Model Output Discussion - 1st July Onwards 18z--->

[mushymanrob]

Bit off topic, but don't need models when I go away on Norfolk broads as guaranteed to be shocking weather just like next week will be. It looks like being a foul week looking at the lows crossing the country especially Monday and Tuesday. Couldn't make it up. Please let it rain at night.

Can anyone shed any good news for weather from Friday for 10 days?

Looking at the ecm, it wont rain..... Itll snow! Lol

[knocker]

The ext ECM anomalies continue with reduction of the upper trough and height rises to the east and west (albeit at this stage not excessive) but it translates to a general swathe of HP from the Atlantic to eastern Europe. About average temps but dry.BANK.

Edited July 21, 2015 by knocker

[snowwonder]

Looking at the ecm, it wont rain..... Itll snow! Lol

lol

Seriously will there be any dry weather about. I am new to model reading but doesn't the ecm look a little better and the GFS control doesn't look a total wash out.

Better towards end of next week after poor start to week?

Really wish I could read the charts better.

CIA

[johnholmes]

lol

Seriously will there be any dry weather about. I am new to model reading but doesn't the ecm look a little better and the GFS control doesn't look a total wash out.

Better towards end of next week after poor start to week?

Really wish I could read the charts better.

CIA

 

Have a look in the Net Wx Guides, there are quite a number of Guides that should help you get a better understanding of the charts. Don't be afriad to ask questions.

[snowwonder]

Have a look in the Net Wx Guides, there are quite a number of Guides that should help you get a better understanding of the charts. Don't be afriad to ask questions.

Thank you John. Will do. Running out of time before I go away but will look. Just a quick question. How do you work out surface temp from the 850's charts. Is it add 8-10c to the number. I remember reading this somewhere. The ecm for next 10 days doesn't look too wet does it compared to GFS for E Anglia in my very very limited knowledge would you agree.

Thanks again. Love reading everyones posts esp the more knowledgeable like yourself.

[seaside 60]

If I believed what some peoples view of the models have been reporting over the last few weeks, esp the GFS my garden should be under water or at least never having to be watered even down south.

However the reality is so different, I am sure some people really believe what the models forecast.

[johnholmes]

Thank you John. Will do. Running out of time before I go away but will look. Just a quick question. How do you work out surface temp from the 850's charts. Is it add 8-10c to the number. I remember reading this somewhere. The ecm for next 10 days doesn't look too wet does it compared to GFS for E Anglia in my very very limited knowledge would you agree.

Thanks again. Love reading everyones posts esp the more knowledgeable like yourself.

 

That is a fair number to add on, there are various things that will cause that to be somewhat more or less than the numbers you quote but take those as a starter.

re East Anglia, it will very likely be under an upper westerly flow as an average so weather systems should not be as active, when they occur, as over and west of the main hills. Probably about the best place in a westerly. Remember the day to day can be somewhat different, a surface trough or a ridge can occur in an upper westerly. Enjoy reading the Guides and do ask questions. There is always someone who can give you an answer or know where to find one.

have a good holiday.

[snowwonder]

That is a fair number to add on, there are various things that will cause that to be somewhat more or less than the numbers you quote but take those as a starter.

re East Anglia, it will very likely be under an upper westerly flow as an average so weather systems should not be as active, when they occur, as over and west of the main hills. Probably about the best place in a westerly. Remember the day to day can be somewhat different, a surface trough or a ridge can occur in an upper westerly. Enjoy reading the Guides and do ask questions. There is always someone who can give you an answer or know where to find one.

have a good holiday.

Thank you John. Fingers crossed its not too bad weatherwise. Will tell my wife to pack for all conditions. lol

[Cloud 10]

If I could interject here....

 

 

 

 

 

 

 

Some positive signs in FI from the 12z NAEFS for a settling down trend.

 

[Woollymummy]

here's something odd:

 

all summer this first chart has been the norm, very symmetrical, no wibbles or distortion. now with this extremely grim looking section of "summery" weather about to happen, the second chart seems to be becoming more usual. Why? Is the lopsided upper atmosphere causing the cold, wet and lots of lows, or is it the other way round?  Please could someone help explain this?

[Polar Maritime]

The GFS this morning continues to show some nation-wide warm/hot settled weather as we enter the new Month. As High Pressure begins to push a little further North than in recent weeks.

