Model Output Discussion 01/09/17

[snowray]

Fantastic charts, late November snowfall for many of us on here if these charts were to verify.

[SMU]

Record breaking -AO probs around -6.

PV broken. Thats a once in a 20/30 year hemi view.

if we got anywhere close to that set up then snow would become quite widespread at a pretty good time of year....

 

 

[bobbydog]

anyone got a spare vortex?

this one is broken...

thats some siberian high!

[bobbydog]

Just now, Steve Murr said:

Record breaking -AO probs around -6.

PV broken. Thats a once in a 20/30 year hemi view.

if we got anywhere close to that set up then snow would become quite widespread at a pretty good time of year....

 

 

its not the first time that set up has been modelled recently either, so its not out of the question...

[SteveB]

Just now, bobbydog said:

anyone got a spare vortex?

this one is broken...

thats some siberian high!

Don't worry, it has a very nifty trick of mending it's self.

Charts do look interesting, will they happen though, get down to 48-72hrs then your talking. until then it's only eye candy.

[bobbydog]

6 minutes ago, SteveB said:

Don't worry, it has a very nifty trick of mending it's self.

Charts do look interesting, will they happen though, get down to 48-72hrs then your talking. until then it's only eye candy.

if only this was a +48hrs chart...

[blizzard81]

Not a bad ukmo 144hr chart either 

[bluearmy]

13 minutes ago, SteveB said:

Don't worry, it has a very nifty trick of mending it's self.

Charts do look interesting, will they happen though, get down to 48-72hrs then your talking. until then it's only eye candy.

The interesting charts are appearing in the 7/10 day range for me. What happens as latter part of week two progresses on the nwp isn't relevant to me. The hemispheric arrangement in that 7/10 day range matters re the latter part of November and into December. 

[northwestsnow]

41 minutes ago, Steve Murr said:

UKMO 144 shows showers turning increasingly to snow for Scotland especially the hills ( which will get a pasting )

Even higher elevations of NI could see some wintryness !

Also UKMO shows a huge early season blizzard for the NE states of the US...

Yes and GFS fi is now showing some very very interesting synoptics- i suspect the meto may well be onto something with their idea of temps below the norm as we hit late November.

Would be amazing to see a late November cold spell just in time for the opening of the christmas markets etc

[northwestsnow]

21 minutes ago, Steve Murr said:

Record breaking -AO probs around -6.

PV broken. Thats a once in a 20/30 year hemi view.

if we got anywhere close to that set up then snow would become quite widespread at a pretty good time of year....

 

 

Interest meter going up every day now Steve!! Potentially exciting start to the season!!

[nick sussex]

It’s a shame that annoying weak low in the west Atlantic stops better retrogression of high pressure towards Greenland .

The UKMO just about delivers a cleaner progression as the low phases with the amplifying bigger system over the ne USA, the GFS takes the low east and subsequently any colder air hits the fish in the North Sea and further east.

Until the models agree on that low then next weekends prospects are up for grabs.

[ITSY]

Agree with most of what's been said, interest definetly rising. Still only trends for D10+ so there is much to play for. To my eye, exactly 10/20 GEFS members go for extensive N Blocking by end of Low Res, in addition to Op and Control. UKMO encouraging, plus tallies with NAO/AO forecast (see prior page), & EC clusters from earlier today. This evening's ECM will be useful...

Good signs alas, although nothing more just yet...

Edited November 5, 2017 by ITSY

[J-Man]

Its also encouraging that the models predicted both the pre Halloween cold snap and now this bonfire night one.  Both were showing at least 7 days in advance which is a complete turn around to recent years.

Edited November 5, 2017 by J-Man

[coldwinter]

Very solid agreement in the extended between GEFS and ECM EPS

 

Interesting to get such agreement in the extended.  If we can get this big Siberian high and blocking to develop it would not only help with cold chances for the back end of this month, (I note the met are saying dry and below avg temps) but in the long term. Strong Siberian high--->Increased wave activity/poleward heat flux---->weakening of the polar vortex--->-VE AO--->higher chance of colder weather. All speculation for now but an interesting start to the season.

Ryan.

