Model Output Discussion 01/06/2012

[johnholmes]

update this morning and its not good news for anyone wanting dry and heat!

On basis of last ec-gfs and noaa=little if any sign of change in pattern for next 10-15 days

little sign of the possible build of heights to the NE of the last 2 days, all 3 seem to suggest a fairly mobile westerly Atlantic pattern at 500mb into a trough in the UK area, one has it west of the UK, the other two either a pretty flat type of trough the other suggesting even more of a flow north of west into the trough.

Edited June 7, 2012 by johnholmes

[Summer Sun]

Looking at this mornings GFS it is showing no more deep low's coming our way thankfully after Saturday's has cleared through, still plenty of rain or showers around for next week before FI shows HP trying to settle things down, with pressure also falling over Greenland and Iceland

http://www.null/ds/gfs.htm

ECM also show's a similar picture with no more deep lows heading our way, Tuesday could be quite wet in the south

http://www.null/ds/ecm.htm

[azores92]

ECM also show's a similar picture with no more deep lows heading our way, Tuesday could be quite wet in the south

http://www.jp2webdes...o.uk/ds/ecm.htm

that chart suggests a slack flow with a low to our SE, sunshine and showers most probably

[Robbie Garrett]

Hi Robbie, what you post for later in June doesn't seem to tie in very closely with what A Winter's Tale is tentatively suggesting for a slow/gradual possible drier trend into FI, I can see that he's reading different outoput from yours but his conclusions, albeit correctly cautious, do look somewhat different from what you suggest?

IMO everything's still subject to change, and to be over confident about what mid to.late June holds for us is fraught with danger right now.

That's the way it is looking, lower pressure over Greenland, high pressure building in again... but conclusively the run shows a dire result thereafter with unsettled conditions quickly replacing the Azores that ridged over the UK, sometime towards end of month, it pretty much does look like the end result may be a south/north split with more unsettled conditions to the north, but rather intriguingly you have southerly tracking jet-stream that is rather flat, so any high pressure that did build probably would be a 5 minute wonder.

Expect a very warm final week in June, with quite a bit of Thundery Activity but then a week or two of more settled, but probably cloudy conditions from a ridging Azores.

Things look slightly better on this run, but as I say maybe a north/south split... give it a week or two and it might be a bit more clear with regards to the NAO/AO index.

UK Outlook for Tuesday 12 Jun 2012 to Thursday 21 Jun 2012:

Unsettled conditions are likely to continue, giving a mixture of bright spells and showers with some longer outbreaks of rain at times. Some of the showers are likely to be heavy with hail and thunder possible, especially towards southern and southeastern areas, and with mainly light winds, showers will be slow moving, giving a risk of locally high rainfall totals. Towards the end of next week there is a slightly increased chance of some drier, brighter intervals. Little change then through the rest of the period, with the focus of the unsettled weather shifting towards the north, while the south and west could have lengthier dry and bright spells. Temperatures generally slightly below average, perhaps recovering to near average later.

UK Outlook for Thursday 21 Jun 2012 to Thursday 5 Jul 2012:

Indications suggest that conditions may continue rather unsettled at first with showers or more persistent rain at times, interspersed with drier and brighter interludes. Towards the end of the month, there are signs that these drier and brighter periods may become more prolonged.

[shedhead]

A rather more optimistic looking 06 GFS by this time next week. Clearly we need to see where this run sits within the ensemble suite, but the slow, steady trend towards higher pressure through week 3 continues, lets hope it gathers pace too across the next 2 or 3 days.

Edited June 7, 2012 by shedhead

[Summer Sun]

GFS 06z looks better this morning with high pressure doing its best to build later next week and into the following week

http://www.null/ds/gfs.htm

[Thundery wintry showers]

Certainly a very "autumnal" outlook over the next 2-3 days with a deep depression bringing wind, cloud and rain today, and while tomorrow looks brighter and more showery, with strong winds and embedded fronts I think most parts of the UK will remain quite cloudy, with minimal chance of thundery activity.

