Model Output Discussion

[Backtrack]

It's not a "terrible" output at all, except for those who expect the UK to be part of the Mediterranean. Realistically speaking, perhaps disappointing for some and acceptable for others.

Low pressure and fronts continue to be delayed for over the weekend so a bright, fairly warm Saturday with a scattering of showers, and Sunday may well be bright too with a scattering of showers, though I think Sunday will probably have more cloud overall. Wednesday-Friday continue to look bright, showery to begin with (especially in the NE where scattered weak thunderstorms are possible) and showers largely fading away by Friday due to the advancing ridge of high pressure.

It continues to look dodgy for warmth/sun/dryness out into FI with low pressure transferring towards Scandinavia, but teleconnections outputs suggest that the models may be being too progressive here, as noted in some earlier posts which favoured the main trough staying to the NW.

Yes it's not terrible for this week with plenty of sunshine on offer, but it's next week where the uncertainty comes from.

The UKMO have the trough out West where as the ECM goes for the trough just West of Scotland, which would bring more rain and cloudy, cool, damp conditions with it again. I hope the UKMO are right here, but for those looking for summer heat, then the output is not very good!

[Bottesford]

To me it all looks fairly reasonable - and I'm keeping a close eye out with going to a festival Fri to Sun!

Generally dry with some showers temperatures around the high teens but warmer on Saturday (good!) and less chance of rain Fri & Sat too (good!).

Beyond that subject to change but models currently showing low pressure maybe coming back after the high from Fri/Sat decays. We shall see.

[Downpour]

Yes it's not terrible for this week with plenty of sunshine on offer, but it's next week where the uncertainty comes from.

The UKMO have the trough out West where as the ECM goes for the trough just West of Scotland, which would bring more rain and cloudy, cool, damp conditions with it again. I hope the UKMO are right here, but for those looking for summer heat, then the output is not very good!

How many people really are actually looking for heat though? Heat like yesterday's furnace in London is good for nothing - totally unpleasant. Most members surely are looking for planning weather - I.e. Will I have to buy a rain shelter for my party on July 8?

[Backtrack]

How many people really are actually looking for heat though? Heat like yesterday's furnace in London is good for nothing - totally unpleasant. Most members surely are looking for planning weather - I.e. Will I have to buy a rain shelter for my party on July 8?

I can refer back to previous posts here. Your climate is very different to us 'Northerners' it's rare we can get a day above say 28/29C where as that's near average for you in summer. So whilst you may be looking for average weather, I am looking for Summer weather, this being heat and sunshine. Love a good thunderstorm too.

I'm sure many people will agree that the heat we just experienced was highly uncomfortable though as you just said, but this wasn't down to the actual air temperature, it was down to the high humidity and very high dewpoints, hence why the 'feels like' factor wasn't far from 40C for London.

The models show none of the heat I am looking for, but non the less, this week looks great for me. Lovely blue skies and average temperatures at around 18-20C. One can't complain at that.

[Jason T]

It makes me laugh at times in here, We have gone from extreme boring june, to extreme 2 day heat fest, followed by extreme storms in a day. Now we are worried what the model output shows for next week, even though from tomorrow upto the weekend we have lovely weather,comfortable temps. I still believe that through july and into august even in to september will be a much improved summer period.

Why worry about output 5 to 7 days out, Anything can change by the weekend. Without prejudice to forecasters look what happend with the storm scenario forecasting, what should have happend by information to hand so to speak did not happen, and what did follow surprised everyone the predictable was unpredictable.

Lets see what the output is through th weekend.

[Backtrack]

It makes me laugh at times in here, We have gone from extreme boring june, to extreme 2 day heat fest, followed by extreme storms in a day. Now we are worried what the model output shows for next week, even though from tomorrow upto the weekend we have lovely weather,comfortable temps. I still believe that through july and into august even in to september will be a much improved summer period.

Why worry about output 5 to 7 days out, Anything can change by the weekend. Without prejudice to forecasters look what happend with the storm scenario forecasting, what should have happend by information to hand so to speak did not happen, and what did follow surprised everyone the predictable was unpredictable.

Lets see what the output is through th weekend.

All is true apart from the bit I have highlighted.

I think it would be very unfair to criticize the weather forecasters for yesterday's prediction. The CAPE and Lifted Index were through the roof, over 2,000 CAPE and -8 LI. Now this is a perfect recipe for thunderstorms, and with that instability in the atmosphere you would of expected severe storms to break out. Obviously they didn't (John Holmes explained why in one of his posts earlier) but the potential was there. Shame the cap was higher than the instability though. One of the reasons why.

