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Model Output Discussion 12z 20/04/13


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Posted
  • Location: Evesham/ Tewkesbury
  • Weather Preferences: Enjoy the weather, you can't take it with you 😎
  • Location: Evesham/ Tewkesbury

Ecm shows some potential for thundery downpours for the Southern Uk

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Posted
  • Location: Castle Black, the Wall, the North
  • Weather Preferences: Spanish Plumes, Blizzards, Severe Frosts :-)
  • Location: Castle Black, the Wall, the North

Let's hope we can eventually tap into some of that continental warmth/heat/humidity well to the east of the uk on the Ecm 12z charts, there is a chance we eventually will do if the FI retrogression of the cool trough continues, late may could become generally warm and dry, better late than never.smile.png

 

Although i'm a cold weather fan, i've had enough of the northern blocking now and want to see things warming up properly in the coming weeks and months, either from the east or via the azores high, the gfs 12z op run went with the azores anticyclone ridging northeast later in FI but the gefs 12z mean is pushing for a pattern change from the east with the european high pressure block edging westwards.

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Edited by Frosty039
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Posted
  • Location: Windermere 120m asl
  • Location: Windermere 120m asl

Reliable timeframe - a  very unsettled outlook with the UK locked underneath the influence of a deep long wave atlantic trough meaning plenty of wet occasionally windy weather and often cool but with some sunny spells at times. Quite dissapointing given we are entering the middle of May which can be a lovely time of year. Its a pattern we have become very accustomed too over the past 6 summers.. The pattern does look worringly ominuous in the sense that we have had 4 really quite dry blocked months with a preety ineffective atlantic, much like many recent late winter/early spring periods only to see the return of the trough coinciding with the start of the warm season. Lets hope it doesn't mark the start of a lengthy wet unsettled period. The azores high is lurking to the SW waiting to pounce and long term signals are quite promising in that we may see much more blocking to our NE rather than NW this summer which whilst not conducive to sustained dry pattern is conducive to warm weather at times as we lurk on the western edge of the ridge as opposed to firmly being sat inbetween two ridges under a stubborn trough.

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Posted
  • Location: Worcestershire/Warwickshire/North Oxfordshire
  • Location: Worcestershire/Warwickshire/North Oxfordshire

The 15 day ensemble forecast of cumulated rainfall for London continues to show an upward trend for more rain.

ensemble-rrrcum-london.gif

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Posted
  • Location: Truro, Cornwall
  • Weather Preferences: Winter - Heavy Snow Summer - Hot with Night time Thunderstorms
  • Location: Truro, Cornwall

The 15 day ensemble forecast of cumulated rainfall for London continues to show an upward trend for more rain.

ensemble-rrrcum-london.gif

 

 

Well of course it would show an upward trend being 'Cumulative'.... rofl.gif 

Anyhow, I think that rainfall chart could look worse imo. Some rain bands now and again but more sunshine and showers inbetween im thinking. Yes the charts are rather unsettled right now but I find it frustrating how people think this is where summer ends already. Just a few seem to have that motive. A nornal summer will contain spells of unsettled weather. Who knows, Summer 2013 may go like the last few, it may not but lets leave that judgement to the professionals, not our gut instincts or pessimistic or optimistic minds.

 

Aside from that, with Northern Blocking id expect these charts to continue to show unsettled weather for the next 2 or 3 weeks possibly. I wouldnt expect Northern blocking to just suddenly 'collapse'. Drifting a touch here I know but if this low pressure in summer is related to low Arctic sea ice, hasnt it been reported that in April, Arctic sea ice levels have been the highest for some years? I might be wrong and cant quite remember but perhaps its a reminder we are in the UK, we are not the Med, Low pressure, wind and rain is not uncommon even in an average summer etc.

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Posted
  • Location: Morecambe
  • Location: Morecambe

Models have been hintng at possible dull cloudy easterly winds but are not really edging into the medium term as of yet which is good news as I rather have the more showery SW'ly airflow that the models are hinting at than that. 

