Jump to content
IGNORED

Model Output Discussion 12z 08/07/13


Recommended Posts

Posted
  • Location: Nuneaton,Warks. 128m asl
  • Weather Preferences: Snow then clear and frosty.
  • Location: Nuneaton,Warks. 128m asl

A new thread then ready for the 12z model runs.

The usual requests to please keep on topic and respectful to other members.

 

I know we all have our preferences wrt weather but remember this thread is to talk around what the models actually show.

Any other type of views should go into the Model moan and ramp thread here-

http://forum.netweather.tv/topic/76235-model-banter-moans-and-ramps/

 

A reminder there is also our more in-depth Model discussion thread here-

http://forum.netweather.tv/topic/76236-in-depth-model-discussion-and-summaries/

 

OK then please continue below. Posted Image

 

Link to comment
Share on other sites

  • Replies 1.2k
  • Created
  • Last Reply

Top Posters In This Topic

Posted
  • Location: Nuneaton,Warks. 128m asl
  • Weather Preferences: Snow then clear and frosty.
  • Location: Nuneaton,Warks. 128m asl

I am sure many of us are enjoying this real taste of Summer and It looks like the heat may last until  the weekend before the high starts to ease back towards the Azores early next week.

This trend has been discussed by a number of us and again shows up in the 00z mean outputs.

post-2026-0-29501400-1373298077_thumb.gipost-2026-0-27742900-1373298089_thumb.gi

 

we can see we will pick up some fresher/cooler feeling Atlantic air next week as the westerly flow spreads in,more noticeable of course further north.

The Aberdeen and London ens graphs show pressure falling off somewhat next week as this evolution gets underway.

post-2026-0-34821300-1373298105_thumb.pnpost-2026-0-69242200-1373298114_thumb.pn

 

Still a decent looking setup for many of us though, a lot of dry weather with some sunshine but more cloud around especially further north where we are likely to see some frontal systems brushing across at times.

Edited by phil nw.
Link to comment
Share on other sites

Posted
  • Location: Peterborough
  • Weather Preferences: Snow and frost in the winter. Hot and sunny, thunderstorms in the summer.
  • Location: Peterborough

Stand off between the GFS and UKMO continues, neither budging really.

Posted Image

 

UKMO sending troughs well to our north and keeping things settled and warmer on Sunday.

Posted Image

 

GFS still wants to develop trough in Scandinavia which brings cooler North Westerlies.

Link to comment
Share on other sites

Posted
  • Location: ILCHESTER
  • Location: ILCHESTER

12GFS remains pretty much in line with the 06, albeit not quite so cool (even cold) across the north on Sunday, but the trend is there for all to see.  Maxima in the teens, perhaps low 20's looks the mark for most by then and even on Saturday any heat over Scotland and N Ireland looks set to be a distant memory. FI however (that's the bit we ignore when not showing what we want) still wants to go for another reasonable strong pressure rise from the SW later next week, so at this stage we may well be looking at a blip rather than a pattern change, but getting HP to the east and a spell of hot, continental weather still looks like an outsider for the 2nd half of July.

Edited by shedhead
Link to comment
Share on other sites

Posted
  • Location: leicester
  • Location: leicester

Ukmo 12z is a beauty and gfs is better than its 06z!!looks like this hot weather is going to carry on till well into next week!!currently friday/saturday look like two scorchers of a day for england and wales!!maybe 30-32 degrees in quite a few places!!

Link to comment
Share on other sites

Posted
  • Location: St Albans, 95m asl
  • Location: St Albans, 95m asl

I suspect the GFS is, once again, picking up the correct solution, just bringing it in a little too early

 

MJO forecasts now heading straight for phase 7 (i had suspected a phase 5-6-7 transition instead), from the UKMO (MOGREPS):

 

 

Posted Image

 

And the bias-corrected ECMWF:

 

Posted Image

 

Given the <1 amplitude for the next 7-10 days not much offer of help from either the MJO or the GWO, but a stronger signal for MJO phase 7 (very similar to phase 5 - trough dominated upper pattern as opposed to recent ridging) also reflected in the mean height anomalies today:

 

Posted Image

 

With a pretty flat looking upper pattern towards days 8-10, and troughing perilously close to the NE of the UK.

