Model Output Discussion 18z 30/09/15

[johnholmes]

That surface chart does not really fit the 3 anomaly charts I use. These suggest the upper high being centred W of the UK with any upper trough to the east over Europe. What is possible, but not showing, is for the pattern to allow colder air to filter round the northern flank. Even so the heights look fairly 'high' as they are originating (for far south of the UK) from northern California and just south of the Gt Lakes. This would not suggest any markedly colder weather in the next 2 weeks to me?

links

http://www.cpc.noaa.gov/products/predictions/814day/814day.03.gif

will drop the latest ECMWF-GF in when they arrive this morning, along with anycomment if they do not look much as yesterday morning's output.

[Polar Maritime]

Yes John agree, High Pressure is shown to stick over the UK for at least the next 10 days or so. The GFS continues to hint a cooler end to Month from the North in low res. The PV is certainly not wanting to set-up camp over Greenland as we enter the last Month of Autumn.

Edited October 11, 2015 by Polar Maritime

[knocker]

The GEFS anomalies do not support the 06z ops analysis and keep the high pretty firmly in place just to the west.

http://www.tropicaltidbits.com/

 

[tinybill]

http://www.meteociel.fr/modeles/gfse_cartes.php?mode=2&ech=204

 

 

i  know  its fantasy world   but lot of the coldies will be coming out of hibenation soon once  they see the charts with the cold weather digging into scotland!!!

[Yarmy]

Intriguing final frame on this morning's ECM. You wonder what would come next.

 

 

 

But the real story is the remarkable size and persistence of the mid-Atlantic high across nearly all models, ensemble means, etc. 

[NO LONGER POSTING]

Question..

 

As we head further into the realms of winter, and IF that gigantic high in the Atlantic sits there and sways west east North south for the coming few months.. IF it does push North into Greenland SAY at the end of October into November how long can a Greenland high realistically last with the correct set up.. 

[johnholmes]

Question..

 

As we head further into the realms of winter, and IF that gigantic high in the Atlantic sits there and sways west east North south for the coming few months.. IF it does push North into Greenland SAY at the end of October into November how long can a Greenland high realistically last with the correct set up.. 

 

normally not beyond 7-10 days, often less, very infrequently 2 weeks, on past climate/weather data

[Frosty.]

GFS 00z

Hardly an atlantic onslaught is it?

 

Indeed Mucka, it's an Arctic onslaught

The Gfs in particular has been showing wintry polar maritime / arctic shots through late October quite a few times recently and I think we will see a cold shot before the end of October.

[Gibby]

HERE IS MY LATEST ANALYSIS USING DATA SUPPLIED BY THE NWP OUTPUT COVERING 5 OF THE WORLDS MOST POWERFUL WEATHER COMPUTERS ISSUED AT 09:00 ON SUNDAY OCT 11TH 2015

 

THE CURRENT GENERAL SITUATION  A ridge of High pressure will remain anchored across the UK from a High pressure area to the east. Troughs will affect the far NW over the period.

 

http://www.wetterzentrale.de/pics/Rtavn001.gif

 

CURRENT SNOW LYING UK AND NORTHERN HEMISPHERE There is currently no snow lying in the UK with the freezing level ranging from 6500ft across the North and just over 8000ft aross Southern England. Over Europe snow cover is quite extensive now across NW and Northern Russia.

 

http://www.snow-forecast.com/maps/dynamic/uk

 

http://www.natice.noaa.gov/pub/ims/ims_gif/DATA/cursnow.gif

 

MODELS-2 WEEK HEADLINE  Becoming mostly fine and settled with frost and fog patches at night and only very small chances of rain at times.

 

THE GFS JET STREAM FORECAST  The GFS Jet Stream Forecast shows the flow becoming established well to the NW of the British Isles over the next 10 days or so before returning South sharply towards the end of the period across the UK or possibly even to the South by the end of the forecast period.

 

http://www.netweather.tv/index.cgi?action=jetstream

 

GFS OPERATIONAL The GFS Operational Run today shows the weather totally influenced by High pressure firstly positioned to the East of the UK and then more intensely to the West from later this week. This will ensure an East or NE flow for most backing Northerly later ensuring rather chilly but dry weather for nearly all apart from a little rain in the NW at first and a shower in the SE early this week. Low pressure is shown to finally breakthrough the High pressure block from the North at the end of the run with chilly and wetter conditions extending to all parts by Day 14.

