Model Output Discussion

[johnholmes]

It does say on the Meto 6-15 dayer, above avg temps and generally unsettled but hints of more settled later. Looking at the models I would tend to agree but I would take a chance on some very warm weather developing next week.

to avoid mis quotes the full text

UK Outlook for Sunday 31 Jul 2011 to Tuesday 9 Aug 2011:

Sunday, mostly dry towards the southeast of the UK, but cloud and rain in the northwest will spread across most of the UK for Monday, weakening as it does so. An unsettled theme thereafter with England and Wales mostly affected with spells of rain or showers, locally heavy, but perhaps Scotland and Northern Ireland becoming somewhat drier and brighter for a while. Temperatures should be generally near normal or just below towards the north, and above normal towards the south. Towards the end of the week and for the remainder of the period, spells of rain or showers affect all parts of the UK at times with drier and brighter interludes in between. However, there may be signs of some more settled weather into southern areas later in the period.

[shedhead]

In my opinion the 06 GFS has started to nail the general pattern across the next 7-10 days, with high pressure slowly building across the UK and bringing a good deal of fine, warm and settled weather. Eventually though

low pressure will develop towards Biscay and track NE'wards, bringing a spell of unsettled, initially thundery weather, before pressure builds over Greenland, the jet tracks south and we return to our cooler July pattern.

Further evidence from the 12GFS that the 06 run was onto something, the only difference here is the breakdown from the south is a little quicker, something I suspect will continue across subsequent runs. Will be interesting to

see what ECM comes up with later, but it's fair to say UKMO are not really singing from the GFS hymnsheet at T+144hrs.

[Summer Sun]

Quite a big area of low pressure over Greenland in FI,

http://www.wetterzentrale.de/pics/Rtavn3121.png

http://www.wetterzentrale.de/pics/Rtavn3601.png

All in all GFS is quite good tonight just the odd day of low pressure, we've had worse updates.

[William of Walworth]

Quite a big area of low pressure over Greenland in FI,

http://www.wetterzen...s/Rtavn3121.png

http://www.wetterzen...s/Rtavn3601.png

All in all GFS is quite good tonight just the odd day of low pressure, we've had worse updates.

I'm even more than normally cautious about the FI part of this eye candy tease as we've already had so many flips followed by flops and some possible flaps too ...

Perhaps though those tending to ramp up the 'Jet to storm south after the 1st week of August' theme should remember that more LP-dominated evolutions are FI just as much, and themselves fluctuating plenty as well?

Thanks.

Edited July 26, 2011 by William of Walworth

[Mark Burton]

Looks like the nationwide warm up will begin this weekend and into next week,

http://www.wetterzen...s/Rtavn1261.png - Low to mid 20's

http://www.wetterzen...s/Rtavn1501.png - High 20's inland low 20's at the coast and Scotland

http://www.wetterzen...s/Rtavn1741.png - Mid 20's just about ever where, high teens for the far north of scotland

So once the weekend is here so it appears summer will arrive some nice BBQ weather on it's way.

You know, we were looking at charts almost identical to these, last week, for this week. Also, we were making the same comments " the warm up begins.........." So I for one won't believe it until it happens!

Edited July 26, 2011 by Mark Burton

[Costa Del Fal]

Quite a good GFS again, but each run is very topsy turvy in FI. At the very end its gone from a 1040 High in one run to around 1000 Low pressure the next in Greenland. :lol:

Remaining good for most for the rest of the week. With no disrespect and please treat this as an observation and not a dig at anyone but some have been mentioning this spell of weather isn't that good, it actually is for us here in the West. It may not be yet in the East but just because it isn't good there does not mean its bad for all! I thought id just raise this because Ive had the feeling that because its cloudy for the East this is a rubbish spell for everyone else because it isn't. The past 3 days have been excellent here. That aside most should experience good weather by the end of the week with perhaps a brief cloudier spell and a little rain Thursday/Friday. Temperatures nudging the mid 20's by the weekend seem quite possible and early next week but pressure lowering slightly allowing the risk of a little rain or perhaps thundery showers. Beyond mid next week is very uncertain however the CFS is keen on quite a fair bit of High pressure for most of August following a blip of low pressure between about the 5th - 15th but still nothing bad.

I do actually think August will be the most settled of the three true summer months with the end of August perhaps turning briefly hot but thats just my interpretation so feel free to disagree. :lol:

In summary, for most of us, quite a decent outlook.