 

We're not talking deluges here, but it looks to be headed back to the more typical pattern for the summer so far - unsettled, sunshine and showers type - by day 10. The ECM postage stamps today, having been so consistent in the lead up to this settled spell, are also now showing in 3 clusters - two thirds of which promote something more low-pressure dominated.

 

The ECM Glasgow ensembles help to illustrate this too:

 

post-1038-0-38268100-1373301544_thumb.pn

 

Shown above are Tmax and Rainfall projections from the last 3 ECM ensemble runs - a pretty consistent picture of temperatures returning to average values, whilst precipitation amounts also increase towards average.

 

Birmingham ensembles also displaying similar characteristics.

 

We may end up with a North/South split, but I think there is an inevitability into week 2 that most of us lose the settling influence of the Azores HP, and return to something we have become more accustomed to in recent years.

 

SK

 

Link to comment
Share on other sites

Posted
  • Location: ILCHESTER
  • Location: ILCHESTER

Ukmo 12z is a beauty and gfs is better than its 06z!!looks like this hot weather is going to carry on till well into next week!!currently friday/saturday look like two scorchers of a day for england and wales!!maybe 30-32 degrees in quite a few places!!

Even if the UKMO verified as shown, 30-32c would be very unlikely anywhere across the UK this weekend, 27-29c would probably be top of the shop imo and even then only in a very few favoured locations.

Edited by shedhead
Link to comment
Share on other sites

Posted
  • Location: Wilmslow, Cheshire
  • Location: Wilmslow, Cheshire

but getting HP to the east and a spell of hot, continental weather still looks like an outsider for the 2nd half of July.

 

Why do we need this to happen though? We're in quite a hot spell now (most of us anyway) without HP to the east, it doesn't necessarily have to happen for us to get very warm/hot conditions and we could still end up with an above average month for temperature and sunshine without it happening. I still think the GFS may be being too progressive- a spell of north-westerlies does look likely at some point, but I don't think it will arrive for most before the weekend. The UKMO hasn't exactly come into line with the GFS this evening, it will be interesting to see what the ECM produces later.

Link to comment
Share on other sites

Posted
  • Location: ILCHESTER
  • Location: ILCHESTER

Why do we need this to happen though? We're in quite a hot spell now (most of us anyway) without HP to the east, it doesn't necessarily have to happen for us to get very warm/hot conditions and we could still end up with an above average month for temperature and sunshine without it happening. I still think the GFS may be being too progressive- a spell of north-westerlies does look likely at some point, but I don't think it will arrive for most before the weekend. The UKMO hasn't exactly come into line with the GFS this evening, it will be interesting to see what the ECM produces later.

I agree, it doesn't, but there has been some talk of this happening on here and at present that call looks wide of the mark. SK's post above pretty much says it all, there is almost certainly going to be a breakdown for all of us either later in the weekend or early next week (again tho it's all relative), but what isn't quite so clear is how pronounced it will be and how long it will last.

Link to comment
Share on other sites

Posted
  • Location: leicester
  • Location: leicester

Even if the UKMO verified as shown, 30-32c would be very unlikely anywhere across the UK this weekend, 27-29c would probably be top of the shop imo and even then only in a very few favoured locations.

Hopefully ecm will back the ukmo later on!!
Link to comment
Share on other sites

Posted
  • Location: Peterborough
  • Weather Preferences: Snow and frost in the winter. Hot and sunny, thunderstorms in the summer.
  • Location: Peterborough

Breakdown starting this weekend. Saturday likely to be the last 25c. It looks like that could be where things are heading.

GFS yes, UKMO no. Though I think a front will pass through Saturday evening so Sunday would be cooler. UKMO would be pleasant for all and GFS would be pretty chilly in the north and exposed Eastern areas.

