Model Output Discussion - 05/01/2016 18z onwards

[Mucka]

5 minutes ago, Nick L said:

Atlantic starts to win out past +168 but frankly I'm not too concerned, time and again we've seen models being far too eager to shift the cold in the past.

Not quite, energy still moving SE with a Southerly jet screams snow potential.

At least a snowy breakdown.

Don't think it will come to this though, hopefully not. small adjustments and the cold is locked in a la UKMO.

Edited January 12, 2016 by Mucka

[Gazza H]

Arpege 2m temps for saturday 

[Nick L]

1 minute ago, Mucka said:

Not quite, energy still moving SE with a Southerly jet screams snow potential.

At least a snowy breakdown.

For northern hills and lower levels briefly, yes. I'm just interested in the 96-144 period for now anyway, it's uncertain enough at that timeframe. The rest is irrelevant to me!

[Day 10]

I know this is FI now but a good shift in the right direction by the ECM since this morning

[Mucka]

2 minutes ago, Nick L said:

For northern hills and lower levels briefly, yes. I'm just interested in the 96-144 period for now anyway, it's uncertain enough at that timeframe. The rest is irrelevant to me!

Yeah fair comment. The trend is definitely our friend today. 

JMA the party pooper.

Edited January 12, 2016 by Mucka

[feb1991blizzard]

1 minute ago, Nick L said:

For northern hills and lower levels briefly, yes. I'm just interested in the 96-144 period for now anyway, it's uncertain enough at that timeframe. The rest is irrelevant to me!

I take it your not on the Long range team in your job then!!  you would be worried if you had to call something in the 200s given the output!!!!

[BLAST FROM THE PAST]

 

And all of a sudden the sliding stops.  But still very workable from there.  This is very interesting model watching.

 

SE News showed 8c today dropping to 3 c by Sat....well that is plainly ridiculous, it was 3c at 3-30pm today in Redhill...not 8c

 

BFTP

Edited January 12, 2016 by BLAST FROM THE PAST

[Nick L]

Just now, feb1991blizzard said:

I take it your not on the Long range team in your job then!!  you would be worried if you had to call something in the 200s given the output!!!!

Nope, that's the problem of certain colleagues!

We've been here plenty of times before seeing the cold swept away with ease later in the output, I'm not convinced. For now it's just encouraging to see the EC side with the UKMO.

[Mucka]

216 shows how ECM isn't a definitive breakdown with Atlantic dominance. Snowy up North and marginal adjustments to give widespread snow across England.

If that turns out the worse case scenario then I'll take it.

[Day 10]

Poor GFS as usual wanders off too far, gets lost and now can't find his way back!

[J10]

I really like the angle on the ECM T+144 chart, SE winds ahead of a front edging in is what you want, so often in the past we get SW winds and the mild air wins out before a fight.

However so often in the past this is forecast this far out and seldom materialises.

Overall better runs (for wintry potential) tonight and plenty of interest going forward.

Edited January 12, 2016 by J10

[nick sussex]

I wonder what the lowest temps might be especially in the Scottish Glens. The flow looks slack up there for quite a few days and there is likely to be some snow cover which would help those temps dip.

Overall the trend to hang onto the cold has picked up pace this evening. As to where we end up if the models keep on this course, the UKMO could well have further trough disruption off that upstream troughing past T144hrs.

The ECM still looking the mid ground solution between the GFS and UKMO. I do hope the GFS 18hrs run can take another bigger step towards the UKMO. Better still I wouldn't mind if there was a power cut at NCEP, the mood is certainly more festive this evening so if that failed to appear I wouldn't mind. Its had a habit over recent days of deflating things somewhat.

 

[Nick L]

1 minute ago, nick sussex said:

I wonder what the lowest temps might be especially in the Scottish Glens. The flow looks slack up there for quite a few days and there is likely to be some snow cover which would help those temps dip.
 

Grid points showing -15c in places, so would expect a -20c or two on that.

[Hull snow]

2 hours ago, bradythemole said:

GFS 12z Yesterday 144                                     Same time on todays run (120)

Further west, trough more negatively tilted with higher heights around Iceland and southern Greenland.

GFS 168 yesterday                                        GFS same time today (144)

Doubt monday's front will even make the UK if the westward corrections continue. The GFS clearly isnt a UKMO style output but it is slowly correcting the energy more SE.

 

[nick sussex]

1 minute ago, Nick L said:

Grid points showing -15c in places, so would expect a -20c or two on that.

 

Wow that sounds interesting. Is that from the ECM output? Its amazing just how low temps can get if theres no mixing.
 

