Model Output Discussion 12z 23/05/13

[phil nw.]

A new thread ready for the 12Z model runs etc.

 

Please remember to post discussions around what the models actually show and keep things polite.

 

If you disagree with anyone's views then put your own by referring to the charts rather than just a one line subjective comment which adds nothing to discussion.A small number of these had to be removed in the last thread unfortunately.

 

For more general chat around your hopes or disappointments about the charts we have a more relaxed thread here

http://forum.netweather.tv/topic/76235-model-banter-moans-and-ramps/

 

or for those members who wish to give a more in depth interpretation of the model outputs in a quieter thread then you can post here

http://forum.netweather.tv/topic/76236-in-depth-model-discussion-and-summaries/

 

and finally for discussing Summer prospects and other views around the possible weather patterns for the up and coming season then please go here

http://forum.netweather.tv/topic/76293-summer-2013/

 

and of course there are plenty of other threads for various aspects of weather discussion so let's keep this thread on topic so that it`s informative and pleasant reading for all.

 

OK thanks everyone please continue below...

 

 

 

[phil nw.]

Looking at the BH weekend we have a weak ridge crossing the country after the showery low moves away later tomorrow which should bring a dry and bright couple of days pretty widely.Feeling warmer too-maybe 16 to 17C in some favoured spots.

 

 

Monday see`s the next system moving in from the west but areas further east may end up dry and reasonably fine for much of the day before cloud and rain arrives later.

 

So not too bad for many of us considering the unsettled and cold pattern we are currently in.

A timely opportunity to enjoy outdoor activities perhaps before things go downhill again during next week when the next low moves down over the country.

 

[Frosty.]

For those of us searching and waiting patiently for a settled and warm spell, the GEFS 06z mean is promising just that, like the 00z before it, the azores anticyclone becomes a major feature in FI with a general rise in pressure across the uk and temperatures eventually into the 70's F, there are those who will continue to mock the gfs/gefs for only showing good charts in FI but on this occasion, the gefs is likely to be on the right track since the met office are now firming up on a generally fine spell in early June and looking further ahead for at least the north & west of the uk to have the driest, sunniest and most pleasantly warm conditions for a change with high pressure to the northwest/north of the BI and occasionally low to the southeast/east.

[phil nw.]

Yes the GFS mean 500hPa continue to show an improving trend into June Frosty and the 00Z ECM mean outputs at day 5 and 10 are also starting to show a gradual warming out of the UK trough too.

 

see those thickness bands easing north as time goes on-not so bullish as the GFS outputs but we can see the improving trend when comparing those 2 charts above.

 

It looks like we will have another few days or so of showery and rather cool conditions after the BH weekend as the next low moves in and becomes slow moving over the UK but then the drain of energy from the north west becomes cut off and the low is modeled to fill in situ.

 

Some uncertainty beyond this then on how strong the heights will be from the Azores high but at least we do seem finally to be easing out of this current pattern.

 

Of course like everyone i will be happier to see this come into the 5 day range so a little time to go yet.

Edited May 23, 2013 by phil nw.

[Summer Sun]

UKMO has now developed the deep low early next week which GFS and ECM have been showing for a few days now

 

 

T144 is when we see the main difference with UKMO building pressure across Iceland this will probably drift towards the UK once the low pulls away.

 

 

UKMO 12z is on the left and GFS 12z is on the right to compared the two

Edited May 23, 2013 by Gavin.

[mushymanrob]

For those of us searching and waiting patiently for a settled and warm spell, the GEFS 06z mean is promising just that, like the 00z before it, the azores anticyclone becomes a major feature in FI with a general rise in pressure across the uk and temperatures eventually into the 70's F, there are those who will continue to mock the gfs/gefs for only showing good charts in FI but on this occasion, the gefs is likely to be on the right track since the met office are now firming up on a generally fine spell in early June and looking further ahead for at least the north & west of the uk to have the driest, sunniest and most pleasantly warm conditions for a change with high pressure to the northwest/north of the BI and occasionally low to the southeast/east.

