Model output discussion 02/02/20

[Don]

2 hours ago, snowblind said:

Reckon at that range they're overdoing the mild just like they overdo the cold. Expect it will be milder than average but not to the extent shown here.

I certainly wouldn't bet against the mild they are showing!  That's certainly not to say I want them to be correct mind!

[Cheshire Freeze]

Sleet/snow will likely fall to modest levels Monday afternoon/evening across the Midlands/ Wales associated with a little front crossing the country. Winds shown to fall light as it passes

This should support a marginal event- uppers borderline, thickness borderline, but a good chance of seeing some snow fall nonetheless

[Don]

5 minutes ago, CreweCold said:

Sleet/snow will likely fall to modest levels Monday afternoon/evening across the Midlands/ Wales associated with a little front crossing the country. Winds shown to fall light as it passes

This should support a marginal event- uppers borderline, thickness borderline, but a good chance of seeing some snow fall nonetheless

I suspect this could be the snow of the winter for many?  Not in the far south mind.

[Cheshire Freeze]

1 minute ago, Don said:

I suspect this could be the snow of the winter for many?  Not in the far south mind.

Well all the ingredients are there for a period of heavy, wet snow.

Won't stick for most but will be nice to see it fall.

[LRD]

Well I was mocked, yesterday, for calling a 'heatwave' (half jokingly) but, in relative terms, it still looks far more likely than this phantom northerly some on here were seeing

Awful, especially that a horrible spring will likely follow

Edited February 7, 2020 by LRD

[Don]

27 minutes ago, CreweCold said:

Well all the ingredients are there for a period of heavy, wet snow.

Won't stick for most but will be nice to see it fall.

Yes, absolutely.  Doubt I will see any and it's now looking likely it will be one of those winters where I don't see a single flake, which is rare even in the south during a mild winter!

[Cheshire Freeze]

2 minutes ago, LRD said:

Well I was mocked for calling a 'heatwave' yesterday but, in relative terms, it still looks far more likely than this phantom northerly some on here were seeing

Awful, especially that a horrible spring will likely follow

CFS averaged runs are showing a continuation of HP to the S and SE until April. By May we see a flip and N blocking starts to take hold

May

June

[Don]

1 minute ago, CreweCold said:

CFS averaged runs are showing a continuation of HP to the S and SE until April. By May we see a flip and N blocking starts to take hold

May

June

They still look like potentially warm months, though with an air mass from a southerly/south easterly quadrant.  Obviously too far away to really go into that sort of detail, though!  

[Cheshire Freeze]

1 minute ago, Don said:

They still look like potentially warm months, though with an air mass from a southerly/south easterly quadrant.  Obviously too far away to really go into that sort of detail, though!  

Warm and potentially very wet/thundery I get from that...especially June.

Edited February 7, 2020 by CreweCold

[LRD]

10 minutes ago, CreweCold said:

Warm and potentially very wet/thundery I get from that...especially June.

Yes that's how I read that June chart. Hot and wet. What's not to like?!  

Edited February 7, 2020 by LRD

[Nick F]

UKMO fax chart for noon Monday shows a frontal wave crossing the southern half of Britain during the afternoon. Could be a spell of snow for north Wales. N Mids, southern side of northern England along the apex of the frontal wave moving east as colder sub 528 dam air undercuts from the west.

UKV charts for 12z and 15z Monday 

Otherwise, plenty of snow showers peppering Scotland, N England, island of Ireland, Wales on Tuesday and Wednesday. Settling probably confined to higher ground during the day and on Wednesday showers turning more to sleet and rain away from higher ground as the day wears on. BUT will there be a few flurries getting further east in the south too Tuesday?

After that, quite a bit of disagreement with the mid-to-late week low tracks and the lows following it.

12z GFS and similar last few runs swings the first of its mid-to-late week lows N as it approaches NW Britain before another low hot on its heels merges with it and this low tracks NE close to Scotland. The next low behind it also merges and GFS keeps a flatter zonal flow going through the weekend and into the early following week. 

UKMO as far as it goes, EC and GEM more southerly tracking with a mid week low, then EC and GEM, unlike GFS, blow up the next low behind over the NW Atlantic and track it NE across Iceland, forcing the Azores ridge across Europe, southern UK becoming settled in contrast to GFS. 

Even the GFS's own ensembles mostly agree with EC and GEM, EC well-supported by EPS members looking at the 50 members, so for now, would think last few runs of GFS op showing continuation of southerly and zonal jet track not the favoured solution going forward into 2nd half of the month. 

Be interesting to see if the 18z GFS rolling out continues the the of the last few op runs ...

 

Edited February 7, 2020 by Nick F

[Don]

4 minutes ago, CreweCold said:

Warm and potentially very wet/thundery I get from that...especially June.

Yes, I would agree with that.  So, although northern blocking is evident on those charts, the UK is still warm, much like last summer!

Edited February 7, 2020 by Don

[Mike Poole]

For info re Sunday, posted in storm thread...copied here as is model related.