Edited July 26, 2011 by Blizzards

[Mark Burton]

Quite a good GFS again, but each run is very topsy turvy in FI. At the very end its gone from a 1040 High in one run to around 1000 Low pressure the next. :lol:

Remaining good for most for the rest of the week. With no disrespect and please treat this as an observation and not a dig at anyone but some havementioning this spell of weather isn't that good, it actually is for us here in the West. It may not be yet in the East but just because it isn't good there does not mean its bad for all! I thought id just raise this because Ive had the feeling that because its cloudy for the East this is a rubbish spell for everyone else because it isn't. The past 3 days have been excellent here. That aside most should experience good weather by the end of the week with perhaps a brief cloudier spell and a little rain Thursday/Friday. Temperatures nudging the mid 20's by the weekend seem quite possible and early next week but pressure lowering slightly allowing the risk of a little rain or perhaps thundery showers. Beyond mid next week is very uncertain however the CFS is keen on quite a fair bit of High pressure for most of August following a blip of low pressure between about the 5th - 15th but still nothing bad.

I do actually think August will be the most settled of the three true summer months with the end of August perhaps turning briefly hot but thats just my interpretation so feel free to disagree. :lol:

In summary, for most of us, quite a decent outlook.

Nice summary Blizzards - glad you have good weather where you are! I'm about as far East as you can get (Great Yarmouth) and it's not good. Thick grey cloud with occasional light drizzle and cool Temps. Hopefully our warm up begins tomorrow............. to 19C

[PubliusEnigma]

You know, we were looking at charts almost identical to these, last week, for this week. Also, we were making the same comments " the warm up begins.........." So I for one won't believe it until it happens!

This is the trouble with FI, the warm up always happens 7 days out, some people get fooled into forecasting based on it.

Its better to wait for the "high 20's 27 - 29oC to appear within T72 to be sure of this.. I cant see it happening just yet.

[TonyH]

Well its warm and sunny here, and elsewhere in the West, which is what the models suggested would happen (at times) this week.

Edited July 26, 2011 by Tonyh

[Gibby]

Tonights 12z GFS shows a ridge of high pressure across the UK with weak frontal troughs moving slowly east into it, weakening to insignificance by late Thursday. Despite a lot of cloud there would be some warm sunny spells inbetween for most places. Any rain would be restricted to the far west and North on Thursday. Over the weekend and into next week high pressure declines somewhat and allows weak Low pressure to move up from continental Europe bringing the risk of thundery showers in continuing rather warm conditions. Into the latter half of the run and Low pressure moves up from the SW over the UK before moving away NE and allowing a return of high pressure over the UK by the end of the run. This would translate into an unsettled spell with rain or showers for a while before warm and settled conditions return by the runs end.

UKMO tonight shows a ridge of high pressure maintaining dry and relatively warm weather for the next few days with large cloud amounts at times especially as a weak front moves east through Northern and Western areas on Thursday. Friday will see the remains of this front dissipate over England on Friday perhaps setting off the odd light shower here and there. Over the weekend and into the start of next week the model shows lowering pressure although with a slack atmosphere a lot of dry, warm and sometimes sunny weather would prevail although with time the risk of heavy, slow moving showers increases.

ECM shows another 3 or 4 days of relatively settled weather with some sunny intervals alternating with cloudier spells. It is shown to stay dry apart from a little rain from a weak Atlantic trough in the north and west on Thursday/Friday while the SE could see the odd shower also. as time passes from Sunday on pressure becomes slack with an unstable atmosphere the risk of showers increases although right out until the end of the run high pressure is shown ridging down from the North keeping things basically dry and relatively warm while the south may see a few showers at times close to Low pressure to the South and Southwest.

The basic pattern remains tonight as has been shown for a few runs past where fine weather with variable cloud cover and reasonably warm conditions is maintained for the foreseeable. However, as always there are exceptions and while many places would stay dry throughout from the synoptics shown both GFS and ECM offer support for shower development in places from the end of this coming weekend on as weak Low pressure comes into the mix especially in the south.

[Thundery wintry showers]

Quite a good GFS again, but each run is very topsy turvy in FI. At the very end its gone from a 1040 High in one run to around 1000 Low pressure the next in Greenland. :lol:

Remaining good for most for the rest of the week. With no disrespect and please treat this as an observation and not a dig at anyone but some have been mentioning this spell of weather isn't that good, it actually is for us here in the West. It may not be yet in the East but just because it isn't good there does not mean its bad for all! I thought id just raise this because Ive had the feeling that because its cloudy for the East this is a rubbish spell for everyone else because it isn't. The past 3 days have been excellent here.

