Jump to content

Model Output Discussion 12hrs. 01/10/13


Recommended Posts

Latest from Gibby almost an extension to summer as Autumn remains on hold, though we must watch out from fog which at this time of year could be stubborn to clear

 

Hi everyone. Here is this morning's account of the midnight outputs of GFS, UKMO, GEM, NAVGEM and ECM for today Wednesday October 2nd 2013.

All models show a warm South to SE feed across the UK between High pressure over Europe and Low pressure to the West and SW. A trough of Low pressure is clearing North and East over Eastern and Central areas with a brighter and more showery interlude before another active frontal feature carries heavy and thundery rain North and somewhat East through the day tomorrow. Winds then turn to a briefly cooler and fresher Westerly with showers before pressure builds from the SW in time for the weekend which looks largely dry and bright with some warm sunshine in light winds with a little cloud and rain along with a moderate SW breeze in the far NW.

 

GFS then shows High pressure slipping steadily East but maintains a ridge towards the north of the UK which allows some unseasonably warm surface air to waft over the South of the UK from a warm Continent. With a short sea track in the South there should be plenty of warm sunshine by day but if mist and fog forms overnight it could become stubborn to clear in the morning's which would result in lower temperatures. Little rain is expected next week for nearly all areas away from the far NW and SW later as a cut off Low down near the Azores may throw a few showers ahead of it and then more generally North and East across all areas late in the run as temperatures fall somewhat.

 

UKMO points to a dry spell too next week as the weekend High slips towards SE Europe but maintains a ridge across the UK with the same continental feed as GFS shows keeping conditions bright and warm for the time of year with little chance of rain.

 

GEM is slightly less straightforward though the basic pattern is similar with the difference be that a pocket of unstable air feeds in from the West into the flow and gives the South and west the risk of a few showers at some stage early next week before the SE flow develops in response to High pressure to the East sliding further SE late in the run.

 

NAVGEM is less supportive of a SE feed next week instead keeping winds from a SW point which would be a good deal cloudier with Low pressure close to the NW for a time. Some rain could be expected towards the North and West while Southern areas stay dry and mild though less so than some of the other output. At the end of the run High pressure to the SE throws a ridge NW with fine and dry weather for all with mist and fog at night likely should it verify.

 

ECM today is a little slower in developments with a SW flow and some rain in the NW early next week before High pressure to the SE is superseded by High pressure to the NE with a ridge South from it's centre allowing a exceptionally warm SE feed up across the UK from the Med. It would become very warm in the South with sunny spells though as with GFS it is all dependent on whether fog formation is limited by night. If it is not then clearances of this each morning could become slow and arduous making a big dent in the temperatures where it stays foggy, misty or cloudy.

 

The GFS Ensembles mostly continue with a warm and quite dry outlook with the South seeing most of the dry conditions beyond this week. Only a handful of members opt for anything cooler with the mean for the period keeping the warm side of average for nearly all areas throughout. The operational and Control runs both were milder outliers in the latter stages of the run, maintained in the South.

 

The Jet Stream today is blowing over Northern France. It weakens and turns North over the next few days before breaking up and then realigning to the NW of the British Isles as the High pressure develops close to SE Britain at the weekend. It then continues to blow in this general region well away from the UK and maintaining the UK on it's warm side.

 

In Summary today it looks almost like an extension to Summer from the synoptic pattern this morning. We must not be carried away though by the prospect of fine, settled and unseasonably warm weather next week as such conditions are fraught with danger in October in the shape of mist, fog and low cloud which if forms can be stubborn to clear and give a completely different complexion to the conditions and temperatures. However, as shown with a short sea feed to the SE the SE wind would be quite dry and would give us our best shot of seeing some very warm sunny spells and unseasonably high temperatures especially in the South and West. There are few other factors shown this morning that could spoil what will be yet another dry and fine spell with only the far NW and SW possibly at risk of a few showers at times as the High erodes late in the output period. Once again the absence of any major depressions and accompanying strong winds is all too obvious this morning so Autumn as we used to know it remains on hold this morning.

 

http://www.norton-radstockweather.co.uk/Model-Analysis(2859336).htm

Edited by Summer Sun
  • Like 4
Link to post
Share on other sites
  • Replies 1.3k
  • Created
  • Last Reply

Top Posters In This Topic

No change from yesterday then, only difference being the rather toasty ECM run which brings some very warm uppers along with some nice continental winds. Would see temperatures back in the 20's off that run.

ECM mean well shows no signs of any breakdown

Posted Image

 

Posted Image

Mean uppers also up to 8C now so in the sun the temperatures will be above average by day, maybe some cool nights though under clear skies.

