Model Output Discussion - Spring Has Sprung

[Rain All Night]

This lady's not for turning...

[Rain All Night]

 Don The last 3 runs have been similar. Before that, there was greater spread, and some of the possible minimum values were lower.

Although as recently as the last run, it had looked like there might be a second, lower dip shortly after the first one.

Edited February 11 by Rain All Night

[blizzard81]

Baby steps from the pub run. I would expect no more lol. 

[Daniel*]

GFS been best performing model at day 10.  Probably highlights how poor NWP is doing as a collective.

[Rain All Night]

 Daniel* ECM's average score there looks to be higher

[WYorksWeather]

Medium-range

The ECM ensembles don't hold out much hope. For every cold ensemble, we have an outrageously mild one. Still plenty of time for this to resolve in our favour but that's not an encouraging signal to see temperatures hovering around average.

Meteograms

The meteograms also look uninspiring - average by day and above average by night through to the end (using Reading as the example). This is despite the model favouring easterly winds from around day 7 onwards.

SSTs

The clock is now ticking as well on my regular SST checking. North Atlantic SSTs at days 0, 5, 10 and 15 are below.

You can see that the change between days 10 and 15 is very small, so we are approaching the point at which SSTs bottom out and begin to rise.

SSW

SSW chances still look good, though more ensembles are now re-strengthening the vortex after a brief reversal around the 20th February. The vast majority of runs achieve a reversal.

EC46

The EC46 looks very non-committal for the near future, but tending towards mild for early March. Any cold spell after that is highly unlikely to deliver anything significantly wintry.

19th-26th looks near average.

Possibly a warm up from 26th-4th.

Warmer still through 4th-11th.

Closer to average 11th-18th.

Then a colder week later on (18th-25th)?

Summary

All in all, and ignoring individual OP runs, the latest data from ECM is horrendous from a cold point of view. If EC46 has the right idea we could even be looking at an early spring, though of course that's highly uncertain. If this did happen, the likely cause would be a rapid re-strengthening of the polar vortex, resulting in a reflective-type SSW similar to the one we saw in January, which may have been at least in part responsible for the mild spell since late January.

In the shorter range, it's default mild (at times very mild) for at least the next week, most likely the next 10 days, with possibly one more roll of the dice beyond that. This will likely depend on the details of the SSW response, which are of course speculative at the moment.

Another week to 10 days of this and I'm done, and it'll be roll on spring.

[Daniel*]

4 minutes ago, Rain All Night said:

average score there looks to be higher

The average is taken over a month I’m focusing on past week all models have slumped but GFS has not.

[johnholmes]

 Daniel* Not sure how you get that?

Can you explain your comment please?

thank you

[geordiekev]

 blizzard81 for me there's amplitude & waves about if not in our locale, will hopefully work it's way around, much like a skipping rope.

I'm starting to come to the conclusion, I'm not a fan of fragmented PV as pretty much zero Polar Maritime incursions this season, which yeah doesn't deliver for all but at least it's some excitement every few weeks & a strong ESB storm does often pump up WAA towards Greeny.

Still, we get what we're given but 10 days of falling snow, for me, is a bit poor given the supposed signals

Edited February 11 by geordiekev

[Met4Cast]

I often find the NAEFS to be quite a good guide for the broader evolution of the pattern, it's the GEFS and GEM ensembles combined. 

This currently suggests steady as we are out until the 19th with the pesky Iberian heights making themselves known.

Towards the end of the month, and perhaps more broadly it signals a trough returning to Scandinavia, perhaps introducing colder air as a result but still not exactly blocked. Perhaps something similar to the recent colder spell, i.e Scandi trough led rather than blocking led. 

In any case - It's currently difficult to make an argument for widespread cold/snowfall, if anything that remains a very low probability looking at NWP modelling. It becomes perhaps even lower when factoring in the teleconnections, despite an up-coming major SSW. 

Lets hope for some changes in the coming week.

