Model Output Discussion 12z 10/05/13

[ANYWEATHER]

ecm could not be more different from its 00z and 12z run!

[William of Walworth]

http://www.meteociel.fr/modeles/gfse_cartes.php?mode=2&ech=204

 

 

i wish your right  but  looking  deep in to fantasy  world  its  not looking  nice  ex  when you read  the  jet stream 200miles  worse then it was last year  summer  wash  out  2!!

Please stop this 'write off a whole season' type commentary. There are so many wildly variant evolutions, even for within the next 10 days, on recent/current output. Meaning that comments such as 'summer wahsout 2' above are plain wrong, and certainly 100% unknowable at this stage.

Edited May 13, 2013 by William of Walworth

[Frosty.]

I think we just need to remain patient, the latest GEFS 12z mean is continuing to look much better beyond T+240 hours with the Azores anticyclone building a strong ridge northeastwards across the uk, from then on it gets better and better with a warm and settled end to may and early june, the azores high looks strong and it's only a matter of time before these cool troughs begin to wane.

Edited May 13, 2013 by Frosty039

[rory o gorman]

Looks like a pretty wet GFS 12 z overall albeit with some drier interludes but certainly no long warm dry spell right through to FI.

I suspected there could be a potential deluge over the east / SE at the end of the week.

The mid Atlantic / Azores High seems to want to pull back west on the ECM 12z at 216h after teasing at 196h

 

Cool and showery then with a very wet potential this week a la ECM as well

 

 

 

 

 

Not forgetting UKMO of course!

 

 

 

The gfs 12z has my location at plus 564- geo heights for 80% of the run past friday , and the ECM has a warm stable NE flow that would push 20c plus here in southern Ireland going out to the final frame of the ECM to signal disaster well.. , I love both unsettled convective spells as well as settled.

Edited May 13, 2013 by shuggee

[Gibby]

Good evening. Here is the report on the 12 noon outputs of GFS, UKMO, GEM, NAVGEM and ECM for tonight Monday May 13th 2013.

All models continue to programme a cool and unsettled week as Low pressure slips down from the North. A small but significant Low pressure develops near SW Britain tomorrow with some persistent and heavy rain with unusually low temperatures through tomorrow for Southern parts of England and Wales. The heavy showery type pattern further North will extend to other areas through the week with some hail and thunder in places as winds fall lighter but conditions remain relatively cool. At the weekend the models diverge somewhat in how they handle developments to the East of the UK.

GFS shows the Low over Germany moving SW to the Low Countries then away South early next week. Spells of heavy rain could well affect the East on Sunday in a very chilly Northerly breeze. Brighter conditions with scattered showers on a lighter Northerly wind would affect Western areas with this weather extending to the East soon into the working week. The rest of the run shows High pressure out to the SW and Low pressure drifting ESE to the North of Scotland. The resultant conditions would best be described as bright and at times dry weather in the South while the North mostly maintain the unsettled conditions with rain at times spreading further South at times. With winds always from between West and North temperatures would stay normal at best but would feel OK in sunny breaks in the SE. More generally showery weather develops over the UK at the end of the run as slack Low pressure develops over the UK again.

The GFS Ensembles are still trending in the right direction tonight. In getting to the warmer conditions we are subjected to another week of unsettled and at times wet weather before things slowly become less unsettled. There is quite a spread in the pack tonight towards the end of the run and there is less impact from any warming in Northern locations.

The Jet Stream shows the trough forming in the flow over the UK Sea areas over the coming days where it remains in situ for some time. Eventually the trough collapses with a weak Northern arm of the flow drifting gently East into the UK in a week or so time.

UKMO tonight has a cool and sometimes wet weekend written all over it. Northerly winds will blow fresh for all of the weekend and with Low pressure over Europe closing in on the SE some heavy rain and cloudy skies look likely for many, worst in the East.

