Model output discussion - winter proper underway

[feb1991blizzard]

Just now, CreweCold said:

Pretty sure it has always been forecast close to the solar cycles and the predicted slumber of the sun, Pete. Think 2020 has been the approximate start date for many years now.

Yes, if you look at the solar patterns now, very similar to the Dalton minimum, I believe was 5 and 6, thus the next one should be even lower.

[Higher Ground]

2 minutes ago, LRD said:

So the arctic isn't warming then? Is that what you're saying? Or have I misunderstood? As I say severe cold or not (in the UK) the warming arctic is a worry

I can't say on what timescale the arctic is warming, but I think those links provide some balance when it comes to understanding the teleconnections in the short to medium term.

[feb1991blizzard]

Meanwhile the EPS FI mean pulls the Atlantic trough a tad further west with a possible weak ridge into scandi albeit far too far East. baby steps though - better than the 0z.

[Frosty.]

Tonight's Ecm 12z ensemble mean is as emphatic as the operational about high pressure building in strongly next week, especially across the southern half of the uk. 

[Methuselah]

1 minute ago, Frosty. said:

Tonight's Ecm 12z ensemble mean is as emphatic as the operational about high pressure building in strongly next week, especially across the southern half of the uk. 

All the proof we need, so as to really know that 'winter proper' is now well-and-truly 'underway'!

[LRD]

10 minutes ago, Higher Ground said:

I can't say on what timescale the arctic is warming, but I think those links provide some balance when it comes to understanding the teleconnections in the short to medium term.

With respect don't those links just show blips in an otherwise upward trajectory of temperatures - especially in the Arctic?

https://www.metoffice.gov.uk/research/monitoring/climate/surface-temperature

 

Edited December 12, 2017 by LRD

[bobbydog]

18 minutes ago, feb1991blizzard said:

Yes, if you look at the solar patterns now, very similar to the Dalton minimum, I believe was 5 and 6, thus the next one should be even lower.

i've been watching this over the past few years and this year in particular has seen a very steep rate of decline in solar output. solar minimum is due in 2020 but i believe we will hit minimum numbers before the end of 2018.

both prediction scales have been steadily adjusted downwards all year. there is a lot of scepticism regarding solar output. some seem to view the sunspot count in the same way as tea-leaves and seaweed. the fact is, that solar output affects the stratosphere (i won't go into detail as this is a bit off topic). the last solar minimum was 2009, our last 2 coldest winters came straight off the back of that. frost fairs on the thames occurred during the dalton minimum. its certainly not 'mumbo-jumbo' as some might think...

Edited December 12, 2017 by bobbydog

[Higher Ground]

9 minutes ago, LRD said:

With respect don't those links just show blips in an otherwise upward trajectory of temperatures - especially in the Arctic?

https://www.metoffice.gov.uk/research/monitoring/climate/surface-temperature

 

I think you're debating an argument that I'm not making. Will say no more

[bluearmy]

27 minutes ago, feb1991blizzard said:

Meanwhile the EPS FI mean pulls the Atlantic trough a tad further west with a possible weak ridge into scandi albeit far too far East. baby steps though - better than the 0z.

That's a long range mean Feb - expect larger ridge clusters to our east than the 00z run. Question will be how far north these clusters take any ridge. Sniffs that the Atlantic trough could undercut on the mean although with 51 members detecting much from the xtended eps mean/anomoly is tough (apart from the Alaskan ridge )

note the spread at day 10 in the Atlantic seems to take the ridge further north. That was true on yesterday's 00z run but it didn't gain any traction 

[knocker]

1 hour ago, knocker said:

The ecm det run this evening is more or less showing the pattern  lndictated  by this mornings anomalies before the upstream pattern change and the corresponding knock on affect downstream. If that continues to be indicated this evening then we should see a developing trough in the eastern Pacific, stronger Alaskan ridge of over the Pole and a reorientation of the Canadian vortex lobe and associated  troughs which would suppress the Azones HP being shown here. Ergo a strong westerly upper flow tending unsettled weather with Temps in general around normal, perhaps slightly above

Further to my earlier post the GEFS, NOAA and EPS anomalies this evening  illustrate the point, vis the pattern change quite well. Can't post the 10 15  EPS anomaly but it does extend the vortex trough east to connect with the trough to our east and thus restricts the Azones pushing north. Thus as previously mentioned we are looking at a fairly strong westerly upper flow with possibly the key players being the interaction between the trough to the NW and the HP to the south West.  So something for the det. runs to get their teeth into but the percentage play remains a period of unsettled weather with Temps in genearly around average or a little above.

  

 

Edited December 12, 2017 by knocker

[nick sussex]

Looking at the ECM De Bilt ensembles shows next Monday and Tuesday showing some east/se/ne  solutions for there which means a cluster do have the high further north.

The spreads also showing the main spread to the nw and se of the UK between T144 and T168hrs.

 

 

 

[tight isobar]

21 minutes ago, nick sussex said:

Looking at the ECM De Bilt ensembles shows next Monday and Tuesday showing some east/se/ne  solutions for there which means a cluster do have the high further north.

The spreads also showing the main spread to the nw and se of the UK between T144 and T168hrs.

 

 

 

Optimism -remains-supreme!..

@mild-@blip?!

