Model Output Discussions 12z 01/09/2016

[knocker]

The EPS anomaly this morning is pretty much as already discussed in the 6-10 day range with HP N. Scandinavia with the upper low very adjacent to southern Britain. Ergo a slack easterly flow portending cloudy, cool conditions in England with the better weather in N. Ireland and Scotland.

Now how is this going to pan out? the answer is not obvious, to me anyway, at the moment. The pattern does flatten out a tad but positive heights still remaining over Scandinavia and the Azores pushing north in mid Atlantic so the upper westerly flow is fairly weak and not exactly copybook zonal. All still to play for in this time frame I feel but looking forward to some mild zephyrs from the west and a little boost for the Dracaena trees.

Edited October 5, 2016 by knocker

[bluearmy]

3 hours ago, jvenge said:

Not sure I see the into the freezer Eastern Europe. For my part at least, don't see anything other than seasonal norms at the moment. 

I would hope that this winter would be more than a little bit better than last! That's setting the bar quite low ;-)

Well Warsaw isn't. Below av -  yes but only a few eps even show a frost !!

[Mucka]

3 hours ago, jvenge said:

Not sure I see the into the freezer Eastern Europe. For my part at least, don't see anything other than seasonal norms at the moment. 

I would hope that this winter would be more than a little bit better than last! That's setting the bar quite low ;-)

That was based on yesterdays output and the anomalies show temps a fair bit below the seasonal average - surely sustained -8 to -12 850 anomaly for large swathes of Eastern Europe is by definition not the seasonal norm?

 

Today's output thus far is a little less conclusive though still plenty of anomalous cold air around Eastern Europe/Russia for the time of year.

Max temps struggling next week and an obvious and significant cool down from where they are now.

 

As Knocker mentions the models seem more inclined to want to return to a Westerly flow with the jet ovr the top so far today in FI but I guess we will just have to wait for Mathew to do its thing before we get a better idea how things will shake out in that regard.

 

[Frosty.]

The GEFS 6z mean shows a prolonged blocked spell lasting until beyond mid month with the trend in the coming days for cooler and cooler air to spill across the uk from the north sea and northern Europe..so, temps sliding below average making it feel very seasonal and weatherwise a lot of fine weather with sunny spells and broken clouds and some cold nights with slight frosts where skies clear but occasionally some rain around and rogue showers in the east and really the weak signs of an Atlantic breakdown are currently approx two weeks away and may be shunted back even further!.in my opinion it makes a nice change to be looking east for our weather instead of the usual direction between south and west!

[MR EXTREMES]

but a iceland high pressure would do nicely

 

[phil nw.]

Yes it's lovely out there again today Frosty and that east wind feels fresher already especially out of the sun.

The Scandinavian block is still the main feature for us and indeed much of Europe into next week,continuing to bring that easterly feed which will just drop the daytime temperatures a couple of degrees by the weekend as a cooler pool approaches from the east.

Yes Mr.Extremes i was just typing this as you posted above.I spoke around the Icelandic pressure ensembles a couple of days ago as they hinted that the main +ve heights would extend that way in the coming period and indeed that picture as you just showed is still there

Day 10 anomalies

 

and the latest graph for up there

so next week it seems we see the weakening of heights over to the north east but then moving to our north west with corresponding lower pressure over the nearby continent.At the moment then we look like keeping that easterly, even north easterly later, until mid-month.

Not sure how long this -NAO pattern will hold.Those Icelandic and indeed Scandinavia pressure ens. do show some fall off late on but not enough yet to indicate a strong Atlantic jet.It still looks fairly benign currently as we head towards mid-October.

 

 

[Frosty.]

These would be jaw dropping charts if it was winter with the north sea turned into a snow making machine..but even at this time of year it's like a breath of fresh air to see synoptics like these from the Gfs 12z instead of the run of the mill westerly weather we usually get! 

Anyway, it looks blocked for some considerable time with temps becoming rather cold in places by day and night whilst other areas barely reach average but it's very seasonal quite benign conditions  with occasional disturbances running east to west with some rain / showers mixed with sunny spells and cold enough at night for slight frosts where skies clear.

[knocker]

Keeping last night's 6-10 anomalies in mind perhaps confirming a dismal few days for England and even Cornwall as well.

 

[Frosty.]

15 minutes ago, knocker said:

Keeping last night's 6-10 anomalies in mind perhaps confirming a dismal few days for England and even Cornwall as well.

