Model output discussion - 20th Feb onwards

[Daniel*]

Tilt not great at 72hrs going to topple over still colder than GFS:

[Snowynorth]

9 minutes ago, Steve Murr said:

In terms of polar sourced air this is the boom chart of all winter -

If that's the case it highlights how desperate we are and what a poor winter it has been. Don't get me wrong we see colder air but the northerly flow topples very quickly on that chart!

Edited February 20, 2016 by Snowynorth

[Ice Day]

Very cold uppers at 120hrs, -9's still over the north east 

 

[The Enforcer]

1 hour ago, Ice Day said:

Followed by an almost nationwide snow event at 138

You know what GFS is like at expanding the actual snow risk - that's probably just snow over the tops of the Pennines.

2 hours ago, Banbury said:

Snow across the UK, far from dry

Of course there's a pocket of rain in there, triggering an initial Mild Sector Alert

2 hours ago, Polar Maritime said:

Another cold run from the GFS this afternoon, With a plenty of snow risk by next Friday. It's been a long while since we've seen wintry charts like these 

It seems that elevation is needed in the south to benefit from the snow risk.

 

At least there are only another 23 runs to get through.

Edited February 20, 2016 by The Enforcer

[NorthernRab]

17 minutes ago, Allseasons-si said:

And by 96 hrs,-8's across the country with a pocket of -9

 

There are -10'C uppers shown over the country here. 

[Snowynorth]

5 minutes ago, Daniel* said:

Somewhat underwhelming the good thing is ECM has been keen to lead us up the garden path numerous times also the UKMO has a similar trait this winter the GFS on the other hand less so.

GFS has been shocking of late and the ECM has been the model that's managed to end up being correct.. 

 

I have more faith in the ECM than any other model and I believe again it will be the ECM that nails it.

Edited February 20, 2016 by Snowynorth

[Tim Bland]

So it looks like the snow (M4 corridor) event for Tuesday has all but diassapeared on latest  UKMO / ECM. I wouldn't get too hung up on the details of Friday yet if we can even nail 3 days away! 

[Captain Shortwave]

Day 6 onwards looks very messy on the ECM with an area of low heights dropping towards the Azores with another secondary system moving towards the UK during this period, the result is 2 shallower systems instead of the large deep low shown on the mornings suite.

Before then, we have a 48 hour window in the south (longer in the north) where conditions are good enough for snow to fall to low levels.

   

-7C or lower for near enough all of the UK. Scotland is at this point by midday Tuesday. Can we get a showery trough or occlusion to bring snow during this period as this looks to be the best cold plunge in quite a while.

The latter frame whilst showing a flatter pattern does allow cold air to filter into the Uk, though it is borderline in terms of snow.

Edited February 20, 2016 by Captain Shortwave

[chris55]

25 minutes ago, Snowynorth said:

If that's the case it highlights how desperate we are and what a poor winter it has been. Don't get me wrong we see colder air but the northerly flow topples very quickly on that chart!

Actually look at the charts Snowy, some very cold air remains in situ widely.

Remember Dec 2010? one of the coldest months on record! Check out the 850s during the month, we didn't get that much colder than -10 and in general 850s were consistently around -5ish!

ECM 96 and 120

And at 144 no topple is in evidence!

Try and read the charts for what they are.

 

Edited February 20, 2016 by chris55

[Duane S.]

No real surprise to see the GFS and ECM outputs when looking at the the respective NCEP and ECMWF MJO forecasts of late.

Still it is pretty unusual to see the GFS throwing big ridges into the promised land whilst the Euros are less amplified 

Difficult to call, all to play for though. With the current goings on in the strat, late winter El Niño and the tropical convection where it is, this is the best chance of some proper cold all winter for me.

[IDO]

6 minutes ago, Snowynorth said:

GFS has been shocking of late and the ECM has been the model that's managed to end up being correct.. 

 

I have more faith in the ECM than any other model and I believe again it will be the ECM that nails it.

