Model Output Discussion - 30th November onwards

[Grimsby Snow Lover]

With regards to thoughts of Scandi HP later this month, my outlook suggests block to the east but not a cold Scandi that will really impact the UK and a flow from southern quadrant developing and I remain with my Dec outlook even with an enticing update such as provided by Ian F.  I have also touted that Jan really interests me and have mentioned a possible cold impactual period like 1987 but am not full on for that yet. However, I have pricked my ears up reading RJS recent post.Funnily enough my outlook has big similarities to RJS.I think the models will toy with the Scandi HP down the line with it 'looking good' for us but will eventually ease back on its direct cold influence this month.Anyway we aint got our cold blast yet.  BFTP

An intriguing post BFTP, what exactly has Ian Ferguson and RJS said tonight? I have scanned the past few pages but couldn't find anything. Many thanks in advance GSL

[bobbydog]

Some great charts tonight for Gav and Gaz. Quite an intense PV developing over Greenland with the jet being driven to Western Russia, potentially exceptionally mild and bringing back those charts from the late 80s winters.

 

well ian, it is only one day of charts out of many, which have mostly shown a potential scandi high on the cards. even the Met Office have taken this as a serious option.

 

i had 'the snip ' on saturday, are you trying to make (at least the male) members of netweather feel like i do right now!?

Edited December 3, 2013 by bobbydog

[Weather-history]

It was being widely discussed on the forum at the time that HLB in winter may never occur again, this was a serious topic on weather forums. .

Absolute twaddle it was. How can high latitude blocking in winter become extinct which was effectively being said? It ain't the dodo and it was unprovable. But I'm going off topic.

[Gibby]

Good evening folks. Here's how I see the midday outputs of GFS, UKMO, GEM, NAVGEM and ECM and what they mean for us down on the surface over the next week or two.

 

All models show a weak cold front moving South across Central areas overnight with a band of outbreaks of rain moving South to reach South Wales and the Midlands by morning. The North will see clearer conditions behind the rain with a frost in places and a few wintry showers over the far North. Through tomorrow the rain progresses through the South while another front approaches the North later. Clearer conditions will give the South more sunshine later in the day while Northern areas become cloudier and breezier later. Through tomorrow night and Thursday a rapidly deepening depression moves East then SE to the North and NE of Britain with gale or severe gale force winds over Northern areas and with a short spell of rain moving quickly SE down over all areas through the day. Very cold air will follow with snow showers in the North and East while Southern and Western areas stay dry, breezy and cold. Then after a frost on Friday night High pressure slips SE over Southern Britain allowing milder air and cloudy conditions from the North Atlantic to filter across and down over the UK through the weekend.

 

GFS then shows the rest of the run with the UK under mild SW or SSW winds with Northern and Western areas under risk of rain at times in blustery winds. More Southern and Eastern areas stay largely dry with rather cloudy conditions prevailing and temperatures possibly mild if surface winds stay sufficiently breezy to bring milder uppers down from above to the surface.

 

UKMO tonight shows High pressure over much of France and the Meditteranean Sea with a Westerly flow over Northern Britain with relatively mild and cloudy conditions here. Over Southern Britain winds will be quite light with a lot of cloud at times but with some drier and clearer skies at times too leading to frost and fog patches night and morning with chilly and grey conditions prevailing at other times.

 

GEM shows High pressure to the SE building strongly through next week with mild Atlantic winds affecting the North and West while Southern and Eastern areas stay dry and though rather cloudy at times areas of mist, fog and frost under any clearances in the cloud could give some more rather chilly anticyclonic gloom type days down here.

 

NAVGEM follows the trend of the others with a moist SW flow over the North and West carrying cloud and mild weather across these areas. In the South and East it may well be that we maintain somewhat colder conditions with some frost and fog patches should cloud breaks occur overnight.

 

ECM shows a large High pressure area over France later next week which will maintain mostly fine and settled conditions across many areas. It will not be particularly mild early in the week away from the NW but it does look under the light to moderate WSW flow shown on Day 10 that mild if cloudy conditions look likely for all though with very little rainfall anywhere.

 

The GFS Ensembles show a cold snap over the coming few days before things turn less cold and benign once more as High pressure to the SE wafts Southerly winds up across the UK. Rainfall is shown only towards the latter part of the run for the South from some members with amounts small for all.

 

The ECM 12 noon Ensembles also paint a relatively mild scenario at least aloft with High pressure to the SE of the UK. To obtain cold from these we need an inversion which often means cloudy, grey and rather cold conditions in very light winds. If however, the winds are somewhat stronger at the surface some of those warmer uppers could translate towards the surface though conversely frost becomes an issue at night should drier continental winds make landfall over the South.

 

The Jet Stream shows the flow to the NW turning SE down the North Sea briefly over the next 72 hours before the flow quickly resets in a NE direction over the Atlantic to the NW of the British Isles and on over Northern Scandinavia.

