Model output discussion 24/01/21

[Battleground Snow]

Its going to be on a knife edge whether or not the para can build a scandi high later on in to the run.

[northwestsnow]

Liking the trend on GFS 6Z and para looks even better...

Keep correcting south GFS !

[Griff]

Just now, Griff said:

 

 

Just now, Battleground Snow said:

Its going to be on a knife edge whether or not the para can build a scandi high later on in to the run.

 

Just now, northwestsnow said:

Liking the trend on GFS 6Z and para looks even better...

Keep correcting south GFS !

Mr Hugo saying,

"Those thinking winter is over are likely to be wrong..."

 

[TSNWK]

3 minutes ago, Jason H said:

Snow chances at the weekend, ushered away sharpish by the Atlantic. Then what? 

Thank you.  It's clear as the nose on our faces that the broader pattern is set from when any transitory snow event comes through in Sunday that event will be the transfer of pattern to Atlantic phase next week.  The big pattern changes are signalled accuratly and well in advance. 

[IDO]

The gfs 06z shows no move towards the gem at the weekend. The gfs op is just slower with the Atlantic pushing through and we know from the past, this is expected. The gem undercuts the wedge with some disruption to the Atlantic trough, to prolong the cold:

gfs D6>gem?

Sadly on this chart the gfs is not even close to undercutting. Maybe a blend of the two, no undercut but the low slowing down further?

[Battleground Snow]

3 minutes ago, IDO said:

The gfs 06z shows no move towards the gem at the weekend. The gfs op is just slower with the Atlantic pushing through and we know from the past, this is expected. The gem undercuts the wedge with some disruption to the Atlantic trough, to prolong the cold:

gfs D6>gem?

Sadly on this chart the gfs is not even close to undercutting. Maybe a blend of the two, no undercut but the low slowing down further?

The move to gem was at 72-96, with a stronger wedge

[IDO]

1 minute ago, Battleground Snow said:

The move to gem was at 72-96, with a stronger wedge

I am not sure that a wedge, even stronger, will hold back another Atlantic push? Wedges tend to go with the flow once beyond a breaking point and the gfsP has now come into line with that consensus. I would never trust gem where blocking is concerned as the verification shows in the last 10 days:

gfsP>

[Battleground Snow]

3 minutes ago, IDO said:

I am not sure that a wedge, even stronger, will hold back another Atlantic push? Wedges tend to go with the flow once beyond a breaking point and the gfsP has now come into line with that consensus. I would never trust gem where blocking is concerned as the verification shows in the last 10 days:

gfsP>

For sure the Atlantic pushing through is the favoured option right now, but it's still on a knife edge at 120

Edited January 26, 2021 by Battleground Snow

[northwestsnow]

LOL..

6Z sinking the jet a treat...

Heavy snow into the North West into FI....

[northwestsnow]

Heavy snow moving south...

 

[northwestsnow]

North buried on 6z GFS..

One can dream...

[MJB]

2 minutes ago, northwestsnow said:

Heavy snow moving south...

 

Decent FI for sure 

 

Edited January 26, 2021 by MJB

[IDO]

2 minutes ago, Battleground Snow said:

For sure the Atlantic pushing through is the favourite option right now, but it's still on a knife edge at 120

Never say never with weather, but the trend is your friend, or not in this case, and with only gem and a handful of gefs now pointing in that direction with T-5days, I am doubtful. There is a good chance we may get another stalling front at the weekend before the Atlantic rolls in so fingers crossed for that boundary for some temporary snow?

I am still sitting firmly on the fence as to after the Atlantic trough has emptied east/SE. The gfs op 06z is probably the favourite:

The UK (south) relying on scraps and just not cold enough uppers for anything too interesting. The north and elevation will enjoy that NW'ly flow.

[northwestsnow]

Who needs a Greeny or Scandy high anyway...

[winterof79]

10 minutes ago, IDO said:

Never say never with weather, but the trend is your friend, or not in this case, and with only gem and a handful of gefs now pointing in that direction with T-5days, I am doubtful. There is a good chance we may get another stalling front at the weekend before the Atlantic rolls in so fingers crossed for that boundary for some temporary snow?

I am still sitting firmly on the fence as to after the Atlantic trough has emptied east/SE. The gfs op 06z is probably the favourite:

The UK (south) relying on scraps and just not cold enough uppers for anything too interesting. The north and elevation will enjoy that NW'ly flow.

Any thoughts on Matt Hugos comments /gifs and trends? 

Edited January 26, 2021 by winterof79

[feb1991blizzard]

Oh dear - not great.

[IDO]

1 minute ago, winterof79 said:

Any thoughts on Matt Hugos comments /gifs and trends? 

I have no idea. This is def a one-off year and I would not rule anything in or out? Feb could see quick responses to background signals so looking post-d10 will be less useful than it is normally. If every year was similar to this I would not complain and although it has been more miss than hit in the south so far, it is much better than if the SSWE did not happen. I am one for patterns so I would say more of the same for the remaining Winter if I was pushed.

