Still definate signs of cyclosis in the long term on all the models, we have low latitude lows, sausage shaped lows, and eliptical shaped lows; quite different from circular occluded lows moving relentelessly NE. Also some signs of WAA in canada aswell.

I would be willing to do a friendly wager about a pattern change (i.e betting personal honour only :P) that a pattern change will be in evidence by mid month, and blocked (be it southern or northern) conditions be there by at the 20th at the absolute latest.   

Originally Posted by: Quantum 

Following CFS model around the 18th, you're betting it won't revert back to westerlies and the same old grind? I won't bet but hope you're right for a change in pattern for once

Originally Posted by: Osprey 

Yeh indeed. Of course there is no guarantee I will be right, but I would go as far as to say there is a greater than 50% chance imo. Mostly my reasoning is this:

- Continued favourible conditions in the arctic, Neutral or negative AO and northern blocking been in place since Early january; no sign of letup.

- Signs of cyclosis in the atlantic, in particular the non- circular shaped lows; southerly tracks e.c.t.

- Stratospheric warming event in exactly the right place, admiatadely not propagating well, though evidence of a near vortex split even at 30hpa. Some weaker evidence of at least some propagation into the troposphere  

- Evidence of WAA in Canada at times, not 552 isopleth to greenland admitadely, but certainly above average 850s becoming more prominent, and cold pools becoming less prominent.

- Natural singularities suggest blocked conditions end of february perhaps more likely than at any other time during winter

- Sea ice expansion in Canada and low SSTS (tripole evident) acting as a negative feedback to cyclogenesis from canada, something that should become more important than a cold airmass over canada as the sun gets stronger. 

 

Originally Posted by: Quantum 

I think you would have had the blocking but for these unusual weather circumstances in the States driving the jet and LP's towards us, even the wives tale of what USA gets the UK receives later never came off although we did get their LP systems a few days later (Still early days yet)

Still definate signs of cyclosis in the long term on all the models, we have low latitude lows, sausage shaped lows, and eliptical shaped lows; quite different from circular occluded lows moving relentelessly NE. Also some signs of WAA in canada aswell.

I would be willing to do a friendly wager about a pattern change (i.e betting personal honour only :P) that a pattern change will be in evidence by mid month, and blocked (be it southern or northern) conditions be there by at the 20th at the absolute latest.   

Originally Posted by: Osprey 

Following CFS model around the 18th, you're betting it won't revert back to westerlies and the same old grind? I won't bet but hope you're right for a change in pattern for once

Originally Posted by: Quantum 

Indeed, I would be prepared to take up the friendly wager with anyone that thinks the whole month will be zonal. 

Actually the daily CFS is pretty wintry today around the time you mention with interestingly the origin of the cold being a greenland stype block. The CFS daily charts have been in general suggesting a brief period of moderation of the atlantic train midmonth, although they have been inconsitant wrg to the time, anywhere from before mid feb to early march. But as you say mostly they bring the atlantic train back. Interestingly though, the CFS charts have been broadly going for a below average February for a while now, that might be overoptimistic though. 

Still definate signs of cyclosis in the long term on all the models, we have low latitude lows, sausage shaped lows, and eliptical shaped lows; quite different from circular occluded lows moving relentelessly NE. Also some signs of WAA in canada aswell.

I would be willing to do a friendly wager about a pattern change (i.e betting personal honour only :P) that a pattern change will be in evidence by mid month, and blocked (be it southern or northern) conditions be there by at the 20th at the absolute latest.   

Originally Posted by: Osprey 

Following CFS model around the 18th, you're betting it won't revert back to westerlies and the same old grind? I won't bet but hope you're right for a change in pattern for once

Originally Posted by: Quantum 

Yeh indeed. Of course there is no guarantee I will be right, but I would go as far as to say there is a greater than 50% chance imo. Mostly my reasoning is this:

- Continued favourible conditions in the arctic, Neutral or negative AO and northern blocking been in place since Early january; no sign of letup.

- Signs of cyclosis in the atlantic, in particular the non- circular shaped lows; southerly tracks e.c.t.

- Stratospheric warming event in exactly the right place, admiatadely not propagating well, though evidence of a near vortex split even at 30hpa. Some weaker evidence of at least some propagation into the troposphere  

- Evidence of WAA in Canada at times, not 552 isopleth to greenland admitadely, but certainly above average 850s becoming more prominent, and cold pools becoming less prominent.

