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

[bluearmy]

Just an observation but the fi ecm ops (not that I generally take too much notice of them beyond day 7) are becoming less keen on dropping the high Alaskan anomalies. Hence the ridge doesnt really get across us and the euro trough hangs on to our East. That may still leave us under the influence of the AH rather than the trough but it's higher risk than seems likely judging by the gfs and ens.

Hopefully just ecm op being a bit stubborn but we do know how these ridges, once established, are tough to break down.

[Eugene]

WOW!!

 

 

I'll Bank those charts

 

 

 

Wow those temps have been downgraded by around 10C on GFS 12Z.    

[Methuselah]

Wow those temps have been downgraded by around 10C on GFS 12Z.    

Wow indeed! was it going to be 39C?

[Frosty.]

The GEFS 12z mean shows an end to the rather cool unsettled wly/nwly dross which has made this spring in the northwest of the UK very miserable.

The charts below are just what the doctor ordered, a nationwide increasingly warm and anticyclonic further outlook coinciding with the start of summer. I hope this is just the beginning of a summer to remember for all the right reasons.

[ANYWEATHER]

Hi Folks, Just reading some of the posts on here for the last couple of days it looks certain that June will see high pressure bring a big change in our weather. Misleading to be honest. If you look at the bigger picture there is no concensus that high pressure will build totally across the nation ;any high pressure tease is still pushing the 10 day time frame.....Don't be fooled, just look at the past history of high pressure building in the ten day period and youre expectations will be very much lowered!  Im afraid its hopecasting at the moment!

[Stuie]

Hi Folks, Just reading some of the posts on here for the last couple of days it looks certain that June will see high pressure bring a big change in our weather. Misleading to be honest. If you look at the bigger picture there is no concensus that high pressure will build totally across the nation ;any high pressure tease is still pushing the 10 day time frame.....Don't be fooled, just look at the past history of high pressure building in the ten day period and youre expectations will be very much lowered!  Im afraid its hopecasting at the moment!

Not that I totally agree with you but yes if it was on the flip side and chasing snow this scenario would be downgraded to the hilt and laughed at being FI.

 

I suppose you have to thank the euro pressure rise to combat this. Lets hope it all pans out as other have touted and we can finally get some warmth.

[damianslaw]

Some pleasing charts on offer today from the GFS if you are after something substantially calmer and warmer than recent weeks, alas such charts remain beyond the reliable timeframe and should be treated with caution.

 

Indeed the reliable is for more of the same with a strong jet powering in low pressure from the NW, cool to boot with rain and showers and wind for all, nothing summery..

 

The reason I say be cautious is due to the forecasted power of the jet propelled by a cold pool of SST's to our NW. Don't be surprised to see the GFS backtrack from the ridge positioning itself to the NE and instead keep heights tentatively to our SW, far enough to keep us under the influence of a westerly drift - not necessarily cool, indeed probably a bit above average but cloudy with drizzly bits in the north. ECM is showing such a set up.

[Geordiesnow]

Although the outlook looks unsettled, there is no real trend of any stalling lows, it does seem to be one low then a brief calming moment followed by another look but as its been with this month, it will be how much below average the temps will be. That said, its still not all that unusual too see this type of weather in late May and sometimes early June can be a slow burner to summer 

 

Compare and contrast our temps to those that is forecast in Russia, once again well above average temperatures there is the potential we could even see temps of upto 30C on the Arctic coastline! 

[DAVID SNOW]

Wow indeed! was it going to be 39C?

 

No! The 06 gfs  run today showed highs of 31c  and the 12z gfs  is showing highs of about 21c that's the truth of it... Orientation of 'any' high being key here, just my opinion but I think the Atlantic will soon flatten things as we move through June.

[Nouska]

Don't be surprised to see longer range differences between the GFS and ECM. They are both bringing the MJO back into a more amplified state but have different regions and those make a big difference to our neck of the woods. ECM wants to amplify through the Indian Ocean and that is not good for our prospects. GFS keeps the amplification further west; this correlates to a lovely high pressure scenario as depicted in current low res runs.