 

http://www.wetterzentrale.de/pics/Rtavn1441.gif

 

http://www.wetterzentrale.de/pics/Rtavn3841.gif

 

THE GFS CONTROL The theme of the GFS Control Run is almost a replica of the operational run with the added caveat that the breakdown show from the operational run at the end of the two week period is not supported with High pressure remaining anchored across the UK at that time too with fine, settled and often rather cool and potentially cloudy conditions as a result in what will be a sustained period of benign weather conditions overall.

 

http://www.meteociel.fr/modeles/gefs_cartes.php

 

THE GFS CLUSTERS(14 Days) The GFS Clusters in 14 days seem to endorse a 70/30 split in favour of High pressure holding on in some shape or form across or near the UK with just a 30% group supporting anything that would mean much in the way of wind, rain or showers in any meaningful form across the UK especially the North.

 

http://www.weatheronline.co.uk/cgi-bin/expertcharts?LANG=en&MENU=0000000000&CONT=euro&MODELL=gefs&MODELLTYP=2&BASE=-&VAR=cpre&HH=372&ZOOM=0&ARCHIV=0&RES=0&WMO=&PERIOD=

 

UKMO UKMO today shows the only difference from recent output in as much as it does inch Low pressure over Europe rather closer to the SE at times through the week threatening a few showers and quite a lot of cloud at times while the vast majority of the UK sees variable cloud and some sunshine but cool conditions with some frost, fog and frost by night away from the breezier South.

 

http://www.wetterzentrale.de/pics/Rukm1441.gif

 

THE FAX CHARTS The Fax Charts this morning support the slight changes of the risk of showers in the SE in an otherwise High pressure based outlook with fine and benign mid Autumn weather for most with areas of cloud and some weak sunshine mixed in along with patchy frost and fog by night, this mostly in the North.

 

http://www.weathercharts.org/ukmomslp.htm#t120

 

GEM GEM today also shows a variation of High pressure in control of the weather across the UK for the next 10 days. However as the centre transfers to a point to the West of the UK and pressure remains lower over Europe a chill NE wind persists across the South with the added risk of a shower enhanced later by a cold surge of air from the North so that next weekend and the start of the second week could be noticeably windy and cold across the South with a strong NE wind and showers possible more widely for a time.

 

http://www.wetterzentrale.de/pics/Rgem2401.gif

 

NAVGEM NAVGEM today follows the same route of High pressure dominance for all parts as a ridge across the UK is focused to extend from a strong High in the Atlantic later this week maintaining the best conditions for the NW while a chill NE wind over the South is all too persistent with the risk of a shower at times.

 

http://www.wetterzentrale.de/pics/Rnvg1681.gif

 

ECM ECM this morning finalises the set in maintaining High pressure close to the UK for the foreseeable future gradually anchoring to the West of the UK keeping dry and fine weather for most areas in rather chilly conditions overall. Sunshine amounts and the best weather overall will be focused towards the West and NW while the South and SE could see cloud and breeze temper conditions somewhat and late in the period all parts could be seeing the birth of an eventual and very chilly Northerly as High pressure shows signs of changing it's orientation as well as moving NW somewhat towards Greenland at the end of the period opening the door for a cold northerly blast especially for the East.

 

http://www.wetterzentrale.de/pics/Recm2401.gif

 

ECM 10 DAY MEAN The ECM 10 Day Mean Chart from last night shows High pressure well in control of the weather across all of the UK most likely centred just to the West of Ireland.

 

http://www.wetterzentrale.de/pics/Reem2401.gif

 

NOTABLE TREND CHANGES FROM PREVIOUS RUNS There is very good agreement on fine and settled weather maintained across the UK for the entire period with just small scale features affecting the day to day conditions across the surface in an overall very dry outlook.

