The hunt for cold - Model discussion (late November)

[bluearmy]

The eps clusters look fairly binary later on 

one with a stonking w euro ridge which is slowly trending towards Scandi and would probably have a developing e euro trough - broadly as gfs op 06z

the other cluster looks cool troughy - probably sinking slowly over time 

no idea how the spreads are around these clusters but the Dutch ems reveal some members would have drawn in a cold flow by day 15 

[Chesil View]

22 minutes ago, blizzard81 said:

And more delays judging by that meto update I have just mentioned. 

That,s presuming it's correct. Which at a month out is not necessarily true 

[ArHu3]

9 minutes ago, bluearmy said:

The eps clusters look fairly binary later on 

one with a stonking w euro ridge which is slowly trending towards Scandi and would probably have a developing e euro trough - broadly as gfs op 06z

the other cluster looks cool troughy - probably sinking slowly over time 

no idea how the spreads are around these clusters but the Dutch ems reveal some members would have drawn in a cold flow by day 15 

You have access to some of the restricted data from ecmwf, right? How often did the extended end run, once a week? 

 

Btw can we still see the Icelandic clusters and if so where are they? 

Edited November 26, 2018 by ArHu3

[SLEETY]

As if by magic the HLB which has been prevalent since SSW in late Feb has been replaced by low pressure to the North and high pressure to the South as we enter the winter months of D J F yet again.Seems to happen every winter.Back to chasing teases in fl on gfs again.06 on gfs a good example.Something definitely changed in U.K. climate although it’s always been pretty rubbish for cold or snow away from the Highlands 

[Bruegelian]

5 minutes ago, SLEETY said:

As if by magic the HLB which has been prevalent since SSW in late Feb has been replaced by low pressure to the North and high pressure to the South as we enter the winter months of D J F yet again.

Not sure that's correct, it has been very high pressure dominated since the SSW, but if you look the AO and NAO have been largely positive since then, I think the high pressure has been mostly over Europe (where we want it for summer) , rather than at higher latitudes. 

[Weathizard]

Not even winter proper yet and the toy throwing has begun! Realistically the vortex was always going to fire up at some point as usual in the UK it’s just about patience and hoping the pieces fall into place together at some point. Seems model fatigue has already set in for some, on November 26th.

 

 

 

[feb1991blizzard]

21 minutes ago, ArHu3 said:

You have access to some of the restricted data from ecmwf, right? How often did the extended end run, once a week? 

 

Btw can we still see the Icelandic clusters and if so where are they? 

Yes - here - just select month then day then the 0z /12z and scroll right to the very bottom and select hour.

http://brunnur.vedur.is/kort/ec-ens/2018/

Edited November 26, 2018 by feb1991blizzard

[Tim Bland]

Better from the GFS(p)

Edited November 26, 2018 by Tim Bland

[bluearmy]

23 minutes ago, ArHu3 said:

You have access to some of the restricted data from ecmwf, right? How often did the extended end run, once a week? 

Twice - mon 00z and thurs 00z

Available shortly after 10pm mon and thurs 

[Methuselah]

14 minutes ago, Tim Bland said:

Better from the GFS(p)

Indeed Tim. 850s look good for some much-needed snowfalls, over the Scottish mountains...

[Snowman.]

1 hour ago, ArHu3 said:

From what I understood an initial blocking event can lead to a ssw, which in turn can lead to much more blocking later on 

I believe so. The strat thread holds some good information on it.

[ArHu3]

14 minutes ago, bluearmy said:

Twice - mon 00z and thurs 00z

Available shortly after 10pm mon and thurs 

Hope you keep us informed. Today's 00z OP looks very interesting with the split tpv

[Methuselah]

Welcome to Griceland!

Edited November 26, 2018 by Ed Stone

[Man With Beard]

21 minutes ago, feb1991blizzard said:

Yes - here - just select month then day then the 0z /12z and scroll right to the very bottom and select hour.

http://brunnur.vedur.is/kort/ec-ens/2018/

Such a split sent me reaching for the individual ensembles on weather.us and, quite honestly, the ECM is completely lost after about T168. At that point, we have an Atlantic trough moving through to the NW. After that, chaos. Every weather pattern you can think of, it's in there by T300, and in pretty much equal measure across the 51 options. There's no way of making a forecast based on the ECM after 4th December at the moment.

The GFS parallel has also been all over the place in FI recently. The GEFS ensembles, on the other, have a clear tendency to raise heights close to the UK and go dry, especially in the SE.

