Model Output Discussion 12z 23/05/13

[NeilN]

The UK seems to be getting a similiar climate as Iceland..

 

As wrong and impossible it sounds....can we actually CHANGE the weather ie fire something to kill the low pressure?

[Tony27]

of course if this was winter the azores high would soon bulldoze that trough out of way but we all know in summer that never happens,, shocking ECM tonight. i was feeling much more positive earlier today, i hope the ECM just gone off on one, i won't dismiss this run but this run really does take the ****

[SnowObsessor90]

Typical, the moment I start to get even a little carried away a run like that comes out   

 

[Summer Sun]

Only one run so no need to throw toys out the pram ECM has had wobbles before then the next run it returned back to normal besides we need to wait for the ensemble run in just over an hour to see what support if any it has

[Tony27]

the ensemble mean won't look as bad as the op it never does the op lead the way

Edited May 27, 2013 by Tony27

[Gibby]

Good evening. Here is the report on the 12 noon outputs from GFS, UKMO, GEM, NAVGEM and ECM for tonight Bank Holiday Monday May 27th 2013.

All models show Low pressure sliding SE over the UK along an axis of an occluded trough lying North to South pivoting NW to SE later tonight and tomorrow. An area of rain will move slowly East across Southern England tonight becoming slow moving from the SE to NW Britain. Through Wednesday and the days leading up to the weekend Low pressure will remain off to the East of Britain maintaining a Northerly feed with occasional showers and the odd longer spell of rain too feeding down from the NW in the flow.

GFS then shows the weekend under improving conditions as High pressure ridges in from the SW elongating across the UK to start next week with plenty of dry and bright weather with sunny spells, in which it will feel quite warm in temperatures near to average for early June. Later in the week pressure becomes slack over the UK with the risk of showers somewhat higher for a time as weak upper atmosphere troughs get hung up over the UK. Then towards the end of the run the weather deteriorates more radically over the south as Low pressure edges up into the South with rain at times here while the North stays largely dry and bright with some sunshine especially in the West.

The GFS Ensembles show 850 uppers still above the average in the second half of the output while the operational above was on the warm side of the pack in the second half. Rainfall amounts are relatively small later in the run for all but certainly not non-existent.

The Jet Stream shows the flow moving SE to the West of the UK before the flow weakens and becomes disorganized for a time. later in the run a renewed split flow develops with the Southern arm way South over Southern Europe while the Northern arm moves East across the Atlantic between Iceland and Scotland

UKMO tonight shows High pressure moving in closer to the UK over the weekend with a diminishing risk of showers and bright conditions with good sunny spells and average temperatures.

GEM shows a much less settled evolution tonight with High pressure held further West and maintaining a Northerly feed over the UK with Low pressure flirting with the East Coast throwing occasional rain and showers along with a cool breeze down across the UK. Towards the end of the run High pressure moves further away North of Scotland maintaining some influence over the North with fine and dry weather persisting while Southern Britain remain far more likely to see occasional rain or showers in association with Low pressure to the South and later SW.

NAVGEM tonight is also fairly unsettled and also shows reluctance in bringing High pressure into the UK at a position to benefit all. As with GEM the High benefits the NW with fine and dry conditions eventually developing here while Northerly winds on the Western flank of Low pressure areas over the near Continent maintain cooler and more unsettled conditions towards the South and East.

ECM tonight again looks like showing us the reason why the Meto mid term outlook has shown a lot more pessimism towards a drier and warmer period that some of the models suggest. Again tonight the High ridges North too far West to benefit much of the UK away from the NW with Northerly winds persisting through the weekend with scattered showers before the new week sees a further surge of energy moving South over the North Sea and positioning itself over the UK for the end of the run with heavy showers and light winds for all.

In Summary tonight there is a continuing difference of opinion between the output with High pressure held too far West and eventually North to have a UK wide effect on the weather. If I had to choose a model with the best closing chart I would choose the UKMO model tonight as it brings High pressure in towards the UK on a better trajectory to the rest. However, it's 144hr charts have a poor verification record so perhaps looking at it in isolation throws some doubt on its credibility. I think it's fair to say that those hoping for a very warm and settled spell with lots of sunshine could be disappointed as it looks more and more like evolving as reasonable weather with average temperatures being the most likely outcome with any such spells' longevity open to doubt too.

[Frosty.]

