Model Output Discussion - 1st August 00z---------->

[knocker]

Just to digress a tad there are currently three typhoons in the Pacific which Michael suggests may well impact the models a  week or so down the line.I believe this is unparalleled in any basin  A view of those.

http://earth.nullschool.net/#current/wind/surface/level/orthographic=-161.90,13.11,497

Edited August 30, 2015 by knocker

[Polar Maritime]

Yes knock, As you quite rightly put a few days ago. Will be interesting how the models toy with the tracks of them which will bring some big differences run to run.

[knocker]

A quick summation of the GFS 12z run. A depression which hangs around in the North sea for the week before sauntering east allowing the HP to the west to do likewise. Dry but temps below average.

Charts weatherbell

 

[Frosty.]

The Gfs 12z shows a fine and pleasantly warm spell on the way for all parts of the uk, especially for the south longer term with high pressure becoming dominant for a while before the north of the UK turns unsettled and windier later in low res. In the meantime, an autumnal week coming up with below average temps, especially at night with a chance of ground frosts in rural northern areas and with a cool northerly airflow blowing showers down the eastern side of the UK after tomorrow's persistent rain in the south, gradually becoming fine from the northwest, especially by next weekend onwards as high pressure slides SE over the uk with a risk of fog patches but the days gradually warming up with plenty of sunshine. This is a better run for the south than the 6z but we all have a fine spell through week 2 before the north becomes more unsettled towards mid month and beyond as pressure falls significantly to the n/nw.

Edited August 30, 2015 by Frosty.

[ANYWEATHER]

Evening! A miserable Bank holiday for some and tomorrow for southern areas looks miserable first thing.! The Low developing tonight is really gonna  haunt us this week as its more a feature today than recent runs. High out west, low squeezing in from the East will really give the whole of the Uk  a stark reminder that Autumn is here.    

[Frosty.]

a stark reminder that Autumn is here.    

I'm delighted it's Autumn from Tuesday, a step closer to winter. Looking forward to whatever the weather throws at us and there is something for everyone on the 12z this evening.

[ANYWEATHER]

I'm delighted it's Autumn from Tuesday, a step closer to winter. Looking forward to whatever the weather throws at us and there is something for everyone on the 12z this evening.

Ah Ah, delighted you have "Sniffed The Coffee"

[Milhouse]

After a premature plunge into cool and showery conditions this week it does look like the models want to push high pressure more south and east during next weekend and beyond.

 

#

[knocker]

I think some care should be taken not to exaggerate the influence of the depression to the east when considering the weather for all of the UK this week. Although the UK will be under a northerly flow (certainly not a blast) the influence of the low is confined to the east coast where it could be quite showery whilst the rest of the country will be under the HP as it slips east. Thus the winds will be light and the weather dry albeit the temps will be quite cool and below average. BANK.

Charts weatherbell

Edited August 31, 2015 by knocker

[Summer Sun]

ECM this morning shows the high very slowly moving over the UK whilst no heatwave is in sight temperatures should begin to lift a bit by day as it would cut off the northerly flow. Overnights would still be chilly though with the risk of some rural frosts

 

 

Becoming more breezy and an increasing risk of rain / showers in the NW towards D9 and 10 as low pressure gets that bit closer

 

 

Edited August 31, 2015 by Summer Sun

[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 MONDAY AUG 31ST 2015

 

THE CURRENT GENERAL SITUATION A trough of Low pressure will clear Eastern Britain today followed by a cold and showery Northerly flow between High pressure developing across the Eastern Atlantic and Low pressure near Denmark.

 

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

 

MODELS-2 WEEK HEADLINE Cool and showery this week before things warm up somewhat later with some rain in the NW and mostly dry conditions elsewhere.

 

THE GFS JET STREAM FORECAST  The GFS Jet Stream Forecast pattern shows the Jet Stream clearing out of the UK to the East over the coming days. The flow becomes split and light well South and North of the UK. through week 2 before it strengthens across the Atlantic from Canada and blows East over Northern Britain towards the end of the period.

 

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

 

GFS OPERATIONAL The GFS Operational Run today shows a cool Northerly flow blowing down across the UK through the working days of this week as Low pressure takes it's time to exit the scene East across Europe. Later in the week High pressure topples down across the UK from the West and NW with a settled and quiet spell of weather with warm sunshine by day but chilly and possibly misty nights. Later in the run the High receded back to the SW somewhat maintaining fine if rather cloudy conditions in the South while the North see the return of Atlantic winds and some rain or showers, possibly extending to all areas late in the period as pressure falls generally.

 

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

 

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

 

THE GFS CONTROL The GFS Control Run today shows a very similar evolution through Week 1 with the cool Northerly flow taking until the weekend to be cut off by High pressure toppling SE over the UK. So a showery and cool week before dry and fine conditions develop over next weekend. The trend through Week 2 shows Low pressure slipping South and East across the UK displacing the High with windy and cool weather returning with some rain for all with the weather then turning benign and quite towards the end of the period.