My gut feeling today? I wouldn't be surprised to see something like this by 9th December. Minor height rises to the north west enough to shunt the jet south and possibly open the door to cold for northern areas soon after:

 

 

 

[feb1991blizzard]

6 minutes ago, Man With Beard said:

Such a split sent me reaching for the individual ensembles on weather.us and, quite honestly, the ECM is completely lost after about T168. At that point, we have an Atlantic trough moving through to the NW. After that, chaos. Every weather pattern you can think of, it's in there by T300, and in pretty much equal measure across the 51 options. There's no way of making a forecast based on the ECM after 4th December at the moment.

The GFS parallel has also been all over the place in FI recently. The GEFS ensembles, on the other, have a clear tendency to raise heights close to the UK and go dry, especially in the SE.

 

My gut feeling today? I wouldn't be surprised to see something like this by 9th December. Minor height rises to the north west enough to shunt the jet south and possibly open the door to cold for northern areas soon after:

 

 

 

 

So the 2 clusters in FI are basically rolex then? and you're saying there should be 51 clusters of 1 member (obviously an exaggerated way of putting it)

[Man With Beard]

1 minute ago, feb1991blizzard said:

So the 2 clusters in FI are basically rolex then? and you're saying there should be 51 clusters of 1 member (obviously an exaggerated way of putting it)

Err ... not far off that!!

[Met4Cast]

We’re exactly where we were expecting to be at this stage. We’re seeing the first signs of cold proper in the deeper stages of FI & I don’t expect this to move any closer to T0 just yet - We’re really looking towards days 15-20 for anything of note. 

The models are picking up the blocking signal way out in FI but they don’t know what to do with it yet, hence the massive swings between different cold options & milder options. 

Extended EPS continues to suggest lowering heights across Europe & rising heights towards Scandi post days 10/15. 

MJO phrasing 8-1, add in the lag and you’re looking at a re-newed blocking regime 10-15th December onwards, at the latest 20th Dec. 

Suggestions of an SSW mid-Dec as per GP & the writings on the wall for the Atlantic. Brief incursion before blocking re-builds. This time, they’ll be plenty of true cold readily available.. 

Note; Those of us expecting the switch are a little quiet, we’re waiting, biding our time. Give it 5-7 days, colder solutions will grow within the ensembles. 

[Chesil View]

4 minutes ago, Daniel Smith said:

We’re exactly where we were expecting to be at this stage. We’re seeing the first signs of cold proper in the deeper stages of FI & I don’t expect this to move any closer to T0 just yet - We’re really looking towards days 15-20 for anything of note. 

The models are picking up the blocking signal way out in FI but they don’t know what to do with it yet, hence the massive swings between different cold options & milder options. 

Extended EPS continues to suggest lowering heights across Europe & rising heights towards Scandi post days 10/15. 

MJO phrasing 8-1, add in the lag and you’re looking at a re-newed blocking regime 10-15th December onwards, at the latest 20th Dec. 

Suggestions of an SSW mid-Dec as per GP & the writings on the wall for the Atlantic. Brief incursion before blocking re-builds. This time, they’ll be plenty of true cold readily available.. 

Note; Those of us expecting the switch are a little quiet, we’re waiting, biding our time. Give it 5-7 days, colder solutions will grow within the ensembles. 

My thoughts exactly Daniel.

[Methuselah]

Who would've that, following two less-than-perfect MetO updates, the mood in here would become so down? Would we stop hunting for a rabbit, simply because it's gone behind a tree?

[booferking]

18 minutes ago, Ed Stone said:

Who would've that, following two less-than-perfect MetO updates, the mood in here would become so down? Would we stop hunting for a rabbit, simply because it's gone behind a tree?

Fears are that we could get led up the garden path this winter like many before it but my swingometer is still on the cold side at the moment but that could change come the middle of Dec.

[Methuselah]

5 minutes ago, booferking said:

Fears are that we could get led up the garden path this winter like many before it but my swingometer is still on the cold side at the moment but that could change come the middle of Dec.

There's a reason why I seldom take much, if any, notice of the 'path-leaders', boof... three hits out of sixteen winters is hardly impressive?

[karyo]

The MJO looks rather weak to me to have a significant impact on our weather pattern. 

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/mjo.shtml

Any thoughts from the experts?

[cheeky_monkey]

some very cold and snowy runs beginning to appear on the GFS and ECM for my location

[Mucka]

I'm genuinely surprised by how flat GFS was in the Scandi region day 7+ today, not sure why it wants to put the Atlantic into overdrive and force the jet over the top but even the parallel is much the same.

At least it does sniff a strong Atlantic ridge but that is deep into FI.

ECM looks more akin to what I expected to see and the UKMO looks great if a little optimistic with the Russian and Arctic highs looking to combine to form what would be a formidable block.

It will be very interesting to see which of these models is most consistent in the 7-10 day range though of course we can only compare UKMO day 7.

 

[Methuselah]

I'm of the opinion that the new GFS is a lot better than the last...?