Really, ECM has been fluid as have all the models as this current output has high entropy as to how it will develop. The last three runs for around the same time:

On this run the D7-D8 low looks very marginal for snow for most as uppers are warmed out, probably hills and mountains initially.

The GEFS are all over the place so expect ups and downs in the next few days re Friday's low.

[Ice Day]

Well a very messy run from ECM (not saying it's going to be wrong), however what is still encouraging is that it remains cold throughout.  I think our Scottish members maybe getting a lot of the white stuff over the next week or so!

[nick sussex]

Not sure what to make of the ECM.  It never shows proper pressure rises over Greenland. At least it doesn't have a good block too far west which would really annoy me!

Its output is the sort that would be very interesting in mid winter with lots of shortwaves dropping se towards the UK but at this late stage the issue is the depth of cold.

Whether this output survives till tomorrow is doubtful, messy and unconvincing sums it up.

In terms of whether theres a chance for any snow off that trailing front, I don't think the shortwave low will effect the UK , its whether perhaps a wave develops on the front bringing some precip back north, here its still a bit too far south but this type of scenario looks probably the best chance if its going to happen:

 

 

[Timmytour]

Some of the best looking wintry runs from the models that I've seen this winter since the early days of January. In terms of what the runs looked like they were actually the best I've seen for a couple of years.

I just hope the weather we end up getting delivered ends up bearing a lot more resemblance to what they are showing now, than it did for those stella runs we were seeing six weeks ago!!

Edited February 20, 2016 by Timmytour

[karyo]

Nick, I am more interested in that trough in the northwest.

(somehow, I can't reply to a post)

[nick sussex]

2 minutes ago, karyo said:

Nick, I am more interested in that trough in the northwest.

(somehow, I can't reply to a post)

Oh yes I missed that somehow! lol Something to keep an eye on, it would be good to see something pop up given the 850's especially on the ECM are condusive.  If you look closely at the ECM between T96 and T120hrs you can see a kink in the isobars heading se.

[karyo]

Yes Nick, also the ECM precipitation charts show it nicely.

 

http://en.vedur.is/weather/forecasts/atlantic/#type=prec

 

[Daniel*]

58 minutes ago, Tim Bland said:

So it looks like the snow (M4 corridor) event for Tuesday has all but diassapeared on latest  UKMO / ECM. I wouldn't get too hung up on the details of Friday yet if we can even nail 3 days away! 

Nope there has been a southern 'correction' on ECM it will probably change again for good or worse 

In fact it looks largely south of the M4 corridor on the plus side -5C isotherm gets in 6 hours faster clearing Hampshire coast as of 0600 on the negative side of that there is less ppn available & most intense ppn is out in English Channel. Surprise, surprise still on course for some snow Tuesday morning to snow starved southern counties.

Edited February 20, 2016 by Daniel*

[terrier]

Is it just me or does anyone else feel underwhelmed with the output tonight. Yes the gfs was a decent run but looks like the euros are slightly against the idea. I know the euros are better placed overall in the standings. Maybe model fatigue has set in for me but I'm certainly not banking on that gfs 12z run been anywhere close to what it's showing for back end of next week. But I would love the gfs to prove me wrong. 

[stodge]

26 minutes ago, terrier said:

Is it just me or does anyone else feel underwhelmed with the output tonight. Yes the gfs was a decent run but looks like the euros are slightly against the idea. I know the euros are better placed overall in the standings. Maybe model fatigue has set in for me but I'm certainly not banking on that gfs 12z run been anywhere close to what it's showing for back end of next week. But I would love the gfs to prove me wrong. 

Evening all

I suppose the question would be "what do you expect ?". There are some very exciting and synoptically interesting charts among the model output tonight but you're never going to get complete and unchanging agreement across all models at T+144. Small variations and nuances in the synoptic pattern have big impacts on our small islands.