[nick sussex]

State forecasts for ne USA prefer more amplified solutions for ne USA, think GFS too flat . For coldies we do need to see the more amplified outcome upstream as that corresponds to less energy spilling east and a slower progression east of low pressure which gives ridging a better chance to get further nw. The UKMO seems to look a good match to their thoughts , hopefully the ECM doesn’t jump ship now.

Edited November 5, 2017 by nick sussex

[bobbydog]

ECM not as flat as the GFS at +144

 

good so far....

[nick sussex]

ECM is more amplified than the GFS which is the flattest solution upstream , hardly delivers any cold into the ne USA.

A frequent failing of the GFS upstream it also fails to develop a deeper low off the ne USA which the ECM , UKMO and GEM all do.

Without the annoying Atlantic low next weekends forecast would be straightforward unfortunately that weak low effects any retrogression of high pressure and impacts whether the colder air scores a direct hit on the UK or gets shunted further east .

So either colder wintry showers in the north or drier and cooler depending on that lows behaviour .

Edited November 5, 2017 by nick sussex

[northwestsnow]

ECM offers wintry showers for the north at 168,most likely some snow showers for high ground in some places.

[knocker]

The ecm has very much modified the intense low for Friday and now has a much shallower version running through Scotland Friday morning, still bringing some heavy rain with it. As it tracks quickly into the southern Baltic the UK is left in a showery NW airstream but late on Saturday another perturbation wings around the high pressure and a rain belt crosses southern England.

From this point, as it did on the previous run, amplification takes place with the high pressure to the west ridging north into Iceland and the upper trough to the NE plunges south into central Europe. This veers the surface wind northerly over the UK which lowers the temps somewhat and initiates wintry showery  conditions in Scotland in particular but also elsewhere.

From this point, not forgetting some pretty foul weather in the eastern Mediterranean,  the upstream energy again suppresses the ridge and more fronts impact the UK on Tuesday as normal service is resumed.

Temp contour and anomaly

Edited November 5, 2017 by knocker

[ITSY]

No great cold but the final frame of the ECM shows the PV under enormous strain. Huge WAA into Svalbard all the way from Alaska/Siberia, WAA into E Canada/W Greenland, and initial advection starting to take shape over Scandi - which actually probably makes it quite a mild affair for the UK, albeit while the pieces are moved into place. Trends afoot, but nothing more just yet...

Edited November 5, 2017 by ITSY

[oasis]

ECM showing siberian high extending further into the Arctic than GFS at +240. Expands from 216 to 240. 

[Met4Cast]

1 minute ago, ITSY said:

No great cold but the final frame of the ECM shows the PV under enormous strain. Huge WAA into Svalbard all the way from Alaska/Siberia, WAA into E Canada/W Greenland, and initial advection starting to take shape over Scandi - which actually probably makes it quite a mild affair for the UK, albeit while the pieces are moved into place. Trends afoot, but nothing more just yet...

I think this is the key - Initially it might not be very good for cold weather across the UK but to see WAA pushing into Greenland from 3 different areas and seeing the way the vortex quite literally disintegrates is where the interest lies right now.

Great chart watching! I'd say if things go to plan, the final third of November (similar timing to 2010, actually) could be very interesting.

[bluearmy]

Not sure I see too much WAA on the ecm but the growth of the upper Siberian ridge in the 7/10 day timeframe is one which all three major new models go for. How that impacts on our part of the hemisphere a week or so later is the conundrum and one which will no doubt drive a rather busier thread than has been the case for months and months. 

The AO charts should be worth posting later !!

[syed2878]

These outputs are exciting how ever I think I will hold back until these are in 5-7day time frame, we have been here before and had our fingers burned. I will get excited when UKMO come on bord until then lets waight and see.

[ANYWEATHER]

Evening All, well its certainly fascinating viewing from the ecm and gfs in the days ahead with a very blocky weather pattern. Certainly different from recent Novembers and as I said a few days ago a sniff of 2010 is certainly present on the latest output....Good to be chasing cold and coming to fruition just like tonights very low temps where currently we are are at ground frost level at 8pm. As the fireworks go off on this very cold Bonfire night  our next spell of very cold weather if models are right are for next weekend with snow for Scotland even at low levels and even further south wintriness and snow on the mountains of Wales ,