Model Output Discussion 31/03/14 onwards.

[IDO]

Last night's ECM  op as suggested had limited support for temperature and the suite's mean isn't really running with it:

 

 

 

GFS this morning maintains its overall consistency, with the trough sliding over the UK for the next 8-10 days.

 

 

GEM sends the AH painstakingly slowly towards the UK taking most of the run to find a long enough interlude in the flow of the trough to enable ridging: 

 

Not saying GFS is right as it is clearly very complicated, ECM's recent runs suggest that. There appears to be weak heights to our N/NE and the AH trying to ridge N or NE along with the upper flow from the NW into the lower heights in the Med. How these all interact probably means the surface conditions are very fluid.

 

 

 

 

[knocker]

There is no consensus at all on next weekends analysis. I did the ECM last night (not seen the latest as yet) so a glimpse at what the GFS is offering. Well.

 

A markable different upper air for a start with a north/south split with a high to the north and low to the south of the UK leaving the latter in a NW/SE orientated weak trough. Not good as it translates as wet. Totally different to last nights ECM so I would keep Mystic Meg on speed dial

 

A touch more detail although I feel it a tad pointless at this stage. Still be bold.

 

Friday

Low west of Ireland and generally unsettled and wet for most of the UK.

 

Saturday

Similar situation with frontal troughs crossing the UK bringing wet weather to everyone on an easterly airstream

 

Sunday

The low has slipped down to Biscay but the easterly flow persists continuing the unstable situation with much rain about.

 

Monday

The low has slipped further down to the Med. And the Azores high is taking a peak in the SW but the UK still in a slack easterly with, surprise, a fair bit of rain.

 

I’ll give the temps a miss.

 

Edited May 23, 2014 by knocker

[Chris K]

Well...with the Jet Stream modelled to take a southerly dive with Spain in it's sights, it leaves the UK in a sort of "no mans land" in doing so. The trough in the vicinity of the UK wants to take a bloody long time to show itself out the door...allowing it to continue providing showery rain to some parts for a fair while.

 

The Azores High does try to nose in, but the trend for the moment is it to stick out to our West, eventually giving us a more Northerly feed.

Edited May 23, 2014 by Chris K

[knocker]

The ECM ops is still sticking with a much stronger ridge in mid Atlantic on the 500mb anomaly thus differing with the GFS here and the subsequent surface analysis, Here it still going for the high pressure to the west becoming influential for the latter part of the weekend  Frankly at this stage I wouldn't put any store in any of this until will get more consistency with the anomaly charts.

Edited May 23, 2014 by knocker

[joggs]

This pattern the models are showing is dire imo for late spring into summer.Hope to god the jet buggers of to Iceland,oh wait that will happen in november!!!!

[TwisterGirl81]

This pattern the models are showing is dire imo for late spring into summer.Hope to god the jet buggers of to Iceland,oh wait that will happen in november!!!!

 

I couldn't have said better, that jet really likes the uk and and northwest edges of Europe going by the GFS...argh

[knocker]

Strictly speaking I would hardly call it a jet stream. It would be more to the point the lack of one.

 

NH temp. anomaly.

Edited May 23, 2014 by knocker

[summer blizzard]

GFS still wants to flood me..

 

[Summer Sun]

A few people have been suggesting June could be a good month looking at ECM this morning it starts on a positive note

 

 

Something to keep on eye on for the longer term, shorter term it looks like a mixed week next week with showers around on most days some of these could be heavy and thundery though the further north you are the drier you may stay

[joggs]

Strictly speaking I would hardly call it a jet stream. It would be more to the point the lack of one.

 

NH temp. anomaly.Ah so it changes its name for the summer months lol.Whatever you want to call it,its over or to the south of the uk,grrrrr.

[joggs]

Sorry Knocker,that reply slipped into your quote(on mobile) will amend later.

[IDO]

Still uncertainty re Bank Holiday Monday. The GFS London ENS: 

 

Clear support for a very wet period, initially for the SW/Wales; next 7 days totals (potentially large amounts for some areas if GFS are near the mark):  

 

It arrives Monday morning and the front(s) stalls: Only at T120 does it edge north: 

 

GEM keeps the warm front just to our east so the rain stays in the North Sea : 

 

UKMO is different still, stalling the low from Saturday over Ireland Sunday/Monday so wetter for the NW and West. From the fax it looks like the low on the GFS (for Mon/Tues) then stays across the Channel:

 

 

ECM has Saturday's low and associated rainfall but by Monday it looks unsettled but more mobile than the GFS and the main rainfall maybe further north. Further into FI the ECM mean not as progressive with the op relating to the Azores ridging, though similar pattern:

 

 op: 

 

As for June the CFS anomaly goes with a strong Scandi High (GEFS trend the last week):

 

 

 

So average temps, the jet straddling the UK and wet: 

 

This mean has been running with a warm June for most of the month but about five days ago it has been hinting similar to the latest run. Hopefully just a blip due to current uncertainty.

 

 

[knocker]

Sorry Knocker,that reply slipped into your quote(on mobile) will amend later.

 

No probs. I suppose I was merely pointing out the obvious joggs of the lack of intensity.