GEM today shows a ridge from the Azores High over the NW at the weekend with the European Low further away but close enough to affect England and Wales with a chilly NNE breeze and showers. Through the remainder of the run some dry and bright conditions look likely as the ridge extends it's influence South to England before renewed Low pressure slips into NW areas at the end of the run with rain extending steadily SE across many areas.

NAVGEM tonight shows a NW/SE split tonight from the weekend as a ridge from the Atlantic High pressure ridges NE over Scotland. The NW would become largely dry with some sunny spells through the remainder of the run. With Low pressure over Europe the pressure gradient will be quite steep over Southern and Eastern Britain with strong winds and outbreaks of rain or showers continuing for many here out to the end of the run.

ECM shows a cool and windy weekend for Southern Britain with rain or showers in abundance, some heavy and thundery in a gusty NE or East wind. The North will see some improvements in the same time frame as High pressure builds from the Atlantic, across Scotland and Scandinavia. The end of the run sees a disappointment tonight as it has backed away from it's early summer stance this morning to show a slack, cool and showery Northerly then NW flow over the UK with embedded weak troughs and still rather cool conditions.

In Summary tonight there is a slow step back again from the models with ECM being the biggest disappointment. It seems that it's going to be a slow and painful road to remove the cold pool situated over the UK currently with many setbacks along the way. There is evidence of ridging NE from the Atlantic High at times bringing some more settled conditions with some sunshine should it occur but there is no concrete evidence of any sustained fine and settled weather with warm temperatures tonight with disturbances moving down from the NW overriding any short term improvements continuing to be a favoured option.

[William of Walworth]

ecm could not be more different from its 00z and 12z run!

Variants as wide as that are driving me nuts personally, but surely we can still conclude from such flipflopping that even as early as next week still holds all to play for.

[ANYWEATHER]

Variants as wide as that are driving me nuts personally, but surely we can still conclude from such flipflopping that even as early as next week still holds all to play for.

I think we have to agree that T=96 is the limit for the models although, unfortunately I favour a very unsettled outlook. The weekend storm for the Southern half of the uk, its one which either fades away, or intensifies! Severe weather for some tomorrow in the form of rainfall.....!

[Milhouse]

Please stop this 'write off a whole season' type commentary. There are so many wildly variant evolutions, even for within the next 10 days, on recent/current output. Meaning that comments such as 'summer wahsout 2' above are plain wrong, and certainly 100% unknowable at this stage.

ECM, although disappointingly cool, isnt showing a washout so closer inspection is needed before making such remarks. This guy ramps up snow in Winter so is bound to be well liked outside of the Summer months. It just seems he pops up to proclaim a summer washout very frequently this time of year.

 

I doubt the ensemble mean will swing that much towards the ECM op either but as Frosty has said, its a waiting game and patience is needed.

[phil nw.]

Yes the operational runs are showing some surface differences again as we go into next week.

Sometimes just following the trend in the upper air patterns over a few runs,especially on the mean outputs can help to give perspective.

I believe what we are seeing is thickness levels rising over the UK during next week and the gradual easing of the PFJ to the north.

The main High cell looks to be situated around the Azores with some ridging towards the UK from time to time with still the threat of some unsettled incursions further north from those low Heights towards Greenland in the medium term.

http://modeles.meteociel.fr/modeles/gens/run/gensnh-21-1-240.png?12

 

It does look a more settled and drier period for many of us beyond the weekend though not overly warm-pleasant enough i would think.

In fact a typical Spring pattern which is heading towards a +ve NAO setup -much better for chances of a decent start to Summer than some previous years.

[Mr Frost]

I think the problem here is that some folk have been ramping up high pressure dominated fi charts for 4 weeks now and most of us are still waiting on a decent settled spell of sunny and warm weather. (I have had one day of warm spring sunshine)

On the other hand you have folk who prefer cooler weather so they also post unsettled dominated fi charts and it seems to go down like a lead balloon because most members on here at this time of the year only want to see and read that warm weather is just around the corner. (Nothing wrong with that, we all have our prefences)

I don't think anyone is trolling, yes the member who is being accused of such prefers Wintry weather but he backs up his thoughts with charts and he is not far off with his latest thoughts going solely on the charts he posted.