1 hour ago, Mike Poole said:

I posted this in the MOD yesterday but probably now more relevant in this thread.  It is interesting to post the same charts from the ARPEGE ensembles 24 hours on, these from today's 6z.  The 5 plots below show, for maximum wind gusts through to close of play Sunday, the minimum, 25%, median (50%), 75% and maximum over the distribution of uncertainty:

interesting that the uncertainty doesn't really seem to have reduced if at all, but the 50% and 75% plots seem to have edged upwards a notch, so I think the comments on here about the severity of this, particularly the geographical extent of it, vis-a-vis the MO warnings are entirely justified, and it ties in with what others have said about the ECM 12z op.  However, the point about the wide uncertainty range remains, and this may be why we will need to wait until tomorrow to see if more widespread warnings are issued by the MO.

 

 

 

[Cheshire Freeze]

1 minute ago, Don said:

Yes, I would agree with that.  So, although northern blocking is evident on those charts, the UK is still warm, much like last summer!

At this early point, I'm plumping for the trough to be closer to, or over, the UK for the early summer period.

[Mike Poole]

Just now, CreweCold said:

At this early point, I'm plumping for the trough to be closer to, or over, the UK for the early summer period.

You usually do!

[Cheshire Freeze]

2 minutes ago, Mike Poole said:

You usually do!

Not at all, there has been a couple of times over the past few years where I've diverged from what you're suggesting. 

Not after debate though. Just my early thoughts. 

'Typical' low solar summer for me- can still be a good one though depending where the high lat blocking is centered.

Edited February 7, 2020 by CreweCold

[Mike Poole]

3 minutes ago, CreweCold said:

Not at all, there has been a couple of times over the past few years where I've diverged from what you're suggesting. 

Not after debate though. Just my early thoughts. 

'Typical' low solar summer for me- can still be a good one though depending where the high lat blocking is centered.

I'm joking, I haven't even begun to think of prospects for summer yet!  But re bolded bit, we didn't exactly have a typical low solar winter did we?  

Signals into summer from CFS model are weak at the moment, I think a key thing might be the exact way winter ends and the strat final warming, albeit in spring.

[Don]

9 minutes ago, CreweCold said:

Not at all, there has been a couple of times over the past few years where I've diverged from what you're suggesting. 

Not after debate though. Just my early thoughts. 

'Typical' low solar summer for me- can still be a good one though depending where the high lat blocking is centered.

Lets just hope we see a 'Typical' low solar early 2010's type winter to follow!

Edited February 7, 2020 by Don

[northwestsnow]

Last time i looked the longer range models were hinting at a strong La Nina which i believe is not great news for summer lovers.

I should add the above could be hogwash in all fairness.

[Cheshire Freeze]

1 minute ago, northwestsnow said:

Last time i looked the longer range models were hinting at a strong La Nina which i believe is not great news for summer lovers.

I should add the above could be hogwash in all fairness.

Nina would give us a fair shot of a wet summer

Enso neutral would suggest greater than average chance of repeated Azores HP influence

[Nick F]

1 minute ago, Mike Poole said:

Signals into summer from CFS model are weak at the moment, I think a key thing might be the exact way winter ends and the strat final warming, albeit in spring.

Summer tends to be more tricky to forecast any trends than winter, as the PV is absent and the MJO has little impact on northern hemisphere patterns. I imagine Atlantic SSTs and ENSO may play more of a role. Warmer waters tend to promote higher pressure downwind, so warmer Atlantic to our west maybe attributable to Azores extension, for example. 

[Don]

2 minutes ago, CreweCold said:

Nina would give us a fair shot of a wet summer

Enso neutral would suggest greater than average chance of repeated Azores HP influence

We need a strong La Nina to help suppress the soaring Global temperatures!

[Mike Poole]

5 minutes ago, Nick F said:

Summer tends to be more tricky to forecast any trends than winter, as the PV is absent and the MJO has little impact on northern hemisphere patterns. I imagine Atlantic SSTs and ENSO may play more of a role. Warmer waters tend to promote higher pressure downwind, so warmer Atlantic to our west maybe attributable to Azores extension, for example. 

Agreed, I guess I was thinking a little earlier than that if an explosive final end to the strat vortex was to cause high lat blocking that persisted into summer, I don't necessarily think this will happen this year.  But as I said earlier I haven't given summer that much thought this year yet - probably obviously!

[mb018538]

Suffice to say, all conjecture at this range. I’d also go along and say more 2019 than 2018 too, just because of how strong the PV/AO has been through winter. Just got a hunch it will collapse down to very late northern blocking through late spring, much like last year. 

[MATTWOLVES 3]

Blimey folks, have you got access to the tarot cards with all the talk of summer.. Hey, I tell you what, we should start a new competition for what date the first summer is over post comes in at!! I reckon May 1st.. Just a a quick mention on tonight's ECM mean, we have a window of opportunity for some snow to fall, and perhaps in more places than you may be expecting! Beyond that, pressure is close to the South, with temps on the up again,, still plenty of cold pooling into the North Atlantic, and that big old purple blob shifts ever so slightly East, I tell you what it is still a menacing sight... And I reckon when it finally disrupts we could be looking at some sharp cold devoloping as we enter early spring! Get ready for a good old fashioned Easter dumping...