Model Output Discussion 22/07/12 Onwards.

[Staffordshire]

im surprised no one has commented about the UKMO meteociel charts being faulty for days now, it keeps showing sundays 2 AM chart at T120 and showing intensely low heights in tenerife and north africa,

what?! oh god please no, ill be holidaying in tenerife then! other models arent showing this, however and its looking like lows pushing into the uk for the begining for august.

[phil nw.]

This Summer so far has been notable for the frequency of troughing around north west Europe and the persistence of a southerly tracking jet stream feeding energy into the system and keeping the instabilty going.

We can see this familiar pattern forecasted in the coming week.This is the UKMO chart at T96hrs.

Continuing the outlook of Sunny intervals and showers,perhaps more general rain around Tuesday as that low sends it`s frontal bands across from the south west.

The South East and therefore the Olympic Park will always be prone to some showers but if any area is likely to be favoured for the best conditions then this is it.

It`s always difficult to pin down day to day details at this stage but in this setup weak ridging across the near continent on Monday and later next week would suggest this .Here on the UKMO T144 output.

similar to the GFS 12z.

.

Temperatures look to be rather low though struggling to just below normal in many places during the day.

Those are the Temperature Ens .from the 00z run which show the London 2m daily max/mins.

To sum up then-whilst we can`t look forward to anything really warm and sunny, such as many of us had this week, it wont be a complete washout either with sunshine and showers the main theme for the week ahead.

[Snowy Easterly]

i wish the polar vortex went to tenerife in winter

anyway, GFS shows it getting warm in the east ;later next week lets hope that low don't end up shunting the warm air into holland

Edited July 28, 2012 by Snowy Easterly

[OldMetMan]

In spite of a reasonable consensus among the models on a LP dominated week, I think it has some potential for some interesting weather and some warmer days later in the week.

The GFS in particular is suggesting the possibility of rising thickness values over France as the week goes on brings with it the possibility of thundery activity as the frontal zone waves associated with the LP pull in hot air from the continent. With last weeks storms, we came within a whisker of some very violent storm cells just out in the Channel so maybe things will be further N this time.

The GEM is interesting as it shows a progressive slackening of the pressure pattern across the E Atlantic and much of Europe - this model seems quite good at anticipating trends - so this suggests the temperature may slowly start to rise again - perhaps with slow moving showers and thunderstorms. Early August in my experience seems to be the time when the Atlantic is at its quietest - notwithstanding any ex-tropical storms that might come our way.

Speaking of which, after an unusually early and busy start, the Atlantic hurricane season has gone very quiet for some weeks now. What happens in the coming days on that score could significantly affect our weather if storms begin to form and track up the US east coast as they did early in the season, by pushing a lot of warm air NE and helping to strengthen the Atlantic flow.

I suspect none of this will happen for a while though but I still believe September will bring more reliable HP and dry weather.

[Snowy Easterly]

I suspect none of this will happen for a while though but I still believe September will bring more reliable HP and dry weather.

No surprise there

[phil nw.]

Tonights automated NOAA 500hPa outputs forecast show a persistence of this pattern with the upper trough still around the UK days 8-14.

Unsuprisingly the mean height anomolies for day10 from ECM/GFS and GEM all show a similar picture.

So we enter the first week of August with an unsettled and rather cool regime-showers and sunny intervals with temperatures struggling to reach average in many areas.

This pattern does look entrenched and tonights NAEFs pressure anomls forecast doesn`t offer any real change in the longer term either, unfortunately.

http://176.31.229.22...-0-0-300.png?12

Those heights still modelled around the Greenland area with the trough lying across North West Europe.

With no sign of any increase in angular momentum and a very weak MJO signal currently there`s little indication of any large scale change in current wavelengths.

http://www.esrl.noaa...ascyc.90day.gif

http://www.cpc.ncep....clivar_wh.shtml

I have been looking at those MJO forecasts for a number of days now and they do change but all seem to agree on a very weak signal for the next 15 days so little guidance can be taken from there wrt to future NH patterns at the moment.

Maybe GP with his far greater knowledge on these teleconnections can see a way out of this stubborn pattern beyond the next 2 weeks but for the moment all current outputs show an unsettled and cool outlook.

[damianslaw]

Models painting an unsettled picture for all for the foreseeable future. However, the outlook is different to what much of June and July brought, this time we will see low pressure tracking further north, meaning the wettest weather will be reserved for the NW quarter and the driest for the SE. A very typical set up for the second half of the summer, but unfortunately the jet remains further south than normal and too close for comfort, which isn't going to enable the azores high to ridge NE.

