Model Output Discussion

[mushymanrob]

no more 30c?... more then possible, there might be just over half of summer to go but high temps are by no means a 'given'. in 2007 i only had 25c+ three times all summer, and no 30c's.

the 06z isnt as good a looking run as the 00z, and fi is dominated by the azores enemy, anchoring itself to our west/southwest and feeding us muggy atlantic weather. whilst this might well be quite warm and with little rain, i fear cloud will spoil anything nice happening and lead us to a benign nothingness of a summer. ok it could be worse, it could be cooler and wetter, but hints that we might get at least one decent hot spell (longer then the previous few hours!) seem to be sparse. the mjo forecast is still for it to move towards phase two which we are told (well, i read! lol) by chionomaniac and others that this would be more favourable for settled anticyclonic driven weather especially in the south and east. the ukmo's 16-30 dayer though doesnt support this possibility if its suggesting cooler/average conditions. so... nothing to get excited about, nothing to get too depressed about, but the clock is ticking on this summer and i fear another one without a decent hot sunny period is slowly becoming more of a reality.

[Duane S.]

Medium outlook fairly benign, cloudy, showers, average weather!

However I feel that a Euro high is 'trying' to take hold but being canceled out by other atmospheric factors, lose one or two of these and very quickly and almost out of nowhere we will be under a very warm feed again.

[Summer Sun]

GFS FI show HP slowly taking hold from Sunday, with plently of LP over Greenland, HP is with us right to the end of FI, maybe the second half of July will finally bring summer?

[Eugene]

maybe the second half of July will finally bring summer?

lol its been summer for weeks, 26C today in parts.

LP spell not going to deliver much rain here before pressure rises

Edited July 4, 2011 by Eugene

[bluearmy]

some perspective on the gfs ens for next week shows fair support on the spreads for shortwave incusrions into northern britain despite a favourable looking ens mean. a n/s split looks very much on the cards.

[Upgrade]

all in all it's not been bad in the south east, and the charts look as if this north / south split will continue. some rain in the south, yes, but overall quite pleasant.

[Costa Del Fal]

Surprise surprise what was looking a rather poor week this week is now not too bad with showers at times before High pressure probably builds in by the weekend. FI is showing quite a trend now in which the Greenland High finally goes in the Bin with low pressure towards the region and High pressure with warm to very warm air affecting the UK. Very pleased with the last few GFS runs and so i just hope it stays like that!

Far from a washout this week. Some showers, a few thundery and average temperatures with summer possibly returning by the weekend.

[Summer Sun]

ECM also continues to agree with high pressure returning as early as Saturday, but the full effects of it could be felt by Monday as it spreads across the country, also those high's across Greenland seem to be disappearing quite quickly as the week progresses

http://www.wetterzentrale.de/pics/Recm1201.gif

http://www.wetterzen...cs/Recm1441.gif

http://www.wetterzen...cs/Recm2161.gif

http://www.wetterzen...cs/Recm2401.gif

I expect further upgrades on the ECM throughout the week, and with that blocking over Greenland we could see a decent warm spell longer than 3 or 4 day's, but maybe not wall to wall sun if we get a westerly or south westerly set-up.

Edited July 4, 2011 by Gavin D

[Gibby]

UKMO shows Low pressure dominant over the UK from now until the end of its run centred over Northern regions from Wednesday/Thursday on. After a band of rain moves east over the UK tomorrow in association with an occluded front the weather turns showery for 4 or 5 days with heavy showers or even more prolonged rain at times and temperatures near normal at best in winds that will be between SW and NW.

GFS is similar up to and over the weekend before a slow rise of pressure slowly but surely brings drier and more settled conditions into the UK first in the south but in the north too by the end of the run. Innitially though weak troughs running east into the high pressure will mean some cloudier periods with light rain before a return to pleasant conditions again soon after. Towards the last days of the run a UK based high pressure brings warm and settled conditions for all as it drifts slowly east.

ECM follows the UKMO route with showery Low pressure dominant until Sunday following tomorrow's occluded frontal rain. The final days of the run then show the showery weather slowly giving way to slightly more settled conditions though weak frontal areas could still deliver a little rain chiefly in the north and certainly a lot of cloud in the gentle westerly drift. Temperatures would recover somewhat though.

A showery 4 or 5 days is likely after tomorrows rain supported by all three models. Thereafter a slow improvement looks likely as pressure gradually rises from the SW. Cloud amounts could still be large though as the flow is still shown to blow from the Atlantic with temperatures recovering slowly. Frontal systems would still deliver some rain to the north especially at times.

[Eugene]

http://www.wetterzentrale.de/pics/Recm1681.gif - Cant see it being as sultry as today with a cool ish northerly, you want a very slack southerly flow like today for proper barmy summer warmth not cool northerly followed by toppling ridge.

[ribster]

GFS FI show HP slowly taking hold from Sunday, with plently of LP over Greenland, HP is with us right to the end of FI, maybe the second half of July will finally bring summer?