I wasn't trying to come across that way- I was addressing the sweeping statements saying that we would all have plenty of fine warm dry settled weather to look forward to this week, a big improvement on the rest of July so far etc etc. It is sensitive to one's personal definitions of "fine", "good", "improvement" and "warm" (hence my dislike of those assessments as they are highly subjective) and in parts of the NE in particular, I would contend that dry, cloudy and cool would be a better description. For much of southern and western Britain, warm and sunny may be a fair description- these SW-NE splits are commonplace when we have a north-easterly flow.

Tomorrow is looking like it will be a warmer and sunnier version of today for most, though low cloud will probably hang on in some North Sea areas, and temperatures will still be no higher than average in the east, rising above in the west though. Thursday looks quite interesting for England with plenty of sunshine, temperatures widely around the mid 20s and a scattering of showers possibly breaking out ahead of the advancing frontal system, though I don't foresee thundery activity with relatively low convective available potential energy about.

The longer-term outlook looks pretty interesting- possibly thundery and quite hot with slack highs and troughs floating around, though it is doubtful whether those easterly and north-easterly winds will shift and provide some relief from the low cloud for North Sea areas. GFS shows this being the case, with high pressure transferring east over the weekend and resulting in warm sunny weather extending eastwards with it, but ECMWF keeps winds vectored between north and east throughout the run in eastern Scotland and England promoting a continuation of the cloudy skies in areas close to the North Sea. Away from the North Sea a pretty warm and sunny outlook with possible thundery showers is looking quite likely, though with considerable uncertainty attached.

[bluearmy]

Quite a big area of low pressure over Greenland in FI,

http://www.wetterzentrale.de/pics/Rtavn3121.png

http://www.wetterzentrale.de/pics/Rtavn3601.png

All in all GFS is quite good tonight just the odd day of low pressure, we've had worse updates.

another block is a strong probability gavin. i wouldnt place much faith in a run which drops heights over greenland beyond the middle of next week.

[Summer Sun]

another block is a strong probability Gavin. I wouldn't place much faith in a run which drops heights over Greenland beyond the middle of next week.

Yes a fair point, if we do get a block then it could play a big part for keeping August respectable.

Deep FI I know but this would be a good set-up for a northern blocking system,

http://www.wetterzentrale.de/pics/Rtavn3601.png

Back to a realistic time frame and apart from cloud this week things look very settled untill early next week when the south could see thunderstorms at times whilst the north stay's drier for once, then high pressure is shown to build once more.

[damianslaw]

A very slack pressure pattern with no dominant airmass is the theme for the next few days. In such set ups two things often happen -

- unstable air can quickly develop with shower activity occuring anywhere tnaks to sudden shallow low features and troughs which are notoriously difficult to forecast and

- strong heights eventually will build robustly somewhere.

Looking at the models they seem to be suggesting strong heights will be building to our north, meaning the jet will have nowhere to go but head southwards.

So lots of fine summery conditions, warm for many but nothing exceptional, staying preety dry aswell, but longer term lots of uncertainty with a strong chance of it turning showery and then possible either very unsettled or a cooler drier but cloudier theme. No signs of raging westerlies or southwesterlies, but also no signs of a heatwave, spanish plumes or heights building strongly to our south and east. This could turn out to be a notably cool summer...

[casparjack]

I wasn't trying to come across that way- I was addressing the sweeping statements saying that we would all have plenty of fine warm dry settled weather to look forward to this week, a big improvement on the rest of July so far etc etc. It is sensitive to one's personal definitions of "fine", "good", "improvement" and "warm" (hence my dislike of those assessments as they are highly subjective) and in parts of the NE in particular, I would contend that dry, cloudy and cool would be a better description. For much of southern and western Britain, warm and sunny may be a fair description- these SW-NE splits are commonplace when we have a north-easterly flow.

Tomorrow is looking like it will be a warmer and sunnier version of today for most, though low cloud will probably hang on in some North Sea areas, and temperatures will still be no higher than average in the east, rising above in the west though. Thursday looks quite interesting for England with plenty of sunshine, temperatures widely around the mid 20s and a scattering of showers possibly breaking out ahead of the advancing frontal system, though I don't foresee thundery activity with relatively low convective available potential energy about.

The longer-term outlook looks pretty interesting- possibly thundery and quite hot with slack highs and troughs floating around, though it is doubtful whether those easterly and north-easterly winds will shift and provide some relief from the low cloud for North Sea areas. GFS shows this being the case, with high pressure transferring east over the weekend and resulting in warm sunny weather extending eastwards with it, but ECMWF keeps winds vectored between north and east throughout the run in eastern Scotland and England promoting a continuation of the cloudy skies in areas close to the North Sea. Away from the North Sea a pretty warm and sunny outlook with possible thundery showers is looking quite likely, though with considerable uncertainty attached.