 

THE GFS CLUSTERS(14 Days) The GFS Clusters this morning show a 80/20 split in favour of High pressure either ridged across the UK or centred over the top of us with fine, pleasantly warm  and quiet early Autumn weather as a result. The 20% show a more unsettled feed of  cool West or NW winds and occasional rain from Low pressure towards Scandinavia.

 

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 cool week across the British Isles with the UK sandwiched between High pressure to the West or NW of Scotland and Low pressure over Germany and the continent in general. A showery Northerly flow slowly weakens by next weekend as a ridge slips South over the UK but maintaining a Northerly element to the wind it will still feel cool but become largely dry by then.

 

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

 

THE FAX CHARTS The Fax Charts this morning replicate the raw data fairly well again today with generally Northerly winds and minor troughs running South in the flow especially over the east where showers will be at their most prolific. Elsewhere a lot of dry and fine weather seems likely up to and including most of next weekend. 

 

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

 

GEM GEM today shows High pressure to the west and Low pressure to the East with a Northerly feed down across all parts of the UK through the working days of the week. then at the weekend the High topples over Northern areas before moving away to the NE early next week. So a lot of dry and cool weather with just scattered showers this week before becoming calm and fine over Northern Britain at the weekend while winds though light veer east in the South before pressure gently falls for all next week as lower pressure threatens from the South and West by Day 10.

 

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

 

NAVGEM NAVGEM follows a similar theme with little differences to the overall pattern from the other output. Towards the end of the run the High to the West edges closer in with a trend to back winds to a less chilly West or NW direction especially over the North.

 

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

 

ECM ECM this morning shows a cool Northerly flow being maintained across the UK through this week before the High to the West finally makes it's move across the UK early next week with some fine and warmer weather for a time. Then towards the end of the period at Day 10 Low pressure to the NW declines the High to allow Westerly winds and rain at times to extend slowly SE from the NW towards the back end of next week.

 

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

 

ECM 10 DAY MEAN The ECM 10 Day Mean Chart  from this morning continues to endorse the prospect that the UK could lie under High pressure in 10 days time with the suggestions that it could be sliding away slowly SE in the following days.

 

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

 

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The models have reasserted their desire to build High pressure across the UK at least for a time through the coming weekend and into next week before a slow decline in conditions again thereon.

 

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 96.2 pts followed by UKMO at 96.0 pts and GFS at 95.0 pts. At 5 days UKMO is king at 86.7 pts followed by ECM at 86.2 and GFS at 83.8 pts. Then at 8 Days ECM still leads at 61.7 pts over GFS's 53.5 pts. Finally at Day 10 ECM leads GFS at 41.4 pts to 34.8 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 High pressure remains the dominant theme to talk about in the model output this morning. It's position is far from ideal for the UK though as it spends all this week to the West of the UK and coupled with Low pressure over Northern Europe winds are constantly fed down from a Northerly source across the UK. So after today's remnants of thundery rain exit the East all areas share similar weather with a Northerly breeze, rather strong in the East for a time together with a mix of sunshine and showers. While there shouldn't be many showers across the South and West some Eastern areas could see some heavy and thundery ones at times early in the period and skies here could stay mostly cloudy accentuating the cool feel. It's not until the weekend when the models show a general shift towards bringing the High pressure closer to or indeed over the UK with increasingly fine and sunny and warmer conditions as a result of the Northerly flow being cut off. Night's could stay chilly and misty though despite warmer days. From early next week on there are suggestions from all of the longer term output of at least a temporary return of more unsettled weather, probably from the North-west but the 14 day clusters from GFS still indicate a lot of High pressure dominated weather even at that point so the jury is out on how or how long any breakdown could or will occur. So for the most part the models look a shade better to me than yesterday morning's crop with gently improving conditions over the UK over the upcoming week and while no heatwave being on the cards if the showers can be escaped there will be a lot of dry, fine and eventually a little warmer weather to be enjoyed possibly extending rather longer than this if the longer term models have disposed of the High cell over the UK next week too quickly.

 

Next update from 09:00 Tuesday Sep 1st 2015

[knocker]

The GEFS anomaly this morning is pretty quick to slide the HP SE and establish a warmer westerly flow over the UK. The ecm is not so quick to follow but soon does so in the ext period. How this pans out in the ext period rather depends on whether ridging from the AZ HP exerts more influence than the trough to the NW. At the moment it looks as if it might with temps at least average and possibly slightly above. On the other hand I might be letting too many espressos this morning cloud my judgement

http://www.tropicaltidbits.com/

Edited August 31, 2015 by knocker

[Chris K]

Models seem to agree in a more calmer, settled period moving in as high pressure tries to move Eastwards over the UK. Depending on the proximity of the LP to our East, showers may develop the further East you are. This also results in a cool northerly air-stream for a while until it cuts off as the HP pushes East.

 

Still a bit of uncertainty as to what will follow this. However, both the GFS and ECM ops are keen to move the high eastwards and a trough re-establish to our NW. (Where have we seen that before?...oh perhaps most of this year?) This is a week+ away so likely to alter somewhat.

 

Temps should lift once we lose the Northerly winds and eventually see it swing round from the E/SE. My worry is this will mean cloudier skies, but temps will remain relatively close to average. No heatwaves in sight. as that is pushed back South throughout Europe in the latest runs.

