Model output discussion - hot spell beckons but then what?

[mushymanrob]

1 hour ago, Mattwolves said:

Do I detect a little desperation in your posts Karl!! That's not like you, posting deep FI charts of cool, unsettled and autumnal conditions at 14 days out!! Highly unlikely to verify... Which I'm sure you're aware of. The week ahead looks decent away from the North... Warm sunny spells and showers, some places obviously missing them.. More general rain for Friday which will quickly clear to sunny spells and some showers for the weekend!! What I am noticing over the last few days, is plenty of blue sky gaps, and reasonable sunny spells. Perhaps it's not worth the hassle of taking those day 10-14 charts with much credence. 

oh i dont know.... the charts karl posted might not come off in their entirety, but there are strong signals that they wont be far off...


as for the weekend...



doesnt look very good to me..

[weirpig]

2 minutes ago, mushymanrob said:

oh i dont know.... the charts karl posted might not come off in their entirety, but there are strong signals that they wont be far off...


as for the weekend...



doesnt look very good to me..

yep  as it stands  Unsettled and cool looks the most favourable as we stand     however  the summer has of yet hasnt been that bad around these parts   

[MATTWOLVES 3]

3 minutes ago, mushymanrob said:

oh i dont know.... the charts karl posted might not come off in their entirety, but there are strong signals that they wont be far off...


as for the weekend...



doesnt look very good to me..

Sunny spells and showers don't look to bad to me... Obviously more unsettled further North... What amazes me is how folk will post 10-14 day charts in summer stating how unsettled it is!! Yet when the same cold and snow charts are posted in winter at that range... You instantly get laughed at for posting fi charts that will never come off!!!! Totally bemused by it all. Still a decent final 3rd prognosis from exeter.... Long way off though... But good to see all the same. 

[mb018538]

26 minutes ago, Mattwolves said:

Sunny spells and showers don't look to bad to me... Obviously more unsettled further North... What amazes me is how folk will post 10-14 day charts in summer stating how unsettled it is!! Yet when the same cold and snow charts are posted in winter at that range... You instantly get laughed at for posting fi charts that will never come off!!!! Totally bemused by it all. Still a decent final 3rd prognosis from exeter.... Long way off though... But good to see all the same. 

You can't really compare the two - extreme heatwaves in summer and cold/snowy conditions in the winter usually require highly amplified weather patterns that highly deviate from the UK norm.....and as such are often volatile in nature and aren't properly resolved until much closer to the time. You'd quite rightly want more certainty....we've seen with the heatwaves recently ho much ensemble spread and noise you get. An entrenched period of low pressure domination and a southerly tracking jet can be forecast with much more certainty:



Hence why right out to day 8-10 you've got tight ensemble banding. Forecasting is all about probability and certainty, and at the moment we've got that. You just don't get usually that with potential heat/cold set-ups.

Edited August 5, 2019 by mb018538

[Frosty.]

Looking through the GEFS 6z there are less very disturbed members and more hints of azores ridging or indeed high pressure popping up in various timeframes, again the south is more favoured to take advantage of this during the final third of august but I remain hopeful that we will all see a good end to the meteorological summer and start to autumn!

Edited August 5, 2019 by Jon Snow

[mushymanrob]

1 hour ago, Mattwolves said:

Sunny spells and showers don't look to bad to me... Obviously more unsettled further North... What amazes me is how folk will post 10-14 day charts in summer stating how unsettled it is!! Yet when the same cold and snow charts are posted in winter at that range... You instantly get laughed at for posting fi charts that will never come off!!!! Totally bemused by it all. Still a decent final 3rd prognosis from exeter.... Long way off though... But good to see all the same. 

it depends on whether charts at that range have any further support.

the noaa 500mb charts are the most accurate for their timeframe (6-14 days) (and when consistent)  according to research carried out by john holmes. ive followed that method and i find it to be pretty much accurate. of course NO model suite of any kind is 100%, but more often then not, the anomaly charts do identify the most likely general synoptic pattern between ridging/troughing and the mean upper flow for the periods they cover (6-10, 8-14 day). of course we can only comment on what current data is actually predicting, and that is subject to change, but there is nothing currently in any model suite or anomaly chart or anything at all as far as im aware that suggests anything but unsettled for the next two weeks.

in winter its about point scoring and so many trying to be the next guru of spotting cold. so common sense and sobriety leaves the room (as do i) as the hordes play 'spot the next cold spell game'. so hopes are pinned on unsupported operational runs that show something that they want to see. this isnt as bad in summer.

personally, i view the anomaly charts first, then match the nearest operational run to them. i find that gives a more accurate balanced indication of whats most likely to evolve, and cuts out the inter run/model suite 'upgrades' 'downgrades' mularkey that usually proves pointless.

[knocker]

Quite an interesting day with some quite large Cu, some high Sc and some sunny intervals. At times the Cu looked like it was going to dump a heavy shower but didn't and the midday sounding sums this up with the Cu probably topping out at around 6,000ft where the Sc also resides

Edited August 5, 2019 by knocker

[Frosty.]

Before the 12z runs I thought I would quickly mention the Gem 0z which shows an improvement in the run up to mid August with pressure rising, at least for a time, especially across southern uk!

[mountain shadow]

7 minutes ago, Jon Snow said:

Before the 12z runs I thought I would quickly mention the Gem 0z which shows an improvement in the run up to mid August with pressure rising, at least for a time, especially across southern uk!

