Model Output Discussion 31/07/14 onwards.

[ANYWEATHER]

I noticed PM that on the 6-10 day and 8-14 day output that the below average heights have been removed slightly, however to the north they'll be slightly more unsettled conditions. In two weeks time however it looks like everywhere will get more settled conditions and who knows September may be better than august?

Put the tropical disturbance on the case whose knows......    

[lorenzo]

Picking around 144 for this one as a whole lot going on in the mix.

 

Really solid Scandi High anomaly showing through, interesting to get that in the pattern, some ensembles would have the place foaming at the mouth with hints of eastern promise later in the year.

 

It's a pity the ECM clusters don't go out further than the 120 hrs, still 4 solutions in play at day 5.

 

Also some questions hidden within GFS 12z ensembles -this 24-36 hrs before the re-appearance of summer to launch Autumn.

 

Wonder what delights the pub run comes up with, on par with the 00z at present on verification, 06z still miles off, 12z holding it's own there or thereabouts with UKMO at present.

 

 

 

 

 

[knocker]

I didn't include GEM in my earlier post it's much along the same lines

 

[bluearmy]

next weekends ECM ens graph from the 12z had very few damp runs, yet the 00z pulls out another depression to cross us. It was looking like the onset of the school term would coincide with a return of summer. (It often does). Yet the 00z runs have thrown a curve ball in general.

Is it the succession of ex TD's coming into the Atlantic basin that are creating a lack of continuity in the NWP?

[IDO]

Looking at the D9 GEFS it is hard to find two similar members. Lots of players moving pieces and the GEFS come up with a plethora of options. The London ensemble graph shows the LP system moving in tomorrow and we don't really recover pressure till the end of the week. Good support amongst members for this:

 

 

Surface wise we have weak heights north of Scotland and a slack flow of lower pressure running through the south till next Sunday:

 

  

 

Average temps at best with showers on a westerly flow. By Sunday the GFS 0z op has an attempt to build the ridge again. This is clearly a background signal but keeps getting delayed, Next Sunday:

 

 

With the trough to the west far from stable and the Tropical Storm about to interact then I couldn't be sure that the Azores Scandi link will initiate.

 

GEM for instance links the storm with the Greenland trough and barrels it into the Northern half of the UK:

 

 

 We had the great uncertainty with Bertha pre and post so these nice FI HP charts should not be banked yet. 

 

For instance ECM now keeps lower pressure in charge right out till D9:

 

 

 

It looks like another case where we will be seeing flip flopping for D5+ charts till mid-week at least.

 

 

 

Edited August 24, 2014 by i'm dreaming of...

[knocker]

next weekends ECM ens graph from the 12z had very few damp runs, yet the 00z pulls out another depression to cross us. It was looking like the onset of the school term would coincide with a return of summer. (It often does). Yet the 00z runs have thrown a curve ball in general.Is it the succession of ex TD's coming into the Atlantic basin that are creating a lack of continuity in the NWP?

 

As i noted yesterday the GFS Tropical is not going for settled weather next weekend apart from a brief transient ridge. mind there is a huge amount of uncertainty about the track of the TD.

Edited August 24, 2014 by knocker

[ANYWEATHER]

Well yet again, another example of a Tropical depression making mockery of the model output. Quite opposite to just 24 hours ago.!

[Blessed Weather]

^ Yes Anyweather and I'm dreaming of. Big differences in how the models handle ex tropical storm 96L. Whilst this morning’s ECM 0z shows a similar track and evolution as described in my post yesterday, in the space of 24 hours it has delayed matters by 48 hours. Meanwhile the GFS 0z is having none of it, showing ex-96L fizzling in the Atlantic, whilst GEM, as I'm dreaming of describes, “barrels it into the northern half of the UKâ€.

ECM 0z (the low to the south of Greenland) and GFS 0z (the low in mid Atlantic) 850 hPa charts for 3^rd Sept:

 

 

[knocker]

As others have said astonishing turn about with the anomaly charts for the weekend particularly the ECM although the GFS briefly follows.

 

 

Edited August 24, 2014 by knocker

[draztik]

As anyweather points out, given that the models are being 'tormented' by the track of the little gremlin - models will be jumping about all over the place. Highlighted by yesterdays ecm and this mornings. I mean, the difference is rather shocking. In any case, temps do seem to be on the way up associated w/ lp systems. Tho, tonight we may see HP spreading it's wonders over us. Best get your ticket, it's gonna be bumpy.

Edited August 24, 2014 by draztik

[knocker]

The GFS 06 has an upper and surface low over the UK on Saturday. In fact it has lows queuing up.

[Polar Maritime]

06z is still showing the transient affair, As Knock says Lows queuing up off the Atlantic, But for now Model'd as pushing over the far North of the UK as per the Jet Stream. What-with the Atlantic firing Lows towards us with both barrels, Many more runs are needed for any clarity. Very interesting Model watching all the same with this mix of ingredients.. 

 

Edited August 24, 2014 by Polar Maritime

[knocker]

All GEFS ensembles at 06z were out to sea. pic.twitter.com/I4QpsvYKEn

[summer blizzard]

All GEFS ensembles at 06z were out to sea. pic.twitter.com/I4QpsvYKEn

 

Indeed although the NHC have rubbished the GFS and backed the Euro-UKMO-NAVGEM track and strength.

[Cloud 10]

All GEFS ensembles at 06z were out to sea. pic.twitter.com/I4QpsvYKEn

 

The ECM is "out to sea" regarding this TD at the moment when comparing the day 7 00z and 12z charts.

