Model output discussion - after the beast, what next?

[Summer Sun]

6 minutes ago, Summer Sun said:

Easter day and unsurprisingly we have 3 models showing differing 850's

GFS has cooler air going south

GEM has milder air pushing into the south

ICON is in the middle

And now we can add UKMO into the mix coldest of the lot for Scotland so far -6 line down to around Humberside and the -4 line down to around the Peterborough area

 

[I remember Atlantic 252]

2 minutes ago, Summer Sun said:

And now we can add UKMO into the mix coldest of the lot for Scotland so far -6 line down to around Humberside and the -4 line down to around the Peterborough area

 

sucks really though -5 line, should be looking for charts like this SS, 6 years ago today 25°C

Edited March 26, 2018 by I remember Atlantic 252

[The PIT]

LOL a sudden jump to a colder outlook over the weekend the models really are struggling at getting a grip at the moment. Sadly a long wait for the ECM for a casting vote the tension builds. At least the GFS for us has the weekend dry while Bank Holiday Monday should be interesting for north eastern areas.

[Summer Sun]

4 minutes ago, I remember Atlantic 252 said:

sucks really though -5 line, should be looking for charts like this SS, 6 years ago today 25°C

Remember it well it was a very dry and sunny month for many parts

[Summer Sun]

GFS still hinting at this post-Easter increase in temps

Warmer rain for a good few

[winterof79]

GFS is a pants outlook with low pressure sending a conveyor of rain and fronts.

Whatever floats your boat as it were.

[Purga]

More extensive frost for Easter Morning on the latest GFS run

Low Dew Points and theta-e values

 

UKMO looking good as well

Snow showers clipping the E / EA and probably Kent.

No mildfest quite yet.

 

Edited March 26, 2018 by Purga

[Derecho]

Swingometer update for today

 The OP is well represented by the mean

  Charts like this have started to become more common....

In summary
- Saturday and Sunday are now trending towards being drier but colder. Not too cold though and the days may be quite nice. Chilly by night.
- Monday looks as though it may be wet as milder air is pushed our way from a deepening low out west.
- Many ensemble members develop this, bringing deep lows our way with lots of rain within the mild uppers.
- A few keep them out of trouble to some extent.
- After the first week of April there is a trend towards either cold northerlies or mild SW winds, both appear equally likely at this time.
 

[Cheese Rice]

Well well....

 

[Mike Poole]

Thought it was worth posting the 500mb heights and surface pressures from a number of models at T120 to illustrate the difficulties the models are having with this setup. (Others have posted the 850's)
Context first, southerly tracking jet stream, GFS:

The lows that are causing the model problems are swirling about north of this with no obvious rhyme or reason, and certainly no model agreement.  GFS:

GEM:

ICON:

UKMO:

NAVGEM:

All a bit of a dog's breakfast.  So no wonder the models can't decide how far south the cold uppers get.  Couple more days before the Easter weekend is decided.  The ECM doesn't have the casting vote on this either, but will be interesting to see where it goes.

Edited March 26, 2018 by Mike Poole

[Summer Sun]

Looking at the GFS London ens zoomed in the colder op later on over Easter weekend has 5 or 6 perturbations out of 20 giving it support along with the control which drops to around -7 the vast majority with the mean stay above -5

 

Edited March 26, 2018 by Summer Sun

[Mike Poole]

22 minutes ago, Mike Poole said:

Thought it was worth posting the 500mb heights and surface pressures from a number of models at T120 to illustrate the difficulties the models are having with this setup. (Others have posted the 850's)
Context first, southerly tracking jet stream, GFS:

The lows that are causing the model problems are swirling about north of this with no obvious rhyme or reason, and certainly no model agreement.  GFS:

GEM:

ICON:

UKMO:

NAVGEM:

All a bit of a dog's breakfast.  So no wonder the models can't decide how far south the cold uppers get.  Couple more days before the Easter weekend is decided.  The ECM doesn't have the casting vote on this either, but will be interesting to see where it goes.

And here's the ECM T120 to add to the deck:

T850s:

[Summer Sun]

Coldest air bit further south tonight into Scotland on ECM 12z 24hr comparison below

 

[Summer Sun]

Easter day ECM brings some milder air into the far south-west but colder air hangs on in the north

[Summer Sun]

ECM weeklies for the next 4 weeks to April 22nd generally keep the UK below average temp wise but maybe not as cold by week 3

 

Edited March 26, 2018 by Summer Sun

[Summer Sun]

A fairly mild Easter Monday from ECM

Could be a bit wet tho...

[Badgers01]

2 hours ago, Summer Sun said:

Remember it well it was a very dry and sunny month for many parts

yes and remember the summer that followed !!

[Leon1]

Oooooh!

[bradymk]

Low heights, slack flow. Evaporative cooling under heavy precip effect here? HIRLAM too

[Leon1]

1 minute ago, bradythemole said:

Low heights, slack flow. Evaporative cooling under heavy precip effect here? HIRLAM too

crazy heavy snow there! i hope this comes off!

[stodge]

Evening all

ECM throws the proverbial spanner into the metaphorical works but, remembering the GEFS 00Z, not entirely surprising:

Cold or very cold air for many especially in the north but dry - sharp frosts at night I'd have thought.

[Purga]

Yes, a nice cold surprise could be on the cards!

with this temperature gradient somewhere could get a nice dumping..

[Mike Poole]

For those still looking for the cold solutions, it's not out of the picture.  Here's the 12z FIM9 at T192:

Given the direction of the winds, most precipitation even in the south would probably be snow.

In the battle of the models, Spring's winning over Winter on average, but not conclusively.

edit: the T210 charts are even better:

This model, although experimental is the same resolution as GFS.

Edited March 26, 2018 by Mike Poole

[Summer Sun]

1st couple of days of the Easter weekend in sight for ARPEGE now it keeps the coldest air mainly north of Scotland but it could just clip the far north for a time

Some snow mainly for hills in northern England maybe down to lower levels at times in Scotland

[Mike Poole]

Here's the dilemma, illustrated by the ICON 18z, so early as T36, it's all about where the low pressure goes:

But waiting in the wings is a big blue and purple fish with -12s where it's eyes should be - will it swim in, more runs needed:

This is probably the last in my series of posts seeing things in the model output  varying from beasts, feet, pac-man's, snakes, now fish, during this FANTASTIC period of model watching over the last two months.  Roll on the summer!

Edited March 26, 2018 by Mike Poole