Model output discussion - 5th December 2016 - Into Winter we go

[Kentish Snowman in Yorks]

4 minutes ago, WINTRY WALES said:

Is unsettled the opposite of game on though if Matt was hoping to see cold and winters weather as per winter forecast?

Think he means game on again as in ECM vs GFS ens as has been the case on more than one occasion recently?

European Unsettled vs American Blocked

Not sure which I am rooting for to be honest the way this winter is going literally anything could happen!

Edited December 12, 2016 by Kentish Snowman

[feb1991blizzard]

5 minutes ago, A Frayed Knot said:

That's not going to help us get any nearer to resolving this tonight as the EC46 has the 0z starting data from earlier so even if the EC46 shows blocking, we would still need the 0z ECM EPS tonight to flip back again to confirm (if we will ever be able to do that) a blocked outlook.

And that's assuming the 18z and 0z GEFS don't then flip to full on zonal!

Edited December 12, 2016 by feb1991blizzard

[nick sussex]

The ECM ensemble spreads do tie in with Matt Hugos post. Some interest in those with a lot going on. The main interest might be the angle of any Atlantic attack.

[IM NOT REALLY HERE]

1 hour ago, Nick L said:

Yep, a very unusually large swathe of 100mph+ gusts out at sea. Very nasty.

Was one of fridays 00z runs not showing a similar feature for the same time period? I can't remember which model but I remember thinking if that was to verify then I would need to get my xmas shopping done earlier. 

[Summer Sun]

 

[northwestsnow]

IMHO...this..will..be..ecm..thats..correct,i..suspect..GEFS..will..fall..in..line..tomorrow-

[Penrith Snow]

2 hours ago, nick sussex said:

Oh no, I didn't see this news. I always loved Ian M's forecasts.

I will never forget Ian's weather broadcast in early January 1985, as a cold northerly outbreak engulfed the UK, 

Quote: "don't be fooled by that warm front approaching from the north west, the air behind that front is about as warm as a polar bears pack lunch"

It was a classic! Within 24 hours that same warm front became embedded in the northerly flow and brought 10cms of snow to central London.

It seemed so much easier in those days, no MJO, Ens, ENSo, NAO, etc etc, it just occasionally went bloody cold!

Andy

[Methuselah]

3 minutes ago, nick sussex said:

The ECM ensemble spreads do tie in with Matt Hugos post. Some interest in those with a lot going on. The main interest might be the angle of any Atlantic attack.

And, with that, I'm off to listen to LBC. I am, however, also hoping against all odds that the GFS's post-Christmas Beast From the East is still there, come tomorrow...Needless to say, I am not hopeful!

[Summer Sun]

5 minutes ago, northwestsnow said:

IMHO...this..will..be..ecm..thats..correct,i..suspect..GEFS..will..fall..in..line..tomorrow-

If your keyboard is still broke you can reassign your keys with this official Microsoft programme

https://www.microsoft.com/en-us/download/details.aspx?id=22339

[northwestsnow]

4 minutes ago, Summer Sun said:

If your keyboard is still broke you can reassign your keys with this official Microsoft programme

https://www.microsoft.com/en-us/download/details.aspx?id=22339

Thanks..mate.but.i'm,getting.new..laptop..tomoz!!!-

Edited December 12, 2016 by northwestsnow

[damianslaw]

Sticking to the reliable - the atlantic is having real trouble against the block to our east, frontal systems look very weak affairs, and by the weekend the azores high is forecast to nose in from the SW joining with the block to create generally settled quite cool conditions - could be some very troublesome fog during the 'darkest' weekend of the year. Chance we may see some brighter cleaner air in the north, but its looking a very very overcast week overall- not very cheerful. Temperatures rising mid week before returning closer to near average, with frost quite probable by Friday night - so feeling a bit more seasonal again.

Where do we go from there? jury is still out, wildly odd ECM output today with a very deep low moving in from the NW, doesn't look right, and it is very much an outlier.. GFS is quite interesting, it too shows quite an active jetstream, but also some buckling with colder PM air coming across the country, cold upperds which would produce some wintry precipitation in the north, but with still very strong heights to the NE, the longer term evolution is trough disruption and split jet, with a cold SE wind feeding in.. possible undercut thereafter - all along way off..

So alot of options on the table still, don't underestimate the strength of the block to our east even against what looks like a fired up jet next week, what we may end up with is a battleground scenario, with the trough disrupting to our west, and a cold SE feed ahead.

 

[nick sussex]

At this point I'm willing to take a gamble with the more unsettled outlook if that's correct. I think we need to take a chance that some energy will head se towards Iberia and help to angle the jet more nw/se. The Euro high with some help from Russia could get a lobe of positive heights to the ne and put some forcing on the Atlantic.

[feb1991blizzard]

Just now, nick sussex said:

At this point I'm willing to take a gamble with the more unsettled outlook if that's correct. I think we need to take a chance that some energy will head se towards Iberia and help to angle the jet more nw/se. The Euro high with some help from Russia could get a lobe of positive heights to the ne and put some forcing on the Atlantic.

On the Dutch ens there is still a cold clustering so any zonal flow coming up against the block wont be too far to our East, its very unlikely to be full on zonality for now BUT we are running out of time fast.

[bluearmy]

THe para 12z consistent with general GFS ops in delivering an interesting back end of the run

[phil nw.]

The NH height anomalies show some interest this evening  suggesting a weakening of the Atlantic jet as we go into next week and beyond.

Compare the strength of the current Canadian vortex with it's modeled weakening by day 10 on both suites.