 

 now you see it..   now you don't..

[knocker]

Indeed although the NHC have rubbished the GFS and backed the Euro-UKMO-NAVGEM track and strength.

 

True there is much doubt going around see Jeff Master's blog.

 

http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=2774

 

THE GFS 12z

 

 

Edited August 24, 2014 by knocker

[Frosty.]

Tonight's Ecm 12z run shows high pressure pushing down from the north this week and briefly settling our weather down but after midweek it turns unsettled again from the west, however, by next weekend it shows an improving picture from the south as high pressure tries to build north eastwards which should bring drier, brighter and warmer weather at least to the south / southeast, a brief unsettled blip follows as a shallow trough drifts across the uk but then we may finally see more generally anticyclonic conditions develop, the chart for 3rd september looks very nice and I have a feeling we will see an upturn in fortunes during the first half of september following a disappointing august..july was superb, I hope september can bring back the feel good factor..it will if the last frame of tonight's ecm run is anything like because it's a PEACH...I know a few on here won't want high pressure to return but I think the majority will and i'm not ready to give up on summery weather until october.

[vladthemert]

True there is much doubt going around see Jeff Master's blog.

 

http://www.wunderground.com/blog/JeffMasters/comment.html?entrynum=2774

 

THE GFS 12z

 

 

Thanks Knocker I wonder if it follows Bertha track although I am mindful of reading the article, a lot uncertainty which likely effect tracking and intensity in that Jeff Masters blog.

 

Just looked at Noaa latest on Cristobal 

 

http://www.nhc.noaa.gov/text/refresh/MIATCDAT4+shtml/241453.shtml?

[knocker]

Again looking at the anomalies for next weekend and further afield but after last night this is no time to be definitive.

 

NOAA, GFS and the ECM all appear to be going for the upper low around the North sea area with ridging to the west from the Scandinavian and Azores HP. This low would appear to be a pretty transient affair as it soon gives way to high pressure from the Azores with strong positive anomalies to the north. While in transit the surface analysis follows the same route with low pressure over the UK on Saturday giving way to the Azores HP. No point in looking at the temps until this analysis firms up or, after last night, doesn't.

Edited August 24, 2014 by knocker

[Mark Bayley]

Models indicating a possible pleasant start to September with a weak high pressure system building north eastwards from the south west. Meanwhile an unsettled start to this coming week, followed by pleasant day Wednesday, and thereafter an unsettled end to the week. Too early to say what the rest of September will hold. MJO remains in low amplitude so can't take much guidance from that. Ensembles suggest higher than normal pressure to be centred to the north of the UK. 

 

Edited August 24, 2014 by Mark Bayley

[ANYWEATHER]

No surprise tonight' with an exceptional model dissagrement........ Anyway, the models are addiment on at least a week of unsettled weather, the rest will be......

[mushymanrob]

Again looking at the anomalies for next weekend and further afield but after last night this is no time to be definitive.

 

NOAA, GFS and the ECM all appear to be going for the upper low around the North sea area with ridging to the west from the Scandinavian and Azores HP. This low would appear to be a pretty transient affair as it soon gives way to high pressure from the Azores with strong positive anomalies to the north. While in transit the surface analysis follows the same route with low pressure over the UK on Saturday giving way to the Azores HP. No point in looking at the temps until this analysis firms up or, after last night, doesn't.

 

a very fair analysis, the anomaly charts do suggest the scandi/north/northeastern upper high builds again much as it has done all year.  so after an unsettled week there is scope for a return to more settled conditions as we enter september/autumn.

[knocker]

Quick look to see if there are any surprises this morning.

 

The GFS ens has the low a bit further north on Saturday and the ECM ops has it much firther north wirh the south under the influence of the HP.

 

Edited August 25, 2014 by knocker

[IDO]

Again the models showing for the end of the week the jet splitting allowing an opportunity for pressure to build after the coming weeks westerly flow:

 

 So by Sunday: 

 

The GFS op then keeps us in an upper ridge till around 5th September:

 

D8   D10

 

The flow is not going to bring us highs like July but above average from the Midlands South likely. As the D10 GEFS mean shows there is now a trend for HP to build over the UK:

 

D8: D10  D12: 

 

So the mean showing around a 4-5 day pressure rise for the UK on the GEFS from week 2. Its nice when models start to agree and D8 from the GEM:

 

 and D10: 

 

Like the GEFS there are issues as to where the upper ridge builds and how strong it is, which has a knock on affect to the surface high. Therefore the GEM is not as warm as the GFS. ECM still struggling with its D8-10 charts and it's more a N/S split:

 

D8   D10: 

 

It is different to GFS and GEM in how it handles the Tropical storm at D5. It sends it into the jet: 

 

And the flow eases over the UK ridge preventing any amplification of the upper flow. GEM and GFS stall the Tropical storm south of Greenland, the WAA builds up the UK ridge and we get a more sustained pressure build:

 

GFS  GEM Navgem 

 

It looks like the Euro's are in harmony with UKMO also going for the Storm to interact with the jet: 

 

Interesting to see if GFS can again out  perform the Euros when it comes to pattern changes.

Edited August 25, 2014 by i'm dreaming of...

[Polar Maritime]

Interesting to see if GFS can again out  perform the Euros when it comes to pattern changes.

 

Yes I'm dreaming.. The GFS has been very consistent with it's longer term signals lately. Again this morning continuing to show High Pressure building for the South at the turn of the Month. ECMWF still showing the same broad theme within it's later time-frame, After picking the signal up yesterday.

 

Edited August 25, 2014 by Polar Maritime