 

 

It may be dismal for you but these synoptics are interesting for those who prefer scandi blocks drawing in cooler and crisp air rather than a bog standard mild mushy swly pattern!

Edited October 5, 2016 by Frosty.

[Smiler1709]

Does anyone have any information on how the cfs is performing for the winter ahead? 

[SMU]

Afternoon

 

should the 12z GFS varify then it all but locks in a well below average month - with a flow from a Northerly / Easterly quadrent for the next 10-12 days at least...

it would have to be a big swing to warm southeries to salvage a return to normal values ( it could happen !)

s

 

[knocker]

58 minutes ago, Frosty. said:

It may be dismal for you but these synoptics are interesting for those who prefer scandi blocks drawing in cooler and crisp air rather than a bog standard mild mushy swly pattern!

On the contrary I find, and have found, the evolution of the pattern fascinating and interesting but I can find nothing interesting in the prospect of cloudy grey skies, outbreaks of rain and below average temps in October. Promise me you will buck up.

Edited October 5, 2016 by knocker

[Frosty.]

9 minutes ago, knocker said:

 but I can find nothing interesting in the prospect of cloudy grey skies, outbreaks of rain and below average temps in October. 

That's not the full story though is it Malcolm, there will also be plenty of dry weather, some sunshine and some cold nights with slight frosts.

Edited October 5, 2016 by Frosty.

[MP-R]

What a chart!

Imagine that in December-February with the uppers 5-10C lower. A real beasterly. Let's hope these synoptics repeat over the coming months.

In fact, I'm amazed at how easterly the charts are throughout the models at the moment. Any idea what the most easterly October is? I think the last time I can remember a truly cold spell relative to the time of year from that direction was in October 2003. Sometime around the 20th it was particularly cold with maxes around 4-7C with rain of course.

[Man With Beard]

46 minutes ago, Steve Murr said:

Afternoon

 

should the 12z GFS varify then it all but locks in a well below average month - with a flow from a Northerly / Easterly quadrent for the next 10-12 days at least...

it would have to be a big swing to warm southeries to salvage a return to normal values ( it could happen !)

s

 

It does look so. Chances of a return to warm are now looking slight. Best hope is UKMO - nearly gets something westerly in at T144

but most other output builds a ridge from the Atlantic up to Scandi and results in a true northern block - I saw someone mention March 2013 and I don't think some of the output is far off that (synoptically, not in terms of cold). This ensemble temperature chart for central England shows how the CET could even get below 10C.

Maximums generally 10-15C, minimums around the 5C mark but I guess may get close to freezing as we go deeper into October.

A very, very unusual October by recent standards then. No Atlantic attack at all, no sign of even a 20C day. Out to T360 on the GEFS, absolutely nothing resembling zonality which is startling since you'd expect at least some of the ensembles to drift back to something more "average" - and lots of ensembles suggesting possibly even colder to come as we approach the time when something like winter becomes possible...

Edited October 5, 2016 by Man With Beard

[phil nw.]

.Apologies for repeating these sentiments just my usual cautionary thoughts re the current high latitude blocking.

A couple of archive charts from last year in October

No not exactly the same but really just to point out that this type of blocking is not uncommon before the fully developed vortex.There are further instances of such in other years.

The background drivers of course are not the same so hopefully a weaker vortex will prevail when it really matters-in Winter.

The test will come soon as the Arctic continues to cool.I would say if we are looking at this type of pattern come November then prospects will look very interesting from a cold lovers perspective.

[daz_4]

ECMWF vs. GFS. Hard to say where the high ends up next week.

  

[Severe Siberian icy blast]

18 minutes ago, phil nw. said:

.Apologies for repeating these sentiments just my usual cautionary thoughts re the current high latitude blocking.

A couple of archive charts from last year in October

No not exactly the same but really just to point out that this type of blocking is not uncommon before the fully developed vortex.There are further instances of such in other years.

The background drivers of course are not the same so hopefully a weaker vortex will prevail when it really matters-in Winter.

The test will come soon as the Arctic continues to cool.I would say if we are looking at this type of pattern come November then prospects will look very interesting from a cold lovers perspective.

Hi. First post for a few months.