- Natural singularities suggest blocked conditions end of february perhaps more likely than at any other time during winter

- Sea ice expansion in Canada and low SSTS (tripole evident) acting as a negative feedback to cyclogenesis from canada, something that should become more important than a cold airmass over canada as the sun gets stronger. 

 

Originally Posted by: Osprey 

I think you would have had the blocking but for these unusual weather circumstances in the States driving the jet and LP's towards us, even the wives tale of what USA gets the UK receives later never came off although we did get their LP systems a few days later (Still early days yet)

Originally Posted by: Quantum 

I'm not entirely sure where that old wives tale comes from. I always go by an opposite motto; that cold air in USA usually means mild and wet here; alternativly 'iceland and the UK are two sides of the coin'. I think you are right though, the AO has been negative for a long time now with strong blocking in evident over the arctic, unfortunately all that has done is concentrated the polar vortex onto the atlantic side near greenland and the barents sea, while the pacific has enjoyed high pressure.

I would suggest that if the atlantic does calm down, blocking in the UK would be very likely even if it is the less desired southern blocking; mostly then I am looking out for signs of the atlantic calming down.  

Still definate signs of cyclosis in the long term on all the models, we have low latitude lows, sausage shaped lows, and eliptical shaped lows; quite different from circular occluded lows moving relentelessly NE. Also some signs of WAA in canada aswell.

I would be willing to do a friendly wager about a pattern change (i.e betting personal honour only :P) that a pattern change will be in evidence by mid month, and blocked (be it southern or northern) conditions be there by at the 20th at the absolute latest.   

Originally Posted by: Quantum 

Following CFS model around the 18th, you're betting it won't revert back to westerlies and the same old grind? I won't bet but hope you're right for a change in pattern for once

Originally Posted by: Osprey 

Yeh indeed. Of course there is no guarantee I will be right, but I would go as far as to say there is a greater than 50% chance imo. Mostly my reasoning is this:

- Continued favourible conditions in the arctic, Neutral or negative AO and northern blocking been in place since Early january; no sign of letup.

- Signs of cyclosis in the atlantic, in particular the non- circular shaped lows; southerly tracks e.c.t.

- Stratospheric warming event in exactly the right place, admiatadely not propagating well, though evidence of a near vortex split even at 30hpa. Some weaker evidence of at least some propagation into the troposphere  

- Evidence of WAA in Canada at times, not 552 isopleth to greenland admitadely, but certainly above average 850s becoming more prominent, and cold pools becoming less prominent.

- Natural singularities suggest blocked conditions end of february perhaps more likely than at any other time during winter

- Sea ice expansion in Canada and low SSTS (tripole evident) acting as a negative feedback to cyclogenesis from canada, something that should become more important than a cold airmass over canada as the sun gets stronger. 

 

Originally Posted by: Quantum 

I think you would have had the blocking but for these unusual weather circumstances in the States driving the jet and LP's towards us, even the wives tale of what USA gets the UK receives later never came off although we did get their LP systems a few days later (Still early days yet)

Originally Posted by: Osprey 

I'm not entirely sure where that old wives tale comes from. I always go by an opposite motto; that cold air in USA usually means mild and wet here; alternativly 'iceland and the UK are two sides of the coin'. I think you are right though, the AO has been negative for a long time now with strong blocking in evident over the arctic, unfortunately all that has done is concentrated the polar vortex onto the atlantic side near greenland and the barents sea, while the pacific has enjoyed high pressure.

I would suggest that if the atlantic does calm down, blocking in the UK would be very likely even if it is the less desired southern blocking; mostly then I am looking out for signs of the atlantic calming down.  

Originally Posted by: Quantum 

Even the old building site saying "rain berfore 7 stops by 11" It's all gone out the window.

Drifting off topic here - enough about old wives tales please 

The 06z runs are a little to the NW of the 00z runs with tomorrow's precipitation - small differences but with potentially large impacts, as there looks to be a nasty 'back-end' to the system as it moves away on Friday, in the form of an area of particularly large rainfall rates currently projected to move across the SE.

This run looks better so far

http://cdn.nwstatic.co.uk/gfsimages/gfs.20140205/12/105/h850t850eu.png

Colder air more established over the UK with the "Dartboard LP" enroute from the south.... could be a very snowy setup on this run.

GFS 12Z has that little low tracking further south and into the Pyrenees rather than Northern France.

http://modeles.meteociel.fr/modeles/gfs/runs/2014020512/gfsnh-0-120.png?12

Just a chilly ridge before the Atlantic moves in afterwords.