 

The warmth building over Eastern Europe and into Russia is impressive and potentially bad news for us as normally logic would tell you the UK would be stuck under a trough and cooler conditions and that what we are seeing. 

 

Potential for some good convective weather for Monday and Tuesday but as others have said, too early to place any firm detail on this yet. 

 

Blizzards - Arctic sea ice is quite low at the moment and has been during April, 2012 had higher extent. Its not that unusual too see blocking charts in May, easterlies can be quite common but as I said, our weather is projected to be more influenced by a trough and a showery West to SW'ly wind rather than any easterly winds.

Edited by Geordiesnow
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Posted
  • Location: Hanley, Stoke-on-trent
  • Location: Hanley, Stoke-on-trent

Let's not forget it would depend where any northern blocking set up too. For summer, Greenland bad, but across Northern Scandi, could bring some very nice summer weather, with always the chance of some good thundery stuff from the south. The current models seem to be showing the latter in FI, so let's not be so quick to judge?

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Posted
  • Location: Heswall, Wirral
  • Weather Preferences: Summer: warm, humid, thundery. Winter: mild, stormy, some snow.
  • Location: Heswall, Wirral

Throughout this week, we are very lucky to be projected double figure temperatures at all.. in fact this trough looks like staying for immeasurable amount of time, I would suspect if it continues it's reign over the NW Atlantic, eventually we will see relatively warm, humid air, coming here from Scandinavia. 

 

Jokes aside, it is looking pretty bad, 2013 certainly looks record breaking on my own weather records, and the high pressure over Greenland is doing nothing to alleviate this potential. 

 

I cannot see a way back for mild air, not for western areas anyway, perhaps back and forth or more eastern areas, but warmth is as far away now as it ever has been at any point this year. 

Edited by SP1986
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Posted
  • Location: Truro, Cornwall
  • Weather Preferences: Winter - Heavy Snow Summer - Hot with Night time Thunderstorms
  • Location: Truro, Cornwall

Models have been hintng at possible dull cloudy easterly winds but are not really edging into the medium term as of yet which is good news as I rather have the more showery SW'ly airflow that the models are hinting at than that. 

 

The warmth building over Eastern Europe and into Russia is impressive and potentially bad news for us as normally logic would tell you the UK would be stuck under a trough and cooler conditions and that what we are seeing. 

 

Potential for some good convective weather for Monday and Tuesday but as others have said, too early to place any firm detail on this yet. 

 

Blizzards - Arctic sea ice is quite low at the moment and has been during April, 2012 had higher extent. Its not that unusual too see blocking charts in May, easterlies can be quite common but as I said, our weather is projected to be more influenced by a trough and a showery West to SW'ly wind rather than any easterly winds.

Ahh right it could have been snow cover I was looking at. Nevermind. Anyway I wont clutter this thread up any more about Arctic sea ice. :)

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Guest pjl20101

The current CPC 8-14 day output is here right in front of us and looking very similar to the past two runs, although the hp evidence to scandanavia is intensifying and looks like it will retrogress towards us:

http://www.cpc.ncep.noaa.gov/products/predictions/814day/500mb.php

Which would be quite pleasant if it did, by the way I retweeted one of matt hugo's tweets and he reckons of a change when we get out of the +nao pattern we are in currently. He also changed his mind about rainfall and is now going for rainfall at or above average rainfall now. Looking pretty worrying, but I'm not going to get to much in a tisswas about it.

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Posted
  • Location: Reigate Hill
  • Weather Preferences: Anything
  • Location: Reigate Hill

The differences as to where the trough sets up from about D7 makes all the difference for the UK.

Last night's 18z is close to the UK: post-14819-0-55194700-1368166025_thumb.p This morning: post-14819-0-29828700-1368166042_thumb.p

Further west, like the 0z, and we drag in the warmer continental air, from the Euro ridging:

post-14819-0-05790600-1368166109_thumb.p and after a while: post-14819-0-05682300-1368166136_thumb.p

At the moment the GEFS are split as to where the trough will be: post-14819-0-15711500-1368166169_thumb.g

The control and op mirror the very best scenario from the ensembles at the moment.