 

but karl, we were supposed to be having nice warm sunny days now if recent  gfs outputs was anything to go by, just look how many times this spring the gfs has promised us an end to the cold, how many times you and gavin have posted loads of good looking gfs charts only for them not to materialise? ill look at the gfs, ill note what it says, but (to quote victor medrew) ill not believe it until its got full support from the ecm and ukmo, or its actually happening!

 

as for the met office, thats the same met office that promised us a bbq summer the other year.... im still waiting for it!

 

but for now theres no tangible sign of any change to the current pattern, its been cold all spring (generally) and theres no real sign of it changing. (and im no heat hater, plus i say exactly the same in winter when the cold rampings going on)

[Frosty.]

 

but karl, we were supposed to be having nice warm sunny days now if recent  gfs outputs was anything to go by, 

Hi rob, what you say is true but I can see real potential looking further ahead whereas you remain much more sceptical, hopefully the current gefs trend will continue and will eventually make it into a more realistic timeframe and perhaps then you will be a bit happier. And in the short term, this weekend is thankfully looking a lot better, especially saturday but sunday could also be a fine and pleasant day for most of the uk.

[phil nw.]

Let`s stick to current outputs please Mushy.

No point in going back over old ground people can have different interpretations-why not just put your pov based on the latest runs?

[Polar Maritime]

 

but karl, we were supposed to be having nice warm sunny days now if recent  gfs outputs was anything to go by, just look how many times this spring the gfs has promised us an end to the cold, how many times you and gavin have posted loads of good looking gfs charts only for them not to materialise? ill look at the gfs, ill note what it says, but (to quote victor medrew) ill not believe it until its got full support from the ecm and ukmo, or its actually happening!

 

as for the met office, thats the same met office that promised us a bbq summer the other year.... im still waiting for it!

 

but for now theres no tangible sign of any change to the current pattern, its been cold all spring (generally) and theres no real sign of it changing. (and im no heat hater, plus i say exactly the same in winter when the cold rampings going on)

 

Maybe because that's what the GFS is showing, and this is the model output disscusion...?

[Frosty.]

 

 

 

as for the met office, thats the same met office that promised us a bbq summer the other year.... im still waiting for it!

 

 

I'm not sure they did promise a bbq summer, they may have said there was a higher than average chance but that's not the same as promising one is it?

 

I think they will be right about the pattern change in June, next week's trough will probably be the last in a long line to bring a widespread unsettled spell for some time and the azores anticyclone will finally have it's best chance so far to ridge across the uk, i'm confident the ens mean will continue to support a fine & warmer further outlook.

Edited May 23, 2013 by Frosty039

[weather_it_will]

Nothing resembling summer in the reliable T144 time frame on the GFS or UKMO.

In FI it looks like a repeat pattern with any high pressure being squeezed out the way by the deep lows.

This pattern is not going away anytime soon.

I can't see us getting anywhere near the glorious Bank Holiday Monday weather of 6th May which continued into 7th May and did reach a genuine 20°C here.

Just like previous summers, people only remember April and May as being the best weather of the year, and this one looks no different so far.

I know summer has not started yet, so still plenty of time until the end of August when summer ends.

Edited May 23, 2013 by Hot Wet Windy Cold No Snow

[Staffordshire]

This just shows how pathetic this spring has been so far, i am sat here looking forward to a partly sunny weekend with temps around 16-17c only 6 days away from june. however gefs and gfs looking promising, developing hp over the azores which is only a good sign

Thats my useless mod thread post for the month, ill leave the rest to you guys

[IDO]

Sunday and Monday now looking the best days over the BH:

As the trough moves SE on Monday the low stalls and the associated front fizzles out as it hits the east:

So the next trough in this cycle of ridge/trough is again modeled to be rather slack by Wednesday:

Wed:Thur:

Below average temps but on the rise as the next ridge, again for next weekend moves in:

GEM in agreement:

As others have said, nothing very warm, or any clear signal for high pressure stability. The GEFS mean for 5th June suggests another trough (weak signal this far out, but less pronounced than the 06z) follows the second weekend's ridge:

The GEFS pressure chart highlights this sine wave pattern and there remains very good support for this continued picture:

Not great, but on the plus side, as much as it is not showing warmth, there is no sign of a zonal flow at the moment.