However, the jet does look like slowing down after tomorrow, with a mix of sunshine and showers likely from Saturday through to Tuesday. Thunder activity will increase, most likely over the Midlands and northern England during Saturday, and transferring to southern England during Sunday and Monday. The north-easterly flow showing on the model outputs will probably kill off most of the shower activity over E Scotland and NE England by Monday, though those same areas will also turn cooler with the winds off the North Sea.

There are strong signs of building pressure towards midmonth but it is a mistake to see an anticyclone and automatically assume that it will be warm and sunny- if the GFS 06Z FI verifies for instance, a lot of people will end up disappointed with that brisk north-easterly flow sending stratus in off the North Sea. However the extended ECMWF outputs are hinting at a build of pressure generally over western Europe with the main Azores high centred well away to the west (thus reducing the chances of a northerly or north-easterly flow dominating), which may be more conducive to something dry sunny and warm. It's all very tentative at this stage, but there are at least strong signs of the jet slowing down meaning we probably won't be getting a train of depressions.

[bluearmy]

Certainly a very "autumnal" outlook over the next 2-3 days with a deep depression bringing wind, cloud and rain today, and while tomorrow looks brighter and more showery, with strong winds and embedded fronts I think most parts of the UK will remain quite cloudy, with minimal chance of thundery activity.

However, the jet does look like slowing down after tomorrow, with a mix of sunshine and showers likely from Saturday through to Tuesday. Thunder activity will increase, most likely over the Midlands and northern England during Saturday, and transferring to southern England during Sunday and Monday. The north-easterly flow showing on the model outputs will probably kill off most of the shower activity over E Scotland and NE England by Monday, though those same areas will also turn cooler with the winds off the North Sea.

There are strong signs of building pressure towards midmonth but it is a mistake to see an anticyclone and automatically assume that it will be warm and sunny- if the GFS 06Z FI verifies for instance, a lot of people will end up disappointed with that brisk north-easterly flow sending stratus in off the North Sea. However the extended ECMWF outputs are hinting at a build of pressure generally over western Europe with the main Azores high centred well away to the west (thus reducing the chances of a northerly or north-easterly flow dominating), which may be more conducive to something dry sunny and warm. It's all very tentative at this stage, but there are at least strong signs of the jet slowing down meaning we probably won't be getting a train of depressions.

Ian, the spread on temps and precip post mid month on extended ecm london ens shows how 'vague' the fi ens output remains.

http://www.meteo24.fr/fr/home/meteo-france-et-europe/passion-meteo/ensemble-de-previsions.html?eps=london

[Gavin P]

Hey all,

My model based video musing today is looking at the chance of an improvement in the weather beyond ten days (so from around 17th-20th)

All very tentative though.

[DTHFCJ]

Hey all,

My model based video musing today is looking at the chance of an improvement in the weather beyond ten days (so from around 17th-20th)

All very tentative though.

cheers Gavin....easily understandable for everyone from the knowledgeable to the novices

Edited June 7, 2012 by BALE1

[phil nw.]

Based on recent outputs I can see signs of an improvement away from this cyclonic regime as we go further in to next week.

Looking at the 00z mean 500hPa outputs they do follow yesterday`s modelling of this upper trough receding north from around day7.

As others have suggested we are not looking at an anticyclonic setup immediately as there is still likely to be some shallow surface lows about giving some showers at first.

Indeed the NOAA forecasters have given fairly low confidence in the exact placement of the upper air anomolies in the medium term.

http://www.cpc.ncep....day/fxus06.html

However with a less active Atlantic looking likely we should start to see some warmer and drier periods with more sunshine about.

Edited June 7, 2012 by phil n.warks.

[Gavin P]

cheers Gavin....easily understandable for everyone from the knowledgeable to the novices

Hey thanks.

[picog]

A glimmer of hope perhaps for some drier, average weather towards the 3rd week of June — even in Manchester!

http://www.wetterzentrale.de/pics/MT8_Manchester_ens.png

[The Northern Ramper]

More signs of improvement for next week according to the 12z.

After a slack flow which will be a mixed bag, high pressure moves in from the west around Wednesday.

Small steps and all that.

[The Northern Ramper]

The ukmo looks to be developing the same scenario.

[Summer Sun]

We finally seem to be heading in the right direction with high pressure starting to shows its hand more as we move towards mid month and to be fair GP called it last week when the summer forecast was released

[The Northern Ramper]

The 12z was a bit of an outlier so caution remains, would be nice to see the ECM 144-168 back it up.

