Model Output Discussion - 31/8/14 Onwards.

[Polar Maritime]

Would not argue with that, as the UKMO has a lot more information to hand that we aren't privy to. But bearing in mind what the models were suggesting a couple of days ago us southerners will not be complaining of recent developments

 

Yes the GFS is handling the first Low off the Atlantic much better now it's getting closer into the time-frame, With the South getting away with dryer more settled weather. Further out in the run after the Model'd transient push of Hights it's about as Zonal as it gets, Many more runs and changes to come..

 

Edited September 18, 2014 by Polar Maritime

[Frosty.]

Would not argue with that, as the UKMO has a lot more information to hand that we aren't privy to. But bearing in mind what the models were suggesting a couple of days ago us southerners will not be complaining of recent developments

 

GEFS D8 mean:  gens-21-1-192 (1).png

I agree the south / se looks like escaping lightly from the atlantic lows diving southeast across northern areas compared to recent runs which looked unsettled for all, and if I lived in the south I wouldn't really care about what's likely to be an autumnal, cool, windy and unsettled spell in the NW later next week. It's absolutely normal for the south to do best out of these situations..nothing new.

[IDO]

Yes the GFS is handling the first Low off the Atlantic much better now it's getting closer into the time-frame, With the South getting away with dryer more settled weather. Further out in the run after the Model'd transient push of Hights it's about as Zonal as it gets, Many more runs and changes to come..

 

 

 

The flip side is shown by the Control and I know you will enjoy this run PM:

 

D7:   D10:  D12: 

[Captain Shortwave]

I don't think for a minute that high pressure will dominate the outlook, to me it looks like the further north / north western areas will have a very unsettled spell with gales and heavy rain at times, yes the south & east (SE) currently looks the place to be for fine and warm weather and I take a lot of notice of the met office updates and they indicate unsettled weather taking over more and more of the north and west beyond middle of next week, so for the SE there may not be a noticeable pattern change but the NW will feel it.

I wouldn't necessarily agree with that, some parts of Norfolk and Lincolnshire might get to see the sun next week due to an Atlantic westerly flow instead of a flow off the north sea 

Looks a like a north/south split with a series of transient ridges and troughs, the south looks pretty dry still on the whole, the north west looks more changeable.

GEM again throwing something more amplified,

Summer would be far from dead here with 850s approaching the mid-teens and surface temperatures pushing 80F.

Edited September 18, 2014 by Captain shortwave

[Frosty.]

I wouldn't necessarily agree with that, some parts of Norfolk and Lincolnshire might get to see the sun next week due to an Atlantic westerly flow instead of a flow off the north east

Looks a like a north/south split with a series of transient ridges and troughs, the south looks pretty dry still on the whole, the north west looks more changeable.

GEM again throwing something more amplified,

Summer would be far from dead here with 850s approaching the mid-teens and surface temperatures pushing 80F.

I would say the northwest looks unsettled rather than changeable from mid next week, sorry for nit picking but unsettled is more appropriate for the NW corner of the uk..otherwise I agree.

 

Anyway, roll on winter, that's what most of us are waiting for now

Edited September 18, 2014 by Frosty.

[knocker]

Perhaps the meteorological definition of unsettled and changeable would help people out here.

[Frosty.]

Tonight's GEFS 12z mean shows an unsettled blip for scotland later next week otherwise it's high pressure again.. does that sound familiar temperatures lower but still pleasant in the south during prolonged sunshine and nights chilly with an increasing risk of fog and ground frosts.

[IDO]

  RyanMaue

ECMWF 12z is delayed due to "unforeseen circumstances" at their end. I'm waiting patiently.

18/09/2014 19:42

 

Just in case you were wondering...

[Polar Maritime]

  RyanMaue

ECMWF 12z is delayed due to "unforeseen circumstances" at their end. I'm waiting patiently.

18/09/2014 19:42

 

Just in case you were wondering...

 

 

Cheers for that info, Was just wondering what the hold up was   I agree reg the Control run 

 

The ECMWF is showing the first Low a touch further North on tonight run. With some warm temps holding on for the South as hights push in-land a tad further..

 

Edited September 18, 2014 by Polar Maritime

[ANYWEATHER]

A dramatic change next week with the jet stream making a b line for the uk.

[Scorcher]

A dramatic change next week with the jet stream making a b line for the uk.

 

The ECM is having none of it tonight though, with fronts tracking mainly to the north of the UK and things becoming warmer again towards the end of the week. Even the GFS 12Z shows high pressure waiting in the wings to return after an unsettled spell, never really far away from the south of the UK in any case.

[ANYWEATHER]

The ECM is having none of it tonight though, with fronts tracking mainly to the north of the UK and things becoming warmer again towards the end of the week. Even the GFS 12Z shows high pressure waiting in the wings to return after an unsettled spell, never really far away from the south of the UK in any case.

A long way to go , but there is a definite change to Atlantic weather, Surely you cant keep hoping for warmth and high pressure as we move into Autumn ,October?  I cant get the ecm model tonight, but the trend is to Autumn  weather as we move into October,,,

[johnholmes]

Perhaps the meteorological definition of unsettled and changeable would help people out here.

 

 

Not sure if this would be accepted but unsettled suggests what it says unsettled

changeable suggests just that, so sometimes unsettled sometimes settled but neither for very long?