31 DAY HISTORICAL VERIFICATION STATS FOR GFS, UKMO & ECM The verification Statistics of GFS, UKMO and ECM show at 24 hours ECM leading UKMO at 99.6 pts to 99.5 pts with GFS closely behind at 99.4 pts.  At 3 days ECM is leading with 97.3 pts to UKMO's 97.2 pts while GFS lags behind at 96.2 pts. At 5 days ECM leads with 88.3 pts to UKMO at 87.7 pts then GFS at 85.2 pts. Then at 8 Days ECM still leads at 58.1 pts over GFS's 50.6 pts. Finally at Day 10 ECM leads GFS at 34.9 pts to 29.1 pts.

 

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day1_PMSL_MSL_G2NHX.png

 

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day3_PMSL_MSL_G2NHX.png

 

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day5_PMSL_MSL_G2NHX.png

 

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day8_PMSL_MSL_G2NHX.png

 

http://www.emc.ncep.noaa.gov/gmb/STATS_vsdb/allmodel/daily/cor/cor_day10_PMSL_MSL_G2NHX.png

 

MY THOUGHTS   If today's output is to be realised then we are looking at a very dry October across the UK as there looks unlikely to be very little if any significant rainfall across the UK for the next couple of weeks at least, a theme shared by all output. It's High pressure that's the culprit with the current ridge lying across the UK from Europe intensifying in response to amid latitude block forming over the eastern Atlantic later this week. Once established these can be notoriously stubborn to shift and this one looks no exception with the Jet Stream held well to the North the only way that any incursion of Low pressure can realistically gain entry to the UK is from the North which is hinted at by ECM at Day 10 and from GFS too but due to the close proximity of the High to the West that looks unlikely to happen at any point soon. Pressure is shown to be relatively lower over SE Europe and there is just enough reason to mention the chance of the odd shower from this in the South and East for a time this week but this looks the exception to the overall dry pattern expected. The three factors which will most certainly change the perception of the fine and dry theme is the amounts of cloud floating around along with the likelihood of frost and fog where skies clear at night and in the South a nagging and cool breeze from the NE. All this is of course only small features in an otherwise settled and quiet period of weather across the UK and in the grand scheme of things maintains our generally gentle and benign drift through Autumn so far this year with a continuation of little chance of gales and troublesome weather of any kind looking likely any time soon.

 

WORST CHART OF THE DAY 00z RUN

 

http://www.wetterzentrale.de/pics/Rtavn3841.gif

 

For the worse chart of the day I have had to travel right out to 384hrs from GFS and this is the only chart of all that I could find any meaningful excursion into bad weather across the UK as it shows fallen pressure across Britain with the Jet stream having travelled to a point well South of the UK bringing what would be rain and cold conditions across the UK in blustery Westerly winds in a complete pattern change.

 

BEST CHART OF THE DAY 00z RUN

 

http://www.wetterzentrale.de/pics/Rukm1441.gif

 

The best chart today goes to UKMO at 144hrs but to be honest there are many more than could of qualified. The reason for choosing this one is not for the overall best conditions at the surface at that particular time but for the reason that from this set-up changes in the overall weather pattern is likely to be a long way off with a large blocking mid latitude High of this nature close to the UK.

 

Next update from 09:00 Monday Oct 12th 2015

Edited October 11, 2015 by Gibby

[bluearmy]

That ECM day 10 looks crazy over the Arctic but the extended ens mean builds that very same high anomoly between n Siberia and the Canadian Arctic by the end of week 2. Perhaps the op a little progressive which is fairly normal.

[johnholmes]

as promised the EC-GFS output this morning, both about the same as each other in broad terms and both pushing the idea of blocking over/close by UK

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

[bobbydog]

as promised the EC-GFS output this morning, both about the same as each other in broad terms and both pushing the idea of blocking over/close by UK

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

both very similar there john. have any other years seen this type of pattern persisting through october?

[IDO]

What I have noted so far is that we are not seeing that dreaded N Pacific positive heights anomaly that was seemingly omnipresent last Autumn/Winter. So far the Aleutian Low has been a player. As last year was a bit of a non starter for a seasonal winter, this may be a help as it will shift the long wave pattern to a more favourable position when we do get some amplification.

 

Looking at after about D13 and the GEFS are beginning to show some scatter: http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=324. Looking like a possible pattern change beginning to influence the data. However early days as this may just be a blip.