For the north it is a very dissapointing outlook for high summer, often wet windy and notably cool with temps in the mid teens, high teens at very best. For the south, average temps, with some decent sunny breaks in the SE but nowhere immune from showery downpours.

Perhaps the end of next week might bring a temporary build of heights from the SW for southern parts, meaning some decent warm sunny conditions, but nothing on the scale of the past few days. For the north... summer 2012 remains elusive, and its chances of getting going properly are now fast going down the plug hole I'm afraid, the best that could happen now is a 2 week heatwave in the second half of August - highly unlikely it has to be said, mid august isn't the time for a major pattern change, I think we can now firmly now summer 2012 isn't going to be remembered as a good one, could still rank as not bad, half decent with a month to go, but I suspect in the end we will all be saying what a poor one! we shall see..

[Geordiesnow]

I think a couple of things to note about this upcoming week will be that the strength of the wind will pick up with gales on exposed western coasts possible, may turn milder and more humid for a brief time in Southern and Eastern parts as the low will start anchor just to the West of Ireland helping to pump up some warmer air from France but all in all, an outlook which is similar to the one we have seen for the most of this summer unfortunately.

Not sure if I agree with Damianslaw regarding the outlook is different to the one we seen in June/Some parts of July, it looks more or less the same to me with low pressure in charge and quite cool apart from the odd day or two.

[Scorcher]

Not sure if I agree with Damianslaw regarding the outlook is different to the one we seen in June/Some parts of July, it looks more or less the same to me with low pressure in charge and quite cool apart from the odd day or two.

I keep making this point, but 19-22C looks the norm over much of England in the week ahead, that's much warmer than what we had in most of June.

[damianslaw]

I think a couple of things to note about this upcoming week will be that the strength of the wind will pick up with gales on exposed western coasts possible, may turn milder and more humid for a brief time in Southern and Eastern parts as the low will start anchor just to the West of Ireland helping to pump up some warmer air from France but all in all, an outlook which is similar to the one we have seen for the most of this summer unfortunately.

Not sure if I agree with Damianslaw regarding the outlook is different to the one we seen in June/Some parts of July, it looks more or less the same to me with low pressure in charge and quite cool apart from the odd day or two.

The difference is low pressure is tracking further north than in June and July when it was often over southern england, the reason why the far NW stayed dry. Whilst admittedly the overall pattern is very similiar to much of June and July with low pressure dominating, strong heights over greenland, trogh stuck in situ over the country, strong heights over east europe and the azores high nowhere to be seen, and the jetstream far south of its normal position, there are subtle differences, i.e. a slightly more northerly positioned jet, slightly weaker heights to the NW, and the azores high exerting slightly greater influence. But yes the subtleties are quite small.

[shedhead]

Tonights automated NOAA 500hPa outputs forecast show a persistence of this pattern with the upper trough still around the UK days 8-14.

Unsuprisingly the mean height anomolies for day10 from ECM/GFS and GEM all show a similar picture.

So we enter the first week of August with an unsettled and rather cool regime-showers and sunny intervals with temperatures struggling to reach average in many areas.

This pattern does look entrenched and tonights NAEFs pressure anomls forecast doesn`t offer any real change in the longer term either, unfortunately.

http://176.31.229.22...-0-0-300.png?12

Those heights still modelled around the Greenland area with the trough lying across North West Europe.

With no sign of any increase in angular momentum and a very weak MJO signal currently there`s little indication of any large scale change in current wavelengths.

http://www.esrl.noaa...ascyc.90day.gif

http://www.cpc.ncep....clivar_wh.shtml

I have been looking at those MJO forecasts for a number of days now and they do change but all seem to agree on a very weak signal for the next 15 days so little guidance can be taken from there wrt to future NH patterns at the moment.

Maybe GP with his far greater knowledge on these teleconnections can see a way out of this stubborn pattern beyond the next 2 weeks but for the moment all current outputs show an unsettled and cool outlook.

Regrettably I have to concur wholeheartedly Phil, once locked in this pattern can prove a real pig to shift, in fact it almost appears to act like something feeding on itself. Of course a change will eventually come, but as I've been saying for sometime now this looks very unlikely to occur until deep into week two of August, so for the next fortnight at least Summer looks firmly on hold once again.

