Model Output Discussion - 31/8/14 Onwards.

[Gibby]

Good morning folks. Here's my Sunday attempt of looking at the latest outputs of the models covering the next few weeks.

 

http://www.norton-radstockweather.co.uk/NEW-Model-Analysis(2859336).htm

[knocker]

And the ECM ops

 

[Polar Maritime]

ECMWF showing the Atlantic making in-roads by the 5/6th, With Low pressure dropping over the UK bringing cooler/wetter and more unsettled weather from a N/W flow. GFS is similar but not quite as aggressive with the Low. Interesting Model watching coming up over the next few days as they firm up on detail.

 

Edited September 28, 2014 by Polar Maritime

[Summer Sun]

Models slowly firming up now on a breakdown next weekend and this includes UKMO

 

Settled to start

 

 

But low pressure begins to take over as we move to next weekend warm air at first but cooler air does move into the north west by Saturday, the far south and SE holds on to the driest weather the longest

 

 

So a quick summary for late next week, wet and increasingly windy in the NW, drier and brighter for the SE and remaining warm away from the NW where cooler air starts to move in during the weekend

Edited September 28, 2014 by Summer Sun

[draztik]

It has been a while! But the negative anomaly blues are on their way back. Rejoice autumn fans. And fetch that coat and a dust cleaner of some sort.

Day 6-11 height anom & temp anom. / Ecm ens

Usual caveats apply at this time frame, but the trend is in motion.

Edited September 28, 2014 by draztik

[bluearmy]

naefs takes the upper trough that bit further west than ecm and sinks it west of iberia with it becoming cut off (another trend of recent weeks). 

[Cloud 10]

Some pretty spectacular Blocking over Greenland in the mid to later stages of the GFS 06z this morning.

 

 

 

Not to be taken seriously at that range of course,but still good viewing.

[Milhouse]

In the reliable time frame its more warm and settled conditions with some mist and fog forming overnight in light winds. It stays this way out to next Saturday when a band of rain is set to slip southeast.

 

 Pleasantly warm for the time of year.

 

[knocker]

Bold chart for the 8th. So are we seeing the end of the western Atlantic block with thel ittle fella perched on the Atlantic seaboard?

 

[Frosty.]

I love these charts in low res on the Gfs 06z op run, the first wintry ppn for the north and the first real chill of the autumn with superb wintry synoptics..classic stuff indeed..if this is a taste of things to come during the winter, BRING IT ON.. retrogression with strong height rises to the NW....B..A..N..K   this might bring a few hardcore coldies out of hibernation a bit earlier than usual

Edited September 28, 2014 by Frosty.

[Summer Sun]

I love these charts in low res on the Gfs 06z op run, the first wintry ppn for the north and the first real chill of the autumn with superb wintry synoptics..classic stuff indeed..if this is a taste of things to come during the winter, BRING IT ON.. retrogression with strong height rises to the NW....B..A..N..K   this might bring a few hardcore coldies out of hibernation a bit earlier than usual

 

The 06z run goes to show just how big it can change in a matter of hours

 

00z

 

 

06z

 

[IDO]

Not really seeing an Atlantic zonal flow from the models, quite the opposite, another phase of a meridional pattern. However the trough may not favour the UK this time leading to more unsettled weather.

 

ECM at D10 bullseye for the cut off low/trough: 

 

GEM op is more favourable but its mean suggests closer to ECM:   

 

GFS 06z op and control variations on the same theme:   

 

So the long wave pattern from the models showing continuity, however surface condition after D5 remain very uncertain. For instance at D5 Ecm London 2m temps have members showing lows of 6c, mean of 12c and op at 15c:

 

The GEFS are similar but later at D7, with much scatter: 

 

The GFS op looks an outlier with forecast rainfall in week 2 of three times adjusted monthly rainfall (though not impossible as October is the wettest month of the year on average).

 

So still another 7 days of dry weather for the UK. Then a wave likely from the Pacific Tropical Storm, that sinks a trough into the US and builds an Atlantic ridge and a further trough downstream close to the UK:

 

 

 

That's where the uncertainty lies, as this latter trough looks like it may get cut off and become a medium term feature. The majority of the GEFS have it over the UK with varying amount of intensity: http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=240. 

[Polar Maritime]

Yes Frosty, Some pretty cold synoptic's by the GFS out in the run, A stark difference to what we have been seeing for weeks now. A pattern change is well under way now with-in the Models, As i said this morning very interesting Model watching coming up as they get a grip. Autumn proper on it's way at last, With maybe the first snowfalls for the Scottish Mountains!