If that's an improvement, things must be really bad!

[cheese]

8 hours ago, Summer Sun said:

Still plenty of summer warmth to be had this week it will be unsettled at times but if you manage to avoid the showers it will be nice enough remembering of course it's early August and the sun is still strong

Indeed SS - while people on this thread are practically slitting their wrists over potential weather next week, this week is looking pleasant for most of the country with temperatures in the low to mid 20s. Risk of showers of course but they are hit and miss.

Think people need to get out a bit more. 

Edited August 5, 2019 by cheese

[knocker]

The gfs is deepening the low at the end of the week quite considerably near the left exit of the jet. IIt will be interesting to see the ecm take on this, let alone Exeter

Edited August 5, 2019 by knocker

[weirpig]

Tight clustering  on the ensembles  gfs 12z   for the  next week  or more they all seem  to be in agreement  cool and mixed weather   with uppers around 5c  it's hard to believe it's the height of summer    towards the end there is a slight recovery  for around average temps     

Edited August 5, 2019 by weirpig

[MATTWOLVES 3]

UKMO take on low pressure come the end of the week.. This looks quite intense, it clears to the East by the back half of the weekend, so perhaps a better day for some on Sunday. In the shorter term, some serious heavy Downpours devoloping quite widespread tomorrow afternoon... I would expect further warnings to be issued regarding this before much longer!! Showers on Wednesday look more scattered, but still some places could end up with quite a soaking. 

[Frosty.]

The Gem 12z provides a bit of respite from all the rain with pressure briefly rising towards mid month but then a low swinging down from iceland puts an end to that..  This is certainly an unsettled extended outlook with bands of rain interspersed with brighter, showery spells and an occasional transient ridge..as for this week, not so bad, some warm sunshine and scattered heavy showers but Friday looks wet and windy from the southwest followed by sunshine and heavy showers.

Edited August 5, 2019 by Jon Snow

[MATTWOLVES 3]

19 minutes ago, Jon Snow said:

The Gem 12z provides a bit of respite from all the rain with pressure briefly rising towards mid month but then a low swinging down from iceland puts an end to that..  This is certainly an unsettled extended outlook with bands of rain interspersed with brighter, showery spells and an occasional transient ridge..as for this week, not so bad, some warm sunshine and scattered heavy showers but Friday looks wet and windy from the southwest followed by sunshine and heavy showers.

Personally Karl I think it's to far off to be concerned with... Out to day 10 perhaps it stays unsettled... Beyond that is subject to anything. You mention a low swinging down from Iceland beyond mid month... So very unlikely to pan out that way... I'm staying more focused with the 5-7 day range, it's less stressful mate...

Edited August 5, 2019 by Mattwolves

[mb018538]

That low pressure is a bit of a beast....980mb in early-mid August is very unseasonable. 

Saw some nice graphics showing the TPV starting to cool down....3 weeks time our friend the PV will have officially reformed for the season!

[Frosty.]

Essentially beyond this week the GEFS 12z mean is indicating a predominantly north / south split with at least some azores ridging at times for the south meaning it's less unsettled for southern uk compared to further north but certainly some rain and showers further south but north / northwest uk (especially scotland) bears the brunt of the Atlantic systems.

Edited August 5, 2019 by Jon Snow

[Methuselah]

It doesn't really look as if the late-run warmup has much support within the ensembles though, karl...?

   

   

But you never know -- it might be a nascent trend?

[knocker]

The ecm take on the low

[ICE COLD]

Saturday is looking pretty wet and windy nationwide. Autumn’s coming and we no what comes after autumn . (Silly season) . 

[knocker]

Just a slight digression but when considering August storms it is 40 years, almost to the day, from when the Fastnet disaster occurred ,

Edited August 5, 2019 by knocker

[Gael_Force]

11 minutes ago, knocker said:

Just a slight digression but when considering August storms it is 40 years, almost to the day, when the Fastnet disaster occurred ,

Remember it well: was sent to report on the rescues. If I'm allowed to stray for a moment, a bit of archive coverage.

https://www.yachtingworld.com/features/fastnet-race-1979-storm-122408

 

[knocker]

This may also be of interest

The Fastnet storm of 1979: A mesoscale surface jet

https://rmets.onlinelibrary.wiley.com/doi/pdf/10.1002/j.1477-8696.1997.tb06319.x

[MATTWOLVES 3]

I'm gonna frame this ECM day 7 chart and hope and prey that these Greenland heights are going to be this promising come December... Great heights all the same.... Very good for that - NAO.. 

Edited August 5, 2019 by Mattwolves

[damianslaw]

Not great output for the foreseeable - its August and the atlantic is stirring, par for the course.. some localised downpours possible through tomorrow, more showery on Wednesday and Thursday with temperatures near average, come Friday a deep low for the time of year swinging in from the SW bringing some temporary warmth to SE and east parts, before cooler conditions move in from the NW over the weekend, accompanied by heavy rain and squally showers - not great for the middle of the school holidays.

Looking further ahead, more atlantic driven weather, a cooler trend as well with the jet digging south, heights to the NW, low pressure and troughs moving down from the NW.. Such synoptics are far more likely in August than during the April-July period, for NW parts the month marks the start of the 6 -7 month wet season!