[tinybill]

http://www.meteociel.fr/modeles/gfse_cartes.php?mode=2&ech=6

evening all the best day looks like sunday at the moment after that its looking a bit dire

[Thundery wintry showers]

I know a certain amount of subjectivity is inevitable in a thread like this, but I'd rather see more discussion of what the models are showing, as opposed to what people want them to be showing. For example I can't imagine many of the regulars over at the convective discussion threads agreeing with the general impression that we should write off next week but keep up hope for some settled high pressure afterwards. Particularly for the south and west, the early part of next week could generate a fair amount of thundery activity, and it also looks likely to be warmer and sunnier than the first week of June, feeling more so due to the relative lack of wind.

In the meantime the GFS and UKMO haven't changed significantly for next week- mostly bright and showery except for eastern Scotland and north-east England (here rather cooler with drier conditions but also potential for low cloud) and a slow decline in shower activity as high pressure advances from the west. Before that, the next couple of days look distinctly autumnal with strong winds and belts of rain. The GFS 12Z run places high pressure in a more favourable position for warmth/sunshine than the 06Z did into FI, but I am seeing hints from UKMO and from this morning's ECMWF runs that the high might stay out in the Atlantic, so the outlook remains hard to call beyond the back end of next week.

[The Northern Ramper]

I wouldn't mind hearing how GP expects things to play out, he has been quiet lately.

[ANYWEATHER]

The outlook remains unsettled in the next week ,then models disagree beyond this as to gfs and ecm. At day ten gfs goes for more benign conditions whilst ecm goes for a much more unsettled outlook with deep lows affecting the Southern half of the uk...

[PubliusEnigma]

Ok towards the end of the output however this chart sums up Summer 2012

This weekend sees the very unsettled, cool and wet weather continuing, before things turn a bit cooler next week as a

Northerly flow is introduced once again ;-

Low pressure close to the east maintains the unsettled theme as temps drop back to nearer the low teens mark maybe as low

as 11 or 12oC in the south east corner and probably dull and overcast for most of the day.

Not much changing as we go thru the week as a Low pressure moves down the country from the north, bringing increased cloud

and showery rain or longer outbreaks of rain

Towards the end of the week low pressure encroaches from the south with more general cloud moving north, and a cool easterly

setting up which could bring some lengthy spells of rain into southern parts.

The rain probably continuing into Saturday for many areas as the low pressure edges into the UK, with temps once again

dropping to low to mid teens, and a distinct lack of sun or brightness, jet more cloud and rain.

Into Sunday, a chart that sums up what has summer has been so far.. The only green low on the chart over us, bringing yet more

outbreaks of rain, and probably overcast skies. With the weekend likely to be as poor as The Bank Holiday weekend, and this weekend

to come.

No sign of any settled warmth, or balmy evenings.

[Costa Del Fal]

If the last frame or two of the ECM came off, then surely S Britain would be looking at a lot of rain. Exceptionally bleak charts really. The last ECM frame really reminds me of June/July 2007. *Shrudder*.

However, aside from that the charts are really struggling clearly right now with a real flip flop in solutions beyond the medium time frame. GFS favours a better outlook but is a bit of an outlier at present. Some slight improvement next week does look possible though with the trough moving North/filling out as such.

Sadly, we are none the wiser thus far as to the outlook for the rest of June. It really is all to play for.

[S.G.]

Hey guys can I ask a question please.

When I view the 850hpa temp & SLP chart I would like to know why the High pressure 1024 is in the Atlantic when the thickness line is 10-15 but when it comes over the high pressure start to decreases when the thickness line is near to 20. When I see towards the Mediterranean the surface pressure is lower at 15-20 on the thickness line which it shows its still high pressure if it is or not but can you explain me how it does this and a site which explains it and when the high pressure move out the way the red indicating tend to move towards the north of the country.

[J10]

Next week looks a good deal better than originally thought, it had looked a complete wash out, with low pressure over us, but now a mix with some convective activity , but at least with that you should get some sunshine in between.

A big difference after that between the GFS and ECM, so far too early to call.