You seem to keep banging on about LP over Greenland being the answer to our weather prayers, which it isn't. As some of the more learned members on here have tried to point out (namely JH and TWS amongst others), low pressure there, and high pressure here does not equal dry, warm and settled conditions, there are so many factors at play, not to mention the position of these systems, and hence the direction of windflow.

[Thundery wintry showers]

Indeed, check out this chart from the infamous July of 1954 with a 990mb low over Greenland:

http://www.wetterzentrale.de/archive/ra/1954/Rrea00119540717.gif

[Slowpoke]

You seem to keep banging on about LP over Greenland being the answer to our weather prayers, which it isn't. As some of the more learned members on here have tried to point out (namely JH and TWS amongst others), low pressure there, and high pressure here does not equal dry, warm and settled conditions, there are so many factors at play, not to mention the position of these systems, and hence the direction of windflow.

He hasn't said that it would give us dry, warm and settled conditions. All he has said is it could be the sign of improvements...

[feb1991blizzard]

You seem to keep banging on about LP over Greenland being the answer to our weather prayers, which it isn't. As some of the more learned members on here have tried to point out (namely JH and TWS amongst others), low pressure there, and high pressure here does not equal dry, warm and settled conditions, there are so many factors at play, not to mention the position of these systems, and hence the direction of windflow.

Indeed. Its the same as some people in winter talking about the scandinavian high being the holy Grail, its only the holy grail if it orientates favourably, which the one last february did not, and even then the cold pooling needs to be in the right place to tap into, the atlantic being weak and lower heights to the south are also preferable. SLP is a very important factor in weather, probably the single biggest factor but there a lot of other variables that can make a big difference.

Edited July 4, 2011 by feb1991blizzard

[Uncle_Barty]

High pressure, or to be more exact, high 500mb heights over Greenland usually has a detrimental effect on summer prospects here, but you can get poor summer weather here without those heights over Greenland, as July 1988 shows.

However, the lowering of heights over Greenland after a protracted spell can herald a pattern change which will perhaps lead to an improvement in the weather over the UK generally.

Probably why some (including myself) are very keen to see those heights drop.

[johnholmes]

ECM also continues to agree with high pressure returning as early as Saturday, but the full effects of it could be felt by Monday as it spreads across the country, also those high's across Greenland seem to be disappearing quite quickly as the week progresses

http://www.wetterzen...cs/Recm1201.gif

http://www.wetterzen...cs/Recm1441.gif

http://www.wetterzen...cs/Recm2161.gif

http://www.wetterzen...cs/Recm2401.gif

I expect further upgrades on the ECM throughout the week, and with that blocking over Greenland we could see a decent warm spell longer than 3 or 4 day's, but maybe not wall to wall sun if we get a westerly or south westerly set-up.

and this

GFS FI show HP slowly taking hold from Sunday, with plently of LP over Greenland, HP is with us right to the end of FI, maybe the second half of July will finally bring summer?

Gavin, I love your enthusiasm and that you post links to your views, but can we have a bit more consistency in your views please?

Is it high pressure staying over Greenland or is it low pressure taking over in your view?

Is it true that hp over Greenland will lead to a west or south westerly set up over the UK?

I'm confused as to just what you do mean!

[Summer Sun]

Well how clear do i need to be?

I wrote

The high's across Greenland seem to be disappearing quite quickly- Surely you can work out that with the high's going Low pressure will be taking over.

Is it true that hp over Greenland will lead to a west or south westerly set up over the UK

Have you not read what Gibby also posted?

Thereafter a slow improvement looks likely as pressure gradually rises from the SW. Cloud amounts could still be large though as the flow is still shown to blow from the Atlantic with temperatures recovering slowly.

At present the set-up is showing to be coming from the Atlantic hense why i said a westerly or south westerly, if things change then i would post that.

How much more clear can i be?

[bluearmy]

Well how clear do i need to be?

I wrote

The high's across Greenland seem to be disappearing quite quickly- Surely you can work out that with the high's going Low pressure will be taking over.

Is it true that hp over Greenland will lead to a west or south westerly set up over the UK

Have you not read what Gibby also posted?

Thereafter a slow improvement looks likely as pressure gradually rises from the SW. Cloud amounts could still be large though as the flow is still shown to blow from the Atlantic with temperatures recovering slowly.

At present the set-up is showing to be coming from the Atlantic hense why i said a westerly or south westerly, if things change then i would post that.

How much more clear can i be?

gavin - i think you confused jh with your ref that ' with that blocking over Greenland we could see a decent warm spell longer than 3 or 4 day's,'. i think you meant to say 'leaving' instead of 'over' ????

[johnholmes]

never mind Gavin, Can I just ask politely please read what you had posted-the clue is in there, I'm happy to chat via pm if you wish?

[Thundery wintry showers]

I think the reliance on low heights over Greenland is pretty much an "all or nothing" thing. From around T+144 on the model outputs, a fall in pressure over Greenland and a resurgent jet could easily push us into a pattern more similar to Julys 1954/1988. Or it could shift the jet north and leave us with high pressure. Or it could leave us with a non-descript dry but cloudy westerly on the northern flank of high pressure from the Azores, which would heavily polarise opinion.

