Model Output Discussions 12z 01/06/2017

[Singularity]

  

The model output is too chaotic beyond Wednesday to make it worth saying much so I might as well go with the wildest proposition; from the day 9-10 ECM 00z and GFS 06z charts, I can easily envision the trailing frontal boundary down west of Iberia triggering formation of a low in that area with a ridge over Europe, this coinciding with a lot of heat having piled up over much of Europe as a result of the 'cyclone cannon' firing large troughs N. of there - with subtropical airmasses flung east across Europe - over the preceding 4-5 days. A sequence seen all-too often in the winter months!

Odds are those troughs won't be as deep and the initial build of European heat less dramatic, but this also improves the chances of at least southern parts of the UK seeing some hotter days in early August.

As I said, this is a wild proposition and requires a sizable dose of luck (or bad luck if you don't like heat), but I couldn't think of anything else really worth adding to that already covered by others this morning . Of course even this broad idea has been floating about on here for a few days now, to which I say - well spotted! 

Edited July 23, 2017 by Singularity
Seasonal Similarities

[Frosty.]

It's all a bit meh really when you think back to what the outlook from mid July was indicating by the seasonal models ( prolonged settled and very warm) but it's all gone pete tong. Tuesday looks mainly dry with warm sunny spells but the general pattern is changeable / unsettled with temps mainly on the cool side of average but occasionally a bit warmer across the s / se..Looking into August, there is mention of possible high pressure towards mid month with temps on the warm side of average but the general theme is for a continuation of the current pattern.i.e..changeable / unsettled, especially further north-west with a mixed bag of temperatures ranging from below average / average for most of the uk.

Edited July 23, 2017 by Frosty.

[Singularity]

http://www.theweatheroutlook.com/twodata/chart.aspx?chart=/charts/gfs/12_150_mslp850.png?cb=119

The Atlantic though is a nice distance further north and a bit west on this run. Going to need a pretty big shift from ECM to boost confidence in a fine weekend for much of England, though.

Edited July 23, 2017 by Singularity

[draztik]

26 minutes ago, Singularity said:

http://www.theweatheroutlook.com/twodata/chart.aspx?chart=/charts/gfs/12_150_mslp850.png?cb=119

The Atlantic though is a nice distance further north and a bit west on this run. Going to need a pretty big shift from ECM to boost confidence in a fine weekend for much of England, though.

Indeed; especially considering the outlook from the recent update of the UKMO 12z. 

[northwestsnow]

7 minutes ago, draztik said:

Indeed; especially considering the outlook from the recent update of the UKMO 12z. 

Yes need to see the back of that horrid blocking high over Greenland before there is any hope of the jet moving north..

 

[Frosty.]

1 minute ago, northwestsnow said:

Yes need to see the back of that horrid blocking high over Greenland before there is any hope of the jet moving north..

 

Funny isn't it, a horrid blocking high over Greenland in summer becomes a wonderful blocking high in winter with a southerly tracking jet.

[blizzard81]

1 hour ago, Frosty. said:

Funny isn't it, a horrid blocking high over Greenland in summer becomes a wonderful blocking high in winter with a southerly tracking jet.

Always the wrong way round though. 

[Frosty.]

Well, The Gfs 12z shows high pressure building in across the uk during early August..Yes I know it's deep FI but there are also hints from Exeter of a high during the same period!..

Edited July 23, 2017 by Frosty.

[Frosty.]

There is also support from the GEFS 12z for high pressure to build in during early August with increasingly warm, dry sunny weather across the uk so the op isn't alone..and there are others which show ridging too..hopefully a growing trend! I'm not even bothered about anything hot.. anticyclonic warm and sunny would suit me following a changeable generally less warm spell.

 

Edited July 23, 2017 by Frosty.

[Weatherlad50]

11 minutes ago, Frosty. said:

There is also support from the GEFS 12z for high pressure to build in during early August with increasingly warm, dry sunny weather across the uk so the op isn't alone..and there are others which show ridging too..hopefully a growing trend! I'm not even bothered about anything hot.. anticyclonic warm and sunny would suit me following a changeable spell.