[MP-R]

I think it's fair to say the models are disappointing for anything summery. The saving grace is that everything unsettled appears just outside the reliable timeframe. But lows off the Atlantic aren't an associated feature of summer for many.

GFS paints a stable and mostly settled picture for most for the rest of this week with Friday and Saturday probably being the best days.

[Downpour]

I can refer back to previous posts here. Your climate is very different to us 'Northerners' it's rare we can get a day above say 28/29C where as that's near average for you in summer. So whilst you may be looking for average weather, I am looking for Summer weather, this being heat and sunshine. Love a good thunderstorm too.

I'm sure many people will agree that the heat we just experienced was highly uncomfortable though as you just said, but this wasn't down to the actual air temperature, it was down to the high humidity and very high dewpoints, hence why the 'feels like' factor wasn't far from 40C for

London.

The models show none of the heat I am looking for, but non the less, this week looks great for me. Lovely blue skies and average temperatures at around 18-20C. One can't complain at that.

Fair enough sir - as I have myself posted before we do indeed live in very different climate groups. Here's to a decent weekend, as you suggest - could be bonny and pleasant for a walk or a few drinks in the garden.

[Jason T]

All is true apart from the bit I have highlighted.

I think it would be very unfair to criticize the weather forecasters for yesterday's prediction. The CAPE and Lifted Index were through the roof, over 2,000 CAPE and -8 LI. Now this is a perfect recipe for thunderstorms, and with that instability in the atmosphere you would of expected severe storms to break out. Obviously they didn't (John Holmes explained why in one of his posts earlier) but the potential was there. Shame the cap was higher than the instability though. One of the reasons why.

Without prejudice. Vegito, I am not grinding the axe so to speak on any forecaster,and trust me when i say this i admire all the knowledgables on here. So i apologise if my post was in anyway offensive to you.

[mushymanrob]

nothing much to comment on this morning, no heat, no washout... so some nice pleasant summer days on offer. not good for those seeking a nice hot spell... but not 'bad' summer prospects either, ie no prolonged dull wet cool days. .... just average summer..

[lorenzo]

I hate to say it but output this morning puts us back in 'that' phase after 120 onwards...... still a couple of days without the grey cloud balnket here have been good..

[bluearmy]

the onset of the upper trough for next week looks delayed a bit on the latest runs. i think next week may not be as obvious as it looked yesterday.

[Gibby]

UKMO's 00z shows a pleasant two or three days now spare the odd shower or two with some reasonably warm sunny spells as an area of high pressure trundles into the UK from off the Azores. It looks as though it will last the weekend for most before Atlantic Low pressure moves in from the west by Tuesday.

GFS also brings high pressure in but releases it a day earlier as slack low pressure becomes established early next week over the UK with heavy showers likely for all by then and cooler temperatures. Thereafter, Low pressure is shown in control of the UK weather with days of heavy showers and sunny intervals. A brief respite for the south seems likely then for a while close to high pressure to the south before an almost Autumnal look to end the run takes hold with deep low pressure close to the North.

ECM follows UKMO in timescale with the unsettled theme arriving early next week after quite a reasonable weekend for many spare the odd shower. It then brings the Low pressure into the UK from off the Atlantic to dominate conditions from then until the end of the run with heavy showers or rain at times for all.

Not much overall change this morning but it does look like the south at least will see reasonable conditions between now and early next week as high pressure is shown to be a little more resistant to the Atlantic Low this morning. Then things follow the trend as shown on previous runs of rain or showers in rather cool and breezy conditions as Low pressure moves in close or over the UK.

[Rollo]

From a personal point of view I am off for 3days golf to Peebles next Tuesday and it looks distinctly unsettled-that sort of flabby low meandering just to the west does not auger well for much dry weather but hey ho at least there will not be much wind."

[VillagePlank]

It seems to me that everything is up for grabs here. Here's the coldest of the GEFS run, with the hottest and the average plotted for good measure:

Looks to me like good potential for a (relative) warm up from 1st July to 5th, with a rapid cooldown to the 7th, but after that all bets are off, I'm afraid.

Edited June 29, 2011 by Sparticle

[johnholmes]

that looks a good assessment to me of what the 850 models are currently showing-nice idea to plot the max, min and average.

