Model Output Discussion 12z 10/05/13

[AWD]

Sorry to sound stupid but what is the "MJO"

Madden–Julian oscillation

http://en.m.wikipedia.org/wiki/Madden–Julian_oscillation

[phil nw.]

Sorry to sound stupid but what is the  "MJO"

MJO-Madden- Julian Oscillation named after the study by the 2 scientists.

A moving area of convective rainfall in the warm waters of the Indian and Pacific ocean.It tends to have an active and less active cycle that lasts from 30-60 days.

The activity creates ridging and upstream troughing ahead of it and affects the wavelengths around the hemisphere into mid-latitudes.

Here`s a link to the Wiki page which gives more information

http://en.wikipedia.org/wiki/Madden%E2%80%93Julian_oscillation

 

over a period of time average or composite northern hemisphere patterns have been created for each month depending on where in the tropics(phase)the MJO is active.These can give an idea of the upcoming approximate pattern but are not infallible especially in periods of low activity.

Hope that helps.

[Purga]

12z ENS looking 'average' at best and pretty damp / wet

 

Looking at the T 2M chart most of us will be very lucky to scrap anywhere near 20C as a daytime max - probably nearer to 15C

 

So heading for another below average CET almost for sure after a chilly couple of days coming up with wintry precipitaion in quite a few parts.

[SnowObsessor90]

Well the FI on this latest GFS run certainly seems to more along the lines of what was/is expected as we head into June, hopefully 12z was just going of on one earlier.

[Evening thunder]

12z ENS looking 'average' at best and pretty damp / wet

 

 

Yep but I'll be reasonably happy with average compared to recently (although not convinced of it reaching average soon but hopefully it will..)

 

I have seen much wetter looking ensembles though,most of the time it's only a few ensembles going for any real rain at any one time there. 

 

However it looks like the unsettled pattern continuing for the time being, seems a bit odd for to me the models to suddenly jump from low heights over Greenland with with the Azores high trying to ridge in to us to High pressure over Greenland and a southerly tracking jet, that's FI I suppose.

 

Wouldn't be surprised if the models showed something quite different tomorrow again, whether it's what many want to see or not. In fact the 18z already does show something quite different.

Edited May 22, 2013 by Stormmad26

[nitro_deluxe]

Really is hard to believe? Still the mention of snow and as we knock on the door of a new month? Ahem June..cough splutter!

Really did think we'd put all that behind us - whilst we may need some rain, few sunnier slots maybe even a little warmth.Would be nice.

Really am banking on June now - whilst trying to remain optimistic and realistic both at the same time, I'm sure that I'm not alone in thinking - how time really is flying..next we'll be moving headlong into Autumn!

Daft thing is, this is and usually can be a period when we get some of our nicest weather...

[summer blizzard]

GFS18z is much better in FI, ensemble mean has a ridge building at day 11.

[mushymanrob]

GFS18z is much better in FI, ensemble mean has a ridge building at day 11.

 

the gfs is nearly always good in fi, all the 'good' (settled warm) weather is always in fi, never the reliable.

 

this mornings no different, and yet again hints of a greenland high emerging yet again as we move into june... on the back of the coldest spring since '79, i see no reason why the general pattern is likely to change yet, or why it shouldnt evolve into yet another summer dominated by a greenland block which is a distinct possibility.

 

ill write off summer now, and either be right, or happy as hell to be wrong!

Edited May 23, 2013 by mushymanrob

[Summer Sun]

UKMO at t144 looks very familiar high pressure to the north low pressure stuck over us

 

 

As does

 

 

Looking likely now that northern blocking is going to re-establish next week its just a case of how long its going to hang around this time

[Purga]

_{Mushy is on the right track..}

 

_{The ENS, although trending up in FI (where they always do!), show  tighter grouping of below avrage temperatures and wet weather in the reliable timeframe.}

 

 

_{Not to say there won't be any pleasant days but the overall picture looks decidedly cool & unsettled with only teaser charts in FI}  

Edited May 23, 2013 by Purga

[Frosty.]

the gfs is nearly always good in fi, all the 'good' (settled warm) weather is always in fi, never the reliable.

 

 

No it isn't mushy, for every good gfs FI there is usually a poor one to follow it. There is substance to the current gfs FI fine and warm weather because this is broadly what the met office are expecting to occur as we head into June, high pressure to eventually become dominant to the northwest or north of the uk after covering all parts at least for a time, low pressure doesn't feature much for a change.

