Model Output Discussion

[chapmanslade]

it might be more accurate to describe it as a less warm spell rather than a cool one; only for a couple of days do many places look like being in that category but then our doomsayers will no doubt show us otherwise!

Another thing to consider with maximum temperatures is the soil condition. Certainly here, and for many parts of central southern England the soil is very warm and DRY which is one of the factors influencing the heat. Last summer was just the opposite with wet cool soil holding back the temperatures (together with the lousy weather). 30C in June is pretty unusual as normally we need the drier conditions to establish before we get the real heat in July and August.

I can see the real potential for drought conditions here in the south soon as the recent 'promised' rainfall hasn't materialised, and we only managed 21mm in June. If another Atlantic trough develops in a week or so then it will be largely dry through till August.

[Derp Patrol]

Tell me about dry.. only rain we have had in the last 3 weeks and maybe more was from a thunderstorm, my lawn is almost totally brown

[Cloud 10]

I can see the real potential for drought conditions here in the south soon as the recent 'promised' rainfall hasn't materialised, and we only managed 21mm in June. If another Atlantic trough develops in a week or so then it will be largely dry through till August.

Quite a contrast here,108mm of rain recorded in june,in the meantime the gfs wants to push the jet south. <_<

deja-vu summer 2008?

[Eugene]

Wow i see a pool of sub 528 dam moving southwards on GFS 06Z FI, must be unprecedented for only July, some amazing persistent strong HP over greenland, amazing as in July usually HP belts move up from the south over the UK not like on todays output with strong northerly blocking and a southerly tracking jet which should be heading for greenland not for us in July

Can't see anything but a stinker of July coming up, at least people who can't hack four days hot spells will be happy i guess. <_<

[Costa Del Fal]

Wow i see a pool of sub 528 dam moving southwards on GFS 06Z FI, must be unprecedented for only July, some amazing persistent strong HP over greenland, amazing as in July usually HP belts move up from the south over the UK not like on todays output with strong northerly blocking and a southerly tracking jet which should be heading for greenland not for us in July :o

Can't see anything but a stinker of July coming up, at least people who can't hack four days hot spells will be happy i guess.

Oh dear, Like i said yesterday, Winter will soon be here.

The GFS is overdoing things at the moment i think. The temperatures are a very good example. Expect them to be some 3-5c more than what it says.

[Scorcher]

Doesn't look that bad to me over the coming week, and the countryfile forecast was also reasonable. Yes there will be showers but a lot of places will miss them and temperatures look close to average. Then perhaps signs of something a bit more settled for the weekend? I certainly can't see this 'stinker' of a July that is apparently on the cards.

[chionomaniac]

I would agree entirely with GP with how difficult it is presently in putting out a medium range forecast. The current MJO tropical convection pattern leaves us with no clear signal with which to base a forecast on and until this becomes clearer then it is going to prove difficult to suggest where we go from here.

As GP intimated this morning the MJO forecast leaves no coherent signal.

http://www.cpc.ncep.noaa.gov/products/peop..._CFSOP_GEFS.gif

The MJO has today shown the first sign of reversing in its weak amplitude phase.

http://www.bom.gov.au/bmrc/clfor/cfstaff/m...Last40days.html

With forecasts suggesting that the MJO may return to phase 1 or 2 it is worth looking at the 500 hPa anomaly charts for these phases in July to see what these suggest.

Phase 1

Here we see Atlantic based weather dominating with the UK under the influence of a trough.

Phase 2

No clear pressure signal here.

My guess is that we may end up somewhere in between these two in a weeks time - not particularly brilliant summer weather with a weak trough never far away that may last a little longer than initially thought.

Looking further ahead it may be up to a month before MJO convection becomes organised again going on the CFS OLR forecast.

http://www.cpc.ncep.noaa.gov/products/peop...castolr_cfs.gif

From these by week 4 we have stronger western Pacific convection which would leave the MJO orbiting in phases 6-7. The current pattern for Phase 6 in August is similar to the recent hot spell we have just had.

It may just take a lot of luck to get there with mixed weather in the meantime!

All this highly speculative until the tropical convection sorts itself out and we know where the MJO is likely to be heading. Last month there was a far higher confidence on the likely outcome which culminated in the end of month hot spell.

c

Edit - it is worth also mentioning that if the MJO orbits into phase 3 ( not currently forecast but still a distinct possibilty) then the 500hPa chart is as follows:

Something akin to a northerly positioned Azores ridge elongating over the UK - not bad at all!

Edited July 5, 2009 by chionomaniac

[Nick F]

Very informative post Chionomaniac. One thing that looks likely through the coming week and beyond is that the jet is going to take a hike southwards across France, and as it will be tending to remain fairly flat in flow, it is not really going to allow ridges to build to bring any heat back to us for the forseeable future. At least it generally doesn't look to be too much of a washout - though most days over next 7 days look to have diurnal shower activity somewhere across the UK with LP nearby and low heights.

[ribster]

Doesn't look that bad to me over the coming week, and the countryfile forecast was also reasonable. Yes there will be showers but a lot of places will miss them and temperatures look close to average. Then perhaps signs of something a bit more settled for the weekend? I certainly can't see this 'stinker' of a July that is apparently on the cards.