Lets hope its trending in that direction.

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Posted
  • Location: Kilmersdon Radstock Somerset
  • Weather Preferences: None Really but a snow lover deep down
  • Location: Kilmersdon Radstock Somerset

Hi folks. Here is this morning's breeze through the midnight outputs from GFS, UKMO, GEM, NAVGEM and ECM for today Friday May 10th 2013.

All models
show a unsettled weekend to come as an unstable Westerly flow continues to blow across the UK. With troughs embedded in the flow there will be more extensive rainfall at times in among the otherwise showery spells. However, it won't be all gloom and doom as there could be some sunshine at times too, especially towards the East and SE. It will remain breezy with temperatures close to normal or a little below in general. Through the early days of next week all models continue to programme another Low pressure to sink South over the UK maintaining the showery and changeable theme across the UK in cyclonic variable winds.

GFS shows the Lows to move away to the SE late in the week with a showery trough left over the UK for a time. However, this morning shows a ridge from the Azores High becoming close to Southern Britain next weekend with the next Low pressure area held more to the NW with the attached rainfall reserved for these areas while the South, though not settled will see longer drier, brighter and warmer spells by then. Through the rest of FI the weather becomes warmer everywhere with a lot of dry weather for a time away from the far NW. However, as pressure become lower and slack at the end of the run the warmth would generate some heavy showers or thunderstorms in places in conditions that would turn rather humid.

The GFS Ensembles unfortunately show the operational as a lone species in the warm and humid part of it's output so can largely be disregarded within the main scheme of things as the more likely outcome from the rest of the pack looks like continued average uppers with rain and showers at times.

The Jet Stream maintains something of a split flow for several more days with the Northern arm moving East across the UK. The deeper we move into next week shows the Northern arm to turn South across the Atlantic and join with the Southern arm in it's path East across Southern Europe leaving the UK and NW Europe in a cold pool of air.

UKMO today is resolute in dropping Low pressure down over the UK through the middle of next week and away to the SE leaving a slack and showery NE flow across the UK by next Thursday. Some heavy rain and showers can be expected from this set up for all at times and it might not feel very warm outside of any sunshine.

GEM shows a very similar scenario with the caveat that Low pressure is held closer to the UK in it's later stages of the run maintaining the threat of more prolonged rainfall at times in among the showers. Some brief drier and brighter interludes would occur at times almost anywhere.

NAVGEM shows a similar evolution to GFS with the first Low moving to the SE next week with something of a ridge from the Azores High slowing or blocking the passage SE of the next Low as it ridges NE across the South giving a window of perhaps drier conditions late next week, especially in the South.

ECM too shows this type of scenario with the showers becoming more scattered though still possibly heavy as we move through the end of next week and weekend.

In Summary there is still not too much cheer from the outputs this morning if it's warm and settled weather your after. However, there is a trend shared between some of the models that a ridge from the Azores High may disect the belt of low pressure expected to stretch between the Meditteranean and NW Britain later next week. Where it's shown it's axis is shown to lie across the British Isles and will have the effect of damping down the shower activity and allowing some longer dry spells with some welcome sunshine. It has to be said though that such a prognosis is very tenuous at the moment and there is plenty of support still for as gloomy an outlook synoptically as yesterday. However, it is something to looks for in future runs and let's hope the trend grows further.

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Posted
  • Location: Castle Black, the Wall, the North
  • Weather Preferences: Spanish Plumes, Blizzards, Severe Frosts :-)
  • Location: Castle Black, the Wall, the North

There is light at the end of the tunnel, both the gfs and ecm 00z are showing much warmer weather in their respective later output and we could be looking at sustained warmth rather than a few warm days so let's hope this trend continues to gather pace on future runs.

