Model Output Discussion 18Z 18/6/13 onwards

[chionomaniac]

Time for a new thread. 

 

With a summer depression trying to ruin the weekend what is likely after?

 

Please discuss here.

 

 

Be respectful and please note that this is not a moaning thread.

[Frosty.]

@ DAVID SNOW

 

The decent uppers I was talking about were at T+216 hours on the Ecm 12z, I wasn't talking about T+168 hours, we seem to be at cross purposes there. The charts I posted were T+216 and T+240.

 

Lots of positives to take from some of the 12z output tonight, the Gem 12 & Ecm 12z have brightened the mood and will hopefully be the start of a more positive trend in the coming days.

Edited June 18, 2013 by Frosty039

[DAVID SNOW]

@ DAVID SNOW

 

The decent uppers I was talking about were at T+216 hours on the Ecm 12z, I wasn't talking about T+168 hours, we seem to be at cross purposes there. The charts I posted were T+216 and T+240.

 

Lots of positives to take from some of the 12z output tonight, the Gem 12 & Ecm 12z have brightened the mood and will hopefully be the start of a more positive trend in the coming days.

No probs Frosty, i like your enthusiathic posts,but i replied to your post 1143,(old thread)which showed the ECM 168 chart.

[William of Walworth]

I've spent the last 40 or so minutes catching up with the last 5 or 6 pages of the previous thread, and checked a few runs as well. I'm still seeing some risk of a washout weekend just coming up, but with  reasonably positive indications of improvements next week. Very much all in remaining in flux though.

 

**(just possibly nicely so for us Somerset bound summer preferrers/Glasto goers! But still too early to be all that confident) 

Edited June 18, 2013 by William of Walworth

[Summer Sun]

12z ECM ensemble looks fine again this evening

 

 

Ok its not mega warm but at least it will be dry and settled in the build up Glastonbury

Edited June 18, 2013 by Summer Sun

[William of Walworth]

Perfecto for some of us, depending on location obviously, if that were to verify ... !

 

Big if etc but some hopes of niceness there, especially near the SW

Edited June 18, 2013 by William of Walworth

[Milhouse]

I've spent the last 40 or so minutes catching up with the last 5 or 6 pages of the previous thread, and checked a few runs as well. I'm still seeing a big risk of a washout weekend just coming up, but with  reasonably positive indications of improvements next week. Very much all in remaining in flux though.

 

**(just possibly nicely so for us Somerset bound summer preferrers/Glasto goers! But still too early to be all that confident) 

 

Yes, its a certainty that for much of the UK the weekend will be an unwelcome reminder of what we had to endure throughout much of last June. Thankfully it looks like a temporary unsettled spell (just 2 days for some parts) before the low pulls away to leave Monday a drier day but with a scattering of lighter showers.

 

The ECM mean paints a very encouraging picture from Tuesday onwards with high pressure in charge and upper temperatures gradually recovering.

Edited June 18, 2013 by Milhouse

[Milhouse]

Perfecto for some of us, depending on location obviously, if that were to verify ... !

 

Big if etc but some hopes of niceness there, especially near the SW

 

The south coast looks the place to be next week in the absence of any onshore wind and closer to the warmer upper temperatures.

[Thundery wintry showers]

Looking over the last few frames of the ECMWF ensemble mean, I don't get an impression of high pressure being in charge of the weather- it's more a case of high pressure just to the S and SW with moist westerlies on the northern flank, and the surface weather would be dependent on the amount of moisture associated with the westerlies (e.g. weak frontal disturbances and tropical maritime incursions bringing stratocumulus in off the Atlantic Ocean).  Generally speaking it's a north-south split sort of setup with dry sunny weather most likely in central and southern England and cool cloudy weather most likely in Scotland and north-west England.  Of course it's still a mile away from what we had at this time last year.

 

The other outputs that I'm seeing (NOAA 8-14 day forecast, GFS operational, ECMWF operational) all have the high pressure centred further to the north-west which would promote more of a west-east split with cool cloudy and/or showery conditions (depending on the airmass source) most likely in eastern areas and the west and south-west most likely to be dry and sunny.

Edited June 18, 2013 by Thundery wintry showers

[William of Walworth]

Good cautionary note there TWS. All still to play for obviously.

[legritter]

As some others have pointed out some signs of possibly a more quieter spell next week ,its still a hard one to call at this range with big variations in the Modells .but again the azores high pushes in our direction after this weekends unsettled condition ,but then midweek looks like being a big question mark as low pressure could move in to bring an unsettled end to june .but at this range it could be next thurs /fri before a low arrives , but knowing our friend  GFS the next run could be 20/30 mb different .Certainly enough  interesting Synoptics around currently so enjoy .cheers

[johnholmes]

The 500mb 8-14 NOAA this and last evening showed the smallish +ve height in a long shape centred about 50n 20w then along the 50n parallel into the eastern states?

To me that suggests that any upper ridge would be in about the same position in terms of how far north it was located or am I missing something?

[bradymk]

wow 22c, i suppose we should be grateful for those temps nowadays, i hope the GFS is right as that is saying 26c 27c but i know it overcooks temps it has fooled us into thinking we were going to have a mini heatwave

Think the downgrade may be due to the potential for some heavy thundery rain during the morning resulting in not so high temperatures. Any areas that see the sun without t-storms, will see the highest temp. I attached UKMO precip model for tomorrow morning at 10am, shows the rain in south east.

