Model Output Discussions 12z 08/03/17

[Frosty.]

3 minutes ago, Summer Sun said:

UKMO isn't as unsettled as GFS is - temps still likely to be down compared to late though it wouldn't feel too bad if we got some sunshine would all depend on what sort of setup we get

Agreed, the ukmo 12z isn't showing a cold snap and to be honest the ukmo is right more often than the gfs.

[Frosty.]

The Gem 12z isn't showing a cold snap either, just cool and a bit unsettled but the main interest is later in the run when it becomes anticyclonic..hopefully a sign of things to come during late march / early april.

Edited March 16, 2017 by Frosty.

[Frosty.]

The Ecm 12z is showing a cold snap next week, at least for scotland, n.ireland and parts of northern england with some snow for a time and frosty nights but colder than both the ukmo / gem further south too..so, in order of cold / snow potential we have the Gfs the clear winner then the Ecm 12z with the ukmo and gem not interested.

Edited March 16, 2017 by Frosty.

[cheshire snow]

@Frosty.  some quite impressive uppers for Northern parts of England and Scotland 

I suppose the old saying would be if only it was January however those charts will certainly give snow for the hills Midlands Northwards with perhaps wintry PPN to lower levels especially overnight.

Must say all my enthusiasm for snow has now gone for another season,and like you I am now looking for some spring warmth.

C.S 

[phil nw.]

Latest UK outputs show the change across the UK to more unsettled weather as the jet moves further south and reinvigorates after the recent quieter spell..

Those are day 3 and 5.

A brisk westerly pattern looks like setting now for the next week or so before later outputs suggest the Azores high ridging in again towards later next week.It may well be southern areas miss the worst of the rain as fronts weaken somewhat as they come south. 

The latest gefs for C.England show little in the way of rain through the next  2 weeks with temperatures never far from average.The far north(2nd image above) though somewhat different where colder air digs in during the next few days bringing more rain and some wintry showers especially on the mountains.

A week or so of unsettled and rather colder weather then before signs of something warmer and brighter modeled into week 2.

[ANYWEATHER]

Cold Cold Cold  , for mid next week if the gfs  and ecm is to be believied! Great for snow lovers and for storm lovers too...

Edited March 16, 2017 by ANYWEATHER

[Captain Shortwave]

It does look likely that things will turn more unsettled UK wide for a time next week with a trough in the Atlantic moving eastwards towards the UK. This is then set to stall with low pressure becoming cut off to our south and high pressure building towards Scotland. The airmass does look cold enough for wintry showers in the north even to low levels, there is initially some decent instability to be had so a right mix in the showers of rain/sleet/hail and snow.

      

So becoming drier again for all, though not particularly warm, cloud could also become an issue in the south as a east to north east wind develops.

GEFs the same really

      

So overall fairly non-descript westerlies until the start of next week, then turning more unsettled widely and colder for a time. The pressure build doesn't really fill me with much promise of cold/frosty weather or warm sunny weather. It looks like one of the cool and grey highs which are quite common in the first half of spring. We can hope that is shifts east a bit when we get nearer the time.

[knocker]

There is pretty good agreement on the upper evolution vis the 6- 10 anomalies this evening. Albeit they do not tell as much we don't already know because the detail is very much going to depend on the precise orientation and direction of travel of both the ridge and the upper trough as it sinks.south. this can already be seen on the det. runs and might well take a day or two to get sorted. The best option for the UK would be with the EPS and have the trough a tad west. Either way we are looking at a few days of unsettled cooler weather, how much so dependent on the above

.

In the 10-15 period they have the same idea but complete agreement is quite unlikely anyway.The main features remain still a strong vortex Franz Joseph Land and some positive anomalies and some ridging to the north of the UK with the trough south in the western Mediterranean area. As mentioned previously this leaves a very slack pressure area covering much of the UK and France and Germany  Can't read too much into this at this stage but dependent how this pans out probably reasonable dry apart maybe the NW with temps around average but probably with a fair bit of diurnal variability

.

 

Edited March 16, 2017 by knocker

[Frosty.]

Ok who fancies a spell of anticyclonic weather during late march and potentially early april because that's what tonight's Ecm 12z ensemble mean is indicating.

Edited March 16, 2017 by Frosty.

[Frosty.]

A real wintry mix next week from the Gfs 18z tonight, take your pick.. we have rain, hail, probable thunder, sleet, snow, frosts, ice and some dry weather with sunny spells too. Some areas would get a surprise covering of snow.