The Gefs 00z mean shows a prolonged cool cyclonic spell ahead but eventually the cool trough over the uk fills and drifts away towards iceland/greenland and pressure slowly rises and temperatures recover significantly towards late may so there is now a strong signal for a pattern change to drier and warmer weather beyond the next 10 days or so, it may take a little longer than that but there are more reasons to be optimistic this morning.smile.png

 

In the meantime, a very showery spell with a cluster of very heavy and squally showers with hail and thunder for the southwest later and then spreading further east, sunshine and showers elsewhere with temps 12-16c from north to south. Tomorrow is a day of sunshine and scattered showers, some heavy and thundery with hail and similar temperatures to today, sunday looks a better day for central, southern and eastern england with mainly dry and bright weather but cool and unsettled in the north and west, the unsettled cooler weather spreading to all areas early next week and most of next week looks cool and cyclonic with sunshine and heavy, slow moving showers with hail and thunder and gusty winds in the showers, cool nights with a risk of a grass frost in rural areas but then slowly becoming warmer, also a risk of thundery rain for the south and east by the end of next week and perhaps trending drier and warmer across the north by then.

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Edited by Frosty039
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Posted
  • Location: West Sussex
  • Weather Preferences: Extreme cold & snow
  • Location: West Sussex

The mean trough still looks like remaining over the UK with any significant high pressure well to the west or NE.

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Well backed up by cpc

 

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ENS show GFS a warm outlier in FI

 

MT8_London_ens.png

 

 

 

Cool and wet looks more likely than warm and dry.

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Posted
  • Location: Rossendale 900ft ASL
  • Weather Preferences: Anything out of the ordinary!!!
  • Location: Rossendale 900ft ASL

The mean trough still looks like remaining over the UK with any significant high pressure well to the west or NE.

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Well backed up by cpc

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ENS show GFS a warm outlier in FI

MT8_London_ens.png

Cool and wet looks more likely than warm and dry.

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Posted
  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

The ECM Birmingham monthly update continues to show an upward trend in temperatures as we move into June

 

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After peaking on May 20th rainfall then takes a dip to just above average as we go int June

 

Coleshill_monthts_Rain_09052013_D+XX.png

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Posted
  • Location: Carryduff, County Down 420ft ASL
  • Location: Carryduff, County Down 420ft ASL

To be fair Gavin an increase in temperature's has to be expected given how suppressed they are at the moment.

Whilst the High Pressure build to the East is again being modelled we were in the exact same situation at the start of the month when a block was programmed to be in place now.

Will need to wait another couple of days before I think about getting the deckchairs out.

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Posted
  • Location: Heswall, Wirral
  • Weather Preferences: Summer: warm, humid, thundery. Winter: mild, stormy, some snow.
  • Location: Heswall, Wirral

Will need to wait another couple of days before I think about getting the deckchairs out.

 

Think it'll be a lot lot longer than that!

 

I looked at 0z and thought, surely not a window of warmth opportunity coming up towards the end of May, then the ensembles crushed that idea, and further more the 6z has swept the idea right off the radar. Key is to ignore any departure from the agreement in FI. 

 

Cool and wet looks like continuing for the 'forseeable future'

 

Greenland is acting like a magnet this year! 

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Posted
  • Location: Castle Black, the Wall, the North
  • Weather Preferences: Spanish Plumes, Blizzards, Severe Frosts :-)
  • Location: Castle Black, the Wall, the North

