Model Output Discussions 12z 08/03/17

[knocker]

The Azores ridge's surge NE over the UK is temporarily put on hold today and early tomorrow as decaying fronts associated with a trough far to the north traverse the country bringing some showery outbreaks and some strong westerly/ north westerly winds in Scotland. as the aforementioned trough tracks into Scandinavia.

But the high pressure quickly reestablishes itself, centred just to the south west/south of the UK and by Friday we have this position. Ergo the week improving as it unfolds with some quiet pleasant weather with the usual geographical and diurnal caveats vis cloud and temps.

From here we come to the tricky part and where the ecm det yesterday evening beat an unsupported lonely furrow with the deconstruction of the trough.This morning the GFS doesn't follow that route (I'll be surprised if the ecm does so again) and has the high pressure just hanging in there, apart from the north west, over the weekend as the trough pushes relentlessly east to be centred NW of Ireland by 00z Monday with weak fronts aligned down the Irish Sea.

This signals the pattern change that has been indicated by the anomalies, albeit allowing for some poetic interpretation, with troughs making inroads around the mid Atlantic high pressure and a large low pressure, unsettled, area becoming the order of the day in the eastern Atlantic. Cooler of late but nothing drastic.

A glance at the GEFS anomaly this morning would tend to support, in general terms, this interpretation.

 

Edited April 3, 2017 by knocker

[Frosty.]

In a nutshell, this week is looking generally settled under high pressure with pleasant surface conditions and sunny spells, becoming warmer later this week. Next week looks like becoming a bit cooler and unsettled but compared to yesterday's output, its watered down.

Edited April 3, 2017 by Frosty.

[knocker]

Wrong again knocker! At T168 the ecm is still deconstructing the trough just to the west of Ireland with the cut off low drifting down to Portugal and thus maybe temps reaching 24C in places on Monday. The main difference to yesterday evening is the northern section of the trough continues east with weak fronts traversing the UK on Tuesday before the Azores once more ridges NE . This is certainly a much more watered down version of the upcoming unsettled cooler spell. But the continued disagreement of the models in the later stages doesn't at the moment fill one with confidence as to the likely detailed outcome although optimism is gaining traction that unsettled spell won't be too bad.

Edited April 3, 2017 by knocker

[Frosty.]

The Ecm 00z looks much warmer by the end of this week into early next week, especially the s / se

[Summer Sun]

High pressure holds for the weekend according to UKMO for the vast majority with any rain in the far north and west

It's nice to see the cold air for easter week starting to get watered down hopefully a trend which will continue

[Frosty.]

1 minute ago, Summer Sun said:

High pressure holds for the weekend according to UKMO for the vast majority with any rain in the far north and west

It's nice to see the cold air for easter week starting to get watered down hopefully a trend which will continue

Agreed Gavin, nice to see the Ecm 00z staying warm into next week too, similar to the 12z last evening.

[Frosty.]

The Gem 00z is also showing high pressure lasting until well into the weekend, ergo pleasant surface conditions with good spells of strong spring sunshine, especially across the southern half of the uk..Becoming unsettled and cooler from the NW from sunday onwards although the fine weather could hang on throughout the weekend across the s / se.

Edited April 3, 2017 by Frosty.

[knocker]

The EPS means looking at a brief colder spell beginning to middle of next weak with perhaps a trend to more zonality for the Easter weekend with temps pushing towards average.but not going to get too wrapped up with this for the moment as there is a fair bit of water to travel under the bridge.

Edited April 3, 2017 by knocker

[Frosty.]

In a nutshell, the Ecm 00z ensemble mean looks generally anticyclonic this week, ergo very pleasant surface conditions with sunny spells and light winds and becoming notably warmer across southern areas later this week, especially into the weekend. Thereafter it becomes much cooler and increasingly unsettled next week.

Edited April 3, 2017 by Frosty.

[stodge]

To put a contrary viewpoint, GEM 00Z and to an extent GFS 00Z and, it seems, the 06Z OP (rolling out now) all have the HP lasting to the weekend but declining from there so three or four decent days but the evolution into next week far from certain.

One or two have grasped at the straw of the ECM 00Z and it's a reasonable evolution but both GEM and much of GEFS go down a progressively more unsettled route so by this time next week:

The LP is heading SE to the west of the British Isles and that suggests an E'ly or NE'ly set up as Easter approaches - note the heights building over Greenland as well.

What I don't see is an Easter heatwave - we might get away with a dry holiday weekend but I think it's odds against and whether we get the cold and unsettled set up from GEM or with heights to the north and the more unsettled weather affecting the south, which would be warmer but still far from settled especially for the south, remains to be seen.

 

[Frosty.]

In a nutshell, the cold next week has gone from the Gfs 6z, temps look pretty good really although it does look more unsettled. Meanwhile, back at the ranch..this week looks generally settled with some sunshine, just a few splashes of rain sliding SE tomorrow but followed by high pressure building in..temps wise, low teens celsius with the warmest weather for the weekend when temps could be into the upper teens c across southern uk.

