Model Output Discussion - 15th March onwards

[geordiekev]

16 minutes ago, stodge said:

And for those following the 18Z OP, it gets there without the spoiler LP.

Perfect timing for my Birthday gamble this year to visit Scotland instead of a more obvious snowy location, (Scotland 850s 5⁰ colder than Iceland) though will have to find some elevation me thinks. Weather Gods certainly not ready to adjust their BST hourglasses yet but think I need to start doing the lottery

Edited March 17, 2023 by geordiekev

[geordiekev]

Winter really isnt ready to let go according to GFS

[Tim Bland]

Not bad for nearly April …

[Allseasons-Si]

Who is up for one last hurrah!!!

there have been hints of another colder shot in the models towards months end with some sort of Atlantic ridge/Greenland blocking

the latest anomalies

EPS/EPS clusters and NOAA at day ten

after this though,...i do want some sun and warmth so that i can get out in the garden,don't want to have a cold spring that tenders/damages young plants etc.

 

[Don]

27 minutes ago, Allseasons-si said:

Who is up for one last hurrah!!!

there have been hints of another colder shot in the models towards months end with some sort of Atlantic ridge/Greenland blocking

the latest anomalies

EPS/EPS clusters and NOAA at day ten

after this though,...i do want some sun and warmth so that i can get out in the garden,don't want to have a cold spring that tenders/damages young plants etc.

 

That pesky limpet high pressure to the south these days!

[feb1991blizzard]

Pure Arctic airmass- absolute belter!

[Sun Chaser]

GFS 00z ensembles really are trending much colder from day 8 with some very strong agreement... looks like it's a serious possibility to have our third cold early April in a row (and fourth in five years), almost certainly wasted at this time of year.

On a positive note in all of those years things tend to have settled before mid April - last year saw warmer settled weather by the 12th, 2021 swung to clear blue skies by the 15th and 2019 gave the west some serious early spring warmth from the 19th. So there is hope not too far away.

In the meantime if we do get a northerly outbreak around the 27th it certainly doesn't look too snowy.

[Matt Jones]

I agree probably wasted but can’t really compare as we seem incapable of this kind of synoptic in January and when on a rare occasion we do it still struggles to deliver or sustain. Even if by some miracle we managed 4” of snow here overnight early April it would be the best event here since late nov/dec 10. I am not suggesting that is going to happen though!

[mushymanrob]

On 16/03/2023 at 09:40, mushymanrob said:

Nope, im not buying next week mild and unsettled theme - although its likely to start that way.
Both these charts and the EPS suggest the 528DAM contour is over Northern areas next week, centred on the 23rd. Thats a lot further South than the current GFS suggests. The chances of the GFS and ECMs current vision of a mild unsettled week isnt that sound IMHO. As you know, i back the anomalies any day over a more volatile operational run at that range.
So i expect another short lived cold blast later next week.
 

Well the timing might not have been accurate, but these charts hinted at a cold snap and thats now what the ops are suggesting... anomaly accuracy again... ? time will tell as its not happened yet!

[Mike Poole]

16 hours ago, Don said:

I'm sure you would prefer to have a poor spring followed by a good summer, rather than the other way around though?  Long range models are pointing towards a hot and dry summer currently.

 

Yes, there does seem a signal for that.

16 hours ago, RainAllNight said:

This being my first full year here I am wondering, how often is the guidance from those models accurate?

I think any signal from the long range models for summer is much more tentative than in winter.  In winter, the models can get a sniff of major drivers like vortex strength and SSWs etc. and can give quite a strong signal sometimes.  In summer, those drivers aren’t there so any signal tends to be much more muted.

This year there is a small but possibly significant signal on all models for higher than average heights in the vicinity of the UK for the summer months, particularly ECM and CFS:

In terms of analogues, it is hard to avoid looking at 2018 in my view.  Reasons - La Niña weakening to neutral, and a strong SSW occurring in mid February.  The details of the SSW event may be different, but the timescale for its effect should be similar given the strength of it, i.e. reaching to mid spring.  

