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Model Output Discussion 31/05/14 onwards.


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Posted
  • Location: Reigate Hill
  • Weather Preferences: Anything
  • Location: Reigate Hill

The models have had a NH bias for higher pressure for weeks now, initially ECM but recently GFS showing. So any FI build up of pressure is possibly less likely to be relevant than in the past. The Atlantic Ridge forecast of late for next week may be a case in point.

 

GEM now has a very brief ridge from T108 to T156: post-14819-0-08260100-1403761998_thumb.p

 

Then we have that deep area of LP (showing up regularly on most models) moving in, by D10: post-14819-0-35794800-1403762080_thumb.p

 

A fleeting ridge by UKMOpost-14819-0-95440200-1403762159_thumb.g

 

GFS may be overdoing it but most of the UK never really sees the ridge: 

 

T96: post-14819-0-42110500-1403762275_thumb.p  T126: post-14819-0-01862600-1403762311_thumb.p T180: post-14819-0-65108200-1403762339_thumb.p

 

Too early to say if the models trend this morning will continue as the GEFS remain varied. 

 

London ENSpost-14819-0-58307900-1403762589_thumb.g

 

The control and op and about 33% of members support the transient ridge.

 

ECM op remains the most optimistic with the upper Atlantic ridge, maybe lasting around 3 days.

 

By D8: post-14819-0-20934700-1403765004_thumb.g

 

The better next week due to where the Atlantic short wave low moves at D5.

 

ECMpost-14819-0-91489900-1403764943_thumb.g  GFSpost-14819-0-48618600-1403764956_thumb.p

 

However GEM does not even have this short wave and at D3 look at the differences:

 

GEM: post-14819-0-45923700-1403765278_thumb.p  ECMpost-14819-0-47212900-1403765305_thumb.g

 

Lots to be resolved though 4-5 days of lower pressure from today looks to have high confidence. So cooler than of late with more rain with the west and south west currently in the firing line. 5 day totals:

 

post-14819-0-76045500-1403765568_thumb.g  Temps below average for late June for the next 4-5 days.

 

 

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Posted
  • Location: Drayton, Portsmouth
  • Location: Drayton, Portsmouth

Well the models are still bringing in low pressure later next week though via a completely different route now. Wanting to build heights to the north/north east before pulling it towards Greenland and trapping low pressure near the UK.

Interestingly the ECM goes against the GFS/GEM and UKMO and builds heights right over the UK

Posted Image

 

Then again the next frame suggests the same endgame for the UK.

The ECM for next week looks a bit like this week - a narrow victory for a UK ridge. The trend certainly is to try bring troughing over the UK but, leaving this weekend aside, only the GFS really succeeds. I imagine we could end up with mainly settled weather with occasional westerly incursions - though the much deeper low suggested late on by ECM could be a pattern changer if it remains that deep - unclear whether that would make it more or less settled yet, I think? on recent form, it could as easily stall to the west as end up on top of us.
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Posted
  • Location: Derbyshire Peak District South Pennines Middleton & Smerrill Tops 305m (1001ft) asl.
  • Location: Derbyshire Peak District South Pennines Middleton & Smerrill Tops 305m (1001ft) asl.

Yes Heights do try to push in from the S/W at 144, Only to be run down by quite a deep area of Low Pressure off the Atlantic once again. As Imdreaming says lot's to be resolved after day 5.

 

Posted ImagePosted ImagePosted Image

Edited by Polar Maritime
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Posted
  • Location: just south of Doncaster, Sth Yorks
  • Location: just south of Doncaster, Sth Yorks

The 500mb anomaly charts, the last two have had no input from GFS, are not giving consistent guidance at all for 3 or 4 days now. The pattern over this weekend and into the start of next week is fairly clear though. More trough dominated than ridge dominated with a flow from about west, maybe a touch north of west. Beyond that and overall, in spite of the differences day to day and model to model there is no consistent signal for this to change much. No sign yet of any major ridge development affecting the UK area. The flow is relatively light at 500mb so no major surface lows would seem likely.

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Posted
  • Location: Co Clare, Ireland
  • Location: Co Clare, Ireland

I'm not either of your required helpers but here's what phase one looks like for July. The link is here.