Hi there, I am a little surprised to read that you think tomorrow and Thursday will be generally sunnier than today, we had 5.8 hrs today, 95% of that before lunchtime, yet looking at the FAX charts for 12z tomorrow and Thursday, they suggest remnants of weak fronts hanging around across England and a cross reference with the MetO forecast for my area, Hereford being the nearest town they actually forecast for, predicts solid medium level cloud for the next three days, even the text is only just suggesting a few sunnier spells towards the Marches. I appreciate I don't have access to the GFS cloud prediction charts, but can they be that different?

[bluearmy]

Yes a fair point, if we do get a block then it could play a big part for keeping August respectable.

Deep FI I know but this would be a good set-up for a northern blocking system,

http://www.wetterzentrale.de/pics/Rtavn3601.png

Back to a realistic time frame and apart from cloud this week things look very settled untill early next week when the south could see thunderstorms at times whilst the north stay's drier for once, then high pressure is shown to build once more.

but that chart shows heights dropped over greeny. the ecm spreads show lower 850's working their way around an extension of greenland blocking to our nw - meeting a push ne of higher 850's out of spain in the dutch area. that may well promise settled conditions for us, though unlikely to be too warm, once the possible short burst of higher uppers comes through next week. given a strong greenland block, i reckon thats that scenario is the best option we have.

[thestixx]

I view this forum daily and have done for many years, gaining lots of insight along the way, but I'm getting really wound up by posts of FI charts from 1 run from 1 model, It's a waste of everyones time (in my opinion). RANT OVER

The fact we've got High pressure sniffing around the British Isles again after such a miserable June/Early July (here in Leeds) puts a huge smile on my face. I'm looking forward to the next few relatively settled days too, The sunshine felt very pleasant today. I've got a hunch that High pressure will be around for a while too....

Edited July 26, 2011 by thestixx

[reef]

How about we stick to the models instead of arguing?

Thanks.

[mushymanrob]

Well its warm and sunny here, and elsewhere in the West, which is what the models suggested would happen (at times) this week.

really?... we have been plagued by cloud, as has much of the eastern side of the uk, just as i expected...(bugger....i was hoping to be wrong) even now its really dull. even when the sun did come out it wasnt all that warm, you couldnt sit outside long in short sleeves..

...and the mess continues, i dont like messy synoptics as ive often moaned about. weak areas of both low and high pressure around the country often is cloudy, muggy, warm or cool, some rain some dry, in all a right smorgesboard (sp?) of weather types thatll suit some in favoured areas, but not others . i note the 10c isotherm 'upper' is still around the southeastern half of the country early next week, if this transpires itll either be smashing in any sun, or muggy and humid under any cloud ( i expect milky bright skies).

[TonyH]

Well it was fairly cloudy yesterday in my part of the midlands with some sunny spells but not a lot and it is cloudy again here this morning with the forecast to be for fairly cloudy skies so not wall to wall sunshine here

Indeed it was, but I am in west Wales

Some good sunny spells at times the rest of this week (after Tuesdays weak front) and into the weekend I had expected from studying the models, even in the Midlands.

[Gibby]

Good morning.

GFS this morning shows high pressure west of Britain with a light Northerly flow over the UK. the weather would remain basically fine up to and including the weekend with sunny spells mixed in with cloudier spells as weak troughs get mixed in the airflow giving the chance of a little drizzle or light showers tomorrow especially, and in the south on Friday. As we move into next week winds remain very light as the UK lies in an area of slack pressure gradients but with a fall of pressure from the south with time some showers are likely to breakout there by midweek. In the lower resolution end of the run pressure remains relatively high with no pressure system having overall control with dry, bright and warm weather winning out over the occasional thundery shower in the south for a while. The final frame shows a deep low pressure moving in from the NW.

UKMO shows a weak trough moving into Western and Northern Britain tonight and tomorrow with some light rain and drizzle there while the south and east stay dry and warm or very warm tomorrow. Friday sees the chance of some rain in the south as the remains of the trough interact with the warm air. The North would be dry then. Thereafter the UK is in nomansland with regard to pressure systems hence very light winds would persist with the chance of showers increasing as minor but subtle upper air disturbances meander around the UK with time.

ECM shows declining high pressure moving into the UK by the weekend with dry weather for most apart from the chance of drizzle in the North and West tomorrow and the odd shower in the South on Friday. Through next week pressure pressure falls somewhat with slack low pressure becoming established near southern and western regions with showers breaking out over the UK, some heavy with thunder. Winds would remain light throughout with temperatures occasionally above or at worst near the seasonal normal.

