Model Output Discussion 01/06/2012

[Milhouse]

GFS 6z throws up a nice ridge to deliver most parts a settled and warm weekend. Sunday would see it become increasingly unsettled from the north west but for the majority of England and Wales Sundays chart is looking fairly decent. Monday and Tuesday looking warm but increasingly showery.

The Azores high is knocking on the door at the weekend. Its just whether the jet stream can be kind enough to shift northwards (or tilt) to allow high presure to build.

[Costa Del Fal]

Just more and more depressing charts for the time of year. Britain really is pretty much the only one to suffer and more echoes of the last 5 sumemrs etc. Forecasts of a better second half to June are already likely to be wrong. Just what is causing this constant negative NAO/AO etc in Summer only for it to rise by Winter???

Anyway, strictly on topic, the models are pretty much a constant Mid Atlantic ridge which again seems to sit there all Summer and never move towards us yet it does in Winter!! The next few days will be better with average temperatures but it looks like June will not exceed 22c or so probably. Shockingly poor. Less rainfall this week, however by the end of the week it looks like the next Low is moving in so more cool or cold, rainy days.GFS 06z hints at the Azores ridge next Weekend however it looks like a classic ridge for a day or two before sinking again. Really poor weather tbh.

Edited June 17, 2012 by Blizzards

[Bobby]

The Atlantic seems even stronger on the models lately, they have a 'return of the westerlies' look about them. There's more ridging about and less northern blocking but the Atlantic just steamrolls flat any ridge. So a more traditional pattern coming up perhaps with the weather being better the further SE you are. With the Atlantic looking so active though all areas are at risk of wind and rain.

Starting later this week with the GFS 06z going for a nasty little low yet again

Edited June 17, 2012 by Barb-

[Cloud 10]

Friday's in June= groundhog day.

8th june 15th june

22nd june?

[Thundery wintry showers]

Indeed, the GFS 06Z throws up a ridge from the Azores High to southern areas next weekend while we see a gap in between low pressure systems. Saturday looks likely to be similar to the next three days on the basis of the GFS 06Z, with a fair amount of sunshine and a scattering of slow moving showers, and then dry, sunny and fairly warm for southern and eastern England on Sunday although wet and windy weather pushes into other areas. I have very little confidence in this situation arising though as the UKMO and ECMWF both have a flatter pattern with the ECM showing the next low crashing through on a southerly track during next Sunday.

[Luke McDonnell]

Just more and more depressing charts for the time of year. Britain really is pretty much the only one to suffer and more echoes of the last 5 sumemrs etc. Forecasts of a better second half to June are already likely to be wrong. Just what is causing this constant negative NAO/AO etc in Summer only for it to rise by Winter???

Anyway, strictly on topic, the models are pretty much a constant Mid Atlantic ridge which again seems to sit there all Summer and never move towards us yet it does in Winter!! The next few days will be better with average temperatures but it looks like June will not exceed 22c or so probably. Shockingly poor. Less rainfall this week, however by the end of the week it looks like the next Low is moving in so more cool or cold, rainy days.GFS 06z hints at the Azores ridge next Weekend however it looks like a classic ridge for a day or two before sinking again. Really poor weather tbh.

The funny thing is that the stats say that we have not had one +NAO summer month since July 2006 - how could that be the case that is nearly 6 years of official summer months with a -NAO including what looks like this one - it seems amazing statistically - it is like flipping a coin 16 times and getting tails every time - without fail. Surely, by the law of averages we must be due a +NAO summer month shortly - if it continues in this vain I will seriously start thinking that +NAO months are no longer possible in the summer quarter as strange as that seems.

Luke

[J10]

With the exception of some rain to the SE overnight, looking a bit drier for the start of the next week, with only a few showers likely, not looking as heavy as was forecast for last week, but you never know.

The trend of low pressure set by ECM last night towards the end of next week has been picked up by other models.

However ECM suggesting the low pressure being a bit further north than recent weeks, so perhaps more of north south split, especially with high pressure trying to edge in from the south west.

Be interesting to see if this happens on the 12Hz run, or if it reverts back to its previous location.

[Bobby]

The NAEFS anomaly maps are looking worse if you want summer to start with troughing over us throughout and strengthening towards the end.

+300

Amazing how the troughing is slap bang over us as it has been it seems for ages.

[Milhouse]

The NAEFS anomaly maps are looking worse if you want summer to start with troughing over us throughout and strengthening towards the end.

+300

Amazing how the troughing is slap bang over us as it has been it seems for ages.

Yes, but to be fair there is every chance of high pressure ridging over the southern half of the UK over the weekend and into the start of next week warming things up, As highlighted by the ensembles. I'm not denying that the mean trough is in an unfavourable position. Just saying that there are signs that it may pull northwards for a time.

[Kentish Kiwi]

if it continues in this vain I will seriously start thinking that +NAO months are no longer possible in the summer quarter as strange as that seems.