[Bullseye]

 Is this the first signs of the major pattern change? Alaskian/Aleutian ridge returning this side of Christmas. How often do we see such agreement between ensembles at that range, may not lead to anything and could be gone tomorrow but signs are at least being sniffed out although not surprising based on thoughts on here and Twitter.

[knocker]

• Is it fair to quote the Dalton and Maunder minimums without qualification. Just managed a copy and paste on the tablet. 

https://www.skepticalscience.com/What-would-happen-if-the-sun-fell-to-Maunder-Minimum-levels.html

[BLAST FROM THE PAST]

2 hours ago, LRD said:

Totally agree BB62-63. Very worrying. 

It isn’t worrying as the ‘records’ used are minuscule.  And I think the ‘dampened down’ northerly discussion has had food for thought...

 

BFTP

Edited December 12, 2017 by BLAST FROM THE PAST

[Nick F]

Away from the hunt for the return of cold in the long term, keeping my eye on tomorrow evening on the frontal system / low pressure trough moving SE bringing rain, sleet and snow.

IMO GFS, as usual, looks like overdoing the snow in southern extent, ECMWF snow charts showing N. Ireland, parts of Wales, NW England and parts of the Midlands seeing snowfall from this system. Though no snow to the south of this unlike GFS.

The issue with GFS, I think, is that it has dew points too low for a NWly flow, given long seatrack, so the  model assumes all snow inland right to the south coasts as the system and it's precipitation moves SE.

The 2 charts below highlight the precip and dew point in 5C increments together in one and just the dew point in 1C increments in the other, these DPs too low IMO ...

 

[tight isobar]

18z..

Showing mild can wait...

A few tweaks and its game over-again- mobile/zonal...via 18z..

Sun-17 dec.

Edited December 12, 2017 by tight isobar

[bryan629]

Huge differences between the ECM and GFS anomolies at day ten upstream. 

Ecm shows a weak Alutian/Alaskan ridge , with an obvious stagnating HP over the uk , energy exiting Canada rides over the top , but also tries to dig south mid atlantic. 

Gfs shows a whopping Alutian/Alaskan ridge with the high the ECM has now retrogressing towards Greenland , with energy exiting Canada either stalling out west or possibly heading south east.

   

Obviously one of these are very wrong ( or both) 

Heres the European look 

   

 

 

 

 

 

Insert

[bluearmy]

Operationals at day 10 Bryan ..........

not generally worth analysis, let alone comparison

Earlier post already showed excellent cross model ens agreement at T300

 

Edited December 12, 2017 by bluearmy

[feb1991blizzard]

16 minutes ago, bryan629 said:

Huge differences between the ECM and GFS anomolies at day ten upstream. 

Ecm shows a weak Alutian/Alaskan ridge , with an obvious stagnating HP over the uk , energy exiting Canada rides over the top , but also tries to dig south mid atlantic. 

Gfs shows a whopping Alutian/Alaskan ridge with the high the ECM has now retrogressing towards Greenland , with energy exiting Canada either stalling out west or possibly heading south east.

   

Obviously one of these are very wrong ( or both) 

Heres the European look 

   

 

 

 

 

 

Insert

 

GEFS mean and ECM eps mean at day ten (which is what I would be using at that range) are not dissimilar at all.

Edited December 12, 2017 by feb1991blizzard

[Snowy L]

1 minute ago, feb1991blizzard said:

GEFS mean and ECM mean at day ten (which is what I would be using at that range) are not dissimilar at all.

Much more disorganised looking vortex in the GFS mean. Still a huge Greenland/East Canada lobe unfortunately, but bigger gap between Greenland and Siberia lobes, the presence of a weak Greenland High and Aleutian High digging in to the North Pole much better.

[ACCOUNT DELETED]

Plenty of snow showing on GFS 18z from tomorrow evening right through Thursday although by then, they'll probably be in the form of showers, sometimes heavy with an added risk of hail & thunder especially near the coasts where it could be rain & sleet rather than snow. One to watch though, this cold snap is certainly not giving up yet! 

[feb1991blizzard]

2 minutes ago, Snowy L said:

Much more disorganised looking vortex in the GFS mean. Still a huge Greenland/East Canada lobe unfortunately, but bigger gap between Greenland and Siberia lobes, the presence of a weak Greenland High and Aleutian High digging in to the North Pole much better.

Yes, agree better GEFS but the ens means are much closer than the ops are at D10 so thus a better tool to use.

[Nick F]

46 minutes ago, Bullseye said:

 Is this the first signs of the major pattern change? Alaskian/Aleutian ridge returning this side of Christmas. How often do we see such agreement between ensembles at that range, may not lead to anything and could be gone tomorrow but signs are at least being sniffed out although not surprising based on thoughts on here and Twitter.

That has a classic La Nina look to the 500mb wave pattern, such a pattern change upstream over N America and N Pacific would not necessarily be good for the UK straight away, the day 12.5 (T300) EPS mean shows a strong zonal flow over the UK with low heights to the N and NW and ridging to the south.

However, the -EPO ridge anomaly will certainly help in the long term to warm the 500mb over the arctic with -AO signature.

[BLAST FROM THE PAST]

18z amplifying even more.....changes are coming...or is this a blip

 

BFTP