GEM is backing UKMO

Posted Image

Edited by Captain shortwave
Link to comment
Share on other sites

Posted
  • Location: Savoy Circus W10 / W3
  • Location: Savoy Circus W10 / W3

Breakdown starting this weekend. Saturday likely to be the last 25c. It looks like that could be where things are heading

Last 25c for when where and for how long - forever ? till next year ? Is winter starting next week ?

Link to comment
Share on other sites

Posted
  • Location: Savoy Circus W10 / W3
  • Location: Savoy Circus W10 / W3

I suspect the GFS is, once again, picking up the correct solution, just bringing it in a little too early

MJO forecasts now heading straight for phase 7 (i had suspected a phase 5-6-7 transition instead), from the UKMO (MOGREPS):

We may end up with a North/South split, but I think there is an inevitability into week 2 that most of us lose the settling influence of the Azores HP, and return to something we have become more accustomed to in recent years.

 

SK

Hi SK,

 

I really appreciate your posts and I think your written explanation of methodology / reasoning is also improving as you get more posts under your belt (if you do not mind me saying so). I also appreciate that you do not fence sit and you do have your theories as to where things are headed and I also think that comes across well in your posts. I may disagree with you, with respect to the amount of faith you place in some of these signals but I do respect your methodology.

 

Regards

 

Steve

Link to comment
Share on other sites

Posted
  • Location: st albans
  • Location: st albans

Those two MJO plots, if anything close to verifying, would mean we lose any help from the MJO going forward as the amplitude is very low. it may be frustrating to have to wait but i'm afraid thats what you're going to need to do wrt to late sat and sunday. planty of signs that things could pick up again even if the trough does make inroads further sw. worth popping back on here tomorrow evening after the 12z's are all out to see what solution the models have settled upon.

Link to comment
Share on other sites

Posted
  • Location: St Albans, 95m asl
  • Location: St Albans, 95m asl

Hi SK,

 

I really appreciate your posts and I think your written explanation of methodology / reasoning is also improving as you get more posts under your belt (if you do not mind me saying so). I also appreciate that you do not fence sit and you do have your theories as to where things are headed and I also think that comes across well in your posts. I may disagree with you, with respect to the amount of faith you place in some of these signals but I do respect your methodology.

 

Regards

 

Steve

 

Very kind words and thank you very much :)MJO and GWO obviously only have a limited use (i.e. where BA points out above obviously that below an amplitude of 1 the links to composite climatology are limited) but part of what drives my medium range outlooks is the projection of those signals beyond day 10. Match the expected progression of either the MJO or GWO (for which composites are less convincing at present - the Recretos composites will prove very handy in years to come) to ensemble mean forecasting, and confidence in a forecast can improve drastically.

 

I had sat in frustration for 10 years trying to find a complimentary technique to use alongside ensemble means just to give an indication of how believable their signals are, and in the last two or three years (thanks to the guidance of GP and countless others, not of course forgetting those over on the stratosphere thread) i've found this method to produce some pretty good results for anything out towards 30 days - and then more recently i've been dabbling in longer range stuff, but thats a whole other story....

 

Anyway, thanks once again!

SK

Link to comment
Share on other sites

Posted
  • Location: Fazendas de,Almeirim, Portugal
  • Weather Preferences: The most likely outcome. The MJO is only half the story!
  • Location: Fazendas de,Almeirim, Portugal

Interesting and valuable technical insight into how the pattern might unfoldPosted Image My own little interpretation was that the fine spell would be very slow to erode (longer than 10 days) with the south west especially holding onto to the best of the weather for longest.

