Model Output Discussions 12z 03/05/2016

[MP-R]

The GFS 12Z is quite interesting in September with a number of weather patterns trying to take hold with neither one particularly influencing, so all in all a dry and changeable start to the September looks likely, perhaps with room for something wetter should ex-tropical storms get involved.

W/c 05th September shows something of a thundery easterly which may put an end to the thunder-drought here as we almost always get thunderstorms when there's an easterly influence.

All in all, lots of options on the table for September but one thing that's likely is that at least the start of the month looks like mimicking August with a continuation of warm temperatures for the most part away from the northwest. 

[Summer Sun]

For the south at least it remains warm with little in the way of rain till at least mid-September

[knocker]

Although the anomalies tonight are in the same ball park there are differences which must leave some doubt as to the surface evolution which in any case will be susceptible to the usual day to day vagaries. All are agreed on the Greenland trough but the strength of the European HP ridging into the Baltic and how much the Azores HP will ridge NE is still an open question, NOAA would appear to be a little more bullish in this regard. Again a closer look at the EPS does shed some light as it has the Azores being quite influential T180-T240 before subsiding leaving a SW upper flow and in general temps a little above average. If one was going to take a punt on this I think that the south benefiting from HP influence with Scotland and the north on the flight path of systems tracking NE the safe option. Ergo the south continuing dry and perhaps with temps a little above average with the wetter and cooler weather again consigned to the north.

 

Edited August 28, 2016 by knocker

[damianslaw]

More of the same for the foreseeable it appears, with the azores high holding the atlantic at bay and crucially ex hurricane Gaston, end result remaining largely dry and warmer than average, with the SE seeing further summery conditions, the far NW more prone to cloud and damper conditions, but nothing especially wet nor windy. All quite normal service given early September is often a very quiet period.

Jetstream profile is SW-NE aligned which will help to keep atlantic fronts away from southern UK.

ECM output shouldn't be dismissed though with its suggestion of heights ridging further west and pulling down a trough from the NW, its a plausible evolution if we do see central core of azores heights elongate on a more west-east direct line rather than NE-SW, indeed if trough formation associated with ex hurricane Gaston disrupts this will have the effect of pulling such heights NW - and the resultant pattern would be that shown by the ECM. So keep an eye on this feature, its movement and shape are far from nailed and it will be a pivotal player in how things pan out as we move through the early part of September. The models always struggle with such features at the medium-long range, and quite often the short range as well, they have a habit of doing about turns at the last minute..

Edited August 28, 2016 by damianslaw

[knocker]

Today

A fine day for most but maybe some light showers in the E/SE and rain spreading into N. Ireland and western Scotland.

The GFS this morning

A front trackiing into the NW late Tuesday and moving SE though weds and slowly dissipating. Then brief ridging before an Atlantic depression tracks east and it's associated fronts impact the UK Friday  The continual movement east of the low brings the UK within it's circulation and portends a showery weekend ahead although the GFS is a bit messy with it's evolution. This does appear to welcome the Atlantic in through the front door but I think any interpretaion post the weekend best left for the time being.

[tinybill]

On 8/18/2016 at 19:53, Summer Sun said:

GFS shows things heating up next week about time we had charts like below showing for August instead of the miserable ones we've become use to over the past decade or so

EDIT

ECM is another cracker

 

[tinybill]

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

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

well  if  the  models  are right  make  the most  of  the warm weather this  week   things look like they  might go down hill a bit    just  when i start  my 2 weeks  off on  holiday!!!

 

[knocker]

The ecm also has the Atlantic moving in at the beginning of next week with a 150kt jet. Gaston is middle Atlantic 1003mb on this chart. How much it is influencing proceedings is way beyond my pay grade

Edited August 29, 2016 by knocker

[Summer Sun]

After hints, the 1st full week of September might be settled ECM has done a complete U-turn with low pressure now shown to take over

An autumnal week

Edited August 29, 2016 by Summer Sun

[Summer Sun]

Longer term the GFS ens this morning shows pressure starting to build again towards the end of next week and into the following week

[northwestsnow]

Yes, the models are now hinting at something more unsettled as we head towards the end of the working week and beyond.

Its not the end of the world as August has been a reasonable month here with some warm sunny days mixed in with some more unsettled days, i suspect its been a lovely month further south so one could say quite a traditional summer month.

Whilst it would be great to see more of this current warm dry weather it cant go on for ever,in any case my thoughts are now slowly turning to Autumn and beyond and all the excitement the run up to winter generates, OK it usually ends up in disappointment for cold lovers, but its all about the chase ! ;D

[Polar Maritime]

The GFS shows a traditional start to Autumn this morning, With a strong Westerly flow pulling fronts in off the Atlantic as the Jet sits over the UK.