[Man With Beard]

Still uncertainty re Bank Holiday Monday. The GFS London ENS: http:////f1.nwstatic.co.uk/forum/public/style_images/tctc91_simplify/attachicon.gifgraphe4_1000_306_141___Londres (14).gif

 

Clear support for a very wet period, initially for the SW/Wales; next 7 days totals (potentially large amounts for some areas if GFS are near the mark):  http:////f1.nwstatic.co.uk/forum/public/style_images/tctc91_simplify/attachicon.gifgfsopuktotpcp186.gif

 

It arrives Monday morning and the front(s) stalls: http:////f1.nwstatic.co.uk/forum/public/style_images/tctc91_simplify/attachicon.gifgfs-2-78.png Only at T120 does it edge north: http:////f1.nwstatic.co.uk/forum/public/style_images/tctc91_simplify/attachicon.gifgfs-2-120.png

 

GEM keeps the warm front just to our east so the rain stays in the North Sea : http:////f1.nwstatic.co.uk/forum/public/style_images/tctc91_simplify/attachicon.gifgem-2-96.png

 

UKMO is different still, stalling the low from Saturday over Ireland Sunday/Monday so wetter for the NW and West. From the fax it looks like the low on the GFS (for Mon/Tues) then stays across the Channel:

 

http:////f1.nwstatic.co.uk/forum/public/style_images/tctc91_simplify/attachicon.giffax84s.gif

 

ECM has Saturday's low and associated rainfall but by Monday it looks unsettled but more mobile than the GFS and the main rainfall maybe further north. Further into FI the ECM mean not as progressive with the op relating to the Azores ridging, though similar pattern:

 

http:////f1.nwstatic.co.uk/forum/public/style_images/tctc91_simplify/attachicon.gifEDM1-240 (10).gif  op: http:////f1.nwstatic.co.uk/forum/public/style_images/tctc91_simplify/attachicon.gifECM1-240 (16).gif

 

As for June the CFS anomaly goes with a strong Scandi High (GEFS trend the last week):

 

http:////f1.nwstatic.co.uk/forum/public/style_images/tctc91_simplify/attachicon.gifcfs-1-6-2014.png  http:////f1.nwstatic.co.uk/forum/public/style_images/tctc91_simplify/attachicon.gifcfs-3-6-2014.png

 

So average temps, the jet straddling the UK and wet: http:////f1.nwstatic.co.uk/forum/public/style_images/tctc91_simplify/attachicon.gifcfs-6-6-2014.png

 

This mean has been running with a warm June for most of the month but about five days ago it has been hinting similar to the latest run. Hopefully just a blip due to current uncertainty.

Some really helpful analysis by many this morning.

 

I had been thinking the rain threat for next week might diminish as we get closer to T0 - but with no model keen to give us a proper build of heights until T192+, there's a real risk that the GFS's conveyor of weak systems heading through / stalling over the south might happen. And therefore a risk of dangerous rainfall amounts, as highlighted.

 

I just can't take the ECM seriously at the moment, it looks like a 2 year-old's first effort at drawing a sunset - there may be little of a jet-stream over us but I never find the weather that disorganised.

 

I can only guess that all options except a freeze or a heatwave are on the table for next week, and that the north is more favoured to be driest - but I'm moving slowly to the 'very wet in the south' camp. Warming up quite quickly in any substantial breaks though?

[phil nw.]

Not a great outlook for the rest of May that's for sure.

Looking at the mean height forecasts we can see the problem with a cold pool trapped to our south over the continent with higher pressure to our north.

 

 

The wave 500hPa pattern at first glance looks similar but what makes forecasting difficult is how far north the continental low  will get-the GFS has this closer to the UK than the ECM which would mean unsettled conditions more widely.

If GFS modeling verifies then there could well be a lot of rain for particularly the south and centre of the UK.

It does look like we will be entering June with this type of pattern though.

 

Let's hope the ECM op in it's later frames is onto something in showing the Azores high making a move this way.

[summer blizzard]

GFS6z not much of an improvement over the 0z run..

 

[knocker]

Looking at the 250mb jet and contour heights on the 06z GFS is quite interesting. On Saturday 31st the jet is swinging south to the west of the UK around an upper ridge and then east along N. France. By Sunday this westerly movement ceases abruptly with the formation of an upper low over Biscay. Which surprise, surprise is where the surface low is on the same day with frontal troughs running from France into the UK bringing some  lousy weather.

 

Just about at the apex of the still persisting trough on the 500mb anomaly chart.

Edited May 23, 2014 by knocker

[summer blizzard]

GFS12z is another largely poor run but tonight it is the GEM's turn to horrify me..

 

[ANYWEATHER]

Looks as though the gfs show both in 06z and 12z at the unreliable timeframe of pressure building to the north of the uk drying Scotland out but keeping  the south of the uk under unsettled conditions. I should say that, the unreliable timeframe is T+168hrs , but the trend from the models is just this!   Meanwhile, a very disappointing Bank holiday for most, looks like Sunday seeing the best of the weather

[knocker]

Little change with 12z GFS. for 1st June.

Edited May 23, 2014 by knocker

[ANYWEATHER]

Ecm  at T+168 shows a messy mix , High pressure a lot further north and east on this run. Anyway some yuck weather in the days ahead   :closedeyes:

[knocker]

The ECM ops still playing piggy in the middle on the anomaly chart with the warm and cold air orientated roughly SW/NE north and south of the UK.

 

Not so much emphasis on the low in Biscay as the GFS and the situation to the east and again more build up of the Atlantic high controlling the circulation in the UK by Sunday. Not that pleasant and temps quite cool but this will change by the beginning of next week.

 

[Summer Sun]

Interesting run from JMA with it going for a stronger high to develop from t144 unlike the others

 

 

Not 100% dry but some decent weather for some

 

 

850's gradually increase as the high builds in

 

[Polar Maritime]

Please keep to model Discussion.

[knocker]

The ECM ens supporting the ops with a low in Biscay to the left of the jet on the 31st and build up of heights then encroaching the UK.