Luke

Oh dear. Some people never learn...

[Luke McDonnell]

Oh dear. Some people never learn...

Was not trying to imply that +NAO months in the summer will never happen again - I was just making out how many consecutive -NAO months we have had in the summer quarter since 2006 and how statistically it might seem unlikely. I fully understand that we will get a hot summer month again - like people used to think that cold or very cold winters would not happen again until 2008-09 and 2009-10 came along.

Luke

[Summer Sun]

The next low is set to move in on Thursday

Once that clears through we get a few settled days

After that its a return to low pressure again but this time its moving down from the north rather than from the south west meaning North west Scotland would turn wetter with the south seeing the best of the weather at times but all areas are prone to rain

http://www.null/ds/gfs.htm

[Milhouse]

UKMO much the same as last nights with low pressure showing signs of pulling back into the Atlantic at 144h allowing a warm run of southwesterlies with the best of the settled weather across the SE. Where we go from there all depends on the track of the low just west of Scotland. If it could continue to pull westwards we could see a more nationwide pressure rise although i believe it will slowly drift northeast maintaing the NW/SE split.

[Summer Sun]

ECM's take on the low tonight

After that clears through pressure try's to rise but never takes hold

Edited June 17, 2012 by Gavin D

[damianslaw]

Models showing a very changeable outlook. Quite a lot going on with some marked regional differences. SE parts will see some heavy rain overnight thanks to a frontal feature brushing the SE coast. Quite cool further north under a slack airstream. Tuesday and Wednesday will be showery in western parts, whilst eastern parts could see a couple of dry decent days with temps slightly above average, so feeling more like summer for some.

Unfortunately, by Thursday yet again another low pressure is waiting in the wings to bring another wet day for the west and southwest, this feature then becoming slow moving over the country just like so many have since April to bring heavy downpours adding to the high rainfall totals many have experienced this month. The olympic torch event by the lake looks like being a washout....how beautiful an evening it could have been, occuring on the shortest night of the year..

Longer term - none of the models are suggesting any rise of pressure near/over the country as we move into the latter stages of the month, the jetstream is poorly positioned, we maintain strong heights to the NW, the azores high looks very weak and the trough will remain stuck in situ..though there are signs of the more traditional NW-SE divide taking hold much as it usually does as we hit July. Its a dissapointing outlook it has to be said.

[Weather Boy]

With the exception of ledders' post, am I the only one not wrist-slitting whilst looking at the current model output? Perhaps I am i) not sophisticated enough at reading the models ii) suffering from glass half full mentality iii) being IMYist or iv) all of the above, but it doesn't seem too bad with the exception of Friday. Some rain on Thursday too, I grant you, and I accept:

1. The picture is not especially settled and reasonably changable;

2. No prolonged HP or heat is progged at any point;

3. There will be some notable rain at times.

However, my take on the output generally is that, unlike the last fortnight, we won't be too far away from average summer weather, although it seems likely that there is going to be a significant disturbance mostly during Thurs/Friday, although as someone said it looks set to rattle through fairly quickly. After which, it seems to me to be generally up for grabs with the models changing and the long term signals likewise, and if anything relatively positive (although anyone expecting prolonged HP etc may be hopecasting). Remember as has been said up this thread that the late May fine spell came on us quite suddenly and indeed only ended with less than a week's notice as initially the models were suggesting the Jubilee might be good until quite close to the event.

In short in my view after Friday's Low is gone, more or less anything could happen. Could be dross, could be fine, or anything in between, although a heatwave looks a long shot. Long term signals, and indeed GP's latest tend to the positive rather than the negative.

P.S - Tried to find a link to support that and found that the 12z has the low really dragging heels over Scotland into early next week, so maybe I should stop trying to be positive! Still, being rose-tinted, the following is OK if you ignore deep FI:

I suppose the ultimate point I am trying to make is that even the low point of the models, this Thurs/Fri is no worse than the low for this weekend, and in my location our weather was OK with no real complaints.

In the SE at least, only people looking for over 25C and 16 hours sunshine a day are likely to be disappointed IMO. I think it will be fairly average i.e. OK - transient Highs and the odd front - maybe better than that the further SE you are.

[carinthian]

I know the UK has had a pretty aweful summer season so far, but here in Austria the high humidity has been a feature of the weather so far this summer with a lot of medium level cloud and lightening seen on many occasions, but not a lot of rainfall. Long for some cool star lite nights !