Edited July 28, 2012 by shedhead

[lorenzo]

To be fair the last 2 winters out of the past 3 had plenty of high pressure blocking over Greenland producing 2 of the coldest winters ever. If the blocking over Greenland continues as it is then another cold winter might not be unexpected...

Barb - thanks for your posts over this summer, some great reading deserves recognition..great model analysis.

Looking ahead at winter Chionomaniac has started a great thread perfect for this time of year and 'downtime' in the model run frenzy for teleconnection papers , I urge you all to get on board with this prior to winter..

http://forum.netweather.tv/topic/73911-technical-teleconnective-papers/page__pid__2340136#entry2340136

From the frenzy of the Greenland melt paper being released and subsequent hysteria ( this is a fantastic link worth a coffee and 10 minutes of brain power) look out for some analogs..

There is plenty of discussion on twitter among metos. as for why this summer is an 'exception' in terms of Rossby Waves..

Can't help thinking this locked in theme is a stayer now having witnessed 80-90 day patterns repeating so much these last few years, this summer echoes our ghost PV and NW trough solution mirrors that horrendous AO episode so well..

Winter... long way off, could be anyones guess if the sst anomalies for Greenland over Summer months are anything to go by then raging Northerlies are on the cards..

For today, NAE did not model the convective mayhem experience east scotland, so not even mesoscale layerin has a handle on what the atlantic is kicking through.. Good times and as ever interesting model watching.

Behind it all. The transition of the SOI leading the way..

[bluearmy]

I would avoid meteociel ukmo output until sylvan fixes it. Even experienced model watchers can get caught out by some of the recent charts shown. T120 charts are especially untrustworthy as they don't always look wrong but are. Stick to wz or nw for ukmo for the time being.

As far as the general output is concerned, the trough looks like sticking in our vicinity but the shape of the greeny blocking is a bit different to that witnessed so far this summer and the heights to our south seem a bit more robust. however, as the output comes closer, the trough to our sw seems to become more pronounced. Uncertainty remains the watchword beyond week1 - it doesnt seem as though It will be as poor as June/first half July though.

[legritter]

yes very interesting times a head ,im about early today as mother nature woke me up this morning at 5.30 am ,and had to post on severe weather thread .i will study charts later but as of NOW the next week looks dire for some but perhaps later some warmer air coming up from further south could be on the cards . certainly some very cold air out there this morning ,fresher than some winter mornings ,BUT I WONT GO THERE , cheers

[Iceberg]

I ve not really been following the models recently, so read this page to catch up then looked at the models to see how bad things will be and.......to be honest for me it's not that bad at all, particularly so for London and the olympics. For London gfs has temps at 20 or above on all but one day next week, with a total rainfall of around 10mm, it looks like a classic showers, merging into bands, genially light int he south and east. The worst of the weather for the nw where temps will be depressed and rainfall might be 20-30mm.

This is nothing like the june July rubbish weather and on par with a normal unsettled summer week.

After this coming weak, general signs of the low pressure filling and high pressure returning.

Enjoy it

[William of Walworth]

After this coming weak, general signs of the low pressure filling and high pressure returning.

(Presumably for the South only, the HP returning thing?)

I'd love this to be true -- for later into week 2 especially! -- but I'm not really seeing it in FI parts of models yet. And no-one in recent posts have mentioned it, shoud they be starting to?

What do you say Scorcher?

Edited July 29, 2012 by William of Walworth

[shedhead]

I ve not really been following the models recently, so read this page to catch up then looked at the models to see how bad things will be and.......to be honest for me it's not that bad at all, particularly so for London and the olympics. For London gfs has temps at 20 or above on all but one day next week, with a total rainfall of around 10mm, it looks like a classic showers, merging into bands, genially light int he south and east. The worst of the weather for the nw where temps will be depressed and rainfall might be 20-30mm.

This is nothing like the june July rubbish weather and on par with a normal unsettled summer week.

After this coming weak, general signs of the low pressure filling and high pressure returning.

Enjoy it

To be fair the outlook for London and the SE could be a lot worse, but I have to say your final point looks rather more like wishful thinking as things currently stand, with both the big 2 keeping low pressure firmly in charge as we get into the 2nd week of August.

[Scorcher]

GFS showing an unsettled but average/rather warm week for many temperature-wise. Indeed if GFS is anything to go by the south east could see temperatures in the mid 20s by midweek. Signs in FI of the Azores High possibly ridging north-eastwards to give a setup which would be similar to the one we had last week.