 

 

The CFS week 3-4 mean charts suggest a gradual decline in heights but as Mucka suggests, certainly no quick change to a  zonal onslaught, though week 4 (usual caveats) has the Icelandic Low (west based) returning:

 

 

Worth watching. Solar activity is very quiet at the moment as we continue towards a minimum:

 

 

 

 

 

 

[chionomaniac]

So far October is playing out pretty much as expected - A strong El Nino pattern reinforced and slight emphasised over our shores by a cold Atlantic. One would expect a month dominated by drier and more settled whether and that is what the NAEFS ensembles are suggesting.

 

 

This pattern is likely to be reinforced by the recent WWB and re-invigoration of the EN that the atmosphere is responding to and that is measured by the uptick in GLAAM following a slight drop off in values.

 

 

There is a suggestion that the MJO enters phase 1 which may confuse somewhat - but I suspect that this signal is weak and will be overriden by the underlying Nino atmospheric state.

 

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/clivar_wh.shtml

 

The composite H500 analogs for similar El Nino years suggest that the upcoming global pattern is very El Ninoish but with a slight difference that our cold Atlantic brings - it shifts the pattern slightly over the Atlantic and emphasises the ridging in our area.

 

El Nino Oct Pattern:

 

 

Cold Atlantic similar area, similar years for OCT:

 

 

When you compare these to the anomaly chart above, it can be suggested that EN global teleconnective patterns do have an air of predicatability about them and that those suggesting anything different will not be going with the form horse.

 

And those who like the settled whether should make the most of it this month, because a change in seasonal wavelength patterns suggest that an EL Nino pattern reinforced with the cold Atlantic bring about a complete reversal next month with a strong Atlantic trough dominant. Now that will be a test of the predictability won't it?

 

Nov EN H500

 

 

Atlantic cold Nov H500

 

 

 

 

 

[johnholmes]

both very similar there john. have any other years seen this type of pattern persisting through october?

 

sorry my memory is not up to that sort of filing, someone else may be able to say though. It is different to what we saw at this time last year. Caution though, for you or anyone else, trying to match October patterns to the coming winter. The huge computer facilities at NOAA, UK Met and ECMWF have never been able to get enough to be able to use this, on its own, as any indicator. The issue of 3 month or more forecasting is still in its infancy and it may well take decades before anything shows usable results in my view. That said the model output from UK Met IF looked at objectively is not bad. Well that is my opinion over the last couple of autumn into winter periods. So long as folk look at it like I say objectively and as a background idea.

 

just read the post by chio above, should have done this before I posted, very interesting comments there.

 

apologies to admin and mods if this should really just have a link after the first sentence and be put in the winter thread?

Edited October 11, 2015 by johnholmes

[bobbydog]

thanks for the reply john. chiono's post pretty much answers my question and narrows down the years with similarity. i might have a browse through the NCEP archive charts later. not sure how to find the monthly composites for the winter months of those years in question.

[Frosty.]

Another gfs run showing wintry potential later in october with attempted high pressure retrogression allowing colder air to seep south across the uk and then the end of the run which indicates colder and unsettled weather spreading from the north but for most of the Gfs 6z op run it's an anticyclonic story with first of all the scandi high bringing us largely fine weather which is then replaced by an atlantic high building in across the uk but what really interests me is what happens when the anticyclonic domination ends and I think there is a good chance of a cold outbreak before the end of october.

[Cloud 10]

thanks for the reply john. chiono's post pretty much answers my question and narrows down the years with similarity. i might have a browse through the NCEP archive charts later. not sure how to find the monthly composites for the winter months of those years in question.

 

ESRL : PSD : Monthly/Seasonal Composites

[phil nw.]

So far October is playing out pretty much as expected - A strong El Nino pattern reinforced and slight emphasised over our shores by a cold Atlantic. One would expect a month dominated by drier and more settled whether and that is what the NAEFS ensembles are suggesting.

 

naefsnh-0-0-120.png

 

This pattern is likely to be reinforced by the recent WWB and re-invigoration of the EN that the atmosphere is responding to and that is measured by the uptick in GLAAM following a slight drop off in values.

 

gltotaam.sig.90day.gif

 

There is a suggestion that the MJO enters phase 1 which may confuse somewhat - but I suspect that this signal is weak and will be overriden by the underlying Nino atmospheric state.