[Frosty.]

The Gfs 12z has really slammed the brakes on monday's very unsettled weather compared to the 6z and 0z, the 12z has the fronts much delayed and only affecting the far west of the uk by monday afternoon leaving most of the uk fine and pleasantly warm with temperatures of 17-19c ahead of the rain, also, the front fragments as it pushes east on monday night and we begin a spell of sunshine and heavy showers from tuesday onwards, this saturday and sunday are looking good with long sunny spells and just an isolated shower with recovering temperatures of 16-18c so with our eyes on the unsettled weather next week, in the short term we have a potential 3 day fine spell on our doorstep so to speak. As for FI, the gfs 12z shows next week's trough eventually filling and being shunted away towards eastern europe with high pressure tending to fill the void, it's not a particularly warm run, I would describe it as becoming pleasantly warm and mostly settled beyond next week.

[Uncle_Barty]

I'm not sure they did promise a bbq summer, they may have said there was a higher than average chance but that's not the same as promising one is it?

 

I think they will be right about the pattern change in June, next week's trough will probably be the last in a long line to bring a widespread unsettled spell for some time and the azores anticyclone will finally have it's best chance so far to ridge across the uk, i'm confident the ens mean will continue to support a fine & warmer further outlook.

 

I wish I could be so confident in your assertion of such an improvement in this era of the Modern Summer..... Models keep promising better but then the northern blocking rears it's ugly head.

[Frosty.]

I wish I could be so confident in your assertion of such an improvement in this era of the Modern Summer..... Models keep promising better but then the northern blocking rears it's ugly head.

Well i'm not totally confident in the models and I did say probably be the last trough for a while, so this will test my faith in the models next week. I do think the signs are all there for high pressure to gain the upper hand possibly by as early as the end of next week onwards but the weather doesn't play by any rules so we will have to wait and see.

[ANYWEATHER]

I wish I could be so confident in your assertion of such an improvement in this era of the Modern Summer..... Models keep promising better but then the northern blocking rears it's ugly head.

LOL whats the era of the modern summer??!!!  

[CongletonHeat]

This would just about sum up our weather.

 

[Frosty.]

Tonight's Ecm 12z is a real spoil sport, it shows potential for a while as it builds high pressure to the south with ridging across southern england and the azores anticyclone extending a ridge north in the atlantic but then plants another trough slap bang over the uk, but it would just mean a return to sunshine and heavy showers, the same as we will be having for most of next week. No need to be concerned at this range though because it will be a while yet before we have cross model agreement on the expected (by met office) generally fine and pleasantly warm first full week of June.

[Purga]

This would just about sum up our weather.

 

Absolutely, I was just going to post that chart as well - Frosty must be a blinding optimist and hats off to him for trying.

The strong northern blocking signal is still a dominant feature from ECM and the subsequent south tracking jet will maitain the cool wet / showery weather for as long as can reliably be forecast. Any hope of dry warm weather is fanciful at the moment, good stuff to try to raise moral but with no realistic prospect of it materialising.

 

Some ground frost possible next week as hinted at by METO.

Edited May 23, 2013 by Purga

[Geordiesnow]

I actually find the ECM run a bit of an improvment, better than the UKMO which would be cool and damp really. The ECM should keep things brighter for the most part but with showers developing during the day but perhaps not too many showers as the low centre is away from the UK. 

 

Despite what Frosty says, no real sign of any summery weather but hopefully the ECM is onto something with keeping the low to the West of us, rather it be that than what the UKMO is showing.. 

Edited May 23, 2013 by Geordiesnow

[Uncle_Barty]

LOL whats the era of the modern summer??!!!  

 

Northern blocking, limpet trough just over or close to us. unsettled weather and suppressed daytime temps. (opposite to a Bartlett in winter, in other words, if you like......)