 

Overview.    ECMmonthly                                                                              

The difference between phase 1 and phase 2 for June.

 

 

[knocker]

Don't be surprised to see longer range differences between the GFS and ECM. They are both bringing the MJO back into a more amplified state but have different regions and those make a big difference to our neck of the woods. ECM wants to amplify through the Indian Ocean and that is not good for our prospects. GFS keeps the amplification further west; this correlates to a lovely high pressure scenario as depicted in current low res runs.

 

Overview.    ECMmonthly                                                                              

The difference between phase 1 and phase 2 for June.

 

 

 

Nouska I'm afraid I'm slightly confused. If the ECM amplyfying through the Indian Ocean is not good for our prospects why are the EC32 and tonight's ext anomalies looking good to maintain the HP?

[knocker]

Tonight's GEFS and ECM anomalies are still looking good for HP predominating out to the end of the ext period.

 

Although not in complete agreement at day ten about the alignment of the Greenland trough and European ridge they both get rid of the Alaskan ridge, and push HP over the Pole and relax the Canadian vortex.

 

The exts do show a suspicion of a trough mid Atlantic but otherwise still hunky dory.

http://www.tropicaltidbits.com/

Edited May 26, 2015 by knocker

[Frosty.]

The Ecm 12z ensemble mean shows strong support for the Azores high to build in and settle our weather down and gradually warm our weather up, as far as I can see it's all systems go for a warmer anticyclonic outlook from later next week onwards, summery weather is on the way.

[Nouska]

Nouska I'm afraid I'm slightly confused. If the ECM amplyfying through the Indian Ocean is not good for our prospects why are the EC32 and tonight's ext anomalies looking good to maintain the HP?

 

Hi Knocker, I was ruminating on Nick's post and the potentially different outcomes - that the main models may diverge in the longer term. It is a possibility and not a fact.. With four weeks of underpinning our foundations about to start, I'm desperately hoping for the high and dry solution - being surrounded by a moat was not on the shopping list for our French adventure!

[knocker]

Thanks Nouska. A definite requirement to avoid any convective developments then.

 

A quick look at this mornings GFS after the frontal passage Sunday there isn't much of a lull before a nasty low zips into Scotland on Tuesday with quite strong winds in it's SW/S quadrants. This is the last of the Mohicans before HP comes to nestle. But wait there is an interesting diversion in lulu land as it brings a shallow low up from the SW and swings it into France. Ah well, here today and gone tomorrow.

http://www.tropicaltidbits.com/

Edited May 27, 2015 by knocker

[Polar Maritime]

Yes Knock, The Low swinging in next Tuesday could still bring some problems with severe gales at times. The GFS does show a breakdown of sorts of the up-coming settled spell towards the end of run..

 

Edited May 27, 2015 by Polar Maritime

[bluearmy]

Certainly further indications that the change to a more settled regime could be slightly slower process than earlier indicated. The changeover period still just outside the 'reliable' period re operationals. At the moment, I would say that a settling down will drift north over a five day period with a further low rattling w to e to our north and affecting the n of the UK whilst the south has settled down. The ECM currently coming out is anticipated by me more than any since winter drew to a close.

[mushymanrob]

Hi Folks, Just reading some of the posts on here for the last couple of days it looks certain that June will see high pressure bring a big change in our weather. Misleading to be honest. If you look at the bigger picture there is no concensus that high pressure will build totally across the nation ;any high pressure tease is still pushing the 10 day time frame.....Don't be fooled, just look at the past history of high pressure building in the ten day period and youre expectations will be very much lowered!  Im afraid its hopecasting at the moment!