This morning shows the same pattern we've seen for several days now of relatively warm and settled conditions gradually becoming eroded by the risk of showers as pressure falls somewhat and small disturbances interact with the calm conditions over the UK. Some places as I indicated yesterday would stay dry throughout the term of the outputs while some may well see some heavy, thundery showers with time, especially but not exclusively in the south.

[shedhead]

As Gibby has indicated the models are a real dogs breakfast this morning, with the only certainty being uncertainty as we go into next week. What is becoming very clear though is a lengthy fine spell is looking less and less likely, but that said there should still be plenty of dry weather on offer until early next week, with temperatures more akin to what most would expect from the back end of July.

Edited July 27, 2011 by shedhead

[Costa Del Fal]

This mornings charts are little different to what we have seen over the past few days. That is a mostly dry and warm rest of this week after a little rain tomorrow and early Friday. Next week pressure drops slightly, still being mostly dry but now possibly very warm or even locally hot with the risk of some thundery showers. This is a perfect UK Summer pattern imo. There is little to complain about apart from perhaps Eastern cloud problems maybe.

[Thundery wintry showers]

Hi there, I am a little surprised to read that you think tomorrow and Thursday will be generally sunnier than today, we had 5.8 hrs today, 95% of that before lunchtime, yet looking at the FAX charts for 12z tomorrow and Thursday, they suggest remnants of weak fronts hanging around across England and a cross reference with the MetO forecast for my area, Hereford being the nearest town they actually forecast for, predicts solid medium level cloud for the next three days, even the text is only just suggesting a few sunnier spells towards the Marches. I appreciate I don't have access to the GFS cloud prediction charts, but can they be that different?

You may well be right, I think northern and central areas may generally be brighter than yesterday (though low cloud is still hanging on stubbornly here in Tyneside for example) but the southeast and possibly centre-south of England may end up cloudier.

Re. Backtrack's post, most of the complaining has been regarding cool cloudy conditions in eastern areas for this week. Next week is looking somewhat warmer and sunnier for most central and eastern areas with a scattering of thundery showers for some, as we lose the high pressure to the west and the north to north-easterly regime, leaving us in a sort of no-man's land with neither low nor high pressure in occupation. There is a fair amount of uncertainty involved but I think a much larger proportion of Britain can at least expect some sunny days with temperatures in the low to mid 20s, perhaps nudging the high 20s in the south for a time, and with any low pressure being shallow, some places may miss the showers altogether.

I do think cloud may continue to be an issue in some North Sea areas, particularly E Scotland and NE England, but as time goes on this will probably become confined to the coastal fringes with the winds tending to swing around to a south-easterly rather than a north-easterly.

[casparjack]

You may well be right, I think northern and central areas may generally be brighter than yesterday (though low cloud is still hanging on stubbornly here in Tyneside for example) but the southeast and possibly centre-south of England may end up cloudier.

Re. Backtrack's post, most of the complaining has been regarding cool cloudy conditions in eastern areas for this week. Next week is looking somewhat warmer and sunnier for most central and eastern areas with a scattering of thundery showers for some, as we lose the high pressure to the west and the north to north-easterly regime, leaving us in a sort of no-man's land with neither low nor high pressure in occupation. There is a fair amount of uncertainty involved but I think a much larger proportion of Britain can at least expect some sunny days with temperatures in the low to mid 20s, perhaps nudging the high 20s in the south for a time, and with any low pressure being shallow, some places may miss the showers altogether.

I do think cloud may continue to be an issue in some North Sea areas, particularly E Scotland and NE England, but as time goes on this will probably become confined to the coastal fringes with the winds tending to swing around to a south-easterly rather than a north-easterly.

Having looked at the latest FAX charts they still seem to show influence from fronts for the next 48/72 hours, though the MetO have changed their opinion a little for my area overnight, though that's the computer rather than a human forecaster.

From a 'real' perspective though, it started cloudier than yesterday, then cleared to cloudless skies about 9am, but just starting to fill in with Cu now, just approaching 4hrs of bright sunshine on the recorder...

We'll see, but the 11z visible satellite picture shows the low/mid level cloud pulling back/burning off more readily than yesterday at this time, so despite higher humidity levels than yesterday there does appear to be more widespread sunshine as you predicted. I must upgrade to Extra and get access to the cloud prediction charts!!

P.S. in the space of forty minutes we have gone from 1/8 Cu to 7/8 Cu/Sc - quicker than yesterday!

Edited July 27, 2011 by casparjack