in the strong breeze. FI tonight brings a changeable theme to the weather with some wet and windy conditions for all mixed with some drier, brighter spells especially in the South before the statutory high pressure block forming near the UK in the far distant FI.

UKMO tonight also shows the slow improvement in the weather over the next 24hrs or so as a ridge of high pressure develops over the UK on Thursday. This is nudged away east by Friday as a trough and subsequent low pressure develops quickly over Northern Britain to ease us into an unsettled weekend especially on Saturday when heavy rain and showers could be quite widespread for a time. On Sunday the Low moves off east only to be absorbed within the circulation of a large Atlantic Low in the region of Iceland by Monday pushing another series of troughs towards the UK.

ECM is a mirror of UKMO out to Sunday with the weather events naturally following the same sequence too. As next week progresses a mobile Atlantic setup ensues with Low pressure to the North with High pressure not too far away from the South. The North will maintain unsettled conditions with showers or longer periods of rain while the South see some lengthy drier spells although never immune from rain too. Temperatures would remain close to normal as one would expect in an Atlantic windflow but it could occasionally become rather warmer in the SE.

In Summary there seems something for everybody in tonights output with rain, wind, sun and a little bit of warmth too. There is only one word that describes tonight's output and thats 'changeable'. So in the next two weeks we will all see some further rain at times but some drier, brighter and warmer days too unless you live in the North when the next two weeks quite frankly look little different to the whole summer gone i.e wet and windy.

[Thundery wintry showers]

I think it's all about extent and emphasis- I don't have anything against people preferring a particular type of weather, and it's true that a large majority of people do enjoy warm dry sunny weather in summer, and high pressure is often associated with it in the summer half-year.

The problem is that we get a situation where the desire for one type of weather dominates the thread to such an extent that it's taken for granted that we all only want that type of weather, and discussion of other types of weather is treated almost as off-topic. (the same as with the cold/snow bias in winter and the desire for a sudden flip to a warm spring on the 1st March). Not all of us can easily be categorised as "settled lovers" or "unsettled lovers"- there's quite a number of us who are interested in a range of weather types, including some "settled" and some "unsettled", and there seems to be little room for us at times, as well as the all-out "unsettled lovers". For instance, many people are interested in convection/storms but there was no room for discussion of those in MOD- at best such posts got ignored.

We did get a fair amount of "settled ramping" this summer, e.g. instances when high pressure was shown in FI and various members automatically assumed it would be hot, dry and sunny, despite the model outputs suggesting otherwise, and 16-18C in late July being described as "warm" just because pressure was high, and that does end up disappointing a lot of people.

I don't think JACKONE or William of Walworth have done anything wrong in MOD, it's more an imbalance-of-power problem that arises, it may be that more people need to be encouraged to talk about other kinds of weather (like Mushymanrob does in winter for instance) but it's often tough, as I know from experience of slogging it out in spring in particular.

[johnholmes]

perhaps the clue to this thread is in the title?

Why on earth, instead of discussing/arguing, about what settled, unsettled, or any other term, discuss the model outputs from the main model centres.

Thank heavens for the daily input from Gibby that does just that.

By all means discuss your preferences although there are other threads to post your views in, disagree about what the model is showing be it T+12 or T+240 but please can we have everyone reverting back to the title of the thread-model discussion.

To try and get my post from being deleted for being off topic - all the big 3 show at T+72 a marked trough moving into the UK with rain pushing into Ireland and other western areas by 1200Z.

The T+144 charts all have a fairly deep area of low pressure in the Iceland area although ECMWF suggests less troughing than the other 2 into the UK.

By T+240 and low pressure is straddled across much of the chart from mid Atlantic into Scandinavia although GFS makes rather more of a ridge over the UK than ECMWF does.

apologies if the first part of my post upsets some folks but I am getting rather fed up of folk not posting about what the models are showing rather than what their preferences are. Just think for a moment on what the many many visitors to this site must think.#

[Gibby]

Good morning. Here's my look at the 00zs of the big three this morning.