Edited May 23, 2013 by Frosty039

[Purga]

No it isn't mushy, for every good gfs FI there is usually a poor one to follow it. There is substance to the current gfs FI fine and warm weather because this is broadly what the met office are expecting to occur as we head into June, high pressure to eventually become dominant to the northwest or north of the uk after covering all parts at least for a time, low pressure doesn't feature much for a change.

OK for the NW for June sure - but further south they expect the low pressure to be more in evidence due to a southerly displaced jet.

 

"Towards the south and east, probably staying rather unsettled with some spells of rain but also some drier, sunnier days."

 

This forecast is for a long way out to 20th June and as we all know, often slides towards the cool / damp scenario.

[weather_it_will]

No summer for us on the ECM in FI

[NickR]

No summer for us on the ECM in FI

 

I didn't realise our summer ended on 2 June.

[ANYWEATHER]

No it isn't mushy, for every good gfs FI there is usually a poor one to follow it. There is substance to the current gfs FI fine and warm weather because this is broadly what the met office are expecting to occur as we head into June, high pressure to eventually become dominant to the northwest or north of the uk after covering all parts at least for a time, low pressure doesn't feature much for a change.

You will notice on the 16 to 30 day metoffice update that things "may" settle down to the Northwest. The word "May" holds no weight at all!  

[Frosty.]

The Gfs 00z op run shows an atlantic ridge toppling southeast into scotland tomorrow to bring a fine and increasingly sunny day to scotland & ireland but residual low pressure across england and wales continuing to bring cool and unsettled weather, eventually the trough is pushed into the continent and saturday is the most settled day nationwide with long sunny spells and light winds with pleasantly warm temperatures, by sunday the ridge will be subsiding and pressure slowly falling with the uk in a col. showers develop inland but with sunny periods it will again be pleasantly warm. Bank holiday monday looks like turning into a washout as a band of heavy rain spreads east across the uk followed by sunshine and heavy showers, the rest of next week is then unsettled with a deep trough initially but this trough gradually loses it's venom and becomes a shallow feature but remains in situ with a cool, cyclonic and very showery pattern with hail and thunder but pleasant sunshine inbetween, the trough slowly fills and drifts away east as pressure begins to rise from the southwest with the azores ridging, high pressure builds more strongly and the uk becomes settled and warmer into early June which all ties in with the met office latest further outlook.

 

The Ecm 00z is also showing a slow improvement by T+240 hours but the gfs improvement is much faster.

[Polar Maritime]

You will notice on the 16 to 30 day metoffice update that things "may" settle down to the Northwest. The word "May" holds no weight at all!  

 

It holds more weight than any model or brain that is available to us at the moment at that time-scale.

Edited May 23, 2013 by Polar Maritime

[Frosty.]

You will notice on the 16 to 30 day metoffice update that things "may" settle down to the Northwest. The word "May" holds no weight at all!  

it may be may but it will be june

[NickR]

You will notice on the 16 to 30 day metoffice update that things "may" settle down to the Northwest. The word "May" holds no weight at all!  

 

They always couch their forecasts in cautious terms. To make any more out of it seems churlish at best... although it does continue the general (and ludicrous) "let's write off summer now" feel to several posters on here.

Edited May 23, 2013 by NickR

[Gibby]

Hi everyone. Here is today's A.M. Report on the overnight outputs from GFS, UKMO, GEM, NAVGEM and ECM for today Thursday May 23rd 2013.

All models continue to show a cold 48 hours to come as Low pressure develops and slips down the North Sea to be centred near East Anglia tomorrow. A cold and strong North flow will ensure a showery day today and maybe more prolonged rainfall in the East tomorrow before an improvement reaches NW Britain later tomorrow and then extends steadily SE in time for the weekend. A window of very light winds and bright or sunny conditions look like coinciding with the weekend to give all areas a surprisingly decent Bank Holiday weekend. However, Low pressure will be deepening to the NW on Bank Holiday Monday with rain and strengthening winds to these parts through the day but it maybe these conditions do not reach the South and SE until very late in the day.

GFS then shows Low pressure moving very slowly ESE across the UK through the week with spells of rain and showers scattered about with brief drier and brighter interludes around too. By the weekend the Low has filled and given way to a shallow ridge of High pressure which again coincides with the weekend to give a warm and sunny spell in many places. This improvement is then maintained later in FI with dry and sunny weather to many Northern and Western areas as High pressure lies to the North. Southern areas too will see some of this weather but on the operational an upper cold pool moves SW later giving rise to thundery showers here.

The GFS Ensembles show the current very cool weather giving way to less cool conditions at the weekend and beyond. The trend is slightly upwards through the run but with unsettled conditions at the surface any lifting of uppers beyond the seasonal average may be marred by cloud cover and rain or showers as there is still plenty of members showing precipitation throughout the output, over England especially.