 

http://www.americanwx.com/raleighwx/MJO/MJO.html

 

Posted Image

Whether the phase of MJO has any bearing on the weeks ahead is IMO moot while there is such disagreement between

the main model suite.

 

Posted Image

 

Hi Gael

Could you please tell me how to find the last image above. (With the different forecast plots on one image)

Have been searching been searching NOAA MJO products in vain!

Thanks

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Posted
  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

Looking at ECM next week begins on a fairly settled note with the first signs of a change showing on the Thursday in the north west

 

Posted ImagePosted ImagePosted Image

Posted ImagePosted ImagePosted Image

 

By the Friday low pressure begins to move in introducing rain / showers for just about all over this period

 

Posted ImagePosted ImagePosted Image

Posted ImagePosted ImagePosted Image

Edited by Summer Sun
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Posted
  • Location: Cleeve, North Somerset
  • Weather Preferences: Continental winters & summers.
  • Location: Cleeve, North Somerset

Some sort of agreement between the ECM and GFS until Monday. Then the GFS keeps a 'no man's land' scenario until the following weekend whereas the ECM shows a ridge lasting from Tuesday-Thursday. Both models then show a more organised low pressure area taking hold from the 4th but where the ECM takes on it on a more traditional route to the north of the UK, the GFS is keen on it linking up with a Scandi trough and looping further south. Changeable times ahead and needless to say, there is still uncertainty on what happens after Monday. One positive is the lack of heights around Greenland which is better for the Azores high trying to move in in due course. However, this is useless if the angle of the jet is such that cold pools are sent in our direction. All to play for in the coming week!

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Posted
  • Location: Exile from Argyll
  • Location: Exile from Argyll

Hi Gael

Could you please tell me how to find the last image above. (With the different forecast plots on one image)

Have been searching been searching NOAA MJO products in vain!

Thanks

 

Sorry, should have added the link. It is from Levi Cowan's excellent tropical tidbits site - analysis tools section.

 

http://www.tropicaltidbits.com/analysis/

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Posted
  • Location: Camborne
  • Location: Camborne

Probably just repeating what others have said for next weekend.

 

The GFS and ECM anomaly charts don't agree with the GFS giving more intense troughing to the west but either way. The ECM has a general swathe of cold air Greenland/UK/Scandinavia with a large pool of warm air east of Canada nudging into southern Greenland and stretching east into mid Atlantic.

 

The surface analysis from this follows the scenario it was running on the last run. The Bermuda-Azores high pushing up in mid Atlantic with the colder air running around the top giving cyclonic conditions to the north west, and over, the UK. With the sub tropical air in this position the jet is also positioned to the north and running over the UK.

post-12275-0-34085200-1403775161_thumb.p

post-12275-0-11353500-1403775175_thumb.p

post-12275-0-65480100-1403775186_thumb.p

post-12275-0-76996500-1403775196_thumb.p

post-12275-0-16745200-1403775216_thumb.p

post-12275-0-67652900-1403775223_thumb.p

post-12275-0-39630600-1403775231_thumb.p

Edited by knocker
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Posted
  • Location: just south of Doncaster, Sth Yorks
  • Location: just south of Doncaster, Sth Yorks

Looking like on ECM/GFS 8-10 day mean charts that the ECM brings a trough to the north so indicating a north/south split with the southern most areas having the better conditions whilst up north they have it more unsettled as indicated here:http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.htmlNote that GFS don't have an average mean chart for 8-10 days.

 

 

as per my post earlier, do not, as with any chart, take one chart to try and illustrate what the surface pattern may do from a 500mb chart. It is true, with the usual caveat, that the overall pattern one might deduce, from a rather variable set of outputs, from the 3 main anomaly charts, is for unsettled rather than settled in the 6-15 day time scale. However with so much variability in the anomaly charts in the last 3 days I would wait for some continuity before drawing too many conclusions.

my view and of course pj and others are perfectly entitled to give their view.

As always time will tell how reliable the chart show above is.

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Posted
  • Location: Reigate Hill
  • Weather Preferences: Anything
  • Location: Reigate Hill

The GFS 06z showing differences from this morning at short range. The Atlantic short wave handled differently.

