Model Output Discussion - Early October Onwards

[wimblettben]

The GFS has also been picking up a very intense storm, with some runs showing 956mb depression. As I have mentioned earlier we are in for some very interesting weather over the coming week.

Lots to watch in this active period about to materialise, with potential for very severe weather.

I know it is too far away to be quoting any main details. But even if it verified I doubt winds in the south would get much above 30mph and that isn't a joke.

[Gibby]

Good evening. Here's a look at the 12zs from GFS, UKMO and ECM.

GFS tonight throughout its entire run shows a disturbed, rather cold and often windy spell of weather with periods of rain or showers never far away from anywhere at any given time. Some snowfall can be expected on Northern hills while the South inparticular could see some brief brighter spells between the wetter spells.

The Ensembles for London show a sharp dip over the next few days to well below normal for a day or two before a recovery to a position slightly below the long term mean happens from the 21st. The incidence of rainfall increase greatly from the end of next week as the Low pressures dig further into the UK. For Aberdeen temperatures remain at or below the long term mean throughout with rainfall likely frequently for the entire run.

UKMO refuses to release High pressure far away enough from the South to allow any meaningful rain in the timespan shown. A period of rain will cross the South but total amounts are likely to be small and quickly followed by bright, cool and mostly dry weather. Further North the weather would be much more disturbed with wind, rain and squally showers affecting all parts with some snow at times over Northern elevations.

ECM shows a spell of wind and rain for all early in the week ahead of rather cold and showery conditions for Tuesday and Wednesday. After a brief ridge on Thursday ECM shows much deeper troughing approaching the UK Friday resulting in a deep Atlantic Low moving in close to NW Britain for the final days of the run. The weather would become very windy for all with gales and spells of heavy rain and/or showers. Temperatures would be somewhat below normal with hill snow for Scotland, the cold accentuated by the strength of the wind everywhere.

In Summary it looks a lot colder next week. There are some differentials between GFS and ECM on one side and UKMO on the other. GFS and ECM show increasingly disturbed and windy weather with temperatures on the low side as we move onwards from the end of next week. UKMO looks less disturbed with high pressure staying close to the South with the evolution beyond 144hrs looking less clear.

[Liam J]

I know it is too far away to be quoting any main details. But even if it verified I doubt winds in the south would get much above 30mph and that isn't a joke.

Sorry, being a bit bias to the Northern half of the UK which is looking likely to have some pretty rough weather this week. Things could change regarding the storm later on the ECM and GFS runs, to far out to have much confidence in yet apart from the two models picking this up.

Plenty going on in the short term to keep us occupied. If it keeps showing up in future runs I will take more notice, but until then focus on Monday/Tuesday.

[damianslaw]

A major change for all as we see the atlantic step up a gear. Scotland will see cold conditions for the time of year these extending into N England, even the south will see temps somewhat a little below the average which accompanied with the cloud rain and wind will come as a big shock to many I suspect.

All models agree on weak ridging on Thursday which should bring a shortlived quieter interlude before the next low pressure and active fronts move in from the west. Next week has potential be a rainfest for many places with gales - all models are showing a very slow moving low pressure system becoming stuck over the country suggesting heights will be rising rapidly to the north.

On a personal note my trip to west highlands from tomorrow until next sunday looks a bit of a soggy outing, but hoping at least for some great visibility inbetween the showers and the first proper highland snow of the season will be a bonus - its the wind I am most bothered about- buffeting on the hills makes for very difficult walking!

[snowlover2009]

Im not sure why- but I cant paste into this thread-

The ECM 192 ( YES is a long way away) shows a key component for Winter- the jet diving south-

THe problem in this scenario is look what it brings with it!

A HUGE 960 MB STORM- Thats a real bad one-

http://www.meteociel...H1-192.GIF?15-0

S

All very November 2009 and we know what came after....

The blocking to the north, jet diving south. Perfect.

[phil nw.]