The Jet Stream continues to descend across the Atlantic either over or to the West of the UK towards Southern Europe with the UK keeping itself on the cool side of the flow and in the target zone for Low pressure systems migrating down from the NW on the flows Eastern flank.

UKMO today has Low pressure centred over Central England with showers or rain at times circulating around it with nowhere immune. There will be some drier and brighter spells mixed in too with temperatures average at best.

GEM today shows the same Low pressure for the first half of next week slipping down close to Northern Britain and affecting all areas. With time the Low fills and pressure builds gently from the South to bring next weekend into drier and brighter weather in many Central and Southern areas with temperatures on the rise.

NAVGEM also shows Low pressure slipping SE into Scotland early next week where it revolves around the UK for several days before slipping further SE into NW Europe at the end of it's run. Showers and rain at times would be the likely tone of the weather over the UK with some dry and bright spells for some in between and temperatures still bordering on cool conditions overall.

ECM finally shows little better conditions with the same Low creating unsettled conditions through much of next week. Towards the end of the run the Low fills and isobars do open up allowing lighter winds. However, pressure fails to rise substantially and with a prevailing Westerly flow and Low pressure just to the North and West further incursions of unsettled weather looks likely beyond Day 10 especially considering there is so much Northern blocking over the Arctic still present.

In Summary the weather over the next two weeks or so can best be described as changeable. It will not be a total washout with some spells of drier and brighter conditions when,because it's June some warm sunshine could be felt. The main share of the weather will be given over to Low pressure either centred over or near to the UK with nowhere really for it to go once arrived giving many days of rather cloudy weather with showers or longer spells of rain scattered around. It will often feel cool under these with temperatures overall unlikely to exceed average values at best unless the later GFS operational run verifies. The weather appears to be stuck in a rut at the moment and we need to rid the Northern blocking shown by ECM latterly as if not we could be stuck in this scenario for a long while yet.

[Frosty.]

People here were writing off winter in mid december I don't see why summer should get special treatment!

I'm amazed at the negativity there is growing support for a summery spell to evolve in early June, especially from the met office.

[Frosty.]

It holds more weight than any model or brain that is available to us at the moment at that time-scale.

Spot on mate

[DR(S)NO]

I'm amazed at the negativity:nonono: there is growing support for a summery spell to evolve in early June, especially from the met office.

I think the problem here Frosty is that all the promise of good weather is always in FI

[Frosty.]

I think the problem here Frosty is that all the promise of good weather is always in FI

Yes that's true but there does appear to be a moderately strong signal for a pattern change to generally warmer and settled weather as we go into early/mid june, this has and is the signal from the ensemble mean and most importantly, the met office. And the unsettled spell next week looks like sunshine and showers which is not so bad once the persistent rain clears east later on monday, it will still feel pleasantly warm in the sunny spells so it's not a write off. The Gfs 00z run looked believable with the trough eventually filling and being shunted away to the east with significant pressure rise to the southwest slowly replacing it.

 

And this weekend looks relatively fine and warmer than the next 24-36 hours will be, scotland & ireland look sunny with lighter winds by tomorrow afternoon as a narrow atlantic ridge slowly topples southeastwards, saturday looks sunny and pleasant for most of the uk with light winds, slowly becoming more unsettled to the north & west during sunday and then for all areas by next monday.

Edited May 23, 2013 by Frosty039

[Tamara]

The EPS members at day 7 indicate two thirds, at least, in support of a UK cyclonic pattern with low pressure sitting right over the UK and the remainder have a variety of solutions that are simply slightly less unpalatable but still fairly unsettled variants of the majority with cool temperatures but on the 'positive' side, less intense downpours probably being the best description. However, with such majority agreement, and other models also in agreement, the cyclonic outcome is unfortunately very probable.

 

 

Based on the continued model estimations into the increasingly further uncertain period beyond the middle of next week, there remains no cohesive sign for a change that can be relied on, beyond hoping that the days to come start to show an improvement in the operational and closer time period ensemble data for the start of the new month. At the moment, realistically, we can't rely on any distant signal beyond the 10 to 15 day period; and can we rely on a change in the entrenched amplified jet pattern to oblige in delivering that signal in reality?

 

The NAEFS anomalies maybe suggesting warmer conditions to start June with the trough retreating into the continent a little. That would back up the METO outlook to some degree with conditions still rather unsettled in the south and east closer to the low pressure but maybe an improvement further north and west. However, more outputs required as they say

 

Edited May 23, 2013 by Tamara Road