Remembering the evolution in 2018, I would be looking to see the jet stream make a strong move north from mid-April, taking the flow SW-NE allowing the Azores high to ridge in.  2018 was a more sustained period of dry heat, rather than intense plumes, so I wonder if something similar will pan out this year.

 

Edited March 18, 2023 by Mike Poole

[minus10]

Northerly for 27th on gfs6z..

...all the way from ..Alaska ??

[Cambrian]

Some lively weather around this week as we head into astronomical spring, shown on the 0z ECM operational run. 

A long-fetch westerly at day 4, midweek, brings through a beefy belt of rain. Mild on Tuesday before it arrives, temperatures dropping away through Wednesday and Thursday, all the UK and Ireland pretty much back into single figures by then. 

    

Low pressure crossing the south a week today, brings us into a northerly flow and a chilly weekend next week. There is some fresh snow being modelled for the upland areas from Thursday through to Sunday (at 120h and 180h shown here). 

   

With T850s between -8 and -4 degrees by next weekend, there is plenty of room for some wintry surprises more widely over the UK and Ireland.

This cold snap next weekend looking more definite with each day that passes, but even after that, and even with the attempts at times to bubble up heights to the south, the chief protagonists remain the same through to day 10 and beyond - the low pressure to the west in a continued tussle with the cold air to the northeast, as shown here on the day 10 0z ECM mean. 

  

Along with the fun and games of the coming week, there is plenty to keep us interested over the next while heading into April. Have a great day everyone. 

[Chesil View]

Extended ecm perturbations showing lots of cold scenarios for the start of April. Some looking quite snowy at times too..

[lassie23]

2 hours ago, Chesil View said:

Extended ecm perturbations showing lots of cold scenarios for the start of April. Some looking quite snowy at times too..

I think most cold hunters have signed off for the winter, so it will probably snow now 

[Rain All Night]

Not that it makes much difference to our weather, but it's interesting watching the subtropical air get flushed out of the Atlantic from the 22nd.

[Bricriu]

1 hour ago, lassie23 said:

I think most cold hunters have signed off for the winter, so it will probably snow now 

I am still  hoping for a major snow event that leads to decent accumulations- even if it only lasts a few hours.

[Allseasons-Si]

I think i would take this from the latest gfs

that would be a nice plume setup for storms from the south,had one rumble of thunder not long ago.

[Iceman2606]

Stonking GFS 12z for the end of March. Will most certainly be a major outlier but great eye candy nonetheless.

 

Despite those 850s the surface temps would not be as high as you'd have thought due to the sunshine strength still at this time of year.

[Dancerwithwings]

Not expecting anything sooner 7d regarding spring warmth when looking at the GEFS members 

[Iceman2606]

50 minutes ago, Iceman2606 said:

Stonking GFS 12z for the end of March. Will most certainly be a major outlier but great eye candy nonetheless.

 

Despite those 850s the surface temps would not be as high as you'd have thought due to the sunshine strength still at this time of year.

As expected...

[minus10]

Well i have seen some swings but hey..

 

.

...that is just crazy from the 12z gfs...just makes you wonder what has the high res op seen to make such a dramatic change of direction..the ens keeping calm though..

Edited March 18, 2023 by minus10

[feb1991blizzard]

50 minutes ago, Iceman2606 said:

As expected...

Just our luck that the big warm outlier verifies after none of the big cold outliers did all winter.

[Bats32]

Anyone remember the 40C that the GFS was the first to have a sniff at?.......

[Stuie]

Have been saying `bad words` a lot with the ECM op runs regarding outliers but the GFS op has deffo said hold my pint.

Edited March 18, 2023 by Stuie

[Mike Poole]

1 hour ago, minus10 said:

...that is just crazy from the 12z gfs...just makes you wonder what has the high res op seen to make such a dramatic change of direction..the ens keeping calm though..

A ghost, maybe?

Anyway, not really a solution that appears in the ECM clusters.  I think the direction of travel is actually towards a colder end to the month.  Here’s the clusters for T192-T240 and T264+

Looks to be a signal to push up an Atlantic ridge, which may go on to develop a northerly flow, which in the case of cluster 2 in the extended looks quite potent.  One final hurrah for winter maybe for those further north…