[Captain Shortwave]

A long way to go , but there is a definite change to Atlantic weather, Surely you cant keep hoping for warmth and high pressure as we move into Autumn ,October?  I cant get the ecm model tonight, but the trend is to Autumn  weather as we move into October,,,

I would probably say a westerly type weather pattern with transient ridges and troughs but with the jet still far enough north to keep the southern half of the UK mostly dry and at times still warm. This might be a punt but for many areas down here this September will rival March 2012 in rainfall amounts, another month where it did not rain on a single day.

[johnholmes]

The latest NOAA 6-10, see below, carries on with the idea of a NW-SE split developing in the 6-10 day time frame, say from about mid/late next week, with rather more settled weather for the SE half and the NW half more changeable but not totally unsettled.

http://www.cpc.noaa.gov/products/predictions/610day/500mb.php

[Frosty.]

High pressure dominates tonight's Ecm 12z op run across the south of the uk, it's really up for it in terms of not allowing low pressure to stand a chance of having any meaningful effect across southern areas with pressure staying high to the south / southeast. For scotland it's a different story with at least a few atlantic systems sweeping across to the northwest but even up north it settles down at times..so really tonight's GEFS 12z mean and the Ecm 12z op run have made a mockery of an unsettled outlook, however, although the south looks predominantly fine, it also becomes cooler compared to this weeks warmth / humidity but still pleasant in the sunshine although chilly at night with fog patches forming since it's not long to october now.

Edited September 18, 2014 by Frosty.

[knocker]

The anomalies are by no means settled in detailed. John has already summed up the NOAA 6-10  The ECM has the trough over Greenland with the Azores high ridging over the UK which would be inclined to push settled weather further north, The GFS spot anomaly for Saturday makes less of the trough and has the Azores high ridging NW/SE just west of the UK but could produce settled weather for most of the latter. The jet runs around the persistent positive heights over North America but is quite weak. Looking further afield both the GFS and ECM going for a more zonal flow (not surprising) so at this stage no apparent major pattern changes but this is basically just out of interest.

 

I'm afraid the charts are a complete muddle.

Edited September 18, 2014 by knocker

[Frosty.]

Tonight's Ecm 12z ensemble mean shows a north / south split with high pressure keeping the south generally settled with sunny spells once the risk of thundery showers ends by sunday when it turns fresher, there is no sign of a pattern change as such for england and wales apart from temperatures dropping several degrees from this weeks high values although signs of a warm up by the end of the run as we begin to import continental air wafting into the south of the uk. For scotland it's a more mixed picture, some unsettled, cooler and windy spells but with fine calmer days here and there, especially early and again later..all in all, compared to the very unsettled gfs 6z op run this morning, quite a significant shift back towards predominantly anticyclonic conditions on tonight's output, at least for southern britain.

Edited September 18, 2014 by Frosty.

[Captain Shortwave]

Looks like a pattern change will still happen, though the effects on some parts of the UK will be limited.

High pressure will return to the Azores/Iberia region with enough push northwards to keep the south of the uk mostly fine. In these set ups it's difficult to pin down how much sunshine there will be (especially if we pick up some very warm, moist air from the mid-Atlantic). The north does see a deterioration in conditions with showers or longer spells of rain at times with temperatures near normal. The south should remain warm (especially in the sunshine).

[Frosty.]

Have to say, after this morning's semi unsettled output, quite a change back to settled on tonight's runs once the thundery showers threat is over with by sunday, cooler and fresher from the west for all areas by sunday but fine as atlantic high pressure drifts across the uk and it's influence continues for the first ½ of next week at the very least, the south stays more settled according to the gefs 12z mean, ecm 12z op run and ecm 12z ensemble mean.

[Frosty.]

Don't put the BBQ away just yet, the Gfs 18z op run shows a very summery end to september and early october with low 20's celsius as high pressure becomes centred just to the east of the uk enabling continental warmth to waft our way, very settled looking charts tonight, just a brief unsettled and cooler blip earlier in the run.

[IDO]

Looking at the pressure graph for London it does look that there remains uncertainty on how far south the LP comes for D6-8. However it remains a transient feature on the GEFS with pressure rising and mean pressure staying above 1020mb after D9:

 

 

No obvious Atlantic ingress for the south as the rain spikes highlight. Quite dry in fact. It is a pattern change from the current slack setup to something more mobile with plenty of wet weather running somewhere to the north of Birmingham, mostly nearer Scotland.

 

GFS mean at D10:   D13:  D16: 

 

They continue to show improvement run to run if we are after drier weather.

 

GEM on this morning's run brings a more unsettled spell for D6-8 as the LP encroaches to the south coast but by D10: 

 

ECM has the LP missing most of the UK on D7 and the south is relatively settled through to D10.

 

D7:   D10: 

 

Some places in the S/SE/E could have a very dry September if they avoid the heavy downpours over the next 48 hours. The West Country/SW currently under attack from these storms.

[knocker]

The GFS and ECM anomalies differ this morning regarding the colder air to the north with the GFS far more bullish which means the north of the UK are affected. The ECM gives more credence to the HP. Temps average or slightly above.

 

[IDO]

The GFS 06z is a great run for settled weather for the south with HP dominating through the whole run ending on D16:

 

 The control is similar: 

 

Temps look like perking up and pressure for London is high:

 

 

 

Both push the LP system that we have been watching for the end of next week further north so no real impact for the S/SE/SW/W.

 

It seems that the Atlantic surge was a false alarm and the settled warm(ish) September will continue, possibly into October.

Edited September 19, 2014 by i'm dreaming of...

[Paul]

For those who may be interested - the GFS is getting a major upgrade at some point in the next few months, improving the resolution to 0.25 degrees (from 0.5 degrees) among other things. Will be interesting to see how it affects it, and just in time for winter too!