 

The 06z: post-14819-0-54388800-1403779996_thumb.p   0z: post-14819-0-51906500-1403780017_thumb.p

 

The net effect is this continues the trend to reduce the heights next week so the 06z op by D6 has the UK back under lower pressure:

 

post-14819-0-79110300-1403780114_thumb.p  Support again from the Control: post-14819-0-84609200-1403780872_thumb.p

 

However  there are just as many GEFS going the ECM route as the GFS op route so uncertainty prevails. Especially as the 06z is an outlier synoptically pressure wise:

 

post-14819-0-79681000-1403782672_thumb.g

 

The latest from the Japanese has the UK under a mean trough in both week 1 & 2:

 

 post-14819-0-80404900-1403780191_thumb.p  post-14819-0-94889700-1403780201_thumb.p

 

So the GFS hi-res runs moving in that direction has some continuity. Looking at the GEM ensembles there is a cluster of about 33% going with the GEFS "progressive" evolution around D6 (trending).

 

So at the moment any respite from lower pressure next week looks between 2-4 days depending on the model. The upcoming changeable spell looks more showery, so hit and miss for many. However the second unsettled spell looks to be more frontal with stalling LP systems also in on the act.

Edited by i'm dreaming of...
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Posted
  • Location: Camborne
  • Location: Camborne

Just whiling away this PM and glanced at the ECM for Tues as one does. It looked quite interesting so had a closer look.

 

The global anomaly has a deep cold pool over the Great Lakes, Greenland and to a lesser extent over Scandinavia with a strong ridge from the Bermuda-Azores high mid Atlantic to the north of Scotland. The jet waltzes around these systems ending up zooming over Northern Europe.

 

Leading to a strong looking area of HP to the west of the UK but alas it is quite transient and gives away to the colder air being generated by the flow south of Greenland.

post-12275-0-32503000-1403802928_thumb.p

post-12275-0-59188500-1403802940_thumb.p

post-12275-0-38801200-1403802947_thumb.p

Edited by knocker
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Posted
  • Location: st albans
  • Location: st albans

from where i'm sitting, the issue is the strengthening atlantic jet next week which energises the  accompanying depression to a far greater extent than we have seen for a long while. it seems that we are a victim of circumstance whereby the dumbelling cold uppers around the ne canadian residual p/v meet a push of warm uppers off the eastern seaboard. (this probably due to the facors as listed by tamara above).  the resultant  jetstreak is timed well to co incide with that bit of p/v headed into the atlantic basin. is this cast in stone? not quite but we are getting to the stage where it soon will be. then it comes down to just how much that system will deepen.

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Posted
  • Location: Darlington
  • Weather Preferences: Warm dry summers
  • Location: Darlington

Looking pretty autumnal on the GFS 12z chart at 240 hours with probably the NW quarter of the country faring worst by the looks of this:

http://www.meteociel.fr/modeles/gfse_cartes.php?&ech=240&mode=0

Fortunately after that there are signs of it settling down after that as was suggested in todays 6-15 day forecast and what GFS has suggested tonight.

 

Once that pulls away we get a return to high pressure

 

Posted ImagePosted ImagePosted Image

 

Towards the end of the mid term met office forecast which goes to July 10th they also hint at less unsettled conditions returning

 

Towards the end of the period, there are signals for conditions to become less unsettled, with drier, brighter weather spreading to at least the southwest of the country.

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

ECM still not buying the UKMO/GFS solution for the start of next week, with the weak Azores ridge building across the UK before collapsing.

Posted Image

Posted Image

It's not keen on pulling the ridge northwards and allowing low pressure to take a more southerly track by undercutting the ridge.

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Posted
  • Location: Camborne
  • Location: Camborne

from where i'm sitting, the issue is the strengthening atlantic jet next week which energises the  accompanying depression to a far greater extent than we have seen for a long while. it seems that we are a victim of circumstance whereby the dumbelling cold uppers around the ne canadian residual p/v meet a push of warm uppers off the eastern seaboard. (this probably due to the facors as listed by tamara above).  the resultant  jetstreak is timed well to co incide with that bit of p/v headed into the atlantic basin. is this cast in stone? not quite but we are getting to the stage where it soon will be. then it comes down to just how much that system will deepen.