For a pattern change that doesn't involve a cool cloudy westerly we really need to be looking for high pressure to build north and east and/or for the jet to remain pretty slow (which it is at the moment, hence the persistence of a weak zone of high pressure over the last few days, and the slow moving showery low progged for the next few days). As long as we have a weak jet or a lot of high pressure close by we shouldn't end up stuck in a cool cloudy windy changeable westerly type.

[PubliusEnigma]

Surprise surprise what was looking a rather poor week this week is now not too bad with showers at times before High pressure probably builds in by the weekend. FI is showing quite a trend now in which the Greenland High finally goes in the Bin with low pressure towards the region and High pressure with warm to very warm air affecting the UK. Very pleased with the last few GFS runs and so i just hope it stays like that!

Far from a washout this week. Some showers, a few thundery and average temperatures with summer possibly returning by the weekend.

You'd better ring in to the met office to say you've heard summer is just 5 days away from returning then, because their 6-15

and 16-30 dayers paint generally below average temps, and sunshine.. What can you see that they cant ?

[Geordiesnow]

Surprise surprise what was looking a rather poor week this week is now not too bad with showers at times before High pressure probably builds in by the weekend. FI is showing quite a trend now in which the Greenland High finally goes in the Bin with low pressure towards the region and High pressure with warm to very warm air affecting the UK. Very pleased with the last few GFS runs and so i just hope it stays like that!

Far from a washout this week. Some showers, a few thundery and average temperatures with summer possibly returning by the weekend.

Not quite sure if I agree with your assesment of this weeks weather, too me it looks we are on course for a very unsettled week with showers or longer spells of rain. You say its far from a washout but Wednesday looks like it will be a miserable day for most of Scotland with persistant rain and cool temperatures. Elsewhere we should see convective showers so sunshine in between is likely but it certainly will be a poor week in terms of warmth and dry weather but an interesting week for convective lovers like you and I are Luke.

So its an "poor" outlook for summer but an interesting one weatherwise potentially.

[snowlover2009]

The models showing our unsettled potentially thundery weather for this week and thereafter an improving situation a slow improvement, with a potential does of more summer weather, whether it be dry or warm. To me this summer is shaping up very different to 2007 to 2009, 2010 not too bad but a declining summer none the less. IMO the rest of summer will be a better version of summer 2010 for July onwards, but not perfect, not a classic, but warmer, August last year was quite cool.

But anyway, just for fun, for those who are interested, here are the cfs charts for summer and the rest of year, if you like northern blocking and cold you are in for a treat, people say they are as useful as chocolate fireguards and change, but they have been consistent for the Autumn period. They have changed a lot this year, more than last year, but the general pattern of what they are predicting is the same, with blocking to the north, but the strongest blocking etc has changed. Once again November and December are eye candy, but it is still early to say what will happen, even though I have my own thoughts.

http://www.cpc.ncep.noaa.gov/products/people/wwang/cfs_fcst/images2/glbz700Mon.gif

http://www.cpc.ncep.noaa.gov/products/people/wwang/cfs_fcst/images3/glbz700Mon.gif

I found two links, both different but show vaguely the same scenario dont know why there is two.

[feb1991blizzard]

The models showing our unsettled potentially thundery weather for this week and thereafter an improving situation a slow improvement, with a potential does of more summer weather, whether it be dry or warm. To me this summer is shaping up very different to 2007 to 2009, 2010 not too bad but a declining summer none the less. IMO the rest of summer will be a better version of summer 2010 for July onwards, but not perfect, not a classic, but warmer, August last year was quite cool.

But anyway, just for fun, for those who are interested, here are the cfs charts for summer and the rest of year, if you like northern blocking and cold you are in for a treat, people say they are as useful as chocolate fireguards and change, but they have been consistent for the Autumn period. They have changed a lot this year, more than last year, but the general pattern of what they are predicting is the same, with blocking to the north, but the strongest blocking etc has changed. Once again November and December are eye candy, but it is still early to say what will happen, even though I have my own thoughts.

http://www.cpc.ncep..../glbz700Mon.gif

http://www.cpc.ncep..../glbz700Mon.gif

I found two links, both different but show vaguely the same scenario dont know why there is two.

Yes a decent chart for december, lets hope the shades of orange to the NW and the shades of blue over the continent start to deepen, denoting bigger anomalies on future runs, the chart for october could maybe see a repeat of October 2008.

The difference of the charts are different runs, the analysis data is taken from different dates.

[Costa Del Fal]

You'd better ring in to the met office to say you've heard summer is just 5 days away from returning then, because their 6-15

and 16-30 dayers paint generally below average temps, and sunshine.. What can you see that they cant ?

Their forecasts are not the king of the world. When i say summer, if anyone is thinking plus 30c, blazing sunshine and thunderstorms your totally wrong. The past few days have been what I call summer. Very pleasant temperatures, good amounts of sunshine (If a little cloudy at times here) and warm by night. Not saying the Met Office are wrong but to be just relying on that is not how to approach things in my opinion and if I am honest seems to be what you are doing.