  • Like 1
Link to post
Share on other sites

I would say low to potentially mid 70's F for the south & east and potentially low 20's c for the north and west would be summery by early to mid october standards, the near continent, the azores and southern europe is still very warm and that is where our air will be coming fromPosted Image these are the best charts you could wish for at this stage of the autumn..huge potential with an anticyclone becoming centred to the east enabling a warm flow.

Temps look more like 18-20c in the south and 16-18 in the midlands. The charts are over exaggerating things IMO.
  • Like 1
Link to post
Share on other sites

I would say low to potentially mid 70's F for the south & east and potentially low 20's c for the north and west would be summery by early to mid october standards, the near continent, the azores and southern europe is still very warm and that is where our air will be coming fromPosted Image these are the best charts you could wish for at this stage of the autumn..huge potential with an anticyclone becoming centred to the east enabling a warm flow.

So you say that its gonna be 21c and sunny here next week? Right... Well i'm not gonna bet on that happening.
  • Like 2
Link to post
Share on other sites

I would say low to potentially mid 70's F for the south & east and potentially low 20's c for the north and west would be summery by early to mid october standards, the near continent, the azores and southern europe is still very warm and that is where our air will be coming fromPosted Image these are the best charts you could wish for at this stage of the autumn..huge potential with an anticyclone becoming centred to the east enabling a warm flow.

 

And as CS pointed out yesterday, a double bonus is that massive high is dragging cold arctic air into Northern Scandinavia and Russia. Exactly where we want it now for those playing the long game. I've no interest in getting a cold outbreak to the UK in the immediate future: it's wasted.

  • Like 6
Link to post
Share on other sites

Temps look more like 18-20c in the south and 16-18 in the midlands. The charts are over exaggerating things IMO.

 

I think there's still plenty of warmth left in the tank yet. Thank fully.

  • Like 3
Link to post
Share on other sites

 

GFS 18z run really is showing a rinse and repeat pattern of what we have had since Humberto headed across the Atlantic last month. (Of course i'm not saying it will definitely happen as it shows tonight, as there will never be an "exact" repeat)

 

So...it's currently showing...

  • Trough heads towards the UK, bolstering the high which transfers into Europe bringing mild air originally from the SW, swinging round to a flow from the continent
  • Low pressure system heads NE grazing NW parts.
  • Secondary Low forms and dives to the SW of the UK. Becomes sluggish and begins to fill in
  • Another system starts sliding down towards the Low that is filling in to our SW.
  • Question is...will it then do another push of rain up from our South, similar to what we are having over the next couple of days?

Also, an interesting post from 10 days ago, because in my view, snowking, as well as others, have been very close, if not spot on many times this year. And so far this little summary from him below seems to be on track so far?? (I'm not brown-nosing honest! From a learning perspective, I just enjoy scanning through posts from over a week before to see how people's views have panned out) 

 

----------------------------------------------------------------------------------------------------------

 

Posted Image Posted by snowking on 21 September 2013 - 13:57 in Forecasting Model Discussion

MJO Phase 6 signature (increasingly unsettled) beginning to be reflected in the days 5-10 NWP output. Expect some further swings for a couple of days yet as I imagine NWP is probably still having a little difficulty in resolving the energy fusing in to the jet stream from Humberto. Hopefully in to Monday/Tuesday a more consistent signal should begin to appear...and unfortunately that consistent signal looks as though it will be an unsettled one.

 

The next shot at something more settled currently around days 15-25, with little coherent MJO or GWO signal as both tropical convection and global angular momentum fall to average levels...this is not a guarantee of settled conditions, merely the best chance of such conditions.

 

Beyond that there is a growing trend from OLR plots to introduce something around phases 1/2/3 through the second half of October - all three of which suggest something rather unsettled.

 

So as a rough timetable based upon current projections:

 

27th Sept - 5th October - Unsettled

6th-16th October - Something more settled?

17th October Onwards - Unsettled once again

 

Timings are of course approximate

 

SK

 

-----------------------------------------------------------------------------------------

 
 
I hope he doesn't mind me referencing his comments in this post Posted Image

 

 

No problem at all sir Posted Image

 

I was going to come back to this at the end of the week to see how it had panned out based around the forecast OLR from mid-September and it looks to have panned out reasonably well if current NWP verifies as shown.

 

There is quite a lot of work related to the MJO and GWO going on behind the scenes at the moment and both myself and Lorenzo, along with a few others, are running some experiments for October as a whole with the possibility of some new composites being created based upon the outcome of these.