 

Edited July 22, 2015 by Polar Maritime

[mb018538]

Indeed ti does, but it is one of the warmest 2/3 ensemble members: http://www.theweatheroutlook.com/charts/gefs/gefsens850London0.png

There are many more clustered between 5-10c at 850hpa, so at the moment I guess we should favour that. It doesn't detract from the fact that there is still a very marked improvement shown around the end end of the month on both the extended GFS and ECM runs this morning. As it gets a day closer, we should hopefully bemore confident that it is the right picture being painted!

 

[johnholmes]

The latest EC-GFS anomaly charts this morning show little change in the UK area. One interesting change is in the far west. The ridge and +ve heights off the Aleutians is reduced on both models. This may have effects on the overall pattern with time.

link

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

[Gibby]

HERE IS MY LATEST ANALYSIS USING DATA SUPPLIED BY THE NWP OUTPUT COVERING 5 OF THE WORLDS MOST POWERFUL WEATHER COMPUTERS ISSUED AT 08:00 ON WEDNESDAY JULY 22ND 2015. No report tomorrow-too busy.

 

THE CURRENT GENERAL SITUATION. A somewhat showery WSW flow continues to cover the UK today and tonight with a trough crossing East over England and Wales today.

 

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

 

MODELS-2 WEEK HEADLINE Still rather changeable with some dry and bright conditions mixed with occasional rain or showers. Becoming somewhat drier and warmer everywhere later in the period especially in the South.

 

THE GFS JET STREAM FORECAST The GFS Jet Stream Forecast keeps the flow blowing West to East across the South of the UK this week albeit quite lightly. Towards the start of next week it strengthens and if anything troughs further South over France for a time before retreating back North and weakening away late next week. Towards the end the slack flow over our latitude persists but it looks like a rejuventation of the flow near the UK could develop at the end of the period.

 

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

 

GFS OPERATIONAL The GFS Operational Run today is still trying to bring us into a different weather pattern from the middle of next week. However, every push of High pressure across the UK seems doomed to be nudged away by further interventions of lower pressure from off the Atlantic with some rain or thundery showers at times. In the meantime we have another week or so to go of very changeable and quite cool weather early next week as a more coherent Low pressure crosses East and sets up a temporary NW flow with showers for all.

 

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

 

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

 

THE GFS CONTROL The GFS Control Run is slightly better in the long term with  several attemps of building pressure over the UK restricted to the South later next week before a High cell covers the UK late in the run with only then all of the UK enjoying fine and summery conditions. In the meantime it's business as usual with largely Westerly winds and occasional rain or showers with average temperatures turning rather cool for a time early next week.

 

THE GFS CLUSTERS(14 Days) The GFS Clusters at 14 days are not quite as good this morning with still a predominance biasing a High pressure ridge near the South in two weeks time. The percentage members suggesting something more changeable again with High pressure parked too far to the South or SW has increased somewhat this morning with only a 20% pack suggesting High pressure centred over the UK.

 

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 a deep depression for this time of year crossing the UK by Monday with cloud, wind rain and showers for all for a time followed by a broad trough left over the UK to start next week with cool West or NW winds and showers at times.

 

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

 

THE FAX CHARTS The Fax Charts this morning show a complex weather pattern this morning with slack conditions tomorrow and again on Saturday. On Friday a Low pressure area scoots up the English Channel with some wet conditions for the far South and showers for the North and as this exits the SE on Saturday a ridge is just a temporary phase ahead of another depression moving into the North of the UK to start next week.

 

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

 

GEM GEM today shows a similar theme highlighting the two Low's, one on Friday for the South and a larger one for all areas next week as it moves East. As this Low exits towards next weekend a ridge follows but it looks likely to affect just the South for a day or two before the North and West then become under attack from further Atlantic fronts.

 

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

 

NAVGEM NAVGEM today keeps things altogether slacker across the UK for the whole run with some sunshine and dry weather mixed with changeable conditions when rain and showers feature almost anywhere. The run ends at Day 7 with a cool NW flow with Low pressure close to the NE with cool and showery weather for all.

 

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

 

ECM ECM is showing very changeable conditions for the period with innitially a fairly slack synoptic pattern delivering some showers at times over the coming days and perhaps more prolonged rain in the extreme South for a time on Friday. Sunday looks a reasonable day under a ridge before a depression crosses gently East over the UK through the early days of next week, deepening as it goes and setting up a cool and showery NW flow through midweek. High pressure then trundles in from the West towards next weekend but is almost immediately put pressure on by further Atlantic Low pressure moving in from the North Atlantic by Day 10, pushing it East and SE into NW Europe and probably resetting the pattern as currently.