[Hull snow]

2 hours ago, bradythemole said:

GFS 12z Yesterday 144                                     Same time on todays run (120)

Further west, trough more negatively tilted with higher heights around Iceland and southern Greenland.

GFS 168 yesterday                                        GFS same time today (144)

Doubt monday's front will even make the UK if the westward corrections continue. The GFS clearly isnt a UKMO style output but it is slowly correcting the energy more SE.

 

[Nick L]

1 minute ago, nick sussex said:

 

Wow that sounds interesting. Is that from the ECM output? Its amazing just how low temps can get if theres no mixing.
 

Yep, minimum temperatures on Tuesday morning, widespread minus teens in N England and Scotland. Probably snow cover depending of course.

[Catacol]

Hmmmm  T-24 and ECM produces this:

 

A flip to a -NAO from here would potentially bring some very cold air across from the east.

I think the overall trend remains on course. Cold this week, relaxing of the cold a bit next week - though possibly not as much as the models were suggesting yesterday as we all know breakdowns from the west are often over modelled, and then reestablishment of northern blocking and more intense cold from the end of the week. I'm just restating what GP has already suggested here when he predicted a flip on or around the 23rd.... and the fact that RFS is broadly speaking onboard and Cohen's blog has the wonderfully excited line near the start: " With the AO deep in negative territory and the increased likelihood of a sudden stratospheric warming, if you can’t get excited about the AO blog you probably never will. " all suggests to me that the fun has only just begun, If we do get a full SSW at month's end then Spring is going to be very late arriving....

And while Thursday's snow event may turn out to be a bit of a damp squib, we look perhaps to have another bite at the cherry on Monday. 

Edited January 12, 2016 by Catacol

[Hull snow]

So are we saying if ukmo is right we could see deep cold and snow ?

[Methuselah]

3 minutes ago, Nick L said:

Yep, minimum temperatures on Tuesday morning, widespread minus teens in N England and Scotland. Probably snow cover depending of course.

You might be being a tad optimistic there, Nick? In the 20+ years I stayed near Loch Ness, I think that -20C was only exceeded in 1995/96, 2000/2001 and 2009/10...IMO, it takes a combination of very could uppers (sub -10?) and deep snowcover to achieve minima like that. Is the upcoming spell sufficiently exceptional?

[gottolovethisweather]

26 minutes ago, Nick L said:

Grid points showing -15c in places, so would expect a -20c or two on that.

Imagine predicting those Temps for anywhere at the start of January when we could see nowt in the outputs. As I've said before a week to ten days is a long time in Meteorology. Hence why I often play the game of "get the cold in, the snow should/will come sometime thereafter".

With a wintry mix and snow probabilities being mentioned for parts of lowland UK (mainly the hillier locations currently favoured) within t+48 to t+60 hours and again at around about t+120 to t+132 hours, I for one won't be looking for the BREAKDOWN just yet. Obviously the Atlantic will win out eventually but I'm more intrigued by the entrenched cold and frosts before any of all that rubbish. This is a nailed on seven day cold spell at least, right now.  

Edited January 12, 2016 by gottolovethisweather

[Catacol]

9 minutes ago, Hull snow said:

So are we saying if ukmo is right we could see deep cold and snow ?

In the short term no. I dont think deep cold is on its way in the 10 day period... but beyond that, if the NAO flips negative, it may possibly happen. It is certainly cold to our east, and we have some pretty heavyweight commentators backing a blocked pattern as we head towards the final week of the month.

In the near term we have a much colder pattern than at any time this winter, some marginal conditions that may bring some surprise snow to lowland areas, and the best long term potential I would suggest since March 2013.

[bluearmy]

It seems we have the ops wanting to dispupt in a time period where they should have the upper hand over the ens. 

to me, the questions are

a) can we get the heights north ala UKMO so that the next system goes under aswell

b) if we can't, can we get a weaker system to follow than currently modelled so that it doesn't want to head NE and is happy to disrupt against the weakish upper heights left behind

nickL is only stating what ECM data shows. Min T2m of -18.6C  at T138

Edited January 12, 2016 by bluearmy

[Liam J]

Some bone chilling temps in the north on the ECM!! -10 to -15c into next week  A good covering of snow away from the south but nothing too deep apart from the hills, a few inches or so on lower ground but snow charts not really very accurate tbh. Much better ECM this evening as the cold never really leaves the north and day 10 is sub zero with snow cover still across Scotland and the cold air spreading south again. 

Edited January 12, 2016 by *Sub*Zero*

[Methuselah]

Let's just stick to what the models are suggesting?