Thanks again Gibby for the fantastic summary and to Frosty for his daily updates.

It is only mid May everyone, relax. We have plenty of time for heat and thunderstorms. Summer is approaching!

I for one look forward to a sizzling Summer! (Hopefully!)

The charts could be alot worse and as Phil said earlier, there is more to the outlook that just one run.

Edited May 13, 2013 by Mr Frost

[Frosty.]

The Ecm 12z ensemble mean looks rather better than the operational run, pressure of 1020mb or higher during FI with the Azores high very close to the uk, so whilst the ecm 12z op was relatively poor compared to the 00z, I still think there is enough time to see a better orientated azores ridge next week and beyond.

[legritter]

Yes we must not write off the summer by anymeans yet ,heat thunderstorms and bbqs are still quite possible .but we now have the technology to look at the next 10days in great detail and at twice a day from the ecm and uk met plus Gfs 4 times daily and all the data and forecasts from other sources .so in my personal opinion after looking at tonights data i will say spells of v hvy rain and at times cool conditions will prevail for a time yet with some hints of higher pressure trying to push its way in .but as we are all aware ,what mother nature as got for us in June is probably being cooked up right now in upper atmosphere and depending on where pressure areas set up over the globe and many other variables this will then allow weather systems to develope so right now the fate of this yrs hurricane season is now being moulded by todays events on one massive scale .im patiently awaiting tonights Fax for SAT as this could hint at another spell of hvy rain to follow tomorrows ,a thanks to those who post data and charts and once again Gibby for his twice daily forecast based on modell runs .

[k19]

GfS seems to be tending towards the ECM solution on this run, courtesy of the low being placed over Scotland as opposed to over France.

Once it fizzles out, its position looks like it's going to allow the Scandi and Azores high to link up over us. 

 

 

See how the rest of the run turns out, but at the moment it seems positive.

 

EDIT: Looking at ECM at T192, it's incredibly similar, at least in comparison to the 12Z GFS & ECM

Edited May 13, 2013 by kev19

[Cheshire Freeze]

Not too often you see the 528 DAM line modelled just a few days short of June

 

 

Edited May 13, 2013 by CreweCold

[Guest pjl20101]

Hi CreweCold, been a while since you last posted here. Back to business and it seems like the hp from the north east seems to have pushed the trough further south according to CPC 8-14 day output, that would indicate something more settled but windy as well:

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

It probably relates to snow kings post of the MJO going into phase 1, I think he's spot on with this to be frank.

[Cheshire Freeze]

Hi CreweCold, been a while since you last posted here. Back to business and it seems like the hp from the north east seems to have pushed the trough further south according to CPC 8-14 day output, that would indicate something more settled but windy as well:

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

It probably relates to snow kings post of the MJO going into phase 1, I think he's spot on with this to be frank.

 

Hi,

 

Interesting times at the moment. After a fine start to May (which I believed would be perpetuated throughout the month) we've lapsed back into a cool and rather wet regime. The CFS was interested in a mid latitude high scenario for this month and this can be seen from the chart below which was presented around late April

 

 

As you can see it was leaning towards a mid latitude high scenario with a trough extending from Greenland and into the Atlantic. In reality I think we are witnessing perhaps a mean shift east of this troughing with less influence from the mid latitude high. In reality however, I don't think in the grand scheme of things the anomalies are that far removed from what we are witnessing....slight shifts are making huge changes to our weather and half of the month is left to run.

 

Here is another anomaly chart which was churned out

 

 

Again, anomalous mid latitude HP with two main centres; one extending east from the UK and the other centred further out in the Atlantic. Between these two HP centres there is intimation of a trough like feature (denoted by the weaker anomalous HP suggestion). The CPC anomaly that you have posted is pretty much IDENTICAL to this CFS mean from late April for our neck of the woods (and I mean literally identical) so maybe the month end average height analysis won't be too far away from the aforementioned CFS mean.

