Model Output Discussion - Colder but how cold and for how long?

[Cheshire Freeze]

1 minute ago, Battleground Snow said:

You can tell the gfs is still getting the initial Northernly wrong, it adjusted early on,

Models like arpege and ukmo remain consistent with the straighter northernly

I’m not sure it is getting it wrong…the GFS is good at picking up these small shortwaves.

I guess we’ll see.

[Kasim Awan]

5 minutes ago, Cheshire Freeze said:

Next week looks a fuss about nothing for most on the 0z GFS. A brief initial cold plunge then the Atlantic LP failing to engage the cold troughing to the N and NE.

UKMO looks decent though.

If you animate the models through over the next 7 days you can clearly see the cold northerly / easterly being deflected away from the UK by the Iberian high.

[Cheshire Freeze]

1 minute ago, Daniel* said:

I think this is going to turn out great but there’s a notable adjustment over polar field changes in strat adds more complexity.

IMO Dan it’s the strat that is causing these swings in the polar field…and I’ve been thinking this for a while.

[Battleground Snow]

4 minutes ago, Cheshire Freeze said:

I’m not sure it is getting it wrong…the GFS is good at picking up these small shortwaves.

I guess we’ll see.

Perhaps, but I also think it's getting the Greenland profile wrong too.

This is the adjustment from its last run early on 

 

Edited January 11 by Battleground Snow

[O'Maille80]

How long does the ukmo take to load, seems to take longer than usual?

[Daniel*]

2 minutes ago, Cheshire Freeze said:

IMO Dan it’s the strat that is causing these swings in the polar field…and I’ve been thinking this for a while.

To be clear I was missing a ‘not’ tired eyes UKMO definitely best so far, but we have seen this on a number of occasions this winter.

[Connor Bailey Degnan]

ATM this is giving me Decemeber 2022 vibes, very cold with very little snow 

Atleast Initially, but fingers crossed things improve later on!

[Battleground Snow]

Can't deny the fact the gem is rubbish long term this morning.

Looks nothing like it's 12z run 

[Kasim Awan]

Just now, Battleground Snow said:

Can't deny the fact the gem is rubbish long term this morning.

Looks nothing like it's 12z run 

What we get this morning from the output is a repeat of the late November cold snap.

[Cheshire Freeze]

Just now, Battleground Snow said:

Can't deny the fact the gem is rubbish long term this morning.

Looks nothing like it's 12z run 

The culprit? Strat PV pushed back over Canadian side?

 

This is at just 60 hrs-

On the plus side we might see the E winds blow in Feb?

[Ali1977]

Thankfully a good UKMO - need a better ECM 

[Battleground Snow]

Sounds cliché, but feels like a big ecm coming up this morning when ukmo differs so much compared to gfs and gem

Edited January 11 by Battleground Snow

[Kasim Awan]

A cold but largely dry spell is a strong possibility here. The lows responsible for snow risk appear to weaken upon approach to the UK. Still a decent chance of changes.

[Ali1977]

1 minute ago, Battleground Snow said:

Sounds cliché, but feels like a big ecm coming up this morning when ukmo differs so much compared gfs and gem

Looks like a snow maker but not as cold 850s as I hoped - also didn’t think we’d have such downgrades at this stage - clearly much to be resolved still 

Edited January 11 by Ali1977

[Battleground Snow]

1 minute ago, Ali1977 said:

Looks like a snow maker but not as cold 850s as I hoped 

Needs to see dew points but I imagine it would still be snow away from coastal areas

[Cheshire Freeze]

This all goes back to the failed split SSW IMO. Which I mentioned at the time as being significant.

As the SPV pushes across the N Atlantic it looks to me like we’re seeing rapid downwelling of the upper zonals…hence why the blocking seems to just evaporate. Seems the most plausible explanation to me as there seems to be forcing rapidly overwhelming trop based drivers.

Had we got the proper split I think we’d be staring down the barrel of a memorable and prolonged spell now.

I wonder if analysis by the twitter strat gurus will conclude the same thing post season.

 

[Ali1977]

Just now, Cheshire Freeze said:

This all goes back to the failed split SSW IMO. Which I mentioned at the time as being significant.

As the SPV pushes across the N Atlantic it looks to me like we’re seeing rapid downwelling of the upper zonals…hence why the blocking seems to just evaporate. Seems the most plausible explanation to me as there seems to be forcing rapidly overwhelming trop based drivers.

Had we got the proper split I think we’d be staring down the barrel of a memorable and prolonged spell now.

I wonder if analysis by the twitter strat gurus will conclude the same thing post season.

 

If it’s the SSW causing issues then hopefully the METO models have this ironed out - the arpege looks good and at short range than should be better than the GFS.  Hopefully the op is an outlier too

[Cheshire Freeze]

1 minute ago, Ali1977 said:

If it’s the SSW causing issues then hopefully the METO models have this ironed out - the arpege looks good and at short range than should be better than the GFS.  Hopefully the op is an outlier too

It’s as simple to me as the displacement of the SPV to the Eurasian side of the hemisphere has not been strong or long lasting enough. Displacing back a touch too early to allow blocking in the North Atlantic sector to properly take hold and deliver.

A split would have ensured more opportunity for blocking to manifest and result in a protracted spell of winter weather.

The trop and strat look well coupled to my eyes in places, especially N Atlantic sector and towards the Aleutian side.

[Battleground Snow]

9 minutes ago, Ali1977 said:

If it’s the SSW causing issues then hopefully the METO models have this ironed out - the arpege looks good and at short range than should be better than the GFS.  Hopefully the op is an outlier too

Add jma to the positive list too,

One thing for sure if we are getting model drama every set.

 

[Kasim Awan]

If this morning's runs are correct snow chances will be very few and far between.

[Continental Climate]

It does seem that the blocking is more robust on the European models. UKMO APERGE are good. I know we always say it but a really big ECM this morning. If it follows UKMO then we could squeeze a bit more out of this cold spell. I do however believe that blocking will fizzle out although it was always meant to around the 23rd 24th anyway before the next bout of amplification takes hold end of month. If I can get some snow on the ground that sticks for 5 days I will be happy. This is the UK after all. 

[Battleground Snow]

3 minutes ago, Continental Climate said:

It does seem that the blocking is more robust on the European models. UKMO APERGE are good. I know we always say it but a really big ECM this morning. If it follows UKMO then we could squeeze a bit more out of this cold spell. I do however believe that blocking will fizzle out although it was always meant to around the 23rd 24th anyway before the next bout of amplification takes hold end of month. If I can get some snow on the ground that sticks for 5 days I will be happy. This is the UK after all. 

Forgot about checking the icon this morning for some reason.

So it's icon, jma, ukmo, arpege v gfs and gem in the mid range this morning 

[That ECM]

I thought this morning good or poor direction of travel should be clearer. T168 and these two. 

 

 

[Continental Climate]

I feel some ppl may have been expecting 2010 redux with this cold spell. Reducing your expectations really does help. Like I said in my previous post 5 days with a couple of inches of snow on the ground. Throw in a day or two of freezing fog and I will be very happy. I had 5 days of snow in early December as well. If this spell delivers like I want then I will consider this winter a success regardless of what Feb delivers. 

[nick sussex]

A mixed start to the day with a blend of good and less good output .

The UKMO is the pick of the bunch with a cold extension likely post day 7 .

The NA models want to collapse the block quickly and become very messy.

Edited January 11 by nick sussex