Model output discussion 25th Jan onwards

[shaky]

Here we go again!!ecm saga part 100 of the winter!!can we be lucky this time round for once!!big changes compared to this morning as early as 72 hours!!

[nick sussex]

Hi Nick, 168hrs will be interesting! Do you think the block is being underestimated once again? 

Judging by the ECM at T168hrs yes but its just one run and the GFS and UKMO aren't as good, over the last few weeks the trend has been to pull the pattern further west from the T168hrs timeframe.

 

The low heights over the northern Med are good to see and although it might look an unusual way to get a continental feed back into the UK its plausible, the key really is having the pattern as far west before that energy digs south into the Atlantic.

 

You can see the differences at T120hrs over the USA and this effects the downstream pattern so we'll have to see what NCEP think of the ECM over the USA later on.

 

We don't get much going right at T192hrs as the Siberian vortex decides to send across reinforcements to Canada and a shortwave dives se across to see the Norwegian Fjords!

Edited January 27, 2014 by nick sussex

[Summer Sun]

Another deep low setting up at t192

 

[Downpour]

The low isn't getting through on ECM - leaves us pretty much in no mans land down here. Need it to slide SE but doesn't look like it wants to cross the Irish Sea...

[bluearmy]

ukmo looked 'interesting' at day 6 re split jet se/ne. the gefs T168/T192 have looked 'interesting' for the past few runs. post t192, forget it as the resolution drops off. yesterdays ecm 12z op had the jet split nearly all ne 3rd feb and off the north norwegian coast. today we have the 12z splitting most se and the northern part headed towards iceland.  i really have to get my tax return done !!!!!

[pandit-scholar]

Another huge low at T +192 hrs, which looks to finally collapse the Scandinavian block!!

Edited January 27, 2014 by pandit-scholar

[IDO]

The first thrust from the Canadian Vortex on the ECM is not enough this run to push the Russian High East, so its called on its cousin from Siberia for back up for the second attack:

 

 

A recurring theme. Just delays the inevitable.

[Summer Sun]

t216 sees the centre of the low starting to head north towards Iceland

 

[Stuie]

Another huge low at T +192 hrs, which looks to finally collapse the Scandinavian block!!

That isn`t going to happen, IMO. The low this week gets shoved SE and that low is going to send some energy NE and probably some SW which keeps the Azores in check.

[skadi]

At T+192 the energy of the Canadian Blob is spilling over to the Siberian side, could this be caused by the strong ridges on either side, the Scandinavian/Russian block and its counterpart over Alaska...? Also interesting is the low at the Aleutian Islands. It is preventing the block there from sinking...imo.

 

[Summer Sun]

t240 ends with a 960mb low to the NW of Scotland so another run with no end in sight to the wind and rain unfortunately

 

Edited January 27, 2014 by Summer Sun

[Stuie]

Using the JMA rather than the GFS for the jet stream (more detail to me) @T192 it is South of the UK and would think it would take any lows, like this week, NW/SE. I would also think and hope that once colder air starts to fill Europe then proper battlegrounds could take place.

[nick sussex]

As we can see after a better start it all goes pearshaped as the PV over Canada is replenished ready to haunt us for a while longer, that's a long way off and at least there is something better to look at upto T168hrs.

 

Its very likely that the PV there will get another boost and realistically you would need a much stronger block to the north/ne to fight that off with better trough disruption and more energy going se'wards.

Edited January 27, 2014 by nick sussex

[bluearmy]

At T+192 the energy of the Canadian Blob is spilling over to the Siberian side, could this be caused by the strong ridges on either side, the Scandinavian/Russian block and its counterpart over Alaska...? Also interesting is the low at the Aleutian Islands. It is preventing the block there from sinking...imo.

 

 

 

there is more headed siberia to canada than the other way. either way, when we see this exchange of vortex chunk, we always seem to see a ramping up of the atlantic jet (if that is possible!)  this appears to be happening just the other side of the pole so we probably escape any effects over here. in the longer term, our experimant to see how long the canadian segemnt would sustain without decent siberian support seems to be at an end. that doesnt bode well for the atlantic jet and if you want cold, you need the azores displaced and the jet sunk south with a one way ticket to the med. the increasing se european heights in fi not a good sign in this regard.

[IDO]

The ECM op close to the GFS mean at T240 for our locale synoptically:

 

ECM T240:  GFS Mean: 

 

That is normally the case when we have a clear trend towards a period of zonality; cross-model support out to deep FI.

 

The GEFS have been highlighting the last few days that there are various ways the breakdown of the block to our east will happen, but they have been consistent in bringing back the Atlantic whether it was a fast, slow or a medium push, and always before D10. Holding up the inevitable like the ECM may in the long term be worse than a more progressive Atlantic, who knows, the GEFS only go out to D16 and the Atlantic is still piling in even then; so not a clue at the moment.

Edited January 27, 2014 by i'm dreaming of...

[skadi]

 that doesnt bode well for the atlantic jet and if you want cold, you need the azores displaced and the jet sunk south with a one way ticket to the med. the increasing se european heights in fi not a good sign in this regard.