[Downpour]

It seems to me that everything is up for grabs here. Here's the coldest of the GEFS run, with the hottest and the average plotted for good measure:

Looks to me like good potential for a (relative) warm up from 1st July to 5th, with a rapid cooldown to the 7th, but after that all bets are off, I'm afraid.

Hints of a renewed warm-up again then from the evening of the 7th. Of course it's FI and may not verify but at the moment we seem (in the South at least) to be stuck in a fairly pleasing pattern where midweek is cooler and the weekends more summery. I'm touching wood as I'm writing this!

Edited June 29, 2011 by Downpour

[Glacier Point]

the onset of the upper trough for next week looks delayed a bit on the latest runs. i think next week may not be as obvious as it looked yesterday.

and continued interest from the ECM / UKM and now GFS tropical modelling developing some amplitude to the MJO in week 2 forecasts somewhere in the Indian Ocean / Arabian Sea.

Clearly the trend over the last few days has been to develop something of a strong convective signal (which is a stark contrast to where we are now) in the extended range. I suspect this is going to muddy the waters of NWP considerably for day 10+ forecasts.

IF we get a strong convective signal develop (and that still is a big if), the background global wind oscillation signal should see a strong positive tendency in angular momentum and large Asian mountain torque event, with composites for phase 3/4 looking appropriate, which would go against the Scandinavia trough idea. That would also mean that the longwave trough programmed next week would have to lift out or pull back west.

[shedhead]

As I said at this time yesterday, the way you view the glass (half full or half empty) very much dictates what conclusions you draw from the latest runs. Few would argue that that the overall pattern is not one that is condusive to

searing heat, but at the same time I'd expect the period from now until Monday to see well below average rainfall, slightly above average sunshine and slightly above average temperatures, which to my mind if far from a

disaster. Again as I said yesterday perhaps our level of expectation is a little too high here, yes if we'd paid for a family holiday to Crete and had this forecast we might have the right to expect better, but as we are sat on a small

island in the cold N Atlantic we should probably accept what's coming across the next 4 or 5 days with a little more appreciation, because as we know in reality it could be significantly worse. As for next week much the same is

true in my opinion, OK there looks like being more in the way of rain around as the upper trough becomes slow moving close by, but I see nothing to suggest widespread doom and gloom there either, with all areas still enjoying

some decent spells of sunshine.

[VillagePlank]

that looks a good assessment to me of what the 850 models are currently showing-nice idea to plot the max, min and average.

I'm wondering whether we can actually define FI from a chart like this: Consider my great big black thing:

That, it would seem to me, to be the point where NWP forecasts reliability becomes less than 50% - ie where the Max, and Min diverge ... on the basis of the premise that before the line the ups and downs are broadly the same, it's a question of magnitude, but after that line - there is no similarity.

Just a thought ...

[Thundery wintry showers]

Today and tomorrow continue to look showery for many, but all parts will also have plenty of sunshine. The main focus of intense shower activity has shifted a little on the latest outputs, being concentrated in the east generally rather than the NE. The models continue to delay the onset of the Atlantic low so Friday and much of the weekend look increasingly like being sunny for most, and rather on the cool side due mainly to low overnight minima. A scattering of showers is likely but I don't think there will be many of them about on Friday with a 1025mb high overhead.

Some divergence in the long-term. I can see that ECM keeps the Atlantic very strong, with potential wet and windy weather, while the GFS goes for a weaker Atlantic and a shallow low complex over the British Isles which would probably be more showery/thundery in nature, and UKMO maintains high pressure close by on Monday. A pretty disturbed outlook is likely but there are large disagreements on the specifics and again suspicions that maybe the models have low pressure centred too far east.

[Alex]

It seems to me that the trough is being delayed of its progression eastwards every run and this allows a few ridges to be spun towards the UK however closest to the trough i.e. The northwest of UK i.e. Northern Island and western scotland can expect more unsettled weather. So up until Tuesday it now looks generally settled however a shower or two can't be ruled out.

[Wilks]

I'm touching wood as I'm writing this!

Wrong forum for that!

Sorry I just couldn't resist.

[Downpour]

Wrong forum for that!

Sorry I just couldn't resist.

I walked into that one I guess!

[johnholmes]

I'm wondering whether we can actually define FI from a chart like this: Consider my great big black thing:

That, it would seem to me, to be the point where NWP forecasts reliability becomes less than 50% - ie where the Max, and Min diverge ... on the basis of the premise that before the line the ups and downs are broadly the same, it's a question of magnitude, but after that line - there is no similarity.

Just a thought ...

I'd agree with that assessment of that model run