 

Anyway, back to the here and now, pretty universal agreement out to day 10 for high pressure to build and stay there across much of England and Wales from ensemble means:

 

Posted ImagePosted Image

 

Though as the newly created composites suggest, with OLR forecasts suggesting a low amplitude Phase 1/2 MJO towards the middle of October, we could well end up with a more North/South split, with low pressure close to the North of the UK, and high pressure close to the South - almost a classic +NAO type signal:

 

post-1038-0-28535800-1380704231_thumb.gipost-1038-0-17144100-1380704257_thumb.gi

 

So a North/South split is not entirely out of the question here as we head towards the middle of this month, but before then the low amplitude phase 7 composite sums things up nicely (ignore the dates):

 

post-1038-0-72580400-1380704440_thumb.gi

 

SK

  • Like 9
Link to post
Share on other sites

Temps look more like 18-20c in the south and 16-18 in the midlands. The charts are over exaggerating things IMO.

 

Yeah these look realistic temperatures from all the models and associated temp charts i have looked at. Anyone quoting temps into the mid 70s is just making it up IMO.

  • Like 2
Link to post
Share on other sites

I think there's still plenty of warmth left in the tank yet. Thank fully.

Yes Gaz it looks like we are going to squeeze every drop of warmth out before anything significantly changes..Posted Image

 

PS... Top Post snowking, as usualPosted Image

 

Finally, there is a risk of localized flooding later tonight & tomorrow in some western/sw parts of the uk with torrential thundery rain, 60 to 80 mm is possible.Posted Image

 

But beyond that, high pressure all the way with warm summery weather incomingPosted Image

Edited by Frosty.
  • Like 2
Link to post
Share on other sites

Superb ECM 00z ensemble mean with high pressure building and building and intensifying all the time, it creates a major block with low pressure floundering in the atlantic and high pressure to the east with a very warm continental flow constantly drifting up across the uk, air originating across spain/n.africa, so it would be very much on the warm side, the mean actually becomes even warmer towards the end with a very settled benign, sunny and warm pattern as we head towards mid october. There is no end in sight to this pattern either, BBQ in mid october..BOOMPosted Image Posted Image Posted Image 

post-4783-0-50521300-1380711169_thumb.gi

post-4783-0-24516500-1380711178_thumb.gi

post-4783-0-57879200-1380711196_thumb.gi

post-4783-0-86898000-1380711206_thumb.gi

post-4783-0-73343300-1380711220_thumb.gi

post-4783-0-56733800-1380711230_thumb.gi

post-4783-0-91145600-1380711241_thumb.gi

post-4783-0-32936800-1380711259_thumb.gi

post-4783-0-35647400-1380711266_thumb.gi

post-4783-0-06194000-1380711278_thumb.gi

post-4783-0-11767100-1380711290_thumb.gi

  • Like 3
Link to post
Share on other sites

Short term, GFS runs this morning have shown tonight/tomorrows main pulse of heavy rain to move on a more NE path across the S/SE now, rather than the SW and Central areas? Met Office still sticking to a swathe of it across most parts.

Another main band still situated across the west of England & Wales, parts of Ireland and Scotland.

Edited by Chris K
Link to post
Share on other sites

The GFS 06z op run shows short term pain and long term gain, at least through the high res, a lot of heavy and potentially thundery rain spreading north and east across the uk during the next 24-36 hours with localized flooding and as much as 3 inches of rain in places but once all that has cleared out of the way, the azores high builds in and settles our weather down through the weekend and more particularly throughout next week with a good deal of pleasantly warm and sunny weather, temperatures generally close to 20c give or take a degree or two, the warmth sometimes offset by a freshening E'ly to SE'ly breeze as the anticyclone drifts further northeast. 

 

This run just gives a very general view of how things will improve, I think it will turn out warmer and settled for longer than this operational run shows, i'm basing this opinion on the ecm 00z ensemble mean which is an absolute corker.

 

I posted the ecm 0z ens mean charts further up this page, unfortunately, the 6z charts won't load.Posted Image

Edited by Frosty.
  • Like 2
Link to post
Share on other sites

GFS 06z ens shows the high lasting well into next week for many it doesn't ease away until t264

 

There is just 72 to 96 hours until the high arrives now and once its here it isn't in a rush to leave

 

Posted ImagePosted ImagePosted ImagePosted ImagePosted ImagePosted ImagePosted Image

 

From t264 it slowly backs away

 

Posted ImagePosted ImagePosted ImagePosted Image

 

Apart from some possible fog during early morning next week looks like been another stunner with lots of settled warm weather around with temperatures widely in the high teens to low 20's

 

The beeb will probably call it "very mild" but I'm going to call it warm its too early for "mild" yet November to March is the time for that

 

A frosty Bank to end

 

Posted Image

  • Like 5
Link to post
Share on other sites

To be honest it's hardly summery really, just normal September/October weather. Grey days followed by some warmer days interspersed by spits and spots of rain.....last year was virtually the same in my neck of the woods if a little wetter. Describing it as summery can be a little confusing to new people who are getting to grips with the charts. Might be warmer and more summery the further south you go but here 'oop north it's not necessarily so.

