Model Output Discussion - 3rd May Onwards 00z--->

[mushymanrob]

wow... what a lot of depressing people you lot are! 'like summer 08' 'like summer 12', i dont see anything to worry about ! i dont see an absent azores high , southerly tracking jet with a strong greenland high . im usually 'mr pessimistic' , but thats only when ive got something to worry about.

i dont see charts similar to any washout summers...yet anyway. the ops and anoms are in fairly good agreement that the uk is likely to sit under a trough to our north, trapped in by a large mid atlantic high and another over northern europe. ok its looking on the cool side of average, but im not seeing too much in the way of wet weather. but even in cooler air/uppers, the sun is strong and the air fresh, great!

if you want to play the comparison game... try may 1975... that horrid cold (but sunny) spring that gave way to the first of our two long hot summers that decade.

[Chris K]

Indeed Mushy pattern matching can be useful at times but the smallest of differences can result in a totally different pattern for a particular area, such is the chaos of meteorology.

[knocker]

Looking at tonight's GEFS anomalies I think one can safely say the upper patter is somewhat fluid.

 

T120 is the beginning with the trough setting up over the UK and N. Russia with ridging mid Atlantic. Cool unsettled weather in the UK.

 

By T240 still the trough in situ over the UK and the ridge more defined slightly further east but the trough in N.Russia has gone to be replaced HP building in eastern Europe. This build of heights to the east may well portend some changes from the cooler pattern.

Charts weatherbell

Edited May 14, 2015 by knocker

[ANYWEATHER]

From a merely convective point of view the middleish of next week looks very interesting, as the old saying goes "As the clouds grow tall ,the rain will fall" 

Edited May 14, 2015 by ANYWEATHER

[Milhouse]

Tentative signs of a change appearing in FI with low pressure gradually pulling away to the north

 

 

Mirrored on the GEM too with winds becoming more westerly.

 

[johnholmes]

An assessment of the 500mb anomaly charts suggests this

With all 3 now showing similar in 6-10, trough length of about 60 degrees (suggesting not moving much into 8-14 day time scale and this supported by 8-14 NOAA with similar pattern/intensity of +/- heights, all suggests this pattern will be on the charts for at least 2 weeks possibly into 3 weeks! Cold lovers in winter would likely be in raptures.

links below

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

http://www.cpc.noaa.gov/products/predictions/610day/500mb.php

 

As I usually 'hang my hat' on these charts, unless they show any marked change then there is not much point in me posting for a bit!

Don't get too many summer bedding plants would perhaps be a suggestion (sorry anyone who has their work/job/business in this area) With the heights being predicted, any cloud free nights are going to be quite chilly. With a predicted contour height of 540dm into the far  north of Scotland on the 6-10 day NOAA then showers over the Scottish mountains would very likely be of snow and any frontal ppn at least for a time ahead of any warm fronts, maybe even on the back edge of cold fronts too. With a closed contour, commented above, then unsettled in the north would seem to be the weather perhaps  becoming less unsettled the further south and especially SW one lives.

 

tara for now

Edited May 14, 2015 by johnholmes

[knocker]

Latest EC32 update

 

May 22nd the anomaly has low north of Scotland, ridge mid Atlantic and eastern Europe. Cold NW airstream for the UK with temps lower than average.

 

By the 30th continued height rises to the NE/E becoming more influential with the weaker trough now Greenland and the mid Atlantic ridge is no more with the HP to the SW of the UK. Thus a more slack regime over the UK with temps around average.

 

By the 7th of June not much change for this but perhaps more ingress from the Azores HP and temps above average,

 

By the 15th June again not a huge change with HP dominate to the SW stretching NE into Scandinavia with the LP over Greenland.. Temps still above average.

 

Summary

 

Regime change around the 27th May with the upper trough weakening and moving west accompanied by height rises to the NE/E and continued presence of HP to the SW and the onset of above average temps. Get this current pattern out of the way and...................

 

Just to add, perhaps not surprisingly, last nights ECM ext anomaly supports this towards the end of the run

Edited May 15, 2015 by knocker

[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 FRIDAY MAY 15TH 2015.

 

THE CURRENT GENERAL SITUATION A ridge of High pressure will cross East over the UK today followed by a cold front moving East and South across Britain tonight and at first tomorrow followed by a broad Westerly airflow.

 

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

 

MODELS-2 WEEK HEADLINE Changeable with some showers at times especially over the North and East but spells of dry and fine weather too for all. Generally rather cool, especially by night.

 

THE GFS JET STREAM ENSEMBLE FORECAST The Jet Stream axis will position itself in an Easterly direction across Scotland over the weekend before it moves South in both position and direction as a UK trough develops early next week. This less defined Jet flow then remains blowing in a loosely Southerly direction across the UK for the rest of the run as the trough over NW Europe is largely maintained over the remainder of the period.