 

So there is a test here to see how factors play out and how the models handle them

 

The EPS members at day 7 do show some inroads of low pressure further north east and the High pressure is further west and less influential on most of the members, but (at least at that time) the bulk still have high pressure close enough by for many southern and western areas. I wonder if the breakdown might still be handled a little too progressively yet?Posted Image

 

Posted Image

Edited by Tamara Road
Link to comment
Share on other sites

Posted
  • Location: Truro, Cornwall
  • Weather Preferences: Winter - Heavy Snow Summer - Hot with Night time Thunderstorms
  • Location: Truro, Cornwall

I think what can be said is that right now, we are not looking at troughs slap bang over us, perhaps a time in no mans land really. Although MJO amplitude is low, fwiw phase 7 in July indicates slightly lower than average pressure especially just to our west but strong heights to our east. Potential for further hotter spells should the MJO hold any clues?

Link to comment
Share on other sites

Posted
  • Location: Sunderland
  • Weather Preferences: Hot Summer, Snowy winter and thunderstorms all year round!
  • Location: Sunderland

a couple of posts creeping into the discussion hinting at a breakdown this weekend and inference of the fine spell coming to an end....hmm...sorry, but I'm just not seeing it on the GFS12z output, all I see is a shortwave trough heading SE through the north sea and into the Benelux countries at T111 to T126 (and thus bordering on the realms of FI) giving some showery outbreaks, possibly thundery, to eastern districts which then quickly disappears as the azores high ridges in from the south west giving generally dry and warm to very warm weather for the bulk of the UK for subsequent time frames. Only at the very end of the run do heights rise over Greenland sufficently for the Azores HP to drift south westwards allowing troughing to dig towards the UK, and even then it will be a NW/SE split with the bulk of England enjoying a continuation of warm & dry days

Link to comment
Share on other sites

Posted
  • Location: N.Bedfordshire, E.Northamptonshire
  • Weather Preferences: Cool not cold, warm not hot. No strong Wind.
  • Location: N.Bedfordshire, E.Northamptonshire

Well the output looks like it shows some fluctuation in temps and cloud for most but the overall impresson is cloudy or sunny it will be warm for *most* and if not warmer again in a few days.

Link to comment
Share on other sites

Posted
  • Location: North East London (E4) 147ft
  • Location: North East London (E4) 147ft

Why do we need this to happen though? We're in quite a hot spell now (most of us anyway) without HP to the east, it doesn't necessarily have to happen for us to get very warm/hot conditions and we could still end up with an above average month for temperature and sunshine without it happening. I still think the GFS may be being too progressive- a spell of north-westerlies does look likely at some point, but I don't think it will arrive for most before the weekend. The UKMO hasn't exactly come into line with the GFS this evening, it will be interesting to see what the ECM produces later.

Indeed - good post. I have never grasped this obsession with HP to the east. The current set up is plenty hot enough (borderline too hot today in the working week) and leads to sustained dry conditions.
Link to comment
Share on other sites

Posted
  • Location: North East London (E4) 147ft
  • Location: North East London (E4) 147ft
a couple of posts creeping into the discussion hinting at a breakdown this weekend and inference of the fine spell coming to an end....hmm...sorry, but I'm just not seeing it on the GFS12z output, all I see is a shortwave trough heading SE through the north sea and into the Benelux countries at T111 to T126 (and thus bordering on the realms of FI) giving some showery outbreaks, possibly thundery, to eastern districts which then quickly disappears as the azores high ridges in from the south west giving generally dry and warm to very warm weather for the bulk of the UK for subsequent time frames. Only at the very end of the run do heights rise over Greenland sufficently for the Azores HP to drift south westwards allowing troughing to dig towards the UK, and even then it will be a NW/SE split with the bulk of England enjoying a continuation of warm & dry days
Agree - looks a pretty warm outlook for most of the population of the UK. Surprised to see so many members jumping about the breakdown train at this stage. Edited by Jackone
to tidy up quote
Link to comment
Share on other sites

Posted
  • Location: Slough
  • Location: Slough

Last 25c for when where and for how long - forever ? till next year ? Is winter starting next week ?

Obviously this spell, hardly a difficult one to guess is it. Until when who knows.
Link to comment
Share on other sites

Guest
This topic is now closed to further replies.
×
×
  • Create New...