 

how is it misleading?... all models show a pressure build into june, the ever reliable anomaly charts suggest high pressure build into june. its not misleading to talk about what all models are consistently showing!

it is misleading though to equate pressure rise to heat, because the exact position and orientation of the expected high is far from determined. the chances of high pressure domination later next week is fairly likely ( but not nailed, as you say), and it doesnt have to 'cover the nation' to control and influence the nations weather.

in saying that though, this morning its looking like pressure build has been put back a couple of days or so, and of course might yet not happen... but there is good support for it still... its the timing thats uncertain more then 'will it/wont it'

[coldcomfort]

Well here we are another 24hrs further on, but any improvement remains stubbornly stuck in the 8-9 day range, i.e too far away for any confidence whatsoever.  This already has all the hallmarks of a classic carrot and donkey pattern change imo, whereby the summery carrot always remains tantalisingly out of reach....at least for now.

[bluearmy]

Well here we are another 24hrs further on, but any improvement remains stubbornly stuck in the 8-9 day range, i.e too far away for any confidence whatsoever.  This already has all the hallmarks of a classic carrot and donkey pattern change imo, whereby the summery carrot always remains tantalisingly out of reach....at least for now.

A better ECM op and the trend previously shown comes to a halt. The alsakan heights dropped away and with them, the troughing to our East which allows the ridge to push across. More evidence that the more settled set up will verify.

[coldcomfort]

A better ECM op and the trend previously shown comes to a halt. The alsakan heights dropped away and with them, the troughing to our East which allows the ridge to push across. More evidence that the more settled set up will verify.

I agree, it's not or never really has been a matter of if, just when...but that can be said about the weather at any time to be fair. Bottom line for me is on Monday morning the change was shown as being 8-9 days away, yesterday the change was shown as being 8-9 days away and today the change is shown as being 8-9 days away. Until we can break this pattern of daily delays, I will remain as previous, i.e cautiously optimistic and no more. 

[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 MAY 27TH 2015.

 

THE CURRENT GENERAL SITUATION A trough of Low pressure will move East across the UK later today and tonight before a cool and showery Westerly flow follows.

 

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

 

MODELS-2 WEEK HEADLINE A spell of changeable weather in the first week followed by warmer and more settled weather in Week 2.

 

THE GFS JET STREAM FORECAST The GFS Jet Stream Forecast shows the flow continue to blow West to East close to the UK over the coming days and again near the start of next week. Later in the run the flow weakens and becomes more ill defined as pressure builds for a time from the South.

 

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

 

GFS OPERATIONAL The GFS Operational today shows a spell of breezy and for a time late in the weekend and start to next week a distinctly Autumnal feeling couple of days as a strong jet flow across the UK powers up a deep depression across the UK with rain, gales and squally cool conditions for many lasting until midweel when a slow improvement moves up from the SW, last to reach the North late in the week. Thereafter, things become much more benign as no pressure system takes overall control with warmer and drier conditions with sunshine at times for all and the risk of showers in the South and SW. 

 

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

 

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

 

THE GFS CONTROL The GFS Control run shows a very similar output for the two weeks with the same inclement Low pressure affecting all of the UK in the first days of next week. Then this run shows a more full hearted attempt at bringing High pressure and subsequent warm conditions to much of the UK as High pressure builds across and to the NE later with warm continental air and just the risk of a thundery shower across the South late in the period.

 

THE GFS CLUSTERS The GFS Clusters today continue to project High pressure well in control of the UK weather in two weeks time with a large High pressure centred close by with fine and warm conditions as result. Just 5% of output shows the risk of a deep Atlantic Low with warm Southerly winds and some thundery rain in the far West.

 

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 cool and unsettled weather at the start of next week with cool and strong West or NW winds and showers, heavy at times in association with Low pressure close to NE Britain by Tuesday.

 

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

 

THE FAX CHARTS The Fax Charts continue to show the UK governed by a Westerly Atlantic airflow carrying occasional troughs and depressions East just to the North of the UK with troughs carrying rain followed by blustery showers to all areas especially later.

 

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

 

GEM GEM paints a similar picture in relation to the deep Low crossing England early next week, exiting only slowly away later in the period with better conditions under higher pressure trying desperately hard to move up from the South but never really reaching the far NW in the period and with the threat of some thundery rain in the SE as the cooler plar maritime air across Britain mixes with warm continental air on Day 10.