A major change for all as we see the atlantic step up a gear. Scotland will see cold conditions for the time of year these extending into N England, even the south will see temps somewhat a little below the average which accompanied with the cloud rain and wind will come as a big shock to many I suspect.

All models agree on weak ridging on Thursday which should bring a shortlived quieter interlude before the next low pressure and active fronts move in from the west. Next week has potential be a rainfest for many places with gales - all models are showing a very slow moving low pressure system becoming stuck over the country suggesting heights will be rising rapidly to the north.

On a personal note my trip to west highlands from tomorrow until next sunday looks a bit of a soggy outing, but hoping at least for some great visibility inbetween the showers and the first proper highland snow of the season will be a bonus - its the wind I am most bothered about- buffeting on the hills makes for very difficult walking!

Yes Tues.into Weds.look particularly unsettled especially for Scotland.

A deep low just to our North bringing squally wintry showers into the highlands and much cooler temps. nationwide in the Polar maritime flow.

[cyclonic happiness]

Will we see any rain though? that has to be THE question for much of the midlands and east anglia.

[Grimsby Snow Lover]

Will we see any rain though? that has to be THE question for much of the midlands and east anglia.

Having seen the charts from both the GFS and ECM you would have thought so. I do see your point though as the east/south east has been rain starved all year. Even here we have struggled at times to get the rain across. Only last week the grass around here was looking very brown again.

[phil nw.]

Will we see any rain though? that has to be THE question for much of the midlands and east anglia.

The cold front coming through late Mon into Tues should give a spell of rain to even Central and South Eastern areas but after that it may be quite dry down here untill at least Friday.

As ever apart from the odd shower through the Cheshire gap i can see very little rain for areas that need it during much of the next 5-6 days.

If the UKMO is near the money then even Friday could be dry further South with the High pressure more prominent than modelled by GFS and ECM with the rain held further North West.

Temperatures lower yes as we pick up the PM flow but detail after midweek still to be established as far as rainfall is concerned.

[kold weather]

Does look unsettled this week, the south doesn't really get much in the way of exciting weather, pretty much average in all departments, but the north certainly has alot of different types of weather thrown at it this week.

Pattern slowly becomes more condusive for a wetter than normal set-up even in the south though exactly how it evolves remains to be seen, upper trough looks like sitting close to the UK by 168-192hrs, exact location will make alot of difference.

[Cloud 10]

Does look unsettled this week, the south doesn't really get much in the way of exciting weather, pretty much average in all departments, but the north certainly has alot of different types of weather thrown at it this week.

Pattern slowly becomes more condusive for a wetter than normal set-up even in the south though exactly how it evolves remains to be seen, upper trough looks like sitting close to the UK by 168-192hrs, exact location will make alot of difference.

The NAEFS 12z also picking up on this along with the ECM which SM mentioned earlier.

http://91.121.84.31/...-0-0-192.png?12

[Jason T]

WELL i guess SM was right when he posted 5 weeks ago the 0c line was very close already. Could we all be in for the DADDY of all WINTERS. Model output could be a lipp-smacker.

[peterf]

WELL i guess SM was right when he posted 5 weeks ago the 0c line was very close already. Could we all be in for the DADDY of all WINTERS. Model output could be a lipp-smacker.

anychance of some charts or data to validate your post?

[Liam J]

WELL i guess SM was right when he posted 5 weeks ago the 0c line was very close already. Could we all be in for the DADDY of all WINTERS. Model output could be a lipp-smacker.

Could you clarify this post better please?

NAE 18z showing quite an intense secondary low Monday afternoon, severe gales with potential for mean speeds to approach storm force 10 over coastal areas in the NW areas just south of Scotland.

NAE isotachs MPH chart below.

Edited October 15, 2011 by Liam J

[kold weather]

Whilst not as strong, the 12z ECM also showed a similar feature, with NW England and SW England getting winds in the range of 30-40kts.