C

[bluearmy]

anyone making plans for week two - wouldn't bank on these but they indicate it might be best to avoid monday the 25th and a possible ridge window on thursday the 28th

will be interesting to see if the models begin to firm up on these two days over the next few days.

following on from the 00z runs, the 12z naefs spread continues to show the monday shortwave crossing the uk whilst the ecm 12z spread has picked up a small shallow but discreet system at the same juncture. this is at odds with much of the operational output for monday 25th which at this time looks pretty reasonable. this will be a good test of whether the ens spreads are a better bet than the fi ops. (although a week tomorrow shouldn't ordinarily be seen as particularly fi). the possible ridge for the thursday has dropped off naefs 12z run. it looked a bit of a 'stretch' but we should continue to look out for it on subsequent runs.

i note WB's post above re the may warm spell. it wasnt a surprise to all - many of us were trailing this event at least 10 days before it arrived. it showed up consistently on naefs fi as a high anomoly, initially as a sceuro block at two weeks range and then it began to show as a retrogressing high moving nw towards iceland and ultimately greenland, where its been ever since !!

Edited June 17, 2012 by bluearmy

[johnholmes]

If one looks at the overall trend over the past 3 days or so, yes my old hobby horse-500mb anomaly charts? They are far from showing the same thing, indeed the ECMWF and GFS this morning are chalk and cheese. probably the largest difference in over 3 years of looking at these charts on about 310 days per year over the last 3 years.

That said the overall upper pattern being suggested is for a 500mb flow into the UK from north of west, +ve areas west and -ve areas east or NE of the country equates to mainly unsettled and far from hot on most days for most parts into the next month. yes, odd days that will buck that trend but overall that is the most likely pattern for probably 70% if not more of the time.

[Weather Boy]

i note WB's post above re the may warm spell. it wasnt a surprise to all - many of us were trailing this event at least 10 days before it arrived. it showed up consistently on naefs fi as a high anomoly, initially as a sceuro block at two weeks range and then it began to show as a retrogressing high moving nw towards iceland and ultimately greenland, where its been ever since !!

Yes, I suppose it depends on how you define 'surprise'. Not heavily trailed is perhaps a better way of putting it. Conversley, I recall near the beginning of that spell, the models giving no clear signal of any likelihood of it ending in the foreseeable, but by 2/3 June, the picture had very radically changed.

[Slowpoke]

A huge high developing over much of the Atlantic has been shown in FI on loads of runs recently!

[Milhouse]

GFS 18z gives most areas a settled and increasingly warm weekend. Dont pay too much attention to the temperature charts showing highs of just 20s. A general rule i use is that under high pressure you should expect 20c from upper air temps of 5c. Therefore most parts should see above average temperatures on Sunday. Monday sees a breakdown coming from the north but fine and warm in the SE.

[ZONE 51]

If one looks at the overall trend over the past 3 days or so, yes my old hobby horse-500mb anomaly charts? They are far from showing the same thing, indeed the ECMWF and GFS this morning are chalk and cheese. probably the largest difference in over 3 years of looking at these charts on about 310 days per year over the last 3 years.

That said the overall upper pattern being suggested is for a 500mb flow into the UK from north of west, +ve areas west and -ve areas east or NE of the country equates to mainly unsettled and far from hot on most days for most parts into the next month. yes, odd days that will buck that trend but overall that is the most likely pattern for probably 70% if not more of the time.

Interesting i must say(as all your posts JH) but something significant in this?(bolded) Edited June 18, 2012 by ElectricSnowStorm

[AWD]

All models continue the rather changeable theme this morning. Although not as unsettled as recent days, all places will still see some rain throughout the coming days, and even weeks. The more traditional NW/SE split coming into play more though, with the North West seeing the heaviest and more persistent rain, and with pressure slightly higher in the south, here the rain should be more fragmented, with plenty of sunny interludes inbetween.

Here are the models take on the Low Pressure system which they all agree on for Friday. This system will bring a spell of heavy rain to us all, with the winds strongest further north this time. The GEM and ECM have another very deep system with strong winds, where as the GFS and UKMO have a rather more toned down version.

After this the models then paint a slack, showery period of weather. With slack pressure over the UK, there will be showers for all at times, possibly heavy and thundery, with sunny spells equally too.

In FI, we get the sort of weather that Summer should be about start to show it hand. The Azores High coming up on the GFS bringing increasingly warmer and drier conditions to much of England & Wales & Ireland. Scotland would still be prone to showers however. The ECM possibly pleasing the convective fans more with warm air coming up from the continent and Low Pressure to the WSW of the UK, suggestive of thundery activity, especially over the South. If the ECM 240hr chart verified, then for those that like heat, get a last minute holiday to the Costa Blanca booked, with the 25c 850 air over spain and the Med.

All in all, rather changeable summerises the foreseeable future! Expect rain at times, but also more in the way of sunshine than of recently too. Temps are nothing to write home about however, mainly around average or so!

Edited June 18, 2012 by Active Weather Dude

[shedhead]

I think the best and most succinct way to sum up the latest outputs is better, but still a long way from good. Subtle changes in the orientation of the flow means most of us should see less rain, more sunshine and somewhat higher temps, but it has to be said that Summer as most of us want to see it still remains conspicuous by it's absence. Finally for those who love their dose of morning negativity, the evenings start pulling in from Thursday...