We only have to look back to the Gfs 00z which was showing horrible cool unsettled weather next week and then the 6z showed very warm and humid weather with thundery showers, then the 12z showed warm and settled so the ecm op is probably an extreme outlier with that trough glued to the uk for days and days, I don't think it will be anything like as bad as that next week.

[Geordiesnow]

The ECM set up of a Greenland high developing and a trough stuck right over us is at 168 hours so well in the medium timeframe. The models do agree that high pressure will be near Svalbard so there is some Northern blocking still appearing on the charts.

 

There has been stronger hints in the last few days for the Azores high to ridge in and the GFS and to a lesser extent the UKMO are showing this so its agreed it will be close by but will it affect our weather, who knows.

 

For now though, Northerly winds look like they will dominate and any Azores high ridging is a bit of a struggle but its too early to worry about the ECM output. 

[J10]

Very interesting to see the ECM tonight, and disappointing for summer lovers.

 

However Mr Travolta would be much happier to see the GFS op runs and also excellent ensembles.

 

Hopefully ECM's ensembles run later will be better for summer.

 

I do think though that the 10 days or so are instrumental in setting the pattern right through June. Although ECM does look a bit strange in its evolution, we cannot simply discard a run just because it doesn't show what we want.

 

Next weekend is looking promising though with High Pressure more than ridging in from the South West.

Edited May 27, 2013 by Jackone

[Frosty.]

Very interesting to see the ECM tonight, and disappointing for summer lovers.

 

However Mr Travolta would be much happier to see the GFS op runs and also excellent ensembles.

 

Hopefully ECM's ensembles run later will be better for summer.

 

I do think though that the 10 days or so are instrumental in setting the pattern right through June. Although ECM does look a bit strange in its evolution, we cannot simply discard a run just because it doesn't show what we want.

 

Next weekend is looking promising though with High Pressure more than ridging in from the South West.

Actually, after consideration, the Ecm 12z  is not as bad as it looks, pleasant sunny periods and heavy thundery showers is far from the worst that early summer could throw at us, at least there is no sign of active atlantic depressions next week.

Edited May 27, 2013 by Frosty039

[ANYWEATHER]

Actually it's not even as bad as it looks, sunshine and heavy showers is far from the worst that early summer could throw at us, at least there is no sign of active atlantic depressions next week.

Why don't you take a breather and rest a while....

[049balt]

Yes, the low doesn't look that low, if you know what I mean!

[johnholmes]

It is funny when you try and look dispassionately at comments in here.

It is almost like winter with dismiss this run, op/enesmble is this or that.

Most on here seem to be wanting warm and settled. As in winter what one wants is not always what the models are in reality showing. Something of that in evidence tonight.

For what it is worth, after their hiccup 10-15 days ago with the change over from winter to summer in the northern hemisphere, the 500mb anomaly charts had settled down but they are now showing differences both between themselves and one another. So what you may say. Nothing scientific really but this is sometimes the precursor of a change in pattern. The NOAA output this evening at both 6-10 and 8-14 is showing quite a change from 24 let alone 48 hours ago, and the morning output from ECMWF-GFS was not that similar in some aspects to the new NOAA. Give them 2-3 days to settle and see if they merge to the NOAA view or diverge again.

The major feature on NOAA is the trough, no not the UK one, that way out over the far west, 40+ west is predicted on both to shift quite some distance east. How realistic is why I suggest we wait for 24-48 hours.

Edited May 27, 2013 by johnholmes

[Barry12]

Let's hope the ECM +168 turns out like the NAVGEM +168

 

Edited May 27, 2013 by Barry95

[Cheshire Freeze]

It's always a risk when you've got HP nudging up from the SW that it gets shunted back in that direction by energy from the jet nudging SE. It's what killed off the last projected warm spell for this week. The main issue at the minute is we have 2 HP cores; one off to the ENE and the other centred to the SW. At extended ranges the NWP will naturally 'merge' these 2 areas of HP together hence the good looking ensemble means with HP stretched right from the SW up to the NE. As we get closer the ECM picks up on more energy around the UK with the HP shown as 2 separate cores again or the HP nudged further N and a trough underneath. After this the other models catch on to this.

 

The scenario that many members on here want to see is HP nudging N from the continent (stable settled and hot conditions) or HP to the SE with LP in the form of a trough stuck out west. Both very similar synoptic set ups and ones which would bring something more sustained.

Edited May 27, 2013 by CreweCold

[ANYWEATHER]

It is funny when you try and look dispassionately at comments in here.

It is almost like winter with dismiss this run, op/enesmble is this or that.