Edited August 31, 2015 by Chris K

[johnholmes]

Looking out 10-14 days ahead and upper ridging is predicted on ECMWF-GFS, NOAA (6-10 and 8-14) and out to day 10 on NAEFS charts. So I would be surprised if this upper pattern did not persist through the 6-15 day period. Little sign on any of them of +ve heights SW of the UK, if anything -ve heights suggested, at least, on NAEFS.

What does show is that the +ve anomaly is weakened from about day 9-10.

Edited August 31, 2015 by johnholmes

[Summer Sun]

This mornings ECM ens shows high pressure staying with us for a while once it moves in which it will do very slowly this week

 

 

 

The mornings and nights are likely to be chilly with the risk of localised rural grass frosts mainly in the north, but days would be pleasantly warm in any sunshine

Edited August 31, 2015 by Summer Sun

[Frosty.]

The Gfs 12z shows a pattern change to anticyclonic conditions from next weekend onwards with high pressure becoming centred over the uk and intensifying, eventually drifting just to the NE but staying firmly in control. A very benign spell on the way with lots of pleasantly warm sunshine and light winds but with chilly nights and a growing risk of mist/fog patches with an on going chance of a touch of frost but the frost risk is mainly for rural northern UK. In the short term it looks cool with sunshine and showers, the showers especially further east with a Northerly flow which becomes strong for a time across the far east / northeast. The coldest nights this week look like being further west / northwest with a risk of slight frosts and less showers with longer sunny spells but then it's all change with high pressure set to bring a prolonged spell of settled early Autumn weather to all parts of the UK...and the met office outlook is just as good as the gfs 12z looks beyond T+144 hours.

Edited August 31, 2015 by Frosty.

[Summer Sun]

UKMO shows the high very slowly moving further east allowing some pleasantly warm days but some chilly nights and mornings

 

[Winter Cold]

Strong support for the first half of September to be high pressure dominated and a drier setup coming in. Good cross model support for the high to drift in slowly from the west.

 

GFS 12z ensembles for South Yorkshire have mean pressure values of at least 1020 for pretty much the entire run and up to 1030 into the start of next week:

 

  

[ANYWEATHER]

Strong support for the first half of September to be high pressure dominated and a drier setup coming in. Good cross model support for the high to drift in slowly from the west.

 

GFS 12z ensembles for South Yorkshire have mean pressure values of at least 1020 for pretty much the entire run and up to 1030 into the start of next week:

 

  

The only thing is the first week, or this coming week is hardly high pressure dominated. We have a squeeze of high pressure to the west, low pressure to the east, so we are stuck in the middle , resulting in some dismal and chilly conditions for most. Not settled either with bands of showers moving from north to south during the working week. The weekend shows the high building over the uk for a short time, what happens after remains uncertain, but this week up into Friday remains rather bleak for early September. Indeed the ecm shows a surge of cold out to T+120 across northern Scotland during the early part of the coming weekend resulting in some snow for the mountains . Of course a long way off and subject to great change

[Frosty.]

The Ecm 12z shows high pressure building in from the west next weekend, becoming dominant through the first half of next week with high pressure stretching from the Azores to Scandinavia, there is then a slightly more unsettled blip brushing across the far northwest before a strong surge of high pressure from the Azores by T+240 which promises more fine and warmer weather beyond day 10. The main thing to take from the 12z runs is a change to quieter settled weather is coming.

[knocker]

Both the GEFS and ecm anomalies are re-orientating the HP at T240 and later to  NE/SW thus backing the flow to NW/SW and bringing temps up to around average or slightly above.

http://www.tropicaltidbits.com/

 

[damianslaw]

Models showing a painfully slow moving high pressure cell out to out west, as low pressure to the east intensifies over the coming days maintaining a tight squeeze between low and high pressure and a resultant chilly northerly up until at least the weekend. Trough features running down from the north, so a showery cool few days ahead. GFS, ECM and UKMO all show the high eventually ridging in across the country, however, don't be be surprised to see it stick out to the west longer and not getting such a foothold as we continue to see trough action from the NW.. its progress increasingly seems to be putting back and back...

[Nouska]

Both the GEFS and ecm anomalies are re-orientating the HP at T240 and later to  NE/SW thus backing the flow to NW/SW and bringing temps up to around average or slightly above.

http://www.tropicaltidbits.com/

 

At +240 there's quite a difference between the mean of the old GEFS and the new GEFSP (parallel run - goes live later in the Autumn).

 

http://www.meteociel.fr/modeles/gefs_cartes.php?ech=0&code=0&mode=0&runpara=1

 

Old    new 

[knocker]

The latest fax charts have most of the UK within the HP circulation by 12z Thursday.

 

[knocker]

At +240 there's quite a difference between the mean of the old GEFS and the new GEFSP (parallel run - goes live later in the Autumn).

 

http://www.meteociel.fr/modeles/gefs_cartes.php?ech=0&code=0&mode=0&runpara=1

 

Old    new 

 

I don't have the 12z but this was the 06 anomaly

Chart weatherbbell