The 06z shows the average period in the next 8-days IMBY:

Low chances of snow over the weekend, the op being one of the coldest at that point.

[Vikos]

43 minutes ago, Griff said:

 

 

Mr Hugo saying,

"Those thinking winter is over are likely to be wrong..."

Does he mention where this is? Nowosibirsk is definitely still in game for some colder spells

[Vikos]

17 minutes ago, northwestsnow said:

Who needs a Greeny or Scandy high anyway...

Me. Would even order one at Wish! if they would deliver in time...

[northwestsnow]

1 minute ago, Vikos said:

Me. Would even order one at Wish! if they would deliver in time...

Lots going on ..

MJO could be our wildcard....I'm still looking west or North West height rises as we move through early Feb...

[Catacol]

1 hour ago, Penicuikblizzard said:

Going by recent times March has to be favourite for everything to fall into place for a bitter spell

Good point. A hell of a lot of weather chaos to flow under the bridge yet before we get to March, but with what happened in 2013 and 2018 another cold March this year would raise eyebrows. With 2010 as a distinct outlier it has felt for a while that winter gets delayed, an architect of CC and possibly an effect of stronger vortex development in the autumn combined with a greater propensity for wave flux impacts on the vortex mid winter to create greater SSW potential? I'm thinking aloud really and without anything like the kind of data set needed to begin to contemplate anything robust...but substantial SSW events FEEL like they may be increasing in frequency, meaning the autumnal feel to December brought about by a cooling stratosphere and consequent stronger vortex is then offset by midwinter SSW events - which have a lifespan of 30 to 60 days afterwards. The impacts of what happened a couple of weeks ago will roll through the rest of winter now, and any top up to vortex distress would enhance the probability of a cold March especially given the greater likelihood of blocking patterns as winter moves towards spring.

All interesting stuff. My new job has kept me mighty busy these last 3 weeks, but my head is slowly coming up. Missed some snow on Sunday by about 25miles, but very optimistic about February from here. Trop drivers beginning to engage as we hoped they would at this stage of winter, and a moderate MJO progression with accompanying increase GLAAM may be enough to boss the pattern and grab the steering wheel from the downwelling vortex disruption that has held sway through the last 2 weeks.

Thusfar a slightly perplexing January. Scotland has been buried in parts, and regularly....but the pattern has refused to pull back west far enough to engulf all of England with similar cold and snow, though there have been more frosts and more near/minor snow events this January across many parts of the UK than we have experienced in a long run of Januarys. 

Cant complain...but we all know we havent quite hit the nationwide jackpot. A cold spell digging in for a week with snow spread widely has managed so far to evade us. But February is looking good. Southerly tracking jet, pacific driven height rises once again, weak vortex impacts, cold air more established out east. February has always been our best winter month statistically. Bring it on....

Edited January 26, 2021 by Catacol

[carinthian]

3 hours ago, carinthian said:

Good summary @Nick F. The team over here still think post weekend remains up for grabs. I think your best bet to retain a longer spell of cold is for the undercut scenario to develop. The out parameter results for the snow computer has flagged up some snow depths of 10cm + for parts high ground in the North of England on Saturday with what appears some convective snow rates for a time . However, that is still along way off. What interests me is the now forecasting period over the next 3 to 4 days. The wedge of cold between Scotland and Iceland tries to hold ground.

C

Just out of interest the wedge of cold Arctic air is now locked over Torshavn for a least 4 to 5 days  going by at the latest models. The picture is from the airport and temp is currently -5c with -10c 850mb level temps getting established as shown from the last sounding for the location with a solid Arctic profile way up past 500mb level. Longer term we need to see this set up consolidate and force some undercut into the British Isles. Still out to 96 hours remains up for grabs according to the team over here but current  operational runs apart from GEM not in favour as yet !

C

Edited January 26, 2021 by carinthian

[Battleground Snow]

Mean isn't too bad at 252, alot of the members try to throw a ridge from the Atlantic towards Iceland.

 

 

[Methuselah]

No T+300+ megabeast on today's GFS 06Z -- I guess that's down to 'missing data'! Not to fear though: the 12Z knows more!?

    

[Severe Siberian icy blast]

31 minutes ago, carinthian said:

Just out of interest the wedge of cold Arctic air is now locked over Torshavn for a least 4 to 5 days  going by at the latest models. The picture is from the airport and temp is currently -5c with -10c 850mb level temps getting established as shown from the last sounding for the location with a solid Arctic profile way up past 500mb level. Longer term we need to see this set up consolidate and force some undercut into the British Isles. Still out to 96 hours remains up for grabs according to the team over here but current  operational runs apart from GEM not in favour as yet !

C

You tease so they expect the gem to be along the right lines? 

We've already saw how stubborn the cold can be, these weak heights are hard to model, I'm quite hopefull about the 12z, remember of course anything past 120 atm is just for fun, unless it shows cold and snow then it's picked up on the obvious pattern