 

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

 

NAVGEM NAVGEM has next weeks Low further North than most other output and follows on with a much more meaningful build of pressure across the UK by later next week. There would be a spell of rain then showers in blustery winds early next week before fine, sunny and warm conditions develop from midweek on.

 

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

 

ECM ECM unfortunately backs the majority of the run bringing the deep Lo across the UK early in the week. Improvements are painfully slow and somewhat delayed than on previous output taking until the 10th day of the run to see pressure build sufficiently enough to bring more guaranteed dry and fine weather with warm sunshine as pressure finally becomes High across the UK.

 

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

 

ECM 10 DAY MEAN The ECM 10 Day Mean Chart  from last night does maintain strong support for good weather across the UK by Day 10 under a strong ridge with fine and warm conditions for nearly all away from the far NW.

 

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

 

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The trend for better weather after a week or so remains but is shown by most output to be somewhat delayed in arriving this morning.

 

31 DAY HISTORICAL VERIFICATION STATS FOR GFS, UKMO & 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 95.7 pts and GFS at 95.2. At 5 days ECM  leads UKMO with 86.9 over UKMO's 82.6 pts with GFS at 82.2. At 8 days ECM clocks in ahead of GFS at 52.3 over 45.6. Then at Day 10 ECM remains slightly ahead of GFS at 29.7 pts to 26.2 pts.

 

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 main message read from the models this morning is the uncertainty longer term of how well pressure recovers next week following the inclement conditions from the nasty little Low programmed to attack all of the UK early next week. There is currently a strong Jet stream for this time of year in the vicinity of the UK and over the next 4-5 days this winds up a powerful and unseasonal depression early next week, this following an already cool and unsettled period in the days leading up to this. After the spells of rain, strong winds and heavy showers from this we have to wait and see how the legacy of this influences pressure rises from the South and SW previously shown for the middle and latter days of next week. Most output do still show this rise of pressure still sufficiently strong enough to ensure a settled spell of weather for many with warm temperatures developing late next week but this is a delay in what was being shown only yesterday and synopses to the NW from some output doesn't always look too preventative of Low pressure attacking any rise of pressure from the NW at least in the NW longer term with High pressure resultantly nudged more towards the East, NE or SE. I think the main message is until the early weeks storm's transit is known and confirmed cross model support on the day to day events following it will be unclear and differing one to another but I think there is still enough cross model support for an improvement from the middle of next week with the emphasis gradually shifting away from cool and unsettled to drier and warmer conditions for most but whether this will result in a 'high summer' type event looks a little more fractious from the operational outputs at least this morning.

 

Next update from 08:00 Thursday May 28th 2015

[picog]

I agree, it's not or never really has been a matter of if, just when...but that can be said about the weather at any time to be fair. Bottom line for me is on Monday morning the change was shown as being 8-9 days away, yesterday the change was shown as being 8-9 days away and today the change is shown as being 8-9 days away. Until we can break this pattern of daily delays, I will remain as previous, i.e cautiously optimistic and no more.

Maybe all the models will suddenly get a handle on the change and bring it forward to 5-6 days or less. This certainly seems to happen in the winter months, so no reason (is there?) for it not to happen late spring. BBC have said that weather likely to improve etc next week too.

[Gibby]

Maybe all the models will suddenly get a handle on the change and bring it forward to 5-6 days or less. This certainly seems to happen in the winter months, so no reason (is there?) for it not to happen late spring. BBC have said that weather likely to improve etc next week too.

..and it still will. It's to what degree of improvement that's open to doubt within the models at the moment.

Edited May 27, 2015 by Gibby

[coldcomfort]

Maybe all the models will suddenly get a handle on the change and bring it forward to 5-6 days or less. This certainly seems to happen in the winter months, so no reason (is there?) for it not to happen late spring. BBC have said that weather likely to improve etc next week too.

Maybe, but equally they could continue to delay the change and eventually water it down even more...that is just pure conjecture. Things will improve, of that there is no doubt, but the speed and magnitude of the change still remains very much open to question this morning - with imo rather more uncertainty than has hitherto been touted by many on here.

Edited May 27, 2015 by coldcomfort