[Jason T]

Yes i can,But i believe Steve Murr will validate it for me,Got to admit we was all looking for heat,When Steve posted the 0c line was Close already,but i will find the post. When SM posted then, Alarm bells rang,Im not going to admit im Fantastic at model and data reading,But reading in-between post's built a good picture. For me when Steve Murr and Nick Sussex Post were in business.

[Richie V]

Yes i can,But i believe Steve Murr will validate it for me,Got to admit we was all looking for heat,When Steve posted the 0c line was Close already,but i will find the post. When SM posted then, Alarm bells rang,Im not going to admit im Fantastic at model and data reading,But reading in-between post's built a good picture. For me when Steve Murr and Nick Sussex Post were in business.

Far from true, They're usually here dispensing prozac and valium to calm falsely ramped hopes!

Oops, I bet I've upset the mostly hairy OON being off topic...

Anyways, the 18Z continues with the gale theme mon and tues. Seems to be all over the place later in the week at the moment with low pressure placement and intensity. FI is around +120h at present!

[Polar Continental]

Im not sure why- but I cant paste into this thread-

The ECM 192 ( YES is a long way away) shows a key component for Winter- the jet diving south-

THe problem in this scenario is look what it brings with it!

A HUGE 960 MB STORM- Thats a real bad one-

http://www.meteociel...H1-192.GIF?15-0

S

Hi Steve, just click the ‘toggle-editing mode’ in the left corner of the editor.

Hello all,

Not posted in here for a good few months. As the last of summer embers continue to glow through this weekend, we see the real approach of autumn next week as quite a deep low from off the Atlantic blows us back in to reality. Looking through the 0z GFS this morning it certainly looks as though as the cold front pushes through from the west on Monday night and in to the early hours of Tuesday, there will be a sharp drop in temperature, could possibly be some early sleet over the hill tops of England and Wales. Quite early, only mid October, and also considering how warm it’s been of late; I think quite a shock to the system for many by Tuesday morning. Welcome back, winter

http://hw.nwstatic.co.uk/gfsimages/gfs.20111016/00/51/h500slp.png

[kold weather]

Models just startin to suggest the pattern may not be quite as progressive as first thought with both the GFS/ECM forecasting a little ridge of high pressure to form. I wouldn't be all that surprised to see a Scandinavian high try and set-up by day 10, I've seen this exacvt thing happen many times on the models and they nearly always under-estimate the ability of the ridge.

Probably this time the Atlantic will win out but who knows!

[Slinky]

It certainly looks to be interesting, looking forward to the Autumn weather the models are showing at present.

Kold - think your right backing the Atlantic at the moment.

[Gibby]

Good morning folks. Here's a look at the 00zs from my perspective this morning.

GFS shows low pressure crossing to the North of Scotland bringing spells of rain steadily SE over the next 24-36hrs clearing the SE Tuesday followed by much colder and blustery NW winds and showers, wintry for hills in the North. Later in the week a weak ridge crosses East damping down showery activity before further troughs move in off the Atlantic by the weekend with further rainfall and a slight recovery in temperatures. For the rest of the run details will change but the trend is for the weather to remain disturbed and often rather cold and wet with further snowfall for Northern hills and rain/gales to affect all areas frequently as Low pressure lies over or close to the UK. Frosts at night would be limited due to wind strengths and cloud amounts but temperatures would be somewhat below normal for the most part.

The Ensembles show a marked dip in temperatures down here in the South over the next few days then a recovery to normal values or just below with rainfall expected frequently from the 21st. For Aberdeen temperatures recover from the dip over the next few days to levels close to the long term mean-a feature that is well supported by tight clustering of the members throughout its run.

UKMO today shows a band of heavy rain sweeping SE tomorrow followed by showers and sunny spells. The South then becomes mainly dry and rather cold for the midweek days as winds lighten ahead of a ridge. Later on Friday rain will return across the NW and then subsequently spread SE to other areas next weekend.