Edited March 16, 2017 by Frosty.

[Polar Maritime]

Quite a chilly outlook from the GFS this morning into wk2, With a Northerly flow turning Easterly into the later frames.

Edited March 17, 2017 by Polar Maritime

[Captain Shortwave]

As PM says the GFS looks decided chilly or even cold with a raw wind developing.

      

 

On the flip side the ECM ]makes much less of that trough with a much smaller cut off low developing which allows the high to build further south and more over the UK bringing some warm and pleasant weather by week 2.

      

The differences are quite small in terms of position and location of that high, but the surface conditions would be very different. The ECM would be very mild or even warm under light winds and warm air aloft, the GFS would be cool or cold with a lot of cloud brought in off the north sea.

[lindy2222]

Ive to get snow from wednesday.......

[Sky Full]

I find it fascinating to watch the way the GFS and ECM are competing to model the developing pressure patterns next week.  This morning the GFS has held on to its view that a depression will form right over the UK bringing a late March cold snap to all areas:

GFS +120:

   

GFS +132:

   

GFS +144:

   

After initially agreeing with this pattern, the ECM has now decided that the low pressure will position itself a little further north allowing the Azores high to recover more strongly:

ECM +120:

   

ECM +144:

   

Which of these two patterns will verify?  It seems that a short spell of colder conditions is unavoidable next week but the ECM this morning offers the quickest route to warmer more settled conditions by the end of the month.....

 

 

..............

 

Edited March 17, 2017 by Sky Full
Delete unwanted image

[Frosty.]

The Gfs 6z shows a wintry cocktail of weather next week with rain, hail, thunder, sleet, snow, frosts and ice.. some areas seeing settling snow, especially with any elevation..a step back into winter next week and right at the end of March and beginning of April shows height rises to the NW with arctic air drawn south with further snow. 

Edited March 17, 2017 by Frosty.

[Summer Sun]

GFS seemingly on its own again this morning - given the lack of support for GFS you can't help but think it will backtrack towards the euros

ECM                                                              UKMO                                                        GFS

ECM                                                              UKMO                                                        GFS

[mb018538]

We really need that low pressure to stay well to the south, otherwise the weather will be miserable like the 6z GFs. If it ends up more like the extended ECM we could be looking at glorious spring sunshine, with temps in the upper teens. Fine margins!

 or

[Captain Shortwave]

I think we can see the stark differences at the 5/6 day range. Here are the ECM/UKMO and GFS outputs at day 6

      

Big differences here, the ECM really not making much of the trough with the low becoming quickly cut off west of Iberia, the UKMO makes a little more of it with a visible trough through the UK and south west Europe. The GFS though shows a deep trough which creates a much deeper low eventually to our south. The depth of that low will determine where the high ends up when it builds north east from the Atlantic.

[Summer Sun]

As cold as GFS is for next week GEM isn't

Still huge differences between GFS and UKMO too

[Eugene]

20 hours ago, ANYWEATHER said:

Cold Cold Cold  , for mid next week if the gfs  and ecm is to be believied! Great for snow lovers and for storm lovers too...

 

Potential for heavy snow over the cotswolds/peak district next thursday on GFS 12Z.

Edited March 17, 2017 by Eugene

[mb018538]

Looks like we've got a massive problem with this low pressure developing wed/thu next week. GFS continually wants to blow it up into a nasty little feature, where as the UKMO keeps it less unsettled and the low further south. Will have big effects down the line, so until this is resolved we won't know what will happen after.

[The PIT]

UKMO sticking with it's original forecast GFS going for the next ice age jumping ship possibly. Now we need too see what ECM thinks.  Hopefully it will go with the GFS solution which is very nice. Still outside the reliable time frame so could all disappear into just a slight cool few days.

[Frosty.]

The Gem 12z isn't interested in a cold snap next week either but it's very interested in pleasant temps and high pressure taking over later.

Edited March 17, 2017 by Frosty.

[I remember Atlantic 252]

7 minutes ago, Frosty. said:

The Gem 12z isn't interested in a cold snap next week either but it's very interested in pleasant temps and high pressure taking over later.

rubbish model! hope it's right though! I don't fancy rain/wind, damp at 7-8°

Edited March 17, 2017 by I remember Atlantic 252

[Summer Sun]

ECM is delayed this evening no ETA yet