 

In Summary tonight the cold snap is almost here and still shows a 'blink and a miss it' affair away from Northern and Eastern parts where severe gales and occasional snowfall could be quite noteworthy for a while. However, this is the only noteworthy weather conditions to come out of the 12 noon models tonight. All of them show High pressure moving in close to Southern Britain at the weekend and down to the SE from the start of next week setting up a South or SW flow over the UK. With the proximity of High pressure so close to the SE at times then cloudy and dry weather will probably sum up the weather through most of next week and probably beyond with little or no rain away from the far NW at times. Temperatures will be on the warm side of average over Northern and Western Britain under a maritime SW'ly while Southern and Eastern areas possibly too sharing some of this milder air remain always at risk from incursions of Continental air bringing colder air in from Europe at times with frost and fog issues should it occur. All in all though it looks very likely that it is going to be sometime before our UK weather resembles anything like real Winter weather with most farmers, growers, travellers and the like able to carry out their outside duties and travels unhindered.

[SMU]

Evening All-

 

Missed all the days runs but I haven't missed much-

 

ECM & OP at considerable odds with the MEAN clustering post day 10.

 

I suggest that the models are being over generous with the zonal flow-

http://www.knmi.nl/exp/pluim/vijftiendaagse/index.php?run=12

Its unusal to see the operational such a wild swing away from the MEAN>

 

 

Best run of the day UKMO 144.

http://www.meteociel.fr/ukmo/runs/2013120312/UN144-21.GIF?03-18 with the blue hole suddenly to become a yellow ridge over scandi.

 

S

Edited December 3, 2013 by Steve Murr

[cold snap]

Ian's F post was clear ,don't expect anything from the east to crop up yet.

This is someway down the line and still only a possibility at the stage.

The current toying around by the models ,has no bearing on a Scandinavia prognosis yet.

Edited December 3, 2013 by cold snap

[mcweather]

It was being widely discussed on the forum at the time that HLB in winter may never occur again, this was a serious topic on weather forums.

 

ECM ensembles strongly back the OP.

 

Indeed Ian and all those that thought that at the time were COMPLETELY WRONG as is your remark about the ECM ensembles.

[Gaz1985]

About as cold as it gets this week from JMA

 

 

Very windy for Northern areas Thursday

 

 

 

End of weekend and high pressure sets up to our South bringing in milder air 

 

 

 

JMA run ends with high pressure to our East

 

[Ian Brown]

Evening All-

 

Missed all the days runs but I haven't missed much-

 

ECM & OP at considerable odds with the MEAN clustering post day 10.

 

I suggest that the models are being over generous with the zonal flow-

http://www.knmi.nl/exp/pluim/vijftiendaagse/index.php?run=12

Its unusal to see the operational such a wild swing away from the MEAN>

 

 

Best run of the day UKMO 144.

http://www.meteociel.fr/ukmo/runs/2013120312/UN144-21.GIF?03-18 with the blue hole suddenly to become a yellow ridge over scandi.

 

S

 

No, the jet is going over the top and whilst there is even energy going to the Azores to 'level' the jet angle a little, you would just see the HP build over the UK. Ridging isn't going to come out of the Arctic.

[johnholmes]

The charts are unreal, there's so much resemblance to the winter of 62/63, we had a blast of cold air from the north on the 6th then high pressure dominated at mid latitude very similar tow hat we have now, obviously I'm not saying we're gonna get a severe winter but the patterns are nearly exactly the same, that with the met office update there's something to hold onto to. Let's wait and see.

 

I can see little resemblance to the 4 December 1962 to the T+24h chart at 12z today, can you say what is similar please?

In 1962 there were two marked troughs; one about 20W and as far south as 40N maybe lower and another one at about 20E with an upper ridge between them

Today the T+24 shows no marked trough on the chart with the only upper ridge being at about 60west. Maybe you mean something I am missing?

[chionomaniac]

As I've said in a thread somewhere yesterday Roger - I'm fascinated to see how your December forecast fronts up against reality. There is a fair amount of data mid month pointing to height rises too far north to suggest mild to very mild - but if your methodology should trump all the models then hats off to you once again. What looks very likely is that after a dull week this week we finish with a short sharp blast of cold before tapping into a much milder feed for at least 72 hours. Beyond that we will have to see whether pressure builds north or sinks south ala ECM 12z. Personally I cannot believe that the strat charts screaming height rises to our north and east can be completely wrong. Trop models often misfire, but the strat predictions tend to be less variable, If we get heights as far south as the ECM has it this afternoon then we truly will have a bit of a "disconnect" between the two. Either that or the strat models are going to look very different in the morning!

I have to say CH, I am not as optimistic as you are looking at the strat charts. Firstly, in todays Berlin output which is based on yesterdays 12Z ECM, the best that I can see is any height rises to our NE being positioned too far south and the residual Canadian vortex position also unfavourably positioned to allow further height rises any further north.

 

 

This is backed up somewhat by the latest GFS charts:

 

 

 

I don't think that the wave 2 activity will be strong enough to weaken the vortex sufficiently.

[Roger J Smith]

For another thread on NW, I was looking back at archived weather maps for the period Dec 5-7 and looking for any kind of analogue to this projected deep low in the southern Baltic region. The closest I could find was a 957 mb near Stockholm on Dec 6, 1895 (00z) and second closest was a pattern in 1940 that was similar to current model but not quite as intense, low about 970 mb.