Edited April 3, 2017 by Frosty.

[comet]

I for one feel confident we will see a potent Arctic incursion sometime around mid month lasting for several days perhaps.

[Frosty.]

1 minute ago, comet said:

I for one feel confident we will see a potent Arctic incursion sometime around mid month lasting for several days perhaps.

In a nutshell, I don't

Edited April 3, 2017 by Frosty.

[Polar Maritime]

Some posts have had to go, Please use this thread for constructive model discussion. There is the banter/moan thread for general chit-chat.

Thanks please continue.

 

Edited April 3, 2017 by Polar Maritime

[Frosty.]

It's still looking good after tonight and tomorrow's rain..high pressure building across the uk bringing variable amounts of cloud and sunny spells, the best of the sunshine further s / e..later this week and especially into the weekend it becomes warmer, especially in the south and still mainly dry with sunny spells away from the far n / nw. The current thinking is that cooler and unsettled weather will erratically push southeastwards next week but the south still looks drier than elsewhere.

Edited April 3, 2017 by Frosty.

[Frosty.]

On the face of it, the GEFS 6z mean doesn't show anything to be concerned about next week, it looks more unsettled compared to this week but temperatures still look about where they should be and actually a little above later when the weather improves more generally across the south.

This week it's all about largely settled weather after the rain blip tonight and tomorrow..The main issue will be cloud amounts but we should all see some pleasantly warm sunshine, only the far n / nw look more changeable throughout this week..The transition period from settled to unsettled is sunday according to this but the south could see a fine and warm weekend.

Edited April 3, 2017 by Frosty.

[Summer Sun]

It looks like a fine start to the weekend if UKMO is right with variable cloud and temps at or above average

By Sunday we are likely to see cloud thicken in the north-west allowing some rain to develop remaining dry the further south and east you are

[Frosty.]

Looking at the weekend, the Gfs 12z shows it becoming warmer as the high nudges further east and we draw a warmer continental flow northwards into the uk, especially sunday across the south /southeast where it looks sunny with temps around 20-21c..nice.

Edited April 3, 2017 by Frosty.

[knocker]

The GFS has picked up the ecm trough deconstruction and thus the main section tracking east to the north of the UK. This allows the HP to hang in there in the southern half of the UK, albeit some wet and windy weather in the north on Monday, before the major depression swings by on Wednesday. But that is way too far ahead to be realistically looked at.

Edited April 3, 2017 by knocker

[Frosty.]

The Gfs 12z shows a cold shot from the north later next week with some snow across the north, mainly hills and frosty nights with icy patches but it doesn't last long and the run ends much milder and more benign.

Edited April 3, 2017 by Frosty.

[Scorcher]

14 minutes ago, Frosty. said:

Looking at the weekend, the Gfs 12z shows it becoming warmer as the high nudges further east and we draw a warmer continental flow northwards into the uk, especially sunday across the south /southeast where it looks sunny with temps around 20-21c..nice.

 

The BBC still aren't having those temperatures for Saturday though- not quite sure why as the high looks in a favourable position for sunshine. 12C is showing for my area on the BBC website for Saturday.

My friend is getting married in Shropshire on Saturday and keeps asking for weather updates- I keep telling him that it's going to be dry but not promising sunshine yet as the BBC/Met Office are not board at the moment!

[Frosty.]

3 minutes ago, Scorcher said:

The BBC still aren't having those temperatures for Saturday though- not quite sure why as the high looks in a favourable position for sunshine. 12C is showing for my area on the BBC website for Saturday.

My friend is getting married in Shropshire on Saturday and keeps asking for weather updates- I keep telling him that it's going to be dry but not promising sunshine yet as the BBC/Met Office are not board at the moment!

Hope they come on-board then, the Gfs 12z is showing a very pleasant weekend, at least further south

Edited April 3, 2017 by Frosty.

[snowray]

Yes Saturday should be a scorcher I'd say, 19, 20, 21c very likely. The Midlands, South, E Anglia might do best of all, similar to last Thursday.

[Frosty.]

24 minutes ago, snowray said:

Yes Saturday should be a scorcher I'd say, 19, 20, 21c very likely. The Midlands, South, E Anglia might do best of all, similar to last Thursday.

I would say sunday could be the warmer day, at least for the s / se..21-22c possible..like the SE had recently.

Edited April 3, 2017 by Frosty.

[Captain Shortwave]

How sunny and how warm Saturday gets looks to be dependent on how quickly we can swing the winds to the south and hence draw in drier air.

   

It could be a slow start for many but I would suspect some warm sunshine would be likely. Low twenties looks possible on Sunday before weather fronts move eastwards. After that it looks changeable but the unsettled and potentially cold signal looks to have waned over the last couple of suites.