Indeed, although every day that ticks by of showers and close to average temperatures suits me just fine. And although there may be no signs of a 'stinker' there aren't any of a heatwave either.

[Frosty.]

If the models are to be believed, there is no sign of another heatwave any time soon and overall it looks moderately warm at best and decidedly chilly at worst depending on location as always. Showery troughs and weak ridges seems likely over the next few weeks and slow moving showers in FI as winds fall light but during the next five days we pick up a fresh N'ly in eastern areas with a big drop in temperature from the last week, not exactly BBQ weather ahead of us.

Edited July 5, 2009 by Frosty039

[Glacier Point]

I would agree entirely with GP with how difficult it is presently in putting out a medium range forecast.

With forecasts suggesting that the MJO may return to phase 1 or 2 it is worth looking at the 500 hPa anomaly charts for these phases in July to see what these suggest.

Looking further ahead it may be up to a month before MJO convection becomes organised again going on the CFS OLR forecast.

http://www.cpc.ncep.noaa.gov/products/peop...castolr_cfs.gif

From these by week 4 we have stronger western Pacific convection which would leave the MJO orbiting in phases 6-7. The current pattern for Phase 6 in August is similar to the recent hot spell we have just had.

That week 3 and 4 forecast takes my eye - +ve OLR centred over Indian Ocean, -ve OLR over Pacific = GWO and MJO forcing towards strong Atlantic trough. Is heatwave part duex still on the cards ?

Worth noting that positive mountain torque as continued and the GWO heads towards phase 4 - large question mark of outputs beyond t120 at the moment I think.

http://www.cdc.noaa.gov/map/images/reanaly...ltaum.90day.gif

http://www.cdc.noaa.gov/map/images/reanaly...d.sig.90day.gif

http://www.cdc.noaa.gov/map/images/gcm/gwo_40d.gif

Edited July 5, 2009 by Glacier Point

[chionomaniac]

That week 3 and 4 forecast takes my eye - +ve OLR centred over Indian Ocean, -ve OLR over Pacific = GWO and MJO forcing towards strong Atlantic trough. Is heatwave part duex still on the cards ?

Worth noting that positive mountain torque as continued and the GWO heads towards phase 4 - large question mark of outputs beyond t120 at the moment I think.

http://www.cdc.noaa.gov/map/images/reanaly...ltaum.90day.gif

http://www.cdc.noaa.gov/map/images/reanaly...d.sig.90day.gif

http://www.cdc.noaa.gov/map/images/gcm/gwo_40d.gif

The MJO 2 week verification forecasts are not exactly inspiring. However I could still envisage the tropical convection pattern by weeks 3-4 if not sooner, looking at that positive mountain torque event. Do you think this could enhance and speed up any dateline tropical convection?

[fine wine]

I have noticed with the GFS runs that the LP progged to the north east of the UK next week is being placed 20-30 miles further away from the British Isles with each run. This often occurs with model outputs during the winter (the cols shot being pushed East) but not often during the summer.

EDIT : not on this run!

Edited July 5, 2009 by fine wine

[Thundery wintry showers]

The sunshine-and-showers regime is unlikely to continue beyond Wednesday, as by Thursday we will have a modified northerly regime, the polar air mixing with warmer, stable air from Scandinavia. Therefore the weather for Thursday and Friday is likely to be cool and cloudy for eastern areas, perhaps with some rain at times especially in the northeast and in East Anglia. However, particularly if the low moves well out into the North Sea, western areas should have long sunny periods.

[Glacier Point]

The MJO 2 week verification forecasts are not exactly inspiring. However I could still envisage the tropical convection pattern by weeks 3-4 if not sooner, looking at that positive mountain torque event. Do you think this could enhance and speed up any dateline tropical convection?

It is unlikely to have any impact on the tropics as the torque is an extratropical event. What it will likely do though is destructively interfere with any negative zonal wind signal coming out of the western Indian Ocean.

NWP this morning, especially Euro models, picks up the signal for pressure to lower in the Atlantic. GEM is also along these lines and disrupts the longwave trough, the ECM moves the trough through though day 10.

Edited July 6, 2009 by Glacier Point

[J07]

Wednesday may be a a bit chilly compared to recent times. Looks quite cloudy and 850hPa temperatures 6C at most.

Interesting how the EC really spins up a low in the North Sea further out and then piles it into Denmark.

A flirtation far into the future with an Atlantic trough, but it moves quite quickly eastward so any warm sunny weather would be quite fleeting.

[William of Walworth]

Sometimes I feel quite downbeat about my understanding levels

In the Netweather general forecast from 9 am today (Monday) we have this :

Looking ahead toward Tuesday, the showery setup stays with us, but later in the week, high pressure is likely to ridge up from the southwest though, so that should bring some finer, drier weather into southern and central parts at least.

Yet in recent posts on this thread we have almost no mention of the bolded part ......

And some of the runs I've seen show little obvious signs of it either.

Help me out folks, HP coming in or not?