[William of Walworth]

Of course a change will eventually come' date=' but as I've been saying for sometime now this looks very unlikely to occur until deep into week two of August,[/quote']

Uncertainty remains the watchword beyond week1 - it doesnt seem as though It will be as poor as June/first half July though.

Damian, what do you mean by week 2 o Augist, the scond complete week? The week starting 6th August or the one starting 13 August?

I suspect you meant the latter, but depending on which you meant, bluearmy's take on it might contradict yours a little -- perhaps ...

[Cards on the table here -- my selfish wish is for the second half of the week starting 6th August to prove dryer, pleasanter in the South -- including North Oxfordshire!!! Not expecting a heatwave or anything but LESS RAIN PLEASE! than looks possible for this coming week would be nice] ...

GFS showing an unsettled but average/rather warm week for many temperature-wise. Indeed if GFS is anything to go by the south east could see temperatures in the mid 20s by midweek. Signs in FI of the Azores High possibly ridging north-eastwards to give a setup which would be similar to the one we had last week.

I wondered how much credit to give to this, or even to accept it was possible in FI at all. But it's only signs at this stage isn't it ...

[Summer Sun]

Matt hugo is suggesting the Jet may move north for the second half of August

For the first part of Augst he is suggesting it will stay south of the UK

GFS 00z agrees with that today apart from the period of August 7th to August 10th where high pressure is shown to build

Second half

That looks a pritty good assesment at the moment

Edited July 29, 2012 by Summer Sun

[shedhead]

Damian, what do you mean by week 2 o Augist, the scond complete week? The week starting 6th August or the one starting 13 August?

I suspect you meant the latter, but depending on which you meant, bluearmy's take on it might contradict yours a little -- perhaps ...

[Cards on the table here -- my selfish wish is for the second half of the week starting 6th August to prove dryer, pleasanter in the South -- including North Oxfordshire!!! Not expecting a heatwave or anything but LESS RAIN PLEASE! than looks possible for this coming week would be nice] ...

I wondered how much credit to give to this, or even to accept it was possible in FI at all. But it's only signs at this stage isn't it ...

Firstly I'm not called Damian, hopefully that's not an omen... Secondly... Week 1 of any month is 1st-7th, Week 2 is 8th-14th, Week 3 is 15th-21st and Week 4 is 22nd-28th...week 5 is any days that remain.

So when I say deep into Week 2 I'm talking post 10-11th.

Here's the NAEFS 500mb anom chart for Aug 6th, note troughing still in place across the UK.

Moving onto the T+384hr for mid month, the troughing has lifted out, but there are still no signs of +ive anomolies anywhere near us, so even the 2nd half of August may not see a quick switch to fine, hot and sunny weather.

Edited July 29, 2012 by shedhead

[Backtrack]

CFS painting a very swift pattern change as we move through August into early September.

[shedhead]

CFS painting a very swift pattern change as we move through August into early September.

I think CFS has got this spot on. Slow improvement during Week 3 of Aug, then coming good after the 22nd with a lot of fine warm and sunny weather likely throughout Sept and even early October. Beyond that I'd expect the PV to set up much as last year, bringing us an average to rather mild Winter, but with plenty of dry weather across England and Wales in particular.

Edited July 29, 2012 by shedhead

[Snowmadsam]

I think CFS has got this spot on. Slow improvement through Week 3 of Aug, then coming good after the 22nd with a lot of fine warm and sunny weather likely throughout Sept and even early October. Beyond that I'd expect the PV to set up much as last year, bringing us an average to rather mild Winter, but with plenty of dry weather across England and Wales in particular.

oh lets not start on forecasting winter yet...lets take it one season at a time , I think Matt Hugo's Scenario is most likely and I wont be surprised if we get fine weather in September (school starts up!)

[legritter]

why dont we have a competition and set a date lets say wednesday the 15th of august .and using ALL forecasting tools at our disposal ,place the jet stream in the position that you [postERS]expect it to be . also the position of any high pressure areas and the expected pressure lets say in central britain . its only a suggestion but closing date lets say this tuesday later in the day .it would require an experienced poster with good computer skills and a computer with plenty of memory ,that counts ME out ,but i will regularly contribute SOMETHING along the way .perhaps a storm chase down here in somerset and i will throw in some bacon sandwiches .i had some brilliant storm chases in canada back in june /july missed most and got caught by the police breaking 80km speed limit .friend driving so we eventually kicked it in the head .will look in later after this even charts cheers