 

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

 

ECM 10 DAY MEAN The ECM 10 Day Mean Chart from last night shows something of a ridge close to Southern Britain but this outcome is probably brought about by a mixture of options from members ranging from cool and unsettled Westerlies to High pressure across the UK and therefore I would take more credence from Clusters rather than this mean chart currently.

 

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

 

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The trend towards an attempt of a pattern shift towards High pressure is still shown this morning but not as conclusively as yesterday with pressure being put on any UK High pressure from the Atlantic especially in the North.

 

31 DAY HISTORICAL VERIFICATION STATS FOR GFS, UKMO & ECM The Verification Statistics of GFS, UKMO and ECM. This morning's verification statistics show ECM leading the way at 3 days with 95.5 pts followed by UKMO at 94.9 pts and GFS at 94.1 pts. At 5 days ECM is stll king at 84.2 pts followed by UKMO at 81.4 and GFS at 81.1 pts. Then at 8 Days ECM still leads at 53.9 pts over GFS's 46.3 pts. Finally at Day 10 ECM leads GFS at 33.0 pts to 28.2 pts from GFS.

 

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.prig

 

MY THOUGHTS There are a lot of complexities within the atmosphere over the Northern hemisphere at the moment which continue to play havoc with relatively short term projections from the models let alone longer term ones. This morning's crop of output make things little clearer as there remains doubt on the extent if any on Friday's little Low and the amount of rain if any it brings to the South. Then there does seem some reasonable agreement that there will be a more active Low pressure crossing East over the UK next week with some rain for all and on it's rear side a cool NW flow with showers towards midweek. Pressure then is still shown to build across the UK later next week and weekend but the extent of this looks less defined this morning with a lot of suggestion that should it develop it might not hang around for long before the Atlantic polar fronts and depressions nudge it out of the way to the East and SE and possibly bring us back to the infamous NW/SE divide. It's all conjecture though at this range with such uncertainties lying within the almost here and now let alone a week or two down the line. Unfortunately I have to say what I see and to me it looks a little worrying today if it's fine and prolonged sunny UK wide weather your after for holidays etc. However, the output through the 12zs may offer something more akin to yesterday again and throw the complexion of the runs back more favourably again. The verification Statistics between the models which I update here every day tell their own story of how complex things are at the moment with at 10 days just between 28-32% accuracy in charts shown from ECM and GFS respectively and that likely to fall over the coming week or so. Meanwhile we have what we have and on the whole the weather down here in the South is pretty good for the most part this Summer. Of course that's not true of the North and I am sure inhabitants there would be happy to see the prospect of High pressure as a very welcome visitor in August. I feel we are half way to that verifying this morning but there's a lot of water to cross under the bridge yet before that is a ranked certainty. 

 

Next update from 09:00 Friday July 22nd 2015

Edited July 22, 2015 by Gibby

[Frosty.]

The Ecm 00z shows high pressure building in from the west through the second half of next week with a more settled look to the weather, at least for a time with temperatures slowly rising through that period.

[Nouska]

Well, well. well....Meteo France have finally opened their well shuttered portals!

 

AROME is available on Meteociel - thanks Sylvain.

 

This example is probably best not viewed with a hangover.

 

 

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

[chionomaniac]

here's something odd:

 

all summer this first chart has been the norm, very symmetrical, no wibbles or distortion. now with this extremely grim looking section of "summery" weather about to happen, the second chart seems to be becoming more usual. Why? Is the lopsided upper atmosphere causing the cold, wet and lots of lows, or is it the other way round?  Please could someone help explain this?

You looking at 30hPa charts from the middle strat. It all looks as would be expected. With the nights getting shorter the temperature at this level has now reached its peak and the slow descent towards winter now begins....

 

http://www.cpc.ncep.noaa.gov/products/stratosphere/temperature/30mb9065.gif

 

The lopsided nature of the ridge will make practically no difference to the tropospheric weather patterns at this time of year - for that we need to look at tropospheric teleconnective signals.

[Frosty.]

The Ecm 00z ensemble mean shows a longer lasting high than the op which has an Atlantic low applying pressure to it by T+240 hours, no such concerns with the mean.

Edited July 22, 2015 by Frosty.

[Man With Beard]

Well, well. well....Meteo France have finally opened their well shuttered portals!

 

AROME is available on Meteociel - thanks Sylvain.

 

This example is probably best not viewed with a hangover.