Most on here seem to be wanting warm and settled. As in winter what one wants is not always what the models are in reality showing. Something of that in evidence tonight.

For what it is worth, after their hiccup 10-15 days ago with the change over from winter to summer in the northern hemisphere, the 500mb anomaly charts had settled down but they are showing differences both between themselves and one another. So what you may say. Nothing scientific really but this is sometimes the precursor of a change in pattern. The NOAA output this evening at both 6-10 and 8-14 is showing quite a change from 24 let alone 48 hours ago, and the morning output from ECMWF-GFS was not that similarin some aspects to the new NOAA. Give them 2-3 days to settle and see if they merge to the NOAA view or diverge again.

The major feature on NOAA is the trough, no not the UK one, that way out over the far west, 40+ west is predicted on both to shift quite some distance east. How realistic is why I suggest we wait for 24-48 hours.

In other words ...Changeable to unsettled..!    

[Frosty.]

It is funny when you try and look dispassionately at comments in here.

It is almost like winter with dismiss this run, op/enesmble is this or that.

Most on here seem to be wanting warm and settled. As in winter what one wants is not always what the models are in reality showing. Something of that in evidence tonight.

For what it is worth, after their hiccup 10-15 days ago with the change over from winter to summer in the northern hemisphere, the 500mb anomaly charts had settled down but they are now showing differences both between themselves and one another. So what you may say. Nothing scientific really but this is sometimes the precursor of a change in pattern. The NOAA output this evening at both 6-10 and 8-14 is showing quite a change from 24 let alone 48 hours ago, and the morning output from ECMWF-GFS was not that similar in some aspects to the new NOAA. Give them 2-3 days to settle and see if they merge to the NOAA view or diverge again.

The major feature on NOAA is the trough, no not the UK one, that way out over the far west, 40+ west is predicted on both to shift quite some distance east. How realistic is why I suggest we wait for 24-48 hours.

Words of wisdom there, top post, thank goodness for your unbiased and clinical view of the latest models..and Gibby.

[Barry12]

JMA and BOM similiar to ECM

 

Edited May 27, 2013 by Barry95

[Methuselah]

Please stop the personal jibes...Thank you!

[J10]

John is the NOAA chart you are referring to

 

http://www.cpc.ncep.noaa.gov/products/predictions/814day/500mb.php and is the trough the one just west to the UK, which may or may not stay there.

[Summer Sun]

Surprise surprise ECM Op is an outlier for that low

 

 

[bluearmy]

gem has been keen to send energy east to west under the building block over the past few runs and tonight we see ecm doing the same. ukmo, whilst looking ok at day 6 could easily go the same way. looking at the ecm mean, i really wouldn't be looking forward to summer just yet. some good days i'm sure but settled ?  not really looking that way yet.  even gfs which has been doing its best to bring in summer conditions has managed to introduce transient troughing. as we say in late november as the upcoming northerly gets pushed to our east, at least its early. plenty of time.

[bluearmy]

Surprise surprise ECM Op is an outlier for that low

 

 

 

 

 

is it gav? you wont see a trough like the op modelled on the ens mean at days 7 and 8. i suspect the op wont be a complete outlier on the london temps and precip later.  the spreads have the favoured position for the shortwave day 7 in the north sea and the energy drifts across the uk day 8. the mean has the energy centred over the low countries later in the run.  next week far from worked out yet.

[AWD]

Surprise surprise ECM Op is an outlier for that low

For a MEAN chart, there is quite a pronounced trough to the east/south east of the UK there. Shallower than the Op, yes, but it is still there.

Lets see what tomorrow's runs bring anyway.

EDIT: What Bluearmy said. lol.

Edited May 27, 2013 by AWD

[Weather Boy]

Surprise surprise ECM Op is an outlier for that low

 

 

Yes, Gavin, you're right that's not really surprising at all. However, with the somewhat surprising -inexplicable even- METO update, it's not surprising that any attempt to undermine a settled forecast is taken seriously. I must say, though, that I personally have completely lost face in the METO long range forecast as they seem to me bordering on the random, or they are so vague as to be nonsensical. For example I was looking at the long range for my trip to the cricket last week and by the time it was a week or so away it was obviously laughably wrong.

I would therefore treat the METO update with extreme caution until the time comes. As for the pure model output, it seems to me that what it's currently saying is that after the midweek horror show, we should have a decent spell especially in the west, but tHat may change and even if its right, who knows how long it will last, four weeks or four days: nobody knows that.