 

 

Edited September 28, 2014 by Polar Maritime

[Polar Maritime]

I have just had to delete a post, Can we please only discuss Model Output in here.

 

Many Thanks. PM

Edited September 28, 2014 by Polar Maritime

[IDO]

Yes Frosty, Some pretty cold synoptic's by the GFS out in the run, A stark difference to what we have been seeing for weeks now. A pattern change is well under way now with-in the Models, As i said this morning very interesting Model watching coming up as they get a grip. Autumn proper on it's way at last, With maybe the first snowfalls for the Scottish Mountains!

 

 

 

 

And the control at the same time brings another burst of Summer:  

 

The mean is nowhere near as cool as the op: 

[knocker]

I wouldn't have said the GEFs ens is that extreme.

 

[IDO]

I wouldn't have said the GEFs ens is that extreme.

 

Yes, just qualifying PM's cold chart with the other hi-res run showing a high in charge with above average temps: 

 

I do not expect either will come to fruition!

 

The Scandi trough of the op has two other members supporting it. I expect much chopping and changing in the next few days for that time scale.

[Summer Sun]

UKMO continues this growing trend now to more unsettled weather than we've had over the past 4 or 5 weeks

 

Thursday looks to be the last of the settled weather for England and Wales

 

 

By Friday the wind picks up from the south west as a band of rain spread down from the NW those in the south east should hold onto one more fine day with temps in the low 20's, mid to high teens further north

 

 

Into Saturday and the NW of Scotland continues to see some strong winds, it will be breezier for all with a mix of sunshine and showers, fresher in the north with only the south hanging onto the last of the warmth

 

[knocker]

The GFS for Saturday has the upper trough centred just south of Iceland stretching a little SE. resulting in a NW/SE split over the UK temp wise from just below to above average.

 

[Frosty.]

Tonight's Ecm 12z op run shows a BIG change arriving from the west / northwest by the end of the week ahead as proper autumn weather finally makes an appearance, turning much cooler, windier and unsettled with low pressure taking over from next weekend onwards, indeed the unsettled spell looks like it could last for a while once it gets here and tighten it's grip in the process.

 

In the meantime, tomorrow brings a more unsettled blip with an increasing threat of clusters of heavy and thundery showers breaking out and pushing north across the southern half of the uk but by tuesday it looks fine and pleasantly warm again for most of the uk but nights could turn chilly with fog patches where skies clear, the exception to the generally fine story being the far northwestern corner of the BI where it will be cooler, windier and unsettled for much of the time..and then later in the week that increasingly unsettled atlantic weather pattern takes over more and more of the uk with the SE corner holding on to the fine and pleasant weather for longest. 

[phil nw.]

The models showing the approach of the first real Atlantic low of the Autumn at the end of next week.

Frontal rain and increasing winds spreading south east bringing an unsettled spell after weeks of relatively dry and calm conditions for many of us.

http://www.wetterzentrale.de/pics/Rukm1441.gif

http://www.wetterzentrale.de/pics/Recm1441.gif

http://www.wetterzentrale.de/pics/Rtavn1441.gif

The low currently looks like being cut off from the parent upper trough so becoming slow moving close to the UK through week 2.

Exact positioning still uncertain yet of course but a different outlook to our current setup seems likely.

Tonight,s CPC chart certainly shows a different wave pattern as we go into October.

http://www.cpc.noaa.gov/products/predictions/814day/814day.03.gif

The UK under the upper trough with highs out in the west Atlantic and east over Scandinavia/Russia.

[knocker]

Tonight's anomalies are showing a prevalence for the continuing pattern forecast for this weekend although it's not convincing for a major change to a more dynamic Atlantic, more a a slack zonal arrangement. The jet is still fairly weak and, depending which model the direction is not fixed. A quick summation is that some models have a ridge western Atlantic with a trough around the UK. The difference is the ECM orientates the low further north so the jet nips around the south of the UK intensifying the low a tad. Further on the trough area slackens but no huge indication of an active Atlantic although pattern change is in the air.

Edited September 28, 2014 by knocker

[damianslaw]

Models continue to show a change to a much more unsettled pattern by the end of this coming week - with a trough over the country sandwiched between strong heights to the NW and East  - the trough would very likely become slow moving.

[Cheshire Freeze]

Some stunning NH synoptics on show on the 0z GFS FI. Beautiful example of Greenland blocking

[knocker]

A quick look at the weekend Initially the upper trough is centred north of the UK allowing the south to escape the colder air but it drifts south and it looks (according to the GFS of course) as if the UK will be getting a very cool and unsettled beginning of October. The ridging in the western Atlantic is still in place.