 

[Summer Sun]

Going into next week the ECM ens is better for the south at least with pressure remaining relatively high

Ens

Op

 

[carinthian]

59 minutes ago, Polar Maritime said:

The GFS shows a traditional start to Autumn this morning, With a strong Westerly flow pulling fronts in off the Atlantic as the Jet sits over the UK.

 

Not the ideal scenario PM for the anticipated fine start to Autumn as some of us expected. Ideally , we need now to start to see the progress of a buckle in the jet to provide us with a substantia  high pressure belt in the right zone. However, not seen on this chart you posted. Maybe , the hurricane season with put some extra warm advection pole ward and throw a spanner into this prognosis, hopefully for a better outlook. Looking at other model this morning, maybe a half way house would be the best bet, which is probabaly not good for the north of the British Isles that could do with a spell of warmth and dry weather.

 C

 

[knocker]

The upper Atlantic trough is briefly quite intense at the beginning of next week before it wanes somewhat. The eps has this scenario of the waxing and waning of the trough and the accompanied phasing of the Azores HP into the south of the UK for the rest of the 14 day period. Ergo the usual N/S split over the UK.

[summer blizzard]

I'm finding the GFS high quite interesting. It's interesting to see that it's already generating cooler uppers that could back west if the Atlantic is weaker. 

 

[Summer Sun]

It's all change from GFS for next week we're back to high pressure again

[carinthian]

On ‎28‎/‎08‎/‎2016 at 17:02, carinthian said:

Hi Tamara, interesting comparison of how the flat jet you mention produces a widely different summer, not only on the bigger view of Europe but more locally. Looking at reports from the UK , I would suggest much of Northern Britain has had a poor summer with regular top of rainfall and lack of heat and sunshine. In the other hand lack of rainfall and increasingly hot summer days in pockets of Southern Britain. However, probably not an usual summer scenario. You mention Scandinavia in the same boat, regions further west and north cool , dull summer and even Stockholm not having the best of summers, yet areas further south , like Malmo receiving pulses of intense heat at times this summer. Here in Austria , a indifferent summer, not the best and after lasts years record heat and drought a bit of a shock.Likewise parts of Germany and France have had great diversity in summer weather. On a more upbeat note for the wider influence of a nice spell of prolonged weather for the British Isles and to include much of Western Europe. There is now positive indications the flow in the Upper Atmosphere will begin to undulate with a greater prospect of warm air advection poleward , with the resultant strengthening of the high pressure zone in the area you have mentioned in your latest analysis. Thanks for all that work you put in your posts and best regards from Austria( still in the influence of the easterly drift, us being on the wrong side of the jet ! )

 C

Following on from what Tamara suggested, I hope this latest air pressure chart comes to fruition for you lot in the UK. We need the initial surge of upper level warm air advection to get there in the first place to buckle the jet flow and send the low pressure systems further north. If this happens a fine spell for most in your part of the world. We on the othe rhand in Central Europe are again on the wrong side of the jet with continued cyclonic flow in evidence.

 C

[knocker]

To be fair I think every run at moment is going to be hit and miss regarding next week because we don't have a clue what effect Gaston will have on the upper level circulation.

 

Edited August 29, 2016 by knocker

[I remember Atlantic 252]

58 minutes ago, Summer Sun said:

It's all change from GFS for next week we're back to high pressure again

That's what I wanna see SS!

[blizzard81]

I do hope the ECM op reverts back to what it was showing up until last night. A nice prolonged dry spell up here is long overdue.

[thestixx]

39 minutes ago, I remember Atlantic 252 said:

That's what I wanna see SS!

These charts are oure eye candy, Therefore I can't imagine they'll verify.... I live in hope though.

[Summer Sun]

No great surprise tonight's ECM has come up with something different again next week until they get a grip on Gaston where going to see some pretty big changes between updates

Could be quite humid and thundery in the SE if this came off

Before that ECM has the lows crossing to the north so the south would see the best in the way of drier spells with these lows were likely to see some warm air pulled up from time to time as well

 

[knocker]

The ecm loses Gaston within the large circulation of the main depression

I casually mentioned Gaston to Sidney this morning..........................

 

Edited August 29, 2016 by knocker

[legritter]

Good evening fellow posters ,just would like to say hello to you all .

I,V had a very busy 12 months caring for my Mother in law ,93 yrs old but a happy old soul .

I,v been catching up today with posters comments and have just had a look at latest charts ,looks like its going to be hard for any near accurate forecast for past this weekend ,i,v got a nagging feeling that for some of us who have had a long dry period now for quite a while [not saying drought like ] that we could see a period of wetter conditions creeping up on us soon .

Some of the charts brings in low pressure ,some keeps high pressure ridging towards us ,I will be checking back from time to time ,a great thanks for usual posters for keeping us all informed ,cheers gangonly joking about the christmas Deer .