Cold hunt - models and chat

[snowbob]

6 minutes ago, MidnightSnow said:

The second part of Marco Petagna's in case anybody didn't see it.

"2/2 All might not be lost though as models are widely in favour of shifting the tropical #rain bearing #MJO phenomenon firmly into phase 6 or 7 in the next couple of weeks...which ties in nicely with our UKMO forecast of #cold or v cold #weather developing end Jan into Feb"

 

 

I now get mjo basics

phase 7

greenland hp

-ve nao

uk far better chance 

thank you @Johnp

 

Edited January 21, 2019 by snowbob

[Updated_Weather]

3 minutes ago, MattStoke said:

Doesn’t matter how wet the ground is. As long as it’s cold enough, snow can settle. Seen it loads of times.

Exactly what I was about to say! I remember we had rain and there was puddles and as it got colder, snow began to fall and in the heavier bursts it started to stick. I've always told people it's never to wet for snow to stick

[DanDorsetUK]

Looking at those latest tweets about the SSW downwelling this could be the reason we keep seeing good signs in fi charts. Obviously the models know the SSW has accured but maybe quite simply getting the downwelling time respose wrong or trying to second guess when this happens?

[kold weather]

Well the 18z GFS control run looks a lot more realistic looking pattern in the Atlantic once we do get an attempt at a ridge and although it does bend to the east the set-up with regards to the ridging further NW looks FAR more realistic as well. The GFS op yet again did something different in the Arctic despite looking somewhat better in the Atlantic zone.

Also a much better looking snow attempt between the 29-31st. Will be interesting to see how it reflecs on the GFS ensembles overall, as it was quite marked on the ECM ensembles.

[karlos1983]

I’ll sign off with some much improved EC ENS

Get this weekend out of the way and we nose dive 

Edited January 21, 2019 by karlos1983

[snowbob]

1 minute ago, karlos1983 said:

I’ll sign off with some much improved EC ENS

Get this weekend out of the way and we nose dive 

Now that I do get 

far better

very encouraging signs

[kold weather]

10 minutes ago, Catacol said:

 

Downwelling winds are going to put the brakes on.....and when the point of no return arrives the high will break through to the north, the jet will split and dive south and we will end up in very good conditions for a wintry product.

When? I've given up trying to get timing right this winter - so far we have had to demonstrate extreme patience and trying to put a date on a change to cold has been very difficult. The MetO have been fairly solid for a while now on a turn at the end of Jan/early Feb and more tweets today suggesting the same.... so let's go with them. This would suggest a change in the charts to something dramatic looking within a few days - maybe end of the weekend. When the signal for high pressure breakout is picked up I think it might be a swift transition.

 

Yeah, I mean the GFS for example has been toying with making some good -ve AO action but each run has thrown up something different today so there can really be no confidence in that at all yet.

I'm still sticking with 5-10th Feb for a decent burst of northern blocking. I'll probably be wrong, but I'll go down being wrong!

[Catacol]

1 minute ago, Rapodo said:

Looking at those latest tweets about the SSW downwelling this could be the reason we keep seeing good signs in fi charts. Obviously the models know the SSW has accured but maybe quite simply getting the downwelling time respose wrong or trying to second guess when this happens?

I think errors with the downwelling speed has absolutely been at the heart of the delays....and we are left drumming our fingers. Meanwhile the tropical signal has also not played ball entirely - flattering to deceive in terms of a swift return to 6-7-8. Maybe we were all a bit spoiled by the swift trop response back in Feb/March 18.... but to be fair even the Met thought the change was going to come in Jan....and gradually put it back as the slow downwell became apparent....but eventually proper touchdown HAS to happen. And the tropical signal is coming back around.

We don't want it too late in the season - but let's not forget it is still only Jan 21st. February remains a proper winter month so lots still to look forward to. Let's be honest - if we get as much as a week of frigid snowy conditions most on here will be happy. And we could yet see February deliver much more than this given that, once the block becomes established, the slow progress of the downwell means a slow return to normal..perhaps very slow this year. A cold March too?

If forecasting was easy we wouldn't bother to sign in here. Keep the faith.

[BlackburnChris]

Turned to Heavy snow in Blackburn now, so nearly everyone should stand a chance tomorrow

[Met4Cast]

6 minutes ago, karlos1983 said:

I’ll sign off with some much improved EC ENS

Get this weekend out of the way and we nose dive 

That cold cluster this weekend has caught my attention.. 

[karlos1983]

Just now, Daniel Smith said:

That cold cluster this weekend has caught my attention.. 

I was thinking the same, could we see a surprise in the morning for the weekend? Hard to see how now, but that’s quite a cluster 

[Catacol]

1 minute ago, Daniel Smith said:

That cold cluster this weekend has caught my attention.. 

Yes indeed - quite a tight grouping seeing the cold hang on. Short term changes very possibly in this volatile setup.

[Johnp]

A quick skim through the GEFS and the majority now seem to show northern blocking kicking in after day 10 (and some before that).

[lassie23]

42 minutes ago, snowbob said:

People moaning about how this thread has been split.

i can honestly say I have learnt more these last two days (which doesn’t take much to be honest ) than I have in all the years I have been a member on here.

the fact you can post without fear of being belittled or your post being deleted really helps.

it really was serious on here a few years back.

think I got told of by John Holmes a few times lol

well done mods great idea

cheers

i think it's a good thing because when the models take the mickey so much it's really hard to stay super serious without any banter lol

[karlos1983]

I now feel the need to go looking for individual members to see synoptically how those clusters keep the cold...