[feb1991blizzard]

 Met4Cast

Yes i must say it looks like we're abuggarred now, you called it right the other day.

[Met4Cast]

Maybe the SSW will bring an early spring instead..

Horrific!

[Northern Sky]

 Met4Cast "I can't say I care much for what the det runs show if I'm honest, they could show the next BFTE and feet of snow across the whole of the UK but if it's beyond day 3 it may as well not exist."

I think that's fair comment but it's equally applicable to the guidance given by the varied teleconnections this Winter season. I absolutely respect the desire to understand the science behind the weather patterns and the possibilities of using that understanding to predict the conditions on the ground in the micro detail required to forecast the UK weather weeks in advance. But, imo, this Winter has shown us just how far we are still away from being able to do that in any detail relevant to advanced micro scale predictions for the UK. 

This forum in Winter has varied appeal, with some people having a great interest in the science of weather prediction and others basically interested in when it's going to snow. Most of us fit somewhere inbetween that but personally I've found this a grinding and ultimately unrewarding Winter in terms of the background drivers and long term prediction. The January chase where everything seemed so favourable resulted in a 5/6 day spell of cold weather which usually I would've enjoyed, but given the built up expectations seemed instead to be a major disappointment. (I did still enjoy it though!) 

I'm done with the long term drivers, this Winter has finished them for me. I don't care what they say for either cold or mild. Next Winter (if I'm still around) I'm just going to to follow the models, and as you say take nothing for granted until it gets within 72hrs.  

[Addicks Fan 1981]

 Met4Cast I wouldn't be at all surprised really, SSW doesn't always bring penetrating cold and it all depends on the other variables like GWO, MJO, ENSO and SSTS worldwide.    

[Sweatyman]

 geordiekev Try zero days of falling snow. Hideous so called winter

[Don]

 Met4Cast in view as to how winter has played out, that would be my expectation!

[damianslaw]

 Northern Sky Ive mentioned many a time how quite often reliable timeframe periods can be very short sometimes 72 hrs tops, sometimes 24 hrs, sometimes look outside the window. This winter and indeed last summer has proven the case to expect sudden short term developments scuppering medium range expectations. Always best to be open minded when it comes to the British weather and for sudden changes. The behaviour of the low pressure on Thursday gone and still influencing us now has to be one of the least expected synoptical evolutions I've seen.

 

Edited February 11 by damianslaw

[Rain All Night]

Is the Scandi trough signal anything to do with what's going on in the stratosphere?

The ensemble members on the 24th when that signal looks strongest:

Edited February 12 by Rain All Night

[TQWX]

 WYorksWeather

Not only are SST's likely bottoming out with all the mild air around, but UV is now on the rise. It will be up to level 2 today as far north as Bristol.

[Ali1977]

T300 mean is pretty good 

Edited February 12 by Ali1977

[joggs]

Dreadful output across the suites if it's cold you're after. Can see nothing if note in the reliable and tbh,further out.

Day 10+ charts hardly come to fruition and the means ect too.

I'm ready to call it off now and bring on spring warmth.

Goodluck to those swimming against the tide for winter.......

AN awful excuse of a winter imo.

 

Edited February 12 by joggs

[Nick2373]

 

Cooler conditions still flirting around the 23rd Feb, there is a trend something to watch there is to much faith put in the long range models most of them have shown their true colours this winter.

I'm not ready to chuck anything yet, 10 days is a long time in terms of weather FI To be fair SSW I know doesn't always produce in terms of cold but again given how fickle the UK weather can be nothing is 100% set in stone.     

Edited February 12 by Nick2373

[KTtom]

Ill settle for the ECM 216 please...

[MJB]

GFS                                                                           ECM 

                

lol Bit of a difference at 216

[chrisnoy]

Let's hope the ECM wins out here. Less rain, and pleasant. GFS is awful for rain and muck. ECM still looking as though something can come of heights to our North.