 

Two fine days this week followed by rain on Wednesday.  Brighter on Thursday with showers thereafter a cool and unsettled weekend. I don't believe the settled forecast for early august as it's too far off with poor gfs verification. Let's see at end of the week what the models say

[Fourty Point Three Degrees]

Awful charts with an awful southern Jet that cant get North.. Topsy turvey weather - just cast your minds back to January, not a jet stream in sight for the whole month and the sunniest and driest January for a long time with a pleasant mild SW'ly.  Now if that was July..

[mb018538]

To be fair to the Met Office, if you keep calling heads and it lands tails, eventually you'll be right....

In the here and now things have shifted slightly more towards unsettled for all at eh weekend. The runs showing the SE holding on are sim now, and the form horse is unsettled everywhere. Looks like the shorts will be staying in the wardrobe for my holiday next weekend!

[Man With Beard]

Having had a bit of a wobble yesterday, it seems the original idea in the models of a deep low just off Scotland is back as a firm favorite. I'd question if even the south would escape an ongoing influence from the low, though its in the balance down here. Further north, there really is nothing promising about the D3-D10 period on the models tonight.

I don't pretend to understand the ins and outs of the teleconnections or science behind why, but i do sense there are periods where the models tend to correct north as they come into the reliable and periods where they correct south (probably something going on in the atmosphere that they haven't quite understood yet). Having had a long period of correcting north, I now sense the models are in a period where they are correcting south. That means minor ridges over the UK at T200-T300 being flattened habitually by T120/T144. If I'm right with my hunch, it would mean we have flipped into an unsettled period - the dartboard low of this weekend being the tipping point. We've seen in past summers that such period can last for a few weeks, which would be tragic just at the point when most people's summer holidays are kicking off. Let's hope for a little bit of luck, a bit more of a fight from a Scandi high (as was hinted at yesterday and still shows on the GFS), and maybe some freak development to halt the Atlantic train. Because my "hope" barometer has now fallen into the "pessimistic" range.

[knocker]

After a chilly Monday down the eastern half of the UK as the low moves away east, and a warmer more benign Tuesday, the ecm has a rather elongated (west-east) upper trough in the Atlantic by 12z Wednesday which dictates the configuration of the associated  deep surface low.  The fronts of which are lying across the UK making the day wet and windy particularly in the north.

By Thursday 00z the fronts have tracked north east into the North Sea leaving the UK in a showery westerly but the main Atlantic low is is on the move east and filling and by Friday 12z is just north of Scotland At the same time more upper  troughs have been fed into the Atlantic on the Canadian conveyor belt so another surface low is tracking rapidly ENE to bring rain to the UK on Saturday and showers in the westerly airstream on Sunday after it passed through.

So all in all a pretty unsettled week, which continues to the end of the run, with the usual caveats that this will include dry and pleasant interludes which will as usual have a very much N/S bias.

[Fourty Point Three Degrees]

40 minutes ago, Frosty. said:

There is also support from the GEFS 12z for high pressure to build in during early August with increasingly warm, dry sunny weather across the uk so the op isn't alone..and there are others which show ridging too..hopefully a growing trend! I'm not even bothered about anything hot.. anticyclonic warm and sunny would suit me following a changeable generally less warm spell.

 

When its 72 hours within a reliable timeframe i'll believe it

[CK1981]

1 hour ago, Frosty. said:

Well, The Gfs 12z shows high pressure building in across the uk during early August..Yes I know it's deep FI but there are also hints from Exeter of a high during the same period!..

I think we can now take what Exeter says with a huge pinch of salt. Keep up the good work though, Frosty. Hopefully this subtle shift in the models will bear fruit down the line!

[Singularity]

ECM and UKMO show a setup conducive to gales, maybe even severe in the case of ECM, in just 3 days time, when GFS and GEM have it little more than very breezy!

It comes down to a feature with some tropical characteristics that swings into the upper trough and deepens substantially. The precise track of this makes a big difference to how windy it is Wed-Thu (and how wet for western parts on Thu). 

Not only that but it makes it harder to get much of a ridge in Fri-Sun although ARPEGE still looks to be having a fair go of it as of +114 despite having the low close to the ECM position at +72.