A fair bit northern blocking though in FI.

GEM is a little more interesting than the GFS, because it shows really significant amounts of cyclosis, to the extent that we have a filling low with 8 concentric circles. I don't think I have ever seen that many before, maybe 4 or 5 at the most. Meanwhile the greenland high is blowing up.

GFS of course is interesting too, but mostly because of what happens after 192 (transient snowfalls aside) - ofc before 192 there are still tell tale signs of cyclosis, but after 192 we really get some decent WAA to greenland and a classic easterly turnover to end the low res.

The other interesting aspect on the GEM is the showing of a somewhat arctic feed, rather than just a polar continental in Europe. You can tell this instantly by looking at the pressure charts (to be clear it isnt a direct feed to siberia but it is close) but also by these very cold 850s

http://modeles.meteociel.fr/modeles/gem/runs/2014020512/gemnh-1-240.png?12

http://modeles.meteociel.fr/modeles/navgem/runs/2014020512/navgem-0-168.png?05-18

Hope NAVGEM has lost the plot. 

I thought so too but I'm not sure... A few more runs. Have a gut feeling for a change

http://expert-images.weatheronline.co.uk/daten/proficharts/en/2014/02/05/basis12/ukuk/rart/14021112_2_0512.gif

http://expert-images.weatheronline.co.uk/daten/proficharts/en/2014/02/05/basis12/ukuk/rart/14021118_2_0512.gif

JFF  Still a wintry flavour from GFS

More of the same only a little colder. No major change signalled until late in FI.

I,m afraid that there is liitle support for change amongst GEFS right out to 384h-overwhelmimg majority of ENS still have zonal flow over the UK.

http://www.meteociel.fr/modeles/ecmwf/runs/2014020512/ECH1-144.GIF?05-0

Another bomb from ECM

If it follows that track I think your house will be gone, Marcus.

Would you be willing to take me up in my friendly wager?

Anyway ECM goes mad at 144h 

http://www.meteociel.fr/modeles/ecmwf/runs/2014020512/ECM4-144.GIF?05-0

Very high 850 wind, be interesting to see what the ECM thinks of the surface wind, that hasn't finished running yet though. 

http://www.meteociel.fr/modeles/ecmwf/runs/2014020512/ECM1-144.GIF?05-0

It certainly doesn't look clever

http://www.wetterzentrale.de/pics/Recm1442.gif

A nasty fella!

Well one thing's for sure - the jet is more amplified by T+240; uppers of +8 into southern Newfoundland and -2 creeping into the Azores.

You know what will happen SE, as always happens when we get the worst kind of winter - just when the sheep are lambing, the daffodils are blooming and the bluebells are unfurling their azure colours, winter will start with a vengeance and we shall get frost, snow and ice for the start of March!

I detest winters like this. We should get ice and snow in January and then March should bring in zephyr winds, soft scents and rising sap!

http://www.meteociel.fr/modeles/ecmwf/runs/2014020512/ECU1-144.GIF?05-0

That would be perhaps a record-breaker...

http://modeles.meteociel.fr/modeles/navgem/runs/2014020512/navgem-0-168.png?05-18

While that would be... similar in terms of pressure gradient, but crazy in terms of central pressure.

What ECM and NAVGEM are picking up on is the potential that comes with the southern jet picking up disturbances moving up from the Gulf of Mexico; if any one of those systems positions favourably, it can bomb out.

GFS and UKMO are not seeing that kind of development and that's largely down to them being slower with the disturbance - it reaches a favourable position close to the East U.S. coast rather than in the middle of the Atlantic, and at that time it's not picked up much eastward momentum so it doesn't get nearly as far... or at least, not on the GFS 12z op run. The UKMO run seems to have the trough nearly as slow as GFS but doesn't have the development stage occuring quite so far west.

There looks to be a fair number of those little disturbances entering the Atlantic over the coming week - it's like a game of Russian Roulette where the southern jet is the gun and those disturbances are the bullets 

Within the reliable time frame, Euro 4 goes for 2 inches of rain locally over the next 2 days

Serious flooding potential clearly signalled by the short term models in the SE corner.

http://www.weatheronline.co.uk/cgi-bin/expertcharts?LANG=en&MENU=0000000000&CONT=ukuk&MODELL=euro4&MODELLTYP=1&BASE=-&VAR=rsum&HH=48&ZOOM=0&ARCHIV=0&RES=0&WMO=&PERIOD=