Model Output Discussion 31/03/14 onwards.

[knocker]

The ECM surface and 500mb anomaly for the weekend

Edited April 14, 2014 by knocker

[knocker]

Sunday and Monday

 

The GFS has a weakening upper ridge in mid Atlantic with the cold air north of Greenland troughing towards the UK by Monday. Significantly a pool of colder air in northern France with warmer air still to the east.

 

On the surface low centred over northern France on Sunday giving wet weather along the south coast and  generally dry for the rest in an easterly flow. By Monday the low has moved east with the wind backing NE.

 

Deep low SE of Greenland with a frontal area between it and Scotland.

[winterof79]

Not often seen any time of year but welcome nontheless

http://www.metoffice.gov.uk/weather/uk/uk_forecast_weather.html

Edited April 15, 2014 by winterof79

[Summer Sun]

UKMO now showing a breakdown to something slightly more unsettled during Easter Sunday and more so Easter Monday

 

Tthe further east you are on Sunday the drier its likely to be as you'll be closer to the high

 

 

Monday looks more unsettled in general but hopefully it'll be more sunshine and showers rather than prolonged rain

 

Away from Scotland it won't be cold

 

[Polar Maritime]

Such a fine balance in the outputs over the last week.. But it continues to show an unsettled and cooler period from the 20th onwards, how much so remains to be seen.

[Summer Sun]

Such a fine balance in the outputs over the last week.. But it continues to show an unsettled and cooler period from the 20th onwards, how much so remains to be seen.

 

Indeed

 

Looking at the 00z ensembles the further south you are the drier and warmer it could be 850's never go below average from the 19th rainfall amounts look relatively low after Easter Monday

 

 

Manchester ensemble also shows the 850's never going below normal from the 19th rainfall amounts look relatively low over the Easter weekend slightly higher longer term but nothing too bad

 

 

So for England temperature always look to be at or above average even with the slightly lower 850's on Friday and Saturday London's highs are expected to be 15c Friday and 16c Saturday, Manchester will be slightly cooler at 12c Friday but back upto 14c by Saturday 

[johnholmes]

The past 5 days or so has been fascinating to watch how all the models have to some extent struggled with even the broad scale upper pattern. From a coolish unsettled start to Easter (on the anomaly charts) to a settled fairly mild/rather warm start, declining into something more unsettled and slowly a bit cooler. Well that seems to be the probable pattern when I tried to assess the outputs of the last 4-5 days this morning!

[Polar Maritime]

Meto continue to stress unsettled conditions from the 20th, with bands of rain pushing N/W and temps below average especially in the North, pretty much in line with what the GFS is/has been showing.. At least we have some Spring like weather now which should just about last over the Bank Holiday !

[Polar Maritime]

The past 5 days or so has been fascinating to watch how all the models have to some extent struggled with even the broad scale upper pattern. From a coolish unsettled start to Easter (on the anomaly charts) to a settled fairly mild/rather warm start, declining into something more unsettled and slowly a bit cooler. Well that seems to be the probable pattern when I tried to assess the outputs of the last 4-5 days this morning!

Yes John, I must say the models have been pretty good at continuing to show some kind of change from around mid-month to unsettled conditions, even though it has been dropped and picked up again numerous times over the past week.

[Summer Sun]

Still looks like something more unsettled will develop by Easter Sunday but how unsettled it does turn remains open to doubt

 

Looking at UKMO the further north you are the drier it could be

 

 

GFS has the low further north giving rain for virtually all of England and wales

 

 

Easter Monday continues to show uncertainties for where the low will position its self its looking likely we'll see 2 dry days and 2 wetter days for the BH weekend but the position of the low will be crucial for who gets the most rain

 

 

Day 10 onwards shows high pressure slowly moving in with any rain slowly becoming restricted to Scotland along with the cooler air

 

 

GEM also showing pressure starting to rise again during next week

 

Edited April 15, 2014 by Summer Sun

[Captain Shortwave]

ECM and GEM are virtually identical up to day 9, very strong agreement between the 2 operationals to build a very strong block to our north east. The UK gets stuck under some shallow low pressure systems at times. Both not keen on a return to full Atlantic domination. GFS on the other hand wants to bring the Atlantic back in.

 

GEM

 

GFS

UKMO up to T144 looks similar to the GEM/ECM so the GFS is probably over-doing the Atlantic jet. Worth noting that the models in general have been doing this over the past week or so. 