 

I would agree with much of that but not happy with the role of a tropospheric PV in summer. I mean why isn't the Great Lakes trough just that and not the residual p/v? There has also been some very warm temps in Alaska recently associated the HP  knockng the jet south and now aided and abetted by the developing deep depression west of Canada.Interesting stuff though.

 

GFS 06z still over-cooking temps in SE -- on other end of spectrum, July starts w/Great Lakes trough & chilly wx pic.twitter.com/xmY9y0Eiar

Edited by knocker
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Posted
  • Location: ipswich <east near the a14> east weather watch
  • Location: ipswich <east near the a14> east weather watch

http://www.meteociel.fr/modeles/gfse_cartes.php?mode=2&ech=6

 

http://www.meteociel.fr/modeles/gfse_cartes.php?mode=2&ech=204

 

 

i  don't  like to bring  bad  news  !!!  but  its looking  like rain all the  way will at least 384  hrs!!!!  at  the moment

Edited by tinybill
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Posted
  • Location: sunny sunny Bournemouth
  • Weather Preferences: Winter: Bartlett style mild and benign
  • Location: sunny sunny Bournemouth

Its worth reviewing this prognosis from a week or so back to check verification and a look at the way forward from here. Predicted changes in the Pacific jetstream have verified, and the jet streak arrived on the Pacific west coast is having the domino effect transferred downstream as associated energy spills across the US and breaks down the recent ridging over the UK to be replaced by the Friday/weekend trough.

 

(rest of post snipped )

 

Thanks for that analysis, Tamara, even if it makes for somewhat concerning reading for those who want a reasonably decent July - if this is the NH pattern setting up for the business end of summer, then could we see repeated Pacific-originating jet streaks reinforcing the downwind pattern that means any attemps at ridging over the UK gets flattened by the next LP? 1988 anybody?

 

Incidently, the dry June was broken on this very day in 1988 and that summer never really recovered....

Edited by Uncle_Barty
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Posted
  • Location: Keyingham, East Yorkshire
  • Weather Preferences: Spanish plumes, hot and sunny with thunderstorms
  • Location: Keyingham, East Yorkshire

Not especially noteworthy but im always one to look for the best in the output so im pleased to say that Monday-Thursday dont look that bad. Temperatures rising to around average and fairly dry before it turns unsettled from the west on Thursday.

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Posted
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet

Models make pretty simple viewing tonight as bar the exact placement of the low there is full consensus at day 8 with all models having the UK under the influence of a low to the north west of the UK..

 

Posted Image

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Posted
  • Location: Camborne
  • Location: Camborne

Having a flight of fantasy this morning and looked at the ECM and GFS upper anomaly for the 7th. Certain similarities with the weak trough east of the UK with the Atlantic dominated by a ridge, The cold air over Scandinavia dissipating and in fact furthe down the line according to the ECM it's gone leaving the Atlantic in a westerly flow. Oh I've just awoken. Another funny dream.

post-12275-0-46146400-1403848485_thumb.p

post-12275-0-64336100-1403848492_thumb.p

post-12275-0-40990400-1403848499_thumb.p

Edited by knocker
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Posted
  • Location: ipswich <east near the a14> east weather watch
  • Location: ipswich <east near the a14> east weather watch

http://www.meteociel.fr/modeles/gfse_cartes.php?mode=2&ech=204

 

hope they got plenty of rain tyes for silverstone  next weekend  might need  then looking at the fantasy weather at the moment

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

Some agreement that the first half of next week will be decent with the UK under a weak ridge of high pressure.

Posted Image

Posted Image

ECM and UKMO are in pretty decent agreement up to day 6. The GFS and GEM try to push the low towards the UK, again the GEM most bullish, unfortunately it has had a bias for this evolution for months now. On the other hand the ECM looks mostly dry even into Friday next week.

Posted Image

Just some rain for the north, becoming warm in the south

 

ECM then goes very typical ECM by trying a very ambitious cut-off low attempt over the UK, that's not going to verify :p

Edited by Captain shortwave
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