[johnholmes]

as the headline says mate

brief but its there, look at the Fax chart T+120

as to beyond we have to wait and see; read the reliable mposters for any forecast is the comment I would make-you must know who they are by now!

Edited July 6, 2009 by johnholmes

[Snowyowl9]

The HP will suite me fine just for 2 dry days later this week.

After that it looks like we`re back to S-ly tracking lows, which is a better postion to to bring heavy thundery downpours in different places to today.

http://91.121.93.17/pics/Rtavn1501.png

[BLAST FROM THE PAST]

My own take on the situation remains the same. A general reloading pattern with initial troughing over Scandi giving way as Northern blocking takes hold squeezing LPs on souhterly track and we end up with similar to what we had ie northern blocking mainly to east quadrant and stalled LPs to our SW or being sent into Europe. Was the recent heat 'faux' heat? I didn't see it as a widespread hot hot episode. I think mid to high 20s likely latter July [locally hot] but as hinted at LP from S / SW may play bigger part this time and some serious storm potential figured for last few days of July [28-31] as breakdown arrives. For what its worth August then to follow similar pattern. July CET of slightly above average looks on the money.

BFTP

Edited July 6, 2009 by BLAST FROM THE PAST

[Eugene]

Poor output again tonight i`m sure we're all used to it now, just been browsing through the ensembles on meteociel and next week is looking extremely poor indeed with atlantic lows coming at us one after another, things are so bad TWO model chat is dead and they have reverted to talking of winter 2009/10 prospects in early July<LOL wow even i feel early July is way too early to be thinking of winter, i`m looking ahead to late July into August for maybe some improvement, it must get better because it really can't get much worse than the outlook for the next two weeks.

[ribster]

Man, how do you do it? EVERY single post is just plain pessimism and to be quite honest with you, you don't have a clue what's going on. People say don't respond to your posts but I'm just absolutely baffled at what you say. There are experts on here who say that towards the end of this month things should warm up considerably but also the threat of thundery weather exists.

Eugene, you must know by now that your posts are just not helping the model output discussion, your view is not balanced, it's just one sided. For if only one day out of the month was cooler than average and the rest were very warm or hot, you would be talking about the cooler day and then start saying that it proves this year will be another 2007.

I wish someone would ban you from here. Where the hell is the ignore option??

Experts? Where? Last time I checked this was a forum for amateurs, albeit some more knowledgeable than others. As for his posts helping the model discussion, I wasn't aware that was what they were meant to do. He has just as much right to post as anyone else on here, perhaps you ought to be banned with outbursts like that!

[tinybill]

http://www.meteociel.fr/modeles/gefs_carte...de=0&mode=2

i must carefully what i say looks not to good up to 14 July at the moment it will warm up I'm on Holiday a week later for 2 weeks one of I'm on the isle of white for a week!!!

Edited July 6, 2009 by tinybill

[Snowaddict]

Poor output again tonight i`m sure we're all used to it now, just been browsing through the ensembles on meteociel and next week is looking extremely poor indeed with atlantic lows coming at us one after another, things are so bad TWO model chat is dead and they have reverted to talking of winter 2009/10 prospects in early July<LOL wow even i feel early July is way too early to be thinking of winter, i`m looking ahead to late July into August for maybe some improvement, it must get better because it really can't get much worse than the outlook for the next two weeks.

Good Evening Eugene,

It was myself who was posting about long term prospects on TWO after another poster had remarked about the re-appearance of the 528dam pool to the far north in the extended range guidance. As to it being far too early to discuss prospects for Winter 2009/2010, I simply don't agree with that & the UKMO will be issuing their NAO index outlook for Winter 2009/10 very shortly. I don't know the exact date, but perhaps JH could help on this?

Anyway, whilst I do like wintry weather I also recognise output for what it's for when it occurs. Whilst there is no mistaking the fact that the coming 5 - 7 days at least won't be near as warm as it has been recently, conditions are not going to be horrific or anything like it. As an upper ridge approaches from the west into Wednesday and Thursday, conditions will likely become fairly pleasant, especially further south across the UK, with maxima still possibly reaching 20C. I'm sure that a return to less humid fresher conditions is a welcomed prospect by those who suffer from respiratory difficulties or who simply don't like the exceptionally warm and humid conditions that have been experienced recently.

To put it nicely, you endeavour to always portray the worst possible slant on the outlook available given that it is currently summer. It's all down to personal opinion as to how the outlook is shaping up. For example, there were several t-storms over Ireland today, although it was much fresher than recently. Now many people may not have liked the cooler conditions, but several would have liked the t-storms (within reason and observing safety) & therefore that would not have been a bad outlook to them or anything of the sort.

The point I am trying to make is that your posting recently seems to be wholly subjective and not reflective of the general guidance available. You distort the longevity of any settled or warmer patterns and seem to always take a negative slant upon the outlook.

For example, 850mb temps will increase towards the coming weekend & whilst it certainly won't be completely settled by any means, conditions will become somewhat warmer once more, possibly rather more humid again.

So please take a more objective approach when posting Eugene as it would be very helpful to many members.

SA

Edited July 6, 2009 by Snowaddict

[La Bise]

Is there such a thing as "faux heat" then?