 

I'd say this post is more misleading personally, high teens/low 20s is not usually described as 'normal' October weather. We've actually had it very good up here recently- in fact over the weekend it was sunnier here than in the South East for example. If we get a southerly we tend to do very well in NW England.

  • Like 3
Link to post
Share on other sites

I'd say this post is more misleading personally, high teens/low 20s is not usually described as 'normal' October weather. We've actually had it very good up here recently- in fact over the weekend it was sunnier here than in the South East for example. If we get a southerly we tend to do very well in NW England.

Spot on Scorcher, there is nothing in common with last year when the azores high generally remained at home, this year is chalk and cheese, the azores high has been and continues to be our friend, the upcoming fine spell looks as though it will be a noteworthy addition to all the other meteorological highlights this year.Posted Image

  • Like 2
Link to post
Share on other sites

GFS 06z ens shows the high lasting well into next week for many it doesn't ease away until t264

 

There is just 72 to 96 hours until the high arrives now and once its here it isn't in a rush to leave

 

Posted ImagePosted ImagePosted ImagePosted ImagePosted ImagePosted ImagePosted Image

 

From t264 it slowly backs away

 

Posted ImagePosted ImagePosted ImagePosted Image

 

Apart from some possible fog during early morning next week looks like been another stunner with lots of settled warm weather around with temperatures widely in the high teens to low 20's

 

The beeb will probably call it "very mild" but I'm going to call it warm its too early for "mild" yet November to March is the time for that

 

A frosty Bank to end

 

Posted Image

 

That high pressure is well... GIGANTIC!!!!!!!

  • Like 1
Link to post
Share on other sites

That high pressure is well... GIGANTIC!!!!!!!

 

That is exactly why once it arrives it will take a while to shift

 

The ECM ensemble has it in charge still at day 10

 

Posted Image

 

GFS ens at the same time

 

Posted Image

 

The ECM ensemble would keep that high in place longer than GFS ens

  • Like 2
Link to post
Share on other sites

Keep it coming I say.. However...

 

Posted Image

 

Surely this would draw in a cold easterly?

No because there is no cold air to tap into, mainland europe continues warm or very warm and the SST's are still high.

  • Like 1
Link to post
Share on other sites

Keep it coming I say.. However...

 

Posted Image

 

Surely this would draw in a cold easterly?

 

Don't worry about easterlies for now the weekend just gone had a south easterly and that saw temps widely in the high teens with sunshine

 

It will be 4 to 6 weeks minimum before they deliver colder air

  • Like 1
Link to post
Share on other sites

Don't worry about easterlies for now the weekend just gone had a south easterly and that saw temps widely in the high teens with sunshine

 

It will be 4 to 6 weeks minimum before they deliver colder air

Yep there has to be a few potent cold plunges into europe first and there is no sign of that occuring, I think the formation of this huge euro high will hurt the start of the european & scottish skiing season if it persists for a prolonged period, it could prove very reluctant to depart.

Edited by Frosty.
  • Like 1
Link to post
Share on other sites

UK Outlook for Monday 7 Oct 2013 to Wednesday 16 Oct 2013:

The more settled theme will continue into the start of the new working week. Many areas will be dry, with light winds and sometimes large amounts of cloud, but with some sunny spells after any morning fog clears. Northwestern parts are likely to be unsettled and breezy with rain at times, some of which may well be heavy. Daytime temperatures will be close to or just above average, and rather warm in places. However, nights will tend be colder than of late. Through the rest of the week, the unsettled weather in the northwest may push gradually southeastwards across the UK, though the far southeast may remain largely dry and fine. The following week will probably be largely unsettled, particularly in the northwest, with most places having some rain.

MetO persisting. Until this changes, this "prolonged" spell being suggested is not guaranteed

  • Like 2
Link to post
Share on other sites

UK Outlook for Monday 7 Oct 2013 to Wednesday 16 Oct 2013:The more settled theme will continue into the start of the new working week. Many areas will be dry, with light winds and sometimes large amounts of cloud, but with some sunny spells after any morning fog clears. Northwestern parts are likely to be unsettled and breezy with rain at times, some of which may well be heavy. Daytime temperatures will be close to or just above average, and rather warm in places. However, nights will tend be colder than of late. Through the rest of the week, the unsettled weather in the northwest may push gradually southeastwards across the UK, though the far southeast may remain largely dry and fine. The following week will probably be largely unsettled, particularly in the northwest, with most places having some rain.MetO persisting. Until this changes, this "prolonged" spell being suggested is not guaranteed

 

Those suggesting the settled spell will last 10+ days are mistaken IMO, we are lucky to get that in July. Its october and things can change very quickly.

Edited by Joe8987
  • Like 1
Link to post
Share on other sites
Guest
This topic is now closed to further replies.
×
×
  • Create New...