[kold weather]

3 minutes ago, Daniel Smith said:

That cold cluster this weekend has caught my attention.. 

Yes the ECM ensembles are showing more in the way of NE via the Euro trough mainly.

Also worth noting the 18z GFS ensembles are a total synotic flip from the last 12z suite. Many more northern blocks, though there are a fair number of the runs that have a huge lack of deep cold due to how we evolve into the pattern.

[Kirkcaldy Weather]

26 minutes ago, Catacol said:

I like the look of all the models tonight. It's like watching 2 Sumo warriors hammering into each other - flow off Canada trying to move on a NW/SE axis with the mid atlantic ridge doing its damndest to force its way north. Stalemate in the short to medium range as the two trends repeatedly collide - but everything still points to the atlantic Sumo  running out of steam even if it is doing a hell of a job maintaining its coherence. Temperature gradient will be an ally in this....but High Lat Sumo is going to win out..... By 216 both GEM and ECM have real interest, and JMA is on the same page if a little later and a tad further north.

Downwelling winds are going to put the brakes on.....and when the point of no return arrives the high will break through to the north, the jet will split and dive south and we will end up in very good conditions for a wintry product.

When? I've given up trying to get timing right this winter - so far we have had to demonstrate extreme patience and trying to put a date on a change to cold has been very difficult. The MetO have been fairly solid for a while now on a turn at the end of Jan/early Feb and more tweets today suggesting the same.... so let's go with them. This would suggest a change in the charts to something dramatic looking within a few days - maybe end of the weekend. When the signal for high pressure breakout is picked up I think it might be a swift transition.

Until then - those that can enjoy a cold NW feed - knock yourself out. Not much good for lowland SW (imby) to be honest, but I know some will get a covering this week, something we have been saying all along about this initial trough. It's the next phase that has us all on the edge of our seat...………

  GEFS 18z showing the first hints?    

     

 

Winters over? 

 

Edited January 21, 2019 by Kirkcaldy Weather

[alexisj9]

7 hours ago, Steve Murr said:

Afternoon All-

Im really suprised that noone has picked up on the UKMO 144-

Heights to the NE & a diving jet usually spells Easterly ( around 168 )

I think people are just nervous it'll go wrong again, it does look interesting though, for sure.

[alexisj9]

6 hours ago, matt111 said:

I preferred yesterday’s. The green bit that passes me was pink.  

I prefer this one, it shows, the wind switch around d to the north east with snow showers here. Nice.

[Dave Kightley]

Must be like day 5 of this cold spell with days or weeks to go..  Could be a lot worse... Very rare you get the odd mild day.. Some places might not see double digit temps for over a week plus... Amazing!

Edited January 22, 2019 by Dave Kightley

[Jimmy0127]

All will be well.

Full on NW onslaught this evening and perhaps some flakes for the lucky!!

These are promising times...

[Duane S.]

There are signs that we’ve bounced off the bottom and are slowly but Shirley on the up.Tentative but they’re there. 

I know some have simply got it stuck in their heads that the long term teleconnections got it wrong. Put simply, no.

Fact... The SSW was forecast back at the end of November to occur at the end of December. Smack on correct.

Putting aside the very well known fact that only approx 70% deliver cold to our shores anyway, the downwelling of these reverse Uwinds and subsequent interaction with the Troposphere is always a relative unknown. Sometimes it is quick, as in a few days to a week, sometimes up to 6 weeks. In which case we are still only half way through the waiting period!

But...actually that is not all bad news. It can be a bit of a double edged sword. If we had a super fast QTR, yes that may have brought cold down quickly from the Arctic, given some proper HLB and us a cold spell a couple of weeks ago. The problem is when these Easterlies all flushed down quicker like that, and yes there are caveats to this, but the vortex is given an opportunity to get going again, certainly at time of the season when it can do so more easily.

With what we have here, a much more sedate propagation downwards, the damage to the PV has been occurring nevertheless and been constant. And by the time the Easterlies are out of the way and more zonal conditions are present again in the mid to lower strat, the conditions will not be as receptive for a fully fledged tropospheric vortex to reform. Doesn’t mean it definitely won’t of course, just much less chance.

Hence why a cold February now had to be on the cards IMO. What you see at 500mb may look all purple and angry but is a lot weaker and susceptible than it looks at face value.

Short term pain, long term gain. Over used in here I know,  but I believe relevant now.

 

 

 

[matty40s]

well its sleet with rain in Daventry just now, the mixed layers of air aren't sure what to throw at us - I think it will be very icy in the morning over much of the country - ideal for those incoming snow showers to settle on....

[Walsall Wood Snow]

1 hour ago, Updated_Weather said:

Exactly what I was about to say! I remember we had rain and there was puddles and as it got colder, snow began to fall and in the heavier bursts it started to stick. I've always told people it's never to wet for snow to stick

You're right it can't be when you consider that when conditions are right snow will even stick to deep bodies of water. Seen it a few times on my garden pond or on the canal nearby. It sort of builds up into a slush if it gets cold enough and heavy enough.

[SLEETY]

I've seen heavy rain for hours turn to snow and settle almost immediately and the snow was useless for snowmen and snowball fights, because it was too dry!