 

The winter of 1895-96 then produced relatively average temps, although somewhat milder for that era, with a brief indication of cold in Britain about a week after the low but a mild end to December. The winter of 1940-41 turned quite cold later.

 

I then looked at all cases where the winters turned very cold and the consensus map for Dec 6 showed almost the opposite pressure pattern to what we are likely to see this year.

 

If I were to ignore all other research including my own, those facts taken together would probably argue for a chaotic trend that would average near normal and extend towards both extremes. And in fact that's what my research shows although with a 2:1 bias towards mild.

 

 

 

[Bristawl Si]

Pretty obvious outcome for the week from around 7th to 14th imo.

HP in charge - position over or just to south of the UK.

Where it decides to position itself from say 14th/15th, and assoc flow, still undecided.

I think Ian F's post earlier kinda backed this up.

And posters congratulating LRFs for December as being on the money or similar, on 3rd December......hmmmmm.

[R.P. McMurphy]

About as cold as it gets this week from JMA

 

 

Very windy for Northern areas Thursday

 

 

 

End of weekend and high pressure sets up to our South bringing in milder air 

 

 

 

JMA run ends with high pressure to our East

 

 

In regards to every chart you posted, it's all going to feel cold lol.

Edited December 3, 2013 by Glenn W

[johnholmes]

Almost all my career has been looking at the 0hr to 48hr range. It's really not dull or mundane. There's always something. Apart from the times when there's not.

 

totally agree, perhaps stretch to 72-96h for media work and when dull or mundane in the UK area there was always highly interesting weather in some area of the world that one could spend time looking at.

[terrier]

Just get that feeling from the charts tonight that we could be seeing very little in the way of wintry outlook for at least the next 10 days at least. Let's hope for better come jan. Because dec is looking very uninspiring in my eyes.

[johnholmes]

Tonight's NOAA 8-14 dayer seems to give a slightly stronger signal for height anomalies

to our east/north-east than yesterday.

 

814day.03.gif

 

That has been the pattern over the past two to three days and I have commented on this over the last 24 hours or so. Not just on NOAA but the ECMWF-GFS suite as well. The rise in anomaly heights is also well supported on all 3 models by the corresponding upper ridge. Care is needed with anomaly values. They do need solid support from the predicted contour shapes to be really believable. I would be very very surprised at the time scales of these charts, 6-10 and 8-14 days if the upper air pattern was much different from what they are indicating.

[damianslaw]

Models continue to paint a notably dry outlook, indeed this is becoming a very dry period for the time of year, unusually so. In more normal circumstances given the strength and position of the PV, we should be experiencing a very wet period, but alas the aleutian ridge really has kicked this into touch allowing high pressure to settle in position close to the country for what is now quite a lengthy time and there are no signs of a pattern change anytime soon.

 

A number of forecasts have pointed to a notably dry December, and I suspect it will be the dryness that goes down as the most notable aspect of the month when we come to do our summaries. This is normally the most volatile period of the year, but not this year, it has been exceptionally quiet these last 2/3weeks and the theme continues bar the odd hiccup i.e. the shortlived northerly blast, you can tell the BBC weather forecasters are tired of saying the same old thing at the moment.

[Don]

Just get that feeling from the charts tonight that we could be seeing very little in the way of wintry outlook for at least the next 10 days at least. Let's hope for better come jan. Because dec is looking very uninspiring in my eyes.

 

Well most long range forecasts have not suggested that December will be anything special for wintry weather anyway.  The main hope is for January and February.  The way I see it is that if we get any decent cold snaps/spells between now and New Year at least, it will be a bonus.

Edited December 3, 2013 by Don

[Gael_Force]

I'm not seeing anything too concerning on the Dutch ensembles - eg Dutch SW coast still has a good cluster of cold temps and I would say a bit more definition in that cluster of easterly (90 degree-ish) winds. Det run is a serious outlier at the end - could be new trending from today, of course.

 

temps   winds 

[SMU]

Good post GF-

 

Look where the main clustering is- & the angle of the wind a you've done.....

 

UKMO has classic split flow @ 144 & would see the ridge shooting towards Scandi @ 168..

 

S

[bluearmy]

When have the ops made the running thus far? Anyone forecasting by ens would have done a darn sight better than by ops.

Naefs continues to show energy headed across from canada towards siberia in two weeks time. Plenty of mixed signals for that timescale. Extended ecm visible shortly.

[fergieweather]

We just having a chuckle on phone with UKMO about what certain newspapers will do to 'square' their recent/ongoing/interminable editorial line of late, versus the 12C Theta-W approaching Scotland in the UKMO-GM at T+144... ;-)

[johnholmes]

can one of you clever fellas try a pattern match with the upper air pattern shown below, just for amusement?

http://www.cpc.ncep.noaa.gov/products/predictions/814day/500mb.php

[snow1975]

We just having a chuckle on phone with UKMO about what certain newspapers will do to 'square' their recent/ongoing/interminable editorial line of late, versus the 12C Theta-W approaching Scotland in the UKMO-GM at T+144... ;-)

Barbecue summer, better late than never.