Surface detail if the broad trend is correct will be difficult with fronts and disturbances meandering aimlessly in a slack and complex pattern.

[Summer Sun]

The models seem to have picked up on something tonight around day 10 ECM is also showing a rise in pressure at day 10 along with GEM

 

 

GFS takes a different route to the other 2 it doesn't have a strong very strong block to our north east like ECM and GEM but it shows the Azores high moving up

 

Edited April 15, 2014 by Summer Sun

[ANYWEATHER]

Settled conditions for most apart from Scotland in the next couple of days then becoming unsettled from the south during the second half of the Easter holidays with rain for all as low pressure takes over the Uk.......

[ANYWEATHER]

The models seem to have picked up on something tonight around day 10 ECM is also showing a rise in pressure at day 10 along with GFS and GEM

 

At day 10 is absolutely useless in my opinion and Ive got some experience of that!!! That's why they call it FI and holds no weight into the forecasting  

[knocker]

Some conformity over Sunday and Monday? Between two anyway.

Edited April 15, 2014 by knocker

[damianslaw]

Reliable timeframe - models are showing low pressure moving in from the south by Sunday to bring an unsettled spell for the second half of the easter period, before then, the north will see some rain later tomorrow and through Thursday. A sandwich of pleasant weather inbetween during Friday and Saturday, a very mixed bag it has to be said.

 

Not the worst of outlooks, but certainly not the best.

[knocker]

Sunday –Tuesday

 

Very briefly. The GFS has consolidated it’s position on the breakdown from Sunday and by Tuesday a very familiar story has emerged.

 

On Sunday the upper air pattern has the cold pool over the UK stretching SE and the the main cold area over Greenland with the trough towards the Scotland. The warm air to the SE and NE. By Monday the troughs have consolidated and by Tuesday the deep area of low pressure is in control WNW of the UK with a weak transient ridge effecting the SW.

 

On the surface. Low pressure over the UK Sunday and Monday giving a pretty wet couple of days with by Monday a deepish low mid Atlantic with a transient ridge between.  Very transient as by Tuesday a familiar story has unfolded. Low SW of Greenland, troughs approaching from the west and the UK in a strong westerly airstream with the high pressure slipping south.

 

So the Atlantic is in charge again but as yet there is no uniformity on this position and this may well be the worse case scenario. Fascinating.

[Captain Shortwave]

Models at T144

ECM

 

UKMO

 

GEM

 

GFS

 

GFS is definitely the odd one out here, the other 3 models want heights north or north east of the UK with a shallow low near the UK trapped underneath the heights, whilst the GFS wants to return a westerly pattern to the UK.

Given the set-up, I would feel that the GFS is wrong here as it is well know that is performs poorly in these set-ups.

[Polar Maritime]

Great round up of the models there Knock, was a pleasure to read 

 

Still lot's of detail yet to be resolved as you say as for how unsettled.

[knocker]

There does seem as if a picture is emerging but to my untutored eye still plenty of room for manoeuvre but the ECM has a similar  Atlantic upper air pattern but more emphasis on the build up of heights to NE. Anyway a quick glance.

Edited April 16, 2014 by knocker

[Average Joe]

At day 10 is absolutely useless in my opinion and Ive got some experience of that!!! That's why they call it FI and holds no weight into the forecasting  

Perhaps not, but this is a model discussion thread after all....apparently!! 

[049balt]

Edited April 16, 2014 by 049balt

[vladthemert]

some models showing the shallow low links up drags us back to more series of lows.  Surely this wont happen.

[knocker]

some models showing the shallow low links up drags us back to more series of lows.  Surely this wont happen.

 

I'm not totally sure what you mean but I haven't seen anything along the lines of a series of lows. The GFS is still tending towards Atlantic dominated by low upper heights next week with frontal systems approaching from the west but frankly as the models haven't appeared to sort out the weekend yet I wouldn't bother with it unless just out of interest to see what actually does develop. If anyone asks me about the easter weather I'm still phoning a friend.

[vladthemert]

I'm not totally sure what you mean but I haven't seen anything along the lines of a series of lows. The GFS is still tending towards Atlantic dominated by low upper heights next week with frontal systems approaching from the west but frankly as the models haven't appeared to sort out the weekend yet I wouldn't bother with it unless just out of interest to see what actually does develop. If anyone asks me about the easter weather I'm still phoning a friend.

 

yes sorry knockers that was thinking should worded it better about atlantic domination still learning.

Edited April 16, 2014 by vladthemert