Thanks for clarifying. Could you give an example of a situation where the jet does sink south with all in its wake?

[Bristawl Si]

I suggest those interested in the 'background signals' should read Inheritus's latest post in Strat thread.

Probably explains why, in general terms, the model outputs are refusing to let go of the influence of the PV on our weather and the continuing influence of the atlantic.

If you *truly* believe there will be a longer-lasting change to what we've experienced since mid-December due anytime soon, it seems you'll have to be a lot more patient and *maybe* the change wont come at all this Winter.

[egret]

Using the JMA rather than the GFS for the jet stream (more detail to me) @T192 it is South of the UK and would think it would take any lows, like this week, NW/SE. I would also think and hope that once colder air starts to fill Europe then proper battlegrounds could take place.

Well spotted StuieW

I hadn't seen the JMA but that Jet Stream pattern is more what I would have expected / looked for given what is happening up aloft. If nothing else, that low if moved a bit further South will help nudge other bits of the jigsaw into more interesting positions. OK - verry big IFFs!

Edited January 27, 2014 by egret

[Cloud 10]

there is more headed siberia to canada than the other way. either way, when we see this exchange of vortex chunk, we always seem to see a ramping up of the atlantic jet (if that is possible!)  this appears to be happening just the other side of the pole so we probably escape any effects over here. in the longer term, our experimant to see how long the canadian segemnt would sustain without decent siberian support seems to be at an end. that doesnt bode well for the atlantic jet and if you want cold, you need the azores displaced and the jet sunk south with a one way ticket to the med. the increasing se european heights in fi not a good sign in this regard.

 

NAEFS longer term is rather difficult viewing regarding those euro heights!

[cooling climate]

 

I think a cautionary note on the strat warming.... it's something UKMO's M-R folk have been watching closely all winter (as you'd imagine). I just asked about this, i.e. re their views on the NCEP signals of late. They tell me: "GLOSEA5, the UKMO seasonal model, doesn't seem to support this event all that much and since it hasn't been working so far this season in terms of getting the warmer air down in reality, this signal isn't being used in relation to forecasting a change to colder periods." 

There was a much more pronounced signal emerging back in earlier Jan (modelled for later Jan and into early Feb, as some on this forum are aware), but that was lost.

The GFS stratosphere charts have been a lot more consistent on the warming they

are showing during February than they were with the warming they were showing

at the end of December early January.

Time will tell.

[Troubleatmill]

The GFS stratosphere charts have been a lot more consistent on the warming theyare showing during February than they were with the warming they were showingat the end of December early January.Time will tell.

Indeed time will tell, I know little about the stratosphere therfore can I read that as a warm strat means nothing, It can just stay up there until it cools to gone Chio? Know it doesnt guarantee cold for our shores but always thought it propagated down to somewhere and helped warm the PV and give us some lovely looking heigh rises polward? Sorry if thats a dummies question to you strat experts Edited January 27, 2014 by Nicholas B

[Stuie]

With Thursday being mentioned as maybe an issue this week, decent agreement between the ECM,UKMO and JMA. Not much change required in upper temps.

ECM/UKMO/JMA

But: No precipitation.

 

Saturday looks more promising:

[North-Easterly Blast]

Stratospheric warming encourages high latitude northern blocking to develop, but whether it develops in a favourable location to bring cold weather to Britain, or trough disruption and slider lows allow cold air to reach Britain is a different matter.

 

Minor warmings can take up to 3-4 weeks to have any effect of increasing northern blocking, but sudden stratospheric warmings (huge increases of polar stratospheric temperatures over a small number of days, can increase northern blocking within a week).  Although as I said earlier, with a SSW you still need the location of the blocking and trough disruption and slider lows all to fall into place to deliver a cold spell to the UK.

[cooling climate]

Over the last month I have lost count how many times I have half read a post

before realising it is the same post just reworded differently.It also amazes

me how many claim to have known how bad the winter was going to be with lines

like "we knew it would be February or even later before things turned interesting".

Hindsight makes great long range forcasters out of all of us.

Even with a westerly QBO noboby could have foreseen how poor this winter has been

or how wet and also how strong the vortex has been.I know I certainly didn't.

Yesterday I said that by next Sunday there will be a lot of happy cold weather

lover on the forum excited by the runs they are seeing.I still think that but it

is all down to the forecasted strat warming. If this turns out to be another damp

squid then apart from a couple of days cold here and there perhaps that is the

best we will likely see during February. However I stand by what I posted yesterday

with great expectations for February.

[Froze were the Days]

Gavin P wasn't that far off with his USA forecast he did say the probability of a strong ridge near to the Pacific North West would encourage cold conditions for central and eastern parts but it all went wrong thereafter saying that our winter could be 'dry if not very dry' and temps close to normal but fair play to him.

As for this evenings ECM although better than earlier today it's still difficult to see how any cold continental air can be advected westwards it's just one big high pressure 1500/2000 miles away acting slightly more as a buffer on this run before the inevitable happens.