 

 

 

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

 

Great spot! Will be very interesting to see how this does for very short-term events. It has, however, already failed to get our rainfall right at just T10 - totally missed the large chunk of rain over S Wales:

 

 

compared with: http://www.metoffice.gov.uk/public/weather/observation/map/gcpvn15h9#?map=Rainfall&fcTime=1437512400&zoom=8&lon=-2.20&lat=51.83

 

On to the longer term, still a nose of high pressure on the ENS for the turn of the month, GFS less keen today than ECM though:

 

 

The GFS spread for 00Z gives no guarantee whatsoever of a considerable warm-up, with fewer than half of members returning to the seasonal norm (about 8C-10C atm.) until the very end of the run.

 

ECM ensembles for last night, however, show a gradual warm-up from the 31st:

 

 

but only after a wet week starting Friday (indicative of London but I'm sure will be representative for many areas):

 

[Frosty.]

The Gfs 6z shows pressure rising later next week bringing drier and sunnier weather to the south as a ridge of high pressure pushes east across southern britain but further north it stays unsettled, however, by early August we have a much stronger anticyclone building in from the Atlantic and slowly migrating eastwards with a nationwide increasingly warm and settled spell which would improve further beyond the end of the run. I think we are on course for a pattern change by early next month with high pressure firmly in the ascendancy by then.

I've just read the latest met office extended outlook which is continuing to firm up on a more summery period for most of August, especially for the south of the uk

Edited July 22, 2015 by Frosty.

[mushymanrob]

i note the gfs 06z has pushed back to the end of fi its suggested high pressure/heat build. both the ecm and gfs go for a weak, temporary ridge next weekend. this is in line i think with what the noaa anomaly charts currently suggest ... no strong settled anticyclonic spell within the next 2 weeks or so, but shorter weaker spells are likely in a westerly upper flow



just for fun, this is what i think we would need to see on the anomaly charts

 

 

if we are likely to get the desired strong anticyclonic settled spell that lasts longer then a couple of days, something like this (the current gfs @ t360)

[phil nw.]

Still a very average outlook through to month end, as illustrated in Mushy's post above.

 

The hope for a better start to August expressed in some earlier discussion is still surrounded by uncertainty.

The MJO expert discussions seem unsure if we will see a more active and eastward progression going forward which could change the current wave pattern across the Atlantic.

 

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/MJO/mjo.shtml#discussion

 

along with low confidence expressed in the American  height anomaly forecasts.

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

​

 

Certainly somewhat different views between Naefs and ECM day 10 height forecasts

 

 

so no strong signal as yet for a real pressure build across the UK for the start of August.

Early signs maybe of an improvement from the south from the ECM  but nothing  more at this stage. 

 

In the meanwhile for the next week or so it looks like more of the same with the westerly pattern and a rather changeable outlook and some suppressed temperatures.

 

 

 

​

Edited July 22, 2015 by phil nw.

[Frosty.]

The GEFS 6z mean shows better times ahead from early August onwards with high pressure building in from the southwest and bringing increasingly settled and warmer weather to most of the UK, especially the southern half. I can understand the caution but with the experts on-board for a nicer late summer and the charts steadily improving in the mid / longer range, I think we will see a more summery pattern evolve, if not by the start of August, soon after.

Edited July 22, 2015 by Frosty.

[knocker]

i note the gfs 06z has pushed back to the end of fi its suggested high pressure/heat build. both the ecm and gfs go for a weak, temporary ridge next weekend. this is in line i think with what the noaa anomaly charts currently suggest ... no strong settled anticyclonic spell within the next 2 weeks or so, but shorter weaker spells are likely in a westerly upper flow

814day.03b.gif

just for fun, this is what i think we would need to see on the anomaly charts

 

814day.03bc.jpg

 

if we are likely to get the desired strong anticyclonic settled spell that lasts longer then a couple of days, something like this (the current gfs @ t360)

high.gif

 

That's very bold Mushy. I can't see ridging over the UK as part of the scenario rather as indicated by the ext ECM of height rises to the east accompanied be a retraction of the upper trough allowing an interconnection between the HP to the east and the Azores. As ever as it has been for much of the summer the key is the upper trough and on this occasion some positive build up to the east. That's the theory anyway.

Edited July 22, 2015 by knocker

[mushymanrob]

That's very bold Mushy. I can't see ridging over the UK as part of the scenario rather as indicated by the ext ECM of height rises to the east accompanied be a retraction of the upper trough allowing an interconnection between the HP to the east and the Azores. As ever as it has been for much of the summer the key is the upper trough and on this occasion some positive build up to the east. That's the theory anyway.

 

maybe.... but im only an amateur with little technical knowlege just trying to find the easiest, least complicated way of seeing what might lie ahead upto 2 weeks time. hence the noaa charts suit my needs for trying to understand the general pattern. i cant claim to be always right...im not... but at least ill try.