So comments on tonight's output:

1) GFS: you can almost feel the OP attempt to go for all out northern blocking but it doesn't quite make it (though a number of the Ensemble Members do). Into low-res and the possibility of the HP setting up close to or just south of the UK remains and can't be ignored.

2) ECM isn't bad output at all in my view either albeit it's messy (the synoptic pattern is sometimes) and you'd like to see stronger heights to the NE or NW.

3) UKMO looks the most interesting of all the output tonight and you'd love to see the T+168 chart and whether WAA gets going up the east coast of America to support the strong mid-Atlantic HP.

4) GEM is a disappointment but I always find this model the most progressive and creates stronger LP areas than most.

5) Here's JMA hot off the press. Note the signs of heights over Scandinavia - we need these to build and quickly otherwise the Atlantic pushes back topples the ridge and it's back to square one. Problem is of course the 850s - if you like your rain cold, no problem. I think we'd see snow to elevation but rain further south.

[feb1991blizzard]

The ECM ensembles at D10 are horrendous, lets hope the MOGREPS hold firm.

[Man With Beard]

On the NOAA 8-14, you can easily see the potential for a Nly or NEly at times, with pressure high to our west and low to our east

The GFS mean at D10 isn't entirely different, and would favour a northerly flow (or even NE) of some kind. 

A look at the GEFS members sees a fair few useful blocks to the WNW / NW, leading to cold solutions D10-D13.

But by this time the ECM mean has the high a bit more to the SW than W, and suggests no long-term northern blocking for the time being:

Of course, this chart doesn't demonstrate any clusters, but at the very least suggests a number of members going for low pressure moving in more of a straight line between Greenland and Norway - which would promote westerly domination and possibly double-figure temps.

So to sum it all up, there is still a fighting chance of northern blocking emerging for the month's end, but no champagnes to be uncorked as yet (or fits of depression for those longing for spring, either!)

Edited February 20, 2016 by Man With Beard

[mushymanrob]

17 minutes ago, Man With Beard said:

On the NOAA 8-14, you can easily see the potential for a Nly or NEly at times, with pressure high to our west and low to our east

The GFS mean at D10 isn't entirely different, and would favour a northerly flow (or even NE) of some kind. 

A look at the GEFS members sees a fair few useful blocks to the WNW / NW, leading to cold solutions D10-D13.

But by this time the ECM mean has the high a bit more to the SW than W, and suggests no long-term northern blocking for the time being:

Of course, this chart doesn't demonstrate any clusters, but at the very least suggests a number of members going for low pressure moving in more of a straight line between Greenland and Norway - which would promote westerly domination and possibly double-figure temps.

So to sum it all up, there is still a fighting chance of northern blocking emerging for the month's end, but no champagnes to be uncorked as yet (or fits of depression for those longing for spring, either!)

Yep a fair summery,  but what it doesnt support is a strong greenland high like the ecm doesnt.  Therefore id have thought the chances of any chart suggesting a strong greenland high is likely to be wrong. 

[Frosty.]

15 minutes ago, feb1991blizzard said:

 

I agree with feb1991blizzard, the Ecm 12z ensemble mean at day 10 is pish poor compared to last night when the PFJ was down as far south as North Africa whereas tonight it's across southwest England but why worry about day 10 when next week shows a change to colder conditions from the north with increasing frosts and potential for snow for some parts of the UK..day 10 will look different again in the morning and beyond.

[feb1991blizzard]

6 minutes ago, Karl. said:

I agree with feb1991blizzard, the Ecm 12z ensemble mean at day 10 is pish poor compared to last night when the PFJ was down as far south as North Africa whereas tonight it's across southwest England but why worry about day 10 when next week shows a change to colder conditions from the north with increasing frosts and potential for snow for some parts of the UK..day 10 will look different again in the morning and beyond.

Yes, I only remember the 0z from memory though but the GEFS are trending back up in second half of run as well, lets hope the 0z's can continue with the MOGREPS last nights theme.