 

As far as the musings of SK, I agree and can't really add much more to his (first rate) analysis. I do think this is most likely to be a colder and wetter blip in an otherwise HP dominated early summer period rather than the start of the summer monsoon of recent years.

 

MJO phase 1 anomaly for May shows the following

 

 

 

and for June

 

 

Which suggests it's all to play for over the next 4 weeks or so (and yes I'm still favouring a drier than average regime as we enter summer).

Edited May 14, 2013 by CreweCold

[Geordiesnow]

I'm a bit surprised at some of the positive comments from folk on the ECM run, I think for those who want warmth and seasonal type of weather like i know Gavin does then the ECM in my eyes just does not off that at all. The rule of thumb in terms of trends does seem to be one eventuall of Southern and eastern areas are in risk of being wet and chilly whilst the further North and West you are will be drier BUT with winds coming from the NE then I can't see much in the way of real warmth and the wind direction is likely to mean a lack of sunshine. 

 

Not really good charts tbh but not all that unusual apart from the projected massive warm pool over Scandi! 

[William of Walworth]

Not too often you see the 528 DAM line modelled just a few days short of June

 

 

I know its comparing chalk with cheese (different models, applying to diffferent times) but how on earth does what's shownn in kev's post 162 for next week, posted just above this one, evolve into Crewe Cold's possible evolution?

Seems a bit of an extreme contrast so I'm geniunely puzzled, but I am a rank amateur after all. Help me out guys, thanks.

Edited May 14, 2013 by William of Walworth

[AWD]

Another little feature that is continuing to pop up on various model output and gather support all the time;

Something to keep an eye on for those further south next weekend.

[IDO]

Another little feature that is continuing to pop up on various model output and gather support all the time;

image.jpgimage.jpg

Something to keep an eye on for those further south next weekend.

Yes, the GEFS are now hinting at that:

The general rise in pressure is still showing on the ensemble mean but the GFS op runs are showing how complicated the mixing of the AH ridging and the LP systems can be. The AH ridging goes north of the UK and links with the Scandi high on the 0z (a la ECM of late):

The UK is then close to the cut off low/trough. This drags in warm air from the continent pepping up the precipitation:

Somewhere this weekend looks likely to get a washout:

Midlands on this run.

Mr Frost may get his second day of mild temps on Sunday, with the ridging to the north of the UK:

Next week is currently being modelled by the GFS to be mild at times, with some torrential downpours, not a bad scenario:

Monday: Tuesday: LP never far away from us.

The GEFS shows the op run is an outlier late in FI (pressure) so the return of the trough, not supported currently:

Some possible interesting weather ahead...

Edited May 14, 2013 by i'm dreaming of...

[Frosty.]

The GEFS 00z mean is continuing to trend towards a warmer and settled outlook by late may with high pressure in control, temperatures gradually recovering to average and then becoming pleasantly warm, it looks like the azores high is going to feature strongly in the outlook.

[ANYWEATHER]

Ecm has quashed any ridging in its output and gone along the same lines as the gfs! This low pressure for the weekend needs to be watched...could well be a troublemaker!

[Radiating Dendrite]

What are peoples thoughts on Saturday?

I am off to Lords for the 3rd day of the test..........it had better not rain!!

Looking at the models it seems that heavy rain will be around but may track further to the north?

[Purga]

Signs of warmer uppers in FI only but a mostly wet picture showing up from GFS 0z

 

ECM looking very wet over the weekend for many

 

drying out in the longer term and quite pleasant with the Azores high trying to ridge across, cool nights likely

 

Beyond that it looks rather unsettled and cool still with potential wet incursions in the south. A coolish w / wnw flow which could be quite pleasant in parts but no significant warm dry spell looking likely. CPC charts concur

 

[Frosty.]

What are peoples thoughts on Saturday?

I am off to Lords for the 3rd day of the test..........it had better not rain!!

Looking at the models it seems that heavy rain will be around but may track further to the north?

wet and cold..and windy