Well that was a chaotic Gfs 06z op run, especially through FI with the trough over the uk pulled this way and that, eventually the uk becomes warmer and more humid but with thundery rain and the hot and humid air is very close, just across the english channel over the near continent. I can't accuse the gfs of it's usual eastward bias on this run since it's now similar to the ecm with the trough remaining further west but it's a very unsettled run for all areas with only a few drier days on the entire run, this sunday looks relatively fine for southern britain with temps in the mid teens celsius but much cooler and more unsettled for the north and west with rain spreading across, the unsettled and cooler weather spreads south and east to all areas by early next week as the large trough swings southeast across the uk, it would bring widespread heavy showers with hail and thunder which only slowly decay overnight but soon develop again during the mornings, some sunny spells too but next midweek looks thoroughly cool and showery with below average temperatures. There will also be some longer spells of persistent wet weather, especially towards wales and the southwest, even a risk of mountain snow in wales with temps only around 4c in torrential wet spells with local flooding also a risk. Developments further to the northeast are also interesting on this run, very warm air across scandinavia is replaced by a flood of arctic air sweeping southeast across northern norway and finland and eventually further south. There is a lot to keep an eye on next week and beyond but just like the 00z runs, we do become warmer towards late may but will it be warm and settled or warm, humid and thundery.

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Posted
  • Location: Castle Black, the Wall, the North
  • Weather Preferences: Spanish Plumes, Blizzards, Severe Frosts :-)
  • Location: Castle Black, the Wall, the North

The latest met office update is unsurprisingly very unsettled and generally cool for the next few weeks, (especially week 1) the 6z run I described above is probably a fair reflection of what lies ahead in the next 10-14 days with trough (s) either over or very close to the uk throughout with a sunshine and heavy showers mix and occasional ground frosts, periods of persistent rain at times but probably the worst conditions eventually becoming more confined to nw britain with the south & east of the uk becoming drier and sunnier with temperatures recovering to average and then probably becoming warm later in the month but it looks like a long drawn out process, high pressure looks like building across scandinavia and this could begin to influence the weather in northeastern britain towards the end of next week or the following week.

Edited by Frosty039
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Posted
  • Location: Kilmersdon Radstock Somerset
  • Weather Preferences: None Really but a snow lover deep down
  • Location: Kilmersdon Radstock Somerset

Studying the charts as I do I can categorically say that the Jet Profile, although to the South again this year with Northern blocking is somewhat different this year to last. The Jet is higher over the Atlantic before sinking South to Southern latitudes just West of the UK. This enables the Azores High a better chance of ridging in on occasion which was hinted at within the 00zs this morning and I expect it to be repeated in the runs to come. This of course doesn't negate the risk of the Summer being cool and wet but it does give a greater chance that the unsettled conditions being punctuated by more settled conditions as the Azores High ridges NE. It's because of this that I have stated in my 'Summer Predictions Forecast' over on my website that this Summer will almost certainly be less wet and cool than last year's.
 
 See you later for the 12zs.

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Posted
  • Location: Castle Black, the Wall, the North
  • Weather Preferences: Spanish Plumes, Blizzards, Severe Frosts :-)
  • Location: Castle Black, the Wall, the North

Studying the charts as I do I can categorically say that the Jet Profile, although to the South again this year with Northern blocking is somewhat different this year to last. The Jet is higher over the Atlantic before sinking South to Southern latitudes just West of the UK. This enables the Azores High a better chance of ridging in on occasion which was hinted at within the 00zs this morning and I expect it to be repeated in the runs to come. This of course doesn't negate the risk of the Summer being cool and wet but it does give a greater chance that the unsettled conditions being punctuated by more settled conditions as the Azores High ridges NE. It's because of this that I have stated in my 'Summer Predictions Forecast' over on my website that this Summer will almost certainly be less wet and cool than last year's.

 

 See you later for the 12zs.

I agree Gibby, and when the Azores anticyclone does ridge towards the uk, there is a good chance it will then continue to migrate towards scandinavia and help create a large blocking high with low pressure to the southwest and very warm continental air being drawn up across the uk, spanish plume potential too.

Edited by Frosty039
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Posted
  • Location: Nuneaton,Warks. 128m asl
  • Weather Preferences: Snow then clear and frosty.
  • Location: Nuneaton,Warks. 128m asl

Seems a good time to open a new thread ready for the evening discussions so i will be closing this one in a few minutes.

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Posted
  • Location: Nuneaton,Warks. 128m asl
  • Weather Preferences: Snow then clear and frosty.
  • Location: Nuneaton,Warks. 128m asl
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