 

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

 

GFS OPERATIONAL The GFS Operational this morning shows High pressure to the SW over the weekend with a westerly flow across the UK with some rain over the North later on Sunday. Pressure then falls across the UK from the North with Westerly winds driving troughs across all areas early next week with rain clearing to sunshine and showers, heavy in places in rather cool conditions. As the showers lessen briefly later in the week a new Low replaces the one gone and renews the rain then sunshine and shower scenario with only small but subtle improvements in conditions in slack pressure gradients then shown at the end of the run.

 

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

 

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

 

THE GFS CONTROL The GFS Control run this morning increasingly differs from the operational in Week 2 as it holds the second Low more to the North maintaining the generally showery theme of the weather to end week 1. In week 2 though pressure steadily rises with High pressure developing to the North and NE of Britain allowing warmer continental winds to blow up across the UK from the SE later with a lot of dry and sunny weather too though the far SW and West could continue to see occasional rain for a time before things show signs in the end of the run charts of drying up here too.

 

THE GFS CLUSTERS The GFS Clusters are again very High pressure based this morning with High pressure shown by many members to lie across or close to the UK in 14 days time with almost universal support for dry and fine weather for all areas with little chance of rain by then.

 

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 this morning shows a cool and showery trough moving South over the UK early next week with High pressure out to the SW gradually killing off some of the showers by midweek in a generally cool NW feed.

 

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

 

THE FAX CHARTS The Fax Charts endorse the theme of the operational run with rain bearing fronts clearing the UK early next week in increasingly showery and unstable West then NW airflow bloing down over the UK towards the middle of the week.

 

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

 

GEM GEM this morning takes a very showery pattern into it's run this morning as Low pressure areas trundling SE down over the North Sea next week maintains (once arrived) a very showery and cool pattern with winds from the North and NW for the remainder of the run. High pressure is shown to lie out over the Atlantic to the West and NW on the end frames of the run.

 

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

 

NAVGEM NAVGEM like yesterday quickly builds High pressure in from the SW later next week after a couple of days of cool and showery NW winds which in themselves follow an active trough South over Monday and Tuesday.

 

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

 

ECM ECM indicates a less pronounced second attack from the North some of the other output shows this morning instead feeding a filling trough down over the UK then. The first attack early in the week is still well defined though with rain then sunshine and showers likely before the less showery conditions develop late next week and into the Holiday weekend. While a heatwave is not shown the end of the run would likely see a lot of dry and fine weather with just a few afternoon showers in the East.

 

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

 

ECM 10 DAY MEAN The ECM 10 Day Mean Chart  maintains the stance of a slack Northerly flow with sunshine and some showers in temperatures close to or a little below average generally

 

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

 

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The model output trends toward rather cool conditions in Northerly winds slackening later quite well supported with High pressure creeping in close to the UK later in the output runs.

 

31 DAY HISTORICAL VERIFICATION STATS FOR GFS, UKM & ECM The current verification statistics for the past 31 days shows ECM leading the way at 3 days with 96.7 pts followed by UKM at 96.0 pts and GFS at 95.2. At 5 days ECM  leads UKMO with 85.7 over UKMO's 84.2 pts with GFS at 82.3. At 8 days ECM remains the leader with 52.5 pts over GFS's 51.6 pts. Then at Day 10 GFS gains superiority at 34.6 pts over ECM at 34.1. 

 

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 The patterns shown in recent days within all the outputs remain the main focus again this morning with the likelihood of a spell of cool NW or even North winds blowing down across the UK for some time very real again this morning. The weekend will be generally set fair over the South once a band of light rain clears tomorrow morning. The North sees the precursor of the cool and showery theme from Sunday as a trough brings rain which early next week feeds SE across all areas introducing the cool and showery theme to all areas thereafter. The showers look like being heavy and thundery for a few days and even wintry on Scottish mountains before a tempering of conditions later in the week is shown in various degrees of extent as a ridge builds in slowly from the West. Then the behaviour of a second attack from the North is disputed to some degree by the models with a split between the models between a repeat of the showery early week process to a much weaker attack from others meaning less showers for all with more in the way of a chance of dry and fine if not overly warm weather possible for many over the Bank Holiday weekend. Then towards the end of the run there is some encouragement from the GFS camp this morning that warm and dry conditions could become established by the end of the two week period but outside of it's own ensembles support  this can hardly be classed as a universal message at the moment. So in a nutshell after a showery and cool period next week the legacy of which looks like possibly extending through the Bank Holiday weekend for many areas too with a rather cool weekend generally, the weather then looks like it could become more settled late in the period but taken as a whole amounts of rain will not be huge for anyone through the two weeks with a lot of dry weather overall especially towards the South and West. 

