Model Output Discussion 26/08/2012

[gottolovethisweather]

Yup you `ve got it mate.Blues(lows) and Yellows(high`s).

But what about the green highs? I assume they are building heights, i.e. not so strong a high. At least I'm learning the fundamentals but I suspect a few are laughing at my inability.

The good thing about the availability of all the varied output, as individuals, our eyes are drawn to specific parts of the globe. Come the winter rush, these hemispherical views are especially useful, so please do continue posting them.

[gottolovethisweather]

i think you will find that those who attempt to do predictions of the time scale involved do use MJO (when its any use, ie not very close to the origin) along with Stratospheric chart predictions to come up with an idea of what the upper flow may be, along with attempting some kind of verification closer in using the 500mb anomaly charts.

Well that is my way anyway!

Just as I intended to say below, John. Many Thanks go to you too with your analyses of the 500mb charts. One question that raises though is, as to where can I find your occasional musings on these, is there a link?

Blimey, sorry peeps, it's like the gottolovethisweather show in here.

[Gael_Force]

Phil, it looks like a battle between Euro high and Scandi high by day 10. Big differences between runs and between models. FI is most certainly at 5 days.

I am going with Scandi high due to MJO phasing and low early season stratospheric mean zonal wind anomalies.

Which way will August go?

(Probably combined euro Scandi high dragging warm uppers from Africa to Svalbard!)

JMA certainly going for the N Scandinavian high in weeks three and four of October.

[sebastiaan1973]

EC32 is showing dry weather in week 3-4 from now. So just like JMA high pressure in the northern part of Europe. Please remind this is according the LT (3 months ahead) forecast of UKMO.

[SMU]

evening all-

I cant see ANY warm weather barring perhaps 1 day out of a couple of settled days if were lucky in the south-

Im surprised none have mentioned the chance of snow showers over the scottish hills at the start of next week-

S

Edited September 28, 2012 by Steve Murr

[Frosty.]

The Gfs 12z op run is looking unsettled for the majority of next week with low pressure moving slowly east to the north of scotland so it will probably be a rather cool feeling week with strong winds at times and showers and longer spells of rain with some sunny spells but then with high pressure building northeast into the uk by the end of next week and a fine weekend, the fine weather continuing into the following week and warming up in southern and central areas as winds become southerly drawing tropical air northwards, but at the same time, much cooler air is attempting to push south so a bit of a standoff developing, the main thrust of cold arctic air diving south through norway so the first wintry blast would be hitting northern norway but the uk tending to have an anticyclonic influence beyond next week, and then the gfs ends with a chart that would be promising snow if we were much closer to winter.

[Gibby]

Good evening. Here is the latest rundown of the output from the big three tonight.

All models continue to show the theme as has been projected on previous runs of Low pressure moving in from the NW following a ridge of High pressure which gives a settled day for many tomorrow. The Low moves only slowly East between Sunday and Wednesday passing near Northern scotland and becoming quite complex. the general theme would be one of sunshine and showers but troughs embedded in the flow would deliver more prolonged spells of rain, particularly towards midweek. Winds will be fresh and cool from a Westerly point throughout this phase.

GFS then takes the Low pressure slowly East towards the end of the week with a cool High pressure area developing over the UK for the weekend. A fair weekend with sunny spells would be likely for all with mist and fog problems night and morning with a touch of frost possible too. In FI tonight the High pressure slips away SE quickly as a sliding frontal wave slips across the South with a band of rain in tow. a sharp temperature gradient would develop over Britain as High pressure ridges down from the NW with a raw Easterly breeze. The end of the run sees High pressure dominant to the North with shallow Low pressure offering rain at times in the South. With High pressures from northern latitudes any clear skies would result in widespread air frost in the North especially.

The GFS Ensembles show the operational as a cold outlier for Northern areas at the end of the run. 850's alternate just above and below the long term mean and all areas will see some rain at times over the period.

The Jet Stream will continue to stream west to east over the Atlantic and the British isles for the next week or so before GFS shows a sharp weakening and breaking up of the flow towards the end of next week.

UKMO for noon on Thursday shows low pressure over Scandinavia with a slackening westerly flow over the UK as a ridge moves slowly towards the UK from the West. A basically showery setup would see these more restricted to Northern and Eastern parts.