 

Seems to have been our lot in recent summers.

[Gibby]

Good evening. Here is the report on the midday outputs from GFS, UKMO, GEM, NAVGEM and ECM for today Friday May 22nd 2013.

All models show a developing Low in the North Sea drifting SSW towards SE England by tomorrow lunchtime. Some unusually cold and inclement weather is expected for Eastern areas with many other areas of England seeing heavy showers too while Scotland and Northern Ireland see drier and brighter conditions which will spread to all areas of Britain over the weekend. By bank Holiday Monday the next Low pressure will be approaching from thee NW with rain and freshening winds reaching most areas by the end of the day.

GFS then takes us through next week with Low pressure in control but with it's centre nearer the North than previously with a sunshine and shower mix the most likely weather for the week. With Westerly or NW winds some areas may fair quite well missing many of the showers with some pleasant sunshine to be enjoyed. Other areas may see a succession of showers with some heavy ones accompanied by hail and thunder here and there in the afternoons. By the weekend the weather will be improving as a weak ridge crosses slowly in from the West with the weather next weekend closely replicating that of this coming weekend over the UK. Later in FI upper air disturbances getting caught up in the slack winds over the UK could produce further showers, most likely in the South but with a lot of fine and dry weather persisting with OK temperatures for most.

The GFS Ensembles show a steady rise in uppers beyond the weekend with a sharp rise between now and then. The weather will remain unsettled though drier conditions might develop more later in the output to accompany the higher uppers which settle somewhat above average late in the run especially in the North.

The Jet Stream continues to flow SE over the UK or to the West over the week ahead joining the Southern arm still blowing over areas of Southern Europe. The flow falls light at the end of the run showing as a light flow blowing into the UK from the West.

UKMO tonight shows Low pressure having moved SE to be close to Southern England by midday next Wednesday with unsettled weather for all with rain or showers at times and just brief bright intervals and temperatures still technically cool feeling.

GEM tonight shows Low pressure to the NW early next week becoming sucked SE into NW Europe with a spell of unsettled and showery conditions for all before an improvement develops later from the NW. By the end of the run High pressure has ridged NE across the UK to give a spell of warm and settled conditions with some warm sunny spells especially in the North and West with rather cloudier conditions in a NE breeze persisting in the far SE.

NAVGEM too shows Low pressure slipping SE too next week with unsettled conditions for all before improvements move gradually down to at lest Northern and Western areas by the end of the run.

ECM too shows the Low pressure early next week staying further North than it's counterpart models restricting the extent of the unsettled weather with a mix of sunshine and just scattered showers likely for the few days following the rainy Bank Holiday Monday. As the Low fills a new depression develops in it's place and becomes a complex structure over the UK by the end of the run throwing further spells of rain and showers for all by the second weekend.

In Summary there is still some indecision on how things pan out involving the depression's movements early next week. UKMO, GEM and NAVGEM has it migrating SE through the week to be to the SE of the UK by the end of next week while GFS and ECM hold it further NW limiting it's affects to just scattered showers in a Westerly breeze with the majority of showers in the north as well as allowing temperatures to recover somewhat. With it moving to the SE there is a better chance of a rise of pressure from the NW ala GEM while holding it further NW keeps the better weather in the South while there is always the chance of renewed fronts and unsettled weather feeding in later such as ECM shows. It's the age old case tonight of 'more runs needed'.

[Frosty.]

 Frosty must be a blinding optimist and hats off to him for trying.

 

Yes I try and look for the best the models have to offer, and this Bank holiday weekend is now looking good for most of the uk with a nice ridge of high pressure crossing the uk from west to east which may last until the end of monday for central and eastern areas.

[ANYWEATHER]

Yes I try and look for the best the models have to offer, and this Bank holiday weekend is now looking good for most of the uk with a nice ridge of high pressure crossing the uk from west to east which may last until the end of monday for central and eastern areas.

At the end of FI, charts still look dull at t=144!