I would say a few differences that could make all the difference is the strat is forecast to have a fairly large split from bottom to top with it splitting into 2 main areas. I remember the block last year we was all watching but there was a clear difference in behaviour when looking at the top of the strat which was cooling rapidly and becoming organised where as the bottom was weak and unorganised and we all hoped it would continue into the winter. We all no it didn't. So that's different there.

The second major difference although still very early is the fact that last year the whole of Europe  north to south was, in the main covered in warm air  so when we had good synoptics with a south-easterly or easterly air flow we had no cold uppers to tap into. We did actually have about 4 or 5 rain events that would of been snow if we had colder air in Europe. Once we get Europe cold then if in place come December there will normally be some around in Europe for much of the winter which would make it a lot easier for snow and cold etc. For the love of money let's hope so I can't handle another flipping mild winter. . . .  Lol 

Edited October 5, 2016 by Severe Siberian icy blast

[blizzard81]

Could be another plume post day 10 if the ECM 12z is anywhere near accurate. Will be very interesting to see the post day 10 ensembles later on to see if there is any sign of a warm up as we enter the second half of October.

Edited October 5, 2016 by blizzard81

[Frosty.]

The Ecm 12z is dominated by an Ely airflow, quite brisk at times which would really take the edge off the temperatures, it would feel chilly. In a few months time if the same pattern repeats (God willing.. then we would turn all those greens into lovely shades of blue or even purple!

[knocker]

The ecm is continuing to retain the Scandinavian block and progressing the upper low to the south of the UK next week. An interesting feature appears to be the reinforcing of the low pressure with injections of energy from the 'vortex,' in N. Canada. So essentially we are looking at cooler than average temps (perhaps quite significantly), cloudy and some rain. The really cold air is over eastern Europe.

Edited October 5, 2016 by knocker

[Summer Sun]

It's not until D10 that ECM changes the wind direction

Certainly, a chilly feel over the next 7 to 10 day's not as cold as it would be in winter but if you're stuck under any cloud and or rain you'll know about it

[damianslaw]

Both GFS and ECM showing a similiar set up for the foreseeable with only subtle differences. The trend is a cooling one, as we import colder uppers from northern europe, and much more cloud with some showers possibly heavy and drizzle for some, so feeling quite drab in parts - not the crisp autumnal conditions some are suggesting. Far NW looks best for sunshine and clear skies. 

The 4-10 day timeframe is forecast to be decidedly chilly, the first below average spell of temperatures for quite a number of weeks. Both models show a frontal feature development over the near continent which could develop into a shallow low pressure feature producing quite cold wet weather over England and Wales, in the meantime the scandi heights are programmed to retrogress towards Iceland - which would usher in a chilly NE airstream. What may happen next? various options all pure speculation:

• the 'developing' low pressure becomes a stuck feature and we pull in more of a southerly flow, but with energy going into the northern arm of the polar front jet, the jet is forced up and over the heights to the north, and we see then it merges with lower heights and trough feature over scandi pulling down a very raw NE feed.
• energy is pumped into the southern arm of the jet, allowing heights to elongate west-east in towards southern greenland, and weend up with major northern blocking, but generally unsettled cold weather
•  a split jet formation with heights forced to languish in situ near or over the country, with core heights between Iceland and Scotland, bringing fine dry settled chilly weather with frost and fog.

As ever all eyes on the projected strength and position of the jetstream which is a big unknown right now as this will ultimately be determined by the path of hurricane Matthew

What I am seeing is a set up the least conducive to producing a swift change to full on westerly zonal conditions, quite unusual for the time of year, but as some have stated not unprecedented. We are seeing alot of warm air advection into the Arctic at the moment, which is resulting in the PV having a hard time to get its act together, and when warm air pumps into the arctic, by the laws of nature, cold air is always forced south into the northern mid lattitudes, not always universally though.. 

 

Edited October 5, 2016 by damianslaw

[Matthew.]

From this chart on the 8th October we can really see the cooler temps at mid-latitudes:

[jules216]

Sorry if this is not related to the models chat, in Slovakia today there were records broken on 4 official weather stations! For the lowest Tmax for the date 05.10, they record temperatures from as far back as 1940s, on average it was between 7-12 deg. colder then 1981-2010 average, it is not as ordinary blocking as some past Octobers,actually its quite exceptional,not sure how long it will last though but its amazing how quickly continental Europe can cool down under right synoptics, fingers crossed it keep cool and no sinking Euro high develops anytime soon