ECM shows a band of Low pressure from Scandinavia to the Atlantic at 144hrs with a showery and unstable Westerly flow continuing for a while. As the days pass winds back more towards the South in response to High pressure building to the SE and East pulling warm Southerly winds up across the UK. An East/West split is likely to develop in the strong Southerly flow as Low pressure deepens to the West threatening thundery rain to Western areas later while Eastern areas stay dry, bright and rather warm.

In Summary tonight the weather looks like staying basically unsettled for the next week with showers or longer spells of rain at times in brisk Westerly winds. Laterly the weather could become drier and an interesting division is shown tonight between GFS and ECM. GFS shows a cold incursion of High pressure while ECM keeps High pressure to the East drawing up a warm Southerly feed and although a large High sets up over Scandi at the end of the run the weather lookss like breaking down slowly from the SW.

[Cloud 10]

evening all-

I cant see ANY warm weather barring perhaps 1 day out of a couple of settled days if were lucky in the south-

Im surprised none have mentioned the chance of snow showers over the scottish hills at the start of next week-

S

Maybe mountains rather than hills?

[Liam J]

Liking the ECM 12z run this evening showing a southerly plume dragging warm air up from N Africa - This chart would produce some very warm temps for the start of October, 14-16c isotherms over the UK and right up to the Faroe Islands. Very pleasant indeed, if it were to happen of course!

[ANYWEATHER]

Evening Steve-

The ECM seems pretty keen on some mid-Autumn summeriness from T+168-240, with a stout ridge building over Europe and Scandinavia and stalling trough west of the UK-

Bit far out, I know, but FI is more your domain, am I right?

W

Whats the point for looking for warmth.....In October! Anyway models will backdown from anything warm, like the gfs has done tonight. This scenario has shown countless times this year, only to be ridden by a strong Atlantic jet stream flattenning any high towards the Uk......

[michail]

I'm liking the trend for a southerly tracking jet, even if it does produce warm and wet weather it's the synoptic pattern that i'm interested in. I don't post here often, but i've gotta good feeling about this winters' weather patterns.

[Liam J]

Whats the point for looking for warmth.....In October!

You could ask the same question to those looking for cold & snow already, so early into the autumn - Lets not forget the warmth that the UK experienced last October, the short days made it feel out of place though!

Overall things are looking pretty unsettled for the foreseeable future and fairly typical for the time of year, especially for more northern parts of the British Isles.

Edited September 28, 2012 by Liam J

[Glacier Point]

http://www.esrl.noaa.gov/psd/map/images/reanalysis/aam_total/gltaum.90day.gif

A strong global MT. Tendency in relative angular momentum will respond sending the GWO through phase 4. Signal for anomalous (Branstrator) mid latitude ridges.

The idea of increased mobility is being directly challenged here.

With angular momentum still low, a 10 day periodicity in mountain torque looks likely, so what rises will fall back. But all the same, a meridional pattern looks more likely to prevail when the longer range outputs were suggesting otherwise.

[Frosty.]

duplicated..please delete, sorry

Edited September 28, 2012 by Frosty039

[Frosty.]

The thing that concerns me if the ecm is right would be a similar pattern to last october when we also had a late heatwave with temps touching 30c and then the weather patterns were absolutely dire for cold prospects for many weeks, well into winter actually before we got any cold weather of note, the mid to late autumn was generally very mild, I hope the weather does not have a memory and fancies a repeat. I'm looking for a more amplified pattern to arrive as we go deeper into autumn, as GP said recently..please no repeat of what happened in autumn and early winter last year.

[chionomaniac]

The thing that concerns me if the ecm is right would be a similar pattern to last october when we also had a late heatwave with temps touching 30c and then the weather patterns were absolutely dire for cold prospects for many weeks, well into winter actually before we got any cold weather of note, the mid to late autumn was generally very mild, I hope the weather does not have a memory and fancies a repeat. I'm looking for a more amplified pattern to arrive as we go deeper into autumn, as GP said recently..please no repeat of what happened in autumn and early winter last year.