GFS today shows a ridge of high pressure moving east across the UK tomorrow followed by new Low pressure moving in off the Atlantic to be centred over Northern Britain by Saturday, moving SE. After any remaining showers today die out tomorrow will be a dry, bright day with some welcome sunshine before rain moves slowly east and south over Friday to reach all areas by midnight Friday leading into a cool and breezy, showery weekend. Then as we move through next week the Low dissipates in the North Sea, becoming absorbed in the circulation of a large Atlantic Low near Iceland. Consequently, next week will develop into a breezy, changeable one with rain at times with the heaviest of this in the North while the South has some longer dry spells inbetween intermittent rain. Through FI the pattern changes somewhat as High pressure temporarily builds from the SW before a Low slips SE down the North Sea pumping up a large blocking Anticyclone in mid Atlantic by the runs end with North winds and some rain briefly for all then showers from the departing Low to the SE.

UKMO shows a similar breakdown for the next 4 or 5 days as Low pressure replaces tomorrows ridge over Friday and the weekend with rain followed by cool and showery conditions. In the early part of next week winds settle westerly as Low pressure dominates with rain and fresh breezes for the North while the South may see less risk of rain with time and temperatures picking up a little.

The Fax Charts show a ridge tomorrow being followed by a complex Low pressure system moving into the UK on Friday and lasting the weekend as it fills just to the east of the UK by Sunday as a weak ridge approaches the west late in the day.

ECM this morning shows an improving day today with the best day of the week tomorrow as High pressure builds briefly near the UK. As per the other models this is pushed away by Friday and the weekend looks cool and showery as Low pressure drifts across Scotland and out into the North Sea by Sunday. Through next week things improve slowly with some rain in all places at times early in the week but with pressure building from the Azores drier weather would migrate steadily North from the South so that at the end of the run most places will be dry with reasonable temperatures with some mist and fog patches in the South at night where skies clear and winds stay light.

In Summary the weather pattern is nailed between now and the start of next week with a fairly unsettled and showery weekend likely after Thursdays fine blip. However, the behaviour of the large Low near Iceland early next week staying well to the NW and further Low pressure being pushed towards Greenland looks like drawing High pressure up close to or indeed over the South as per ECM and to a lesser degree GFS by midweek which would mean a possible pattern change as the Atlantic weakens somewhat. If it verifies the weather could eventually become dry and reasonably warm by day with mist and fog night and morning and not just in the South.

[Thundery wintry showers]

Apologies for the intensity of the earlier rant, I can't fault what John has said above, excellent post.

After tomorrow's dry sunny calm day, the rain belt coming across on Friday continues to have moderate convective available potential energy tied in with its western flank, suggesting perhaps showers on the backward edge of the frontal systems or maybe an active cold front. It doesn't look likely that thunderstorms will be widespread but maybe some western and central areas could get the odd rumble mixed in. GFS temperature and cloud outputs suggest a dull wet day away from the SE. I agree with Gibby's suggestion of a showery weekend as a polar maritime airmass follows Friday's rain.

Regarding the more anticyclonic interlude in 5-8 days' time, the models again indicate a slow-moving front close to the northern flank of the anticyclone, and the positioning of this front is critical (it would bring a lot of cloud, though not much rain away from exposed western areas). GFS has it to the south of the UK mainland which would result in a sunny spell for most of the country, and dry for most initially although shower activity does pep up towards T+168. If the pattern gets revised further north (which is implied by the ECMWF ensemble mean) we could end up, paradoxically, with cloudy weather in the south and dry sunny weather in the north.

The NOAA 8-14 day pressure outlook suggests that the more anticyclonic influence may be short-lived with low pressure indicated for the 8-14 day period.

[summer blizzard]

From the weekend onwards it does look generally unsettled from all models although with pressure higher to the south, it will likely be drier and warmer than in the north although uppers look fairly cool.

In the latter range close to day 10 there is a massive disagreement between ECWMF, GEM and GFS with a southerly, northerly and westerly all thrown into the mix.

On the whole, now that we seemed to have dropped the recurving influences of Irene and Katia, it looks as though the pattern has changed to one much more in line with what we saw during the summer.