Model Output Discussion - 18z 31/10/15 onwards

[cheshire snow]

The GFS 06z reverts back to a chilly N/NW Flow in FI,With Wintry PPN Over the high ground

Gradually spreading South 

 

C.S

[Polar Maritime]

Yes the 6z GFS seems to bring back the cooler Northerly type flow into the run for around the 19th. Lots of deep Lows to be smoothed out yet, Which is giving the skitty motion within this time-frame. Much to be resolved over the coming days.

Edited November 8, 2015 by Polar Maritime

[blizzard81]

Some very downbeat posts over the last few days with regards to cold in the first half of Winter. I stick to my belief that the last third of November will bring a cold spell and it will feel even colder after the incredibly mild temperatures we have experienced recently. I have also noticed the polar vortex not setting up shop over greenland which is a positive - something Bluearmy alluded to earlier. Add to this the fact that the sst's off the coast of Newfoundland are now rapidly cooling and you will see that it is not all doom and gloom for us coldies as we head towards winter.

[Summer Sun]

GFS 00z OP was one of the warmer runs in the ensembles fairly good agreement till the 14th after this lots of scatter

 

[knocker]

Toasty to go with the coffee

 

[John Badrick]

Toasty to go with the coffee

wow, just look at that cold getting ever so closer to us from both sides and that's not even a winter chart. good find Knocker, here comes the cold!!!!

[Summer Sun]

Some extreme rainfall totals for NW Scotland by d10 over 250mm for some parts over in eastern Scotland some areas just about make 20mm

 

[knocker]

wow, just look at that cold getting ever so closer to us from both sides and that's not even a winter chart. good find Knocker, here comes the cold!!!!

 

And even closer if you are planning spending xmas on Rockall and not barbying on the beach in you know where

Edited November 8, 2015 by knocker

[nick sussex]

Regarding the CFS this used to be posted regularly by those preferring cold as it came out with some outlandish colder scenarios which never verified. So I'd take its output with a huge pinch of salt given its woeful reliability.

 

Regardless of the current very mild temperatures that doesn't tell the whole story because its not a PV driven mild spell, that still shows no signs of setting up in its favourite Greenland position, and its irrelevant how strong that is its where its located that's important.

[bradymk]

No two winters or weather patterns are ever the same and this winter is certainly a lot different to 09/10 in many aspects but it does also have its similarities.

 

 

Mean height anomalies for Mid November 2009, with the ridging developed in Eastern Canada.

 

 

ECM ensemble mean to 384 hours for now, notice the similarities with blocking beginning to intensify in Eastern Canada with trough in US moving slowly eastwards.

 

These aren't the exact carbon copy obviously and i am not saying we are heading for the same winter at all, but certainly similarities in the current output to how November 2009 started to progress. I posted the other day about July AO and following winter. Look how similar the height anomalies were for 2009 summer to 2015 summer...

 

2015                                             2009

 

Again this does not necessarily mean anything, just interesting similarities but this July did feature the second most negative Arctic Oscillation on record, second to only 2009. Out of the top 15 most negative AO July’s on record, 14 of those 15 featured a negative AO in the winter that followed.

 

Lastly, current predicted AO for next few months. Mainly +ve start but -ve later..

 

 

 

[Iceaxecrampon]

Back in line with more winteriness in FI at T+312

 

 

NW flow for the 16th November  - straw clutching but I have that date in mind from older runs last week.

 

 

We will of course see.

 

 

[Summer Sun]

Whilst the GFS 00z OP was one of the warmer runs in the ensembles the 06z OP is one of the coldest from around the 19th good agreement on this run till the weekend then the scatter gets greater

 

[Ali1977]

GEFS ensemble mean has the strongest PV over Alaska and Eastern Siberia - is this a good sign heading into December? Surely better than setting up over Greenland and a Eastern Canada!!

[Mokidugway]

GEFS ensemble mean has the strongest PV over Alaska and Eastern Siberia - is this a good sign heading into December? Surely better than setting up over Greenland and a Eastern Canada!!

isn't El Niño predicted to bring above average temperatures over North America this winter ??.

[phil nw.]

It's often the case when we have a spell where the jet looks like straddling the UK that we see some op runs colder and some milder than the running mean.