I don't think that can be ruled out Frosty - hence my small bracketed fear earlier!

[bluearmy]

the cpc charts are settling into a more confident picture tonight and certainly a far from zonal one. we have a west north american ridge into alaska, an east north american trough, blocking around greenland/iceland and azores trough. a long way from winter but no sign of a strong p/v wanting to form as yet.

[Milhouse]

Whats the point for looking for warmth.....In October! Anyway models will backdown from anything warm, like the gfs has done tonight. This scenario has shown countless times this year, only to be ridden by a strong Atlantic jet stream flattenning any high towards the Uk......

Countless times that happened last Summer but that mattered no one bit when it came to late September when a strong high built to the east of the UK. At the moment The ECM mean looks to be favouring a build of high pressure over the near continent so it looks like things will become warmer and/or more settled for many parts next weekend. The GFS 12z builds high pressure further west than the GEFS mean does so it will likely be on the cold side of the ensembles.

[Frosty.]

I don't think that can be ruled out Frosty - hence my small bracketed fear earlier!

I will be very disappointed if that happens chio.

Anyway, the gfs ensemble mean earlier today was hinting at a more amplified pattern from mid october and todays meto update is too, hopefully it will tomorrow.

[Scorcher]

Whats the point for looking for warmth.....In October! Anyway models will backdown from anything warm, like the gfs has done tonight. This scenario has shown countless times this year, only to be ridden by a strong Atlantic jet stream flattenning any high towards the Uk......

Because lots of people like warm conditions whenever they can get them. Some people would like the opportunity to wear t-shirts and shorts maybe one more time this year, in fact most people in the UK I imagine. We're going to have around 6 months of miserable cold temperatures and heated buildings. If anything the ECM has upgraded the warmth it was showing on the last run.

[snowstorm445]

The thing that concerns me if the ecm is right would be a similar pattern to last october when we also had a late heatwave with temps touching 30c and then the weather patterns were absolutely dire for cold prospects for many weeks, well into winter actually before we got any cold weather of note, the mid to late autumn was generally very mild, I hope the weather does not have a memory and fancies a repeat. I'm looking for a more amplified pattern to arrive as we go deeper into autumn, as GP said recently..please no repeat of what happened in autumn and early winter last year.

The weather in Autumn does not determine what happens during winter. In fact, according to GP, a cold outlook for October tends to favour a milder winter, so there isn't much harm having high pressure nearby.

I really doubt we will see the temperatures we saw last October (which was an absolutely vile month btw). Highs of only in the low 20s at least. Bear in mind that the NAO is currently in a fairly neutral phase to neutral phase, which means the normal westerly pattern will probably prevail.

[Scorcher]

I really doubt we will see the temperatures we saw last October (which was an absolutely vile month btw). Highs of only in the low 20s at least. Bear in mind that the NAO is currently in a fairly neutral phase to neutral phase, which means the normal westerly pattern will probably prevail.

And who decided it was a vile month? I enjoyed it personally, barely any cold to speak of. That plume the ECM is showing for next weekend would easily see some areas reaching the mid 20s. Of course it could be gone in the next run.

[snowstorm445]

And who decided it was a vile month? I enjoyed it personally, barely any cold to speak of. That plume the ECM is showing for next weekend would easily see some areas reaching the mid 20s. Of course it could be gone in the next run.

I am allowed to have an opinion. In my part of the world it was constantly wet, windy and mild for the most part. No other pattern to speak of, generally mild muck for its entirety. Given your location I would suspect you got the lion's share of the warmth that month, so it certainly wasn't "vile" for all of us.

BTW, I don't know about you, but I prefer more seasonal weather. While I didn't mind the wind and rain, it was very mild, although not pleasantly so (i.e. dry weather and warmth).

[chionomaniac]

Please now keep opinions to the current model output.

[johnholmes]

Just as I intended to say below, John. Many Thanks go to you too with your analyses of the 500mb charts. One question that raises though is, as to where can I find your occasional musings on these, is there a link?

Blimey, sorry peeps, it's like the gottolovethisweather show in here.

http://forum.netweather.tv/topic/72606-checking-the-500mb-anomaly-charts-against-the-actual-one/page__st__80#entry2369718