 

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/CLIVAR/clivar_wh.shtml

 

The composite H500 analogs for similar El Nino years suggest that the upcoming global pattern is very El Ninoish but with a slight difference that our cold Atlantic brings - it shifts the pattern slightly over the Atlantic and emphasises the ridging in our area.

 

El Nino Oct Pattern:

 

+PDO EN Oct H500.png

 

Cold Atlantic similar area, similar years for OCT:

 

Cold Atlantic Oct H500.png

 

When you compare these to the anomaly chart above, it can be suggested that EN global teleconnective patterns do have an air of predicatability about them and that those suggesting anything different will not be going with the form horse.

 

And those who like the settled whether should make the most of it this month, because a change in seasonal wavelength patterns suggest that an EL Nino pattern reinforced with the cold Atlantic bring about a complete reversal next month with a strong Atlantic trough dominant. Now that will be a test of the predictability won't it?

 

Nov EN H500

 

+PDO EN Nov H500.png

 

Atlantic cold Nov H500

 

Cold Atlantic Nov H500.png

 

Good stuff Chio.Interesting that you have built in the Atlantic -ve sst's into your composites,something i havent figured into the one i did for November.

 

I had a look at the years with a strong El Nino ie. over +1.5C, leading into Winter and just included the past years with a west based QBO.

 

 

the return of the Atlantic trough with low pressure extending se into Europe. Positive height anomlies back towards Scandinavia.Not a mile away from your first November chart-without the Cold Atlantic sst's included.

It will be interesting to see how much those negative sea anomlies to our west influence the November pattern.

Edited October 11, 2015 by phil nw.

[Polar Maritime]

It will be interesting to see how much those negative sea anomlies to our west influence the November pattern.

Absolutely Phil, An interesting few weeks coming up. 

Edited October 11, 2015 by Polar Maritime

[bobbydog]

ESRL : PSD : Monthly/Seasonal Composites

thanks cloud, working out how to use that should keep me busy for a while...

[phil nw.]

Absolutely Phil, An interesting few weeks coming up. 

Yes PM i thought whilst it's fairly quiet, weather wise currently, it would be a good time for me to do a bit of speculation wrt what may be coming after this pattern we have now.

Looking at the latest naef's this block shows no sign of shifting as we get towards month end

 

 

so we continue to wait for the Atlantic to wake up,which i am sure it will, as the vortex continues to cool and expand.

The question is what form will this take?

[knocker]

The GEFS anomaly at the end of the 06z run is showing the HP weakening and slipping south (not retrogressing) thus introducing a more zonal flow. Something the ext ecm has also been hinting at. There also is the level of uncertainty with the MJO (phase and when) and how the ENSO forcing will interact with it. Using just this it would appear a period wettish cyclonic activity but as always this isn't the full story so I'm not getting too hung up on it.

http://www.frontierweather.com/MJOGraphics/mjoanalogs.html

 

[chionomaniac]

Good stuff Chio.Interesting that you have built in the Atlantic -ve sst's into your composites,something i havent figured into the one i did for November.

 

I had a look at the years with a strong El Nino ie. over +1.5C, leading into Winter and just included the past years with a west based QBO.

 

nov comp.png

 

the return of the Atlantic trough with low pressure extending se into Europe. Positive height anomlies back towards Scandinavia.Not a mile away from your first November chart-without the Cold Atlantic sst's included.

It will be interesting to see how much those negative sea anomlies to our west influence the November pattern.

I made those composites a while back - will need to see how things pan out prior to winter, but a southwards displaced jet into Europe will be a common theme. In the meantime the Atlantic SST, wENSO pattern pretty much as expected for October. The increase in amplitude of the Atlantic ridge may be in response to the MJO forecast into phase 1 by day 10 so that figures and may contribute to some western Eurasia snow gains which will help with the SCE and SAI.

[bluearmy]

The GEFS anomaly at the end of the 06z run is showing the HP weakening and slipping south (not retrogressing) thus introducing a more zonal flow. Something the ext ecm has also been hinting at. l

That's not how I see the ECM extended knocks. remember we only see mean ECM output. mean slp over the south of the UK by day 14 is 1022 mb. Not too shabby with a decent positive anomoly still sitting to our west.