ECM follows a similar trend as UKMO through the week with Low pressure moving in close to the UK by next weekend bringing rain and wind to all areas in rather cold conditions, a pattern that continues through to the end of the run as the Low fills in situ.

In Summary Autumn proper finally arrives for the South this week. Temperatures fall markedly through late tomorrow and Tuesday here. The North and West sees frequent heavy and sometimes wintry showers for the hills and some of these rain showers could reach the South at times before things dry out after Wednesday down here. Charts then suggest low pressure settling close to the UK by the weekend bringing wind and periods of rain to all areas thereafter. Despite recent very stormy looking charts in FI my advice is don't be sucked in to any thoughts of severe weather in the next few weeks. In all essence unless such intense depressions that have recently been shown on some of the output get shown in the T96hrs time frame the chances are they will be removed by subsequent runs. From T120 on its just a matter of trends that I'm looking at and to that end it means standard Autumn fayre of wind and rain at times with temperatures slightly below normal sets the scene for the next few weeks.

Edited October 16, 2011 by Gibby

[Liam J]

Still on course for a spell of very windy weather during Monday afternoon on the 00z run, severe gales over parts of North Wales and battering NW England, with potential for gusts to exceed 70mph as the shortwave deepens rapidly during its passage over the UK from the SW of Ireland heading NE. Meto have 72mph gusts for my location Monday afternoon., there could be some very squally conditions with some severe gusts as the cold front moves through.

Let's see what the 6z runs make of this as we head closer to the event.

the first 6z run out is the NAE and continues where it left off from the last run perhaps slightly more intense wind speeds, severe gales even storm force winds in the North Irish Sea and adjacent coastal areas.

GFS 6z also keeps the same as before, get ready for a BIG blow!

Worth noting it's also showing mean wind speeds of 35-40mph quite a way inland over Northern England

Quite a short lived event but it will be very stormy for a time with S-SW'ly severe gales veering westerly pretty sharply before easing, the winds remain strong westerly before picking up again into Tuesday with further gales likely.

Edited October 16, 2011 by Liam J

[andy_leics22]

Well.. According to the 00z run, we could be looking at sleet/snow showers for a short time during Tuesday night and Wednesday in Western Scotland, Northern Scotland, Northern Ireland, North West England/North Wales. Probably just sleet away from the hills but it's nice to see half of the country under -5 or below 850's again!

[wimblettben]

Still on course for a spell of very windy weather during Monday afternoon on the 00z run, severe gales over parts of North Wales and battering NW England, with potential for gusts to exceed 70mph as the shortwave deepens rapidly during its passage over the UK from the SW of Ireland heading NE. Meto have 72mph gusts for my location Monday afternoon., there could be some very squally conditions with some severe gusts as the cold front moves through.

Let's see what the 6z runs make of this as we head closer to the event.

the first 6z run out is the NAE and continues where it left off from the last run perhaps slightly more intense wind speeds, severe gales even storm force winds in the North Irish Sea and adjacent coastal areas.

Worth noting it's also showing mean wind speeds of 35-40mph quite a way inland over Northern England

If this occours Liam J then there will certainly be some form of damage.

This is mainly because of the fact that even the mean wind speeds will be Near gale to Gale force which is enough to snap twigs off of trees and this isn't including the damage that may occour from the much more stronger gusts.

Edited October 16, 2011 by wimblettben

[cyclonic happiness]

Well.. According to the 00z run, we could be looking at sleet/snow showers for a short time during Tuesday night and Wednesday in Western Scotland, Northern Scotland, Northern Ireland, North West England/North Wales. Probably just sleet away from the hills but it's nice to see half of the country under -5 or below 850's again!

Yes! just think of all those times in the Noughties where we'd be praying for the 528 to get anywhere near us, let alone in october!!

Makes you wonder where all of this synoptic pattern shifting will end?