                    ECM                                                                 GFS                        

Today

 

day10

and further on the gefs at day 15

         

Gefs a bit keener on this process but both trend the same so something of a pattern change upstream with the reduction in the deep Canadian -ve anomalies with a consequent lessening of the Atlantic jet coming off the eastern seaboard.

Blocking still present over the Scandinavian region so with less downstream pressure on the block and the shrinking vortex to our north west this could be the key to extending our block further north.

One element still missing is more extensive lower Euro heights but that could change with easier trough disruption from a weaker Atlantic jet.

It would be a decent outlook if at first we achieve some surface cold and then maybe something even better later on.At least there appears little sign of a strong zonal pattern setting up based on the above. 

 

 

 

[Summer Sun]

D10 continues to highlight the differences between ECM ens and GFS ens

ECM ens                                                       GFS ens

[knocker]

Certainly not many clues to be gained from the anomalies this evening as to the evolution. Oh what a tangled web we weave.

Starting up stream where none can agree on the precise amplification of the eastern Pacific ridge? or the vortex and associated troughs. It's the upper trough in the north west Atlantic which is perhaps causing most of the mayhem as the EPS has it far more negatively tilted, and more intense, into the Atlantic which initially causes more amplification with the very strong jet running NE but (and this doesn't show on the 5-10) it progresses west bringing the trough more into play vis the UK and pushes the HP east. NOAA and the GEFS are having none of this and retain the surface high to the east with the UK well under it;s influence

With this disagreement manifesting itself so early they were never going to agree in the 10-15 period. Actually NOAA and the GEFS are pretty good with a weakening trough mid Atlantic and  the HP still hanging  in there with the surface high still maybe around the southern Baltic, perhaps a little further south, so likele at least the southern half of the UK still under it's influence. The EPS on the other hand has the trough slightly more vigorated and further west thus the UK in a westerly regime

[nick sussex]

Just now, feb1991blizzard said:

On the Dutch ens there is still a cold clustering so any zonal flow coming up against the block wont be too far to our East, its very unlikely to be full on zonality for now BUT we are running out of time fast.

To be honest I'm done with the current rut. We could be chasing this high around for the next few weeks, its risky with the set up in terms of whether we'll get that trough disruption and it could all end in tears but I'm hoping the ECM is correct. We need those projected low heights in Iberia to stick around, for two reasons I might get some snow in the Pyrenees so my husky ride is back on and I'll stop moaning! secondly and important for the UK this stops the Azores high trying to nose in and push the jet ne. The Euro high has delivered zip but could help initially by helping to push a lobe of high pressure towards Svalbard, the Russian ridge can give it a helping hand there.

[Man With Beard]

1 hour ago, bluearmy said:

As Ian has mentioned, the end of the gfs sits broadly with the last ec 46 for xmas/new year

the subsequent gefs/eps have done little to change this potential solution. 

If the 12z eps are consistent with the 00z run then I believe week 3 on the ec 46 later tonight could be quite an exciting set up for coldies. 

The 12z soon out 

BA since I have been critical of the ECM46 in the past, thought I'd mention that I've been going back through the archives and I must admit the D11-D18 period is usually pretty accurate when compared with D0 - it's when it gets to D19 and beyond where, from what I've looked at so far, the signal goes a bit random. So I'm actually looking forward to the update tonight for what it says for between now and the end of the month

[blizzard81]

6 minutes ago, bluearmy said:

THe para 12z consistent with general GFS ops in delivering an interesting back end of the run

The gfs can be very consistent at times. The problem is that more often than not, it is consistently wrong - especially when ecm trends the other way. The gfs will either be wrong in the long run or it will be watered down towards the ecm. The latter scanario may still hold some interest with regards to snow but it will be a fine line to be walked.

[feb1991blizzard]

Just now, nick sussex said:

To be honest I'm done with the current rut. We could be chasing this high around for the next few weeks, its risky with the set up in terms of whether we'll get that trough disruption and it could all end in tears but I'm hoping the ECM is correct. We need those projected low heights in Iberia to stick around, for two reasons I might get some snow in the Pyrenees so my husky ride is back on and I'll stop moaning! secondly and important for the UK this stops the Azores high trying to nose in and push the jet ne. The Euro high has delivered zip but could help initially by helping to push a lobe of high pressure towards Svalbard, the Russian ridge can give it a helping hand there.

One thing I will say, we are better off with some sort of Russian heights as that always gives us a chance down the line if we don't get any ridge far enough North closer to home, don't forget there is no other wave breaking anywhere else now to help slow / stop strat zonal increase downwelling

[nick sussex]

Some interesting news re the MJO. The latest NCEP update still talks about conflicting signals but they suggest there is the potential for this to strengthen over the West Pacific in week 2, that's phase 6 or 7.

Yes we've been hearing the term potential for weeks now so its just that, it might not happen but at this point I'll take any crumbs on offer!

[Summer Sun]

UKMO out to D7 keeps the high in place

[blizzard81]

5 minutes ago, nick sussex said:

Some interesting news re the MJO. The latest NCEP update still talks about conflicting signals but they suggest there is the potential for this to strengthen over the West Pacific in week 2, that's phase 6 or 7.

Yes we've been hearing the term potential for weeks now so its just that, it might not happen but at this point I'll take any crumbs on offer!

That seems to support the gfs version of events. Yet another waiting game though. Why do we put ourselves through this lol.

Edited December 12, 2016 by blizzard81

[Scandinavian High.]

Looking dry  with some frosty weather Christmas.   But BBC long range saying no snow in forecast yet but could change Christmas period.