 

Next update from 08:00 Saturday May 16th 2015

[Summer Sun]

Must admit I wasn't expecting this from ECM

 

 

The cooler northerlies return for a time after but maybe later next week things will settle down a bit allowing temperatures to rise slightly

[Summer Sun]

GFS like ECM is showing a ridge of high pressure moving in around mid next week so for south at least it could become drier and a bit warmer for a time, further north the risk of rain / showers remains

 

Edited May 15, 2015 by Summer Sun

[Milhouse]

Too early to tell if its a definite pattern change but the GFS 12z shows much more settled conditions moving in by Wednesday and extending to all parts. Light winds and temps around average look likely

[Summer Sun]

GFS seems to have gone into high pressure mode this evening from t120 onwards, UKMO meanwhile doesn't bring the high in like GFS for now but its moving in the same direction looking at t120 GFS and UKMO are not far off

 

Edited May 15, 2015 by Summer Sun

[bluearmy]

Signs that the long wave trough seems to be establishing to our west as we head through week 2.

That should encourage temps to increase somewhat.

If we can get it far enough to the west, we could see a settling down in general.

[Cloud 10]

Signs that the long wave trough seems to be establishing to our west as we head through week 2.

That should encourage temps to increase somewhat.

If we can get it far enough to the west, we could see a settling down in general.

 

That would be convenient timing as summer begins...

 

[Summer Sun]

ECM moving towards GFS with pressure steadily rising from mid week

 

Edited May 15, 2015 by Summer Sun

[049balt]

Well,dryer weather on the way.

 

http://wxmaps.org/pix/prec4.html

[Milhouse]

Low pressure back over Greenland, always a good sign at this time of year.

 

[049balt]

Low pressure back over Greenland, always a good sign at this time of year.

 

Some great weather from late next week if the ECM and GFS  are to be believed

[knocker]

There are signs tonight from the anomalies of the UK settling into a more settled period.

 

Both the GEFS and ECM have the N.European trough sandwiched between the Azores ridge just to the west of the UK and the eastern European ridge. The Canadian vortex still in situ. Thus a broad area of HP eastern Atlantic bringing a light NW flow to the UK and a broad area of lowish pressure southern Europe. Equating too dry and cool weather.

 

The ext period seems to indicate evolution along the lines of the EC32 with a broad area of HP from the Atlantic to Scandinavia and the temps warming to average and above.

Charts weatherbell

Edited May 15, 2015 by knocker

[johnholmes]

That would be convenient timing as summer begins...

 

naefsnh-0-0-360.png

 

Quite different to the 3 other anomaly charts?

[Cloud 10]

Quite different to the 3 other anomaly charts?

 

Still to far out to make much impact on those 3 anomaly charts you mention John,so only a weakish signal for now.

[stodge]

Evening all

 

A quick look at the teleconnections from me and the NAO remains neutral to negative in the forecast period

 

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/nao.sprd2.gif

 

The AO, which has been positive of late, trending back towards neutral with a number of members going negative:

 

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/ao.sprd2.gif

 

I'm less convinced than some by talk of a return to a more "traditional" pattern with the Azores HP emerging as the "summer saviour". Here's Perturbation 12 on the GFS 12Z OP set:

 

http://www.meteociel.fr/modeles/gefs_cartes.php?code=12&ech=240&mode=0&carte=0

 

Certainly not on its own keeping substantial northern blocking - No.16 at the same point (Bank Holiday Monday):

 

http://www.meteociel.fr/modeles/gefs_cartes.php?ech=240&code=16&mode=0&carte=0

 

I'm not suggsting a rain fest by any means - merely that the NAO and AO still point toward northern blocking and the HP setting up more to the NW of the British Isles keeping us in a cool and dry air flow towards the latter third of the month.

[049balt]

Evening all

 

A quick look at the teleconnections from me and the NAO remains neutral to negative in the forecast period

 

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/pna/nao.sprd2.gif

 

The AO, which has been positive of late, trending back towards neutral with a number of members going negative:

 

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/ao.sprd2.gif

 

I'm less convinced than some by talk of a return to a more "traditional" pattern with the Azores HP emerging as the "summer saviour". Here's Perturbation 12 on the GFS 12Z OP set:

 

http://www.meteociel.fr/modeles/gefs_cartes.php?code=12&ech=240&mode=0&carte=0

 

Certainly not on its own keeping substantial northern blocking - No.16 at the same point (Bank Holiday Monday):

 

http://www.meteociel.fr/modeles/gefs_cartes.php?ech=240&code=16&mode=0&carte=0

 

I'm not suggsting a rain fest by any means - merely that the NAO and AO still point toward northern blocking and the HP setting up more to the NW of the British Isles keeping us in a cool and dry air flow towards the latter third of the month.

Interesting, that is what the Met have been saying lately, but it is still some way off and we can but hope that it comes good.

[knocker]

Still to far out to make much impact on those 3 anomaly charts you mention John,so only a weakish signal for now.

 

Well it doesn't show up on either the GEFS or the ECM anomaly at that range both are tending towards the NOAA 8-14.

[Geordiesnow]

Low pressure back over Greenland, always a good sign at this time of year.

 

 

It will hopefully help to buckle the jet stream Northwards as the models are at the moment hinting at in the medium term. 

 

Despite some BBC forecasters coming across as a bit impatient of some summery weather, you got to say the weather patterns are quite normal for Mid May, I'm looking forward at the potential of some convective weather to start the week and possibly by the end of the week, something a bit drier.