A reflection of where the differing runs place the boundary between the polar and tropical air either side of the jet.

After the next few days it's still looking like a cool off especially further north as we head into week 2 although overall nothing more than around average.

We are still looking at a mobile westerly pattern with the Azores/Euro high ridging near at times with brief incursions of PM air between.

Edited November 8, 2015 by phil nw.

[SMU]

In amongst the doom & gloom of the recent outputs there seems a window of opportunity for some snow over the scottish hills on friday -

The ECM touting a chilly westerly flow with 850s around -5c i guess will see the freezing level around 3-400M

A few showers blown through on a strong westerly wind....

It wont last long though....

[Polar Maritime]

It wont last long though....

You wouldn't realy expect it to at this time of year Steve, All normal and Autumnal at last.

[radiohead]

If this ECM run continued onward to 300 hours, you'd probably see some ridging up to Greenland.

 

Edited November 8, 2015 by radiohead

[nick sussex]

Will the Euro high ever leave the scene?

 

The ECM at day ten gives some hope but we've see this before and it hasn't happened.The upstream pattern on the ECM looks good to help develop a stronger ridge to the nw and this should force low pressure further se into mainland Europe.

 

The PV still looks uninterested in setting up over Greenland and whilst that remains the case theres always a chance for something colder towards the last ten days of November.

[knocker]

The GEFS 6-10 anomaly shows increasing influence of the European HP which would indicate systems travellling NE and perhaps only impacting Scotland. Temps slightly above average in England.

 

The 11-15 continues with the removal of the HP influence and introducing the trough to the west so once again putting the UK under a westerly quadrant airflow which will include some very unsettled weather with temps varying around average.

 

Tonight's ecm ops epitomises the GEFS 6-10

 

http://www.tropicaltidbits.com/

Edited November 8, 2015 by knocker

[BLAST FROM THE PAST]

John Hammond forecasts the change with temps returning to average back end of the week with more strong winds and rain following through next weekend .   That brings us to midmonth, my target period for change in pattern I spoke of in banter thread back in October.  I think ECM in longer range looks good to me and this euro high won't be the controller imo after next weekend but more of the same for now.  I think as we head through the week we could be getting some MetO warnings if these tasty features are modelled right.  

 

 

BFTP

Edited November 8, 2015 by BLAST FROM THE PAST

[knocker]

The ecm mean anomaly at T240 shows the influence of the HP which is apparent in the ops runs and which is forcing the Atlantic systems NE. In the ext period out to T360 this becomes much less influential and is weak feature to the SE, plus a ridge NE Canada but the main feature is a trough mid Atlantic which portends periods of wet and windy conditions with temps varying around the average.

 

[knocker]

This morning’s gfs run is interesting in the respect that, although the pattern is still mobile, it continues to further increase the influence of the adjacent high pressure. Around T144 for example it extends the European high much further north for a couple of days, diverting the Atlantic train, before relenting somewhat.

 

But it doesn’t allow the Atlantic ingress for long as in the ext period it sets about building HP from the W which travels east becoming a substantial area over Scandinavia. Whilst at the same time sinking troughs into the Atlantic and with a extremely amplified pattern upstream. All very unlikely IMO although perhaps one could foresee with strong ridging NE Canada the possibility of a cold plunge in the eastern Atlantic. Having said that there has been no suggestion on the latest anomalies that this scenario isn’t anything other than the gfs going off on one persistent though it is.

http://www.tropicaltidbits.com/

Edited November 9, 2015 by knocker

[knocker]

This morning's ecm nips a depression NE on Friday that could bring some short lived but nasty gales to the NW of Scotland on Friday depending on the precise track. After that it proceeds to build the European high before sliding it to the east and letting the Atlantic nudge in. Some quite warm air advected in during this process.

http://www.tropicaltidbits.com/

 

[Frosty.]

I went searching for cold or at least potential cold for late november, it was a dark and dangerous journey BUT I found these from the GEFS 00z perturbations, although the meteorological winter is still 3 weeks away, I think there should at least be signs of something colder or as knocker would put it, something nasty lurking in the woodshed, mild fans certainly don't need any encouragement but we coldies do and at least I found something!