At the moment, regarding next weekend's pattern, GFS is in my opinion the best fit for the GLAAM state, but ECM is the best for the rampant C-Pacific trade winds.

As those trades finally look to ease off during said weekend, there is more chance of improvement early-mid next week. ECM and GFS hint at this but with little conviction at this time (and ECM day 10 is just plain rude given the day 9 - give us a break why don't you!  ). That being the difference between our current fortunes with near-neutral GLAAM and when GLAAM goes into a low orbit of the GSDM during these summer months, which is when a longer lasting unsettled period  tends to occur.

I know it all sounds rather tenuous but the fact is we have recently been thrown from the sunny path into the dark jungle and are now struggling to find an escape route while wondering just how much unpleasantness waits in the shadows! 

[draztik]

Op & EPS singing from the same hymn sheet this evening... into mid-term*

days 6-10 & 5-10 height anom.

*important to point out, there are signals appearing, days 11-15 from the EPS of a more settled spell being established with a relaxation of the jet, w/ heights building to the NW of UK... tho temps don't look anything special, at this stage at least. Something to keep an eye on.

 

Edited July 23, 2017 by draztik

[draztik]

Just now, Frosty. said:

Can't really argue with that but the hope is that further into august will bring a spell of high pressure, I would hate to think that there is nothing left to hope for this summer.

I made a quick edit... to suggest just that

[ANYWEATHER]

Hi Folks , I would love to put lipstick on the model output in the next ten days but alas I cant The truth is that we have had a fantastic start to summer below rainfall and well above average temps for most but of course not for all! Its normal British summer folks so some rain but some very pleasant spells of fine weather . remember you only have to get the sun on your skin at this time of year for about three hours and you will get burnt.....Im sure there is more than three hours of sunshine for all of us in the days ahead

[knocker]

Last night's anomalies indicate no significant pattern change in the immediate future. Without looking at the whole pattern the key features as far as we are concerned are low pressure over the Arctic with trough to northern canada which in turn serves as a conduit to the trough centred to the NNW of the UK. Ergo still a strong westerly jet with the Azores suppressed, apart from transitional bursts, all of which is aided and abetted by ridging and positive anomalies over Greenland.

Back to the gfs this morning which essentially is just a repeat of previous assessments with just detail variation. After a pleasant day tomorrow weds sees the elongated trough dominating the Atlantic to the north west with the associated fronts crossing the UK so a fairly damp day for all.

The fronts quickly pass trough giving way to a showery westerly in the North and the Azores ridging NE in the south. Meanwhile the upper trough to the NW is getting more organised and being 'topped' up by the conduit to Canada thus by Friday midday there is a complex low pressure area over the eastern Atlantic.

With this low pressure loitering to the west, being occasionally reinforced, this portends a pretty unsettled weekend with showers and the odd more organized spell of rain. This continues into next week before the next system arrives on Tuesday. The usual caveats apply to the interpretation of unsettled and  it goes without saying the NW/SE bias applies. Temps variable around the average and again the bias will reflect this.

[knocker]

The overall pattern with the ecm this morning is not a million miles away from last night's eps anomaly.

[northwestsnow]

13 minutes ago, knocker said:

The overall pattern with the ecm this morning is not a million miles away from last night's eps anomaly.

And if its settled warm weather you want look away now, ties in with Tomasz on the Beeb last night, pretty much no end in sight to Atlantic driven weather,meanwhile much of Europe is baking...the mainlanders must love the uk trough as all the heat sweeps NE from spain bypassing the UK.

Tbf he did mention the SE may well escape much the Atlantic gunk being on the very periphery of the plumes heading into France Germany Poland etc..

Edited July 24, 2017 by northwestsnow

[knocker]

11 minutes ago, knocker said:

The overall pattern with the ecm this morning is not a million miles away from last night's eps anomaly.

I can't edit the post above but I posted the wrong nh chart. I meant to post this morning's det for comparison

[northwestsnow]

4 minutes ago, knocker said:

I can't edit the post above but I posted the wrong nh chart. I meant to post this morning's det for comparison

Pretty much echos my post above, Europe in the cooker, pretty much , apart from maybe Iceland and the uk..