 

[William of Walworth]

As some others have pointed out some signs of possibly a more quieter spell next week ,its still a hard one to call at this range with big variations in the Modells .but again the azores high pushes in our direction after this weekends unsettled condition ,but then midweek looks like being a big question mark as low pressure could move in to bring an unsettled end to june .but at this range it could be next thurs /fri before a low arrives , but knowing our friend  GFS the next run could be 20/30 mb different .Certainly enough  interesting Synoptics around currently so enjoy .cheers

Bolded bit : All about the track and positioning too. I think it would take a very confident model reader indeed and probably over confident,  to even start to try to attach any detail on that one for the time being.

[Jimmy0127]

There's a part of me that feels like a spoil sport for not being remotely interested in Glastonbury. For what it's worth I've been to Brothers cider in Shepton every week for the last three years. My forecast based on experience: it will rain.

 

As for the models, I haven't really seen any significant amendments or insights in the last two/three days (bar the fluctuating cheeky streak from Labrador). Any ridging from the South West seems tenuous and short-lived to me. 

Edited June 18, 2013 by Jimmy0127

[rmc1987]

Time for a new thread. With a summer depression trying to ruin the weekend what is likely after?Please discuss here.Be respectful and please note that this is not a moaning thread.

What's likely = Without looking looking, low pressure, cloud, rain and a balmy 16c? No, ok maybe 17c then. What is of note to me is dew points of 16c today. Edited June 18, 2013 by rmc1987

[Iceni]

There's a part of me that feels like a spoil sport for not being remotely interested in Glastonbury. For what it's worth I've been to Brothers cider in Shepton every week for the last three years. My forecast based on experience: it will rain.

 

As for the models, I haven't really seen any significant amendments or insights in the last two/three days (bar the fluctuating cheeky streak from Labrador). Any ridging from the South West seems tenuous and short-lived to me. 

 

But Keef (the magnificent) will get his shaman rain sticks out and keep it away for the Stones set

 

The models? He's married to one.

Edited June 19, 2013 by Iceni

[mushymanrob]

nice to see the start of some hope that next week might not be a bad one, at least with a ridge theres hope that it might build and at least it should be largely dry. TWS though pointed out about the cloud risk, and thats what i though when viewing this mornings runs. as long as we are getting airflow off the atlantic, cloud will be a problem.

 

will this be the turning point of the summer (like the last week in june was in 1983) ?

[Frosty.]

A much better Ukmo this morning compared to the 12z last night, the 00z has a much nicer alignment of the azores/atlantic anticyclone with the promise of a fine and warm spell next week, this would be great news for Glastonbury, this looks much more like the Gem 12z last night with the PFJ much further to the northwest.

Edited June 19, 2013 by Frosty039

[Frosty.]

There is pretty much cross model agreement at the T+144 hours range for high pressure to be building in from the southwest with a good chance of a warm and settled spell developing during the course of next week, the navgem 00z is the exception with cool, trough conditions persisting well into next week, the Ecm 00z seems a little more reluctant than the gfs, ukmo & gem but overall, the signs look a lot better than they did 24 hours ago for a return to summery conditions next week after the upcoming cool, windy and rainy weather.

[Frosty.]

The Ecm 00z eventually brings a spell of fine anticyclonic weather next week, especially to the southern half of the uk and a ridge holds across the south until the end of the run, the Gem 00z builds a stronger looking anticyclone across the uk but then gradually pulls the high back into the atlantic but the signs look good for anticyclonic weather to gradually take control next week after the upcoming cool, windy and wet spell.

[Frosty.]

The Gfs 00z operational run also shows a spell of fine anticyclonic and pleasantly warm weather next week but then becomes very unsettled and cooler.

[Gibby]

Hi everyone. Here is this morning's review of the midnight outputs from GFS, UKMO, GEM, NAVGEM and ECM for today Wednesday June 19th 2013.All models are in solid agreement of the removal of the warm and humid air over England and Wales over the next 36 hours as a thundery disturbance develops over the UK with fresh and cooler air following East across the UK in it's wake later tomorrow. Thereafter Westerly winds will usher in Low pressure and troughs across the UK later on Friday and through the weekend with spells of rain and showers in rather cool conditions out until Monday.GFS then takes the Low pressure out over the North Sea where it fills leaving the UK in a slack open ridge of High pressure with drier conditions and just the odd shower here and there with temperatures close to average. Late in the week and through the following weekend a new deep Atlantic Low gives a re-run of this weekend to come with windy and wet conditions for all with very limited bright spells in another session of cool weather as the Low trundles slowly East over the UK. The end section of the run shows the Low slow moving and drifted further North to maintain a basically cool and unsettled spell with rain or showers for all of the UK at times in Westerly winds.The GFS Ensembles show uppers over Southern Britain falling some 10C over the coming 5 days to a position below average before a slow recovery to more average levels is then sustained through to the end of the run. The operational was a cool outlier in it's latter stages but there seems little support or trend towards anything better than average with rain at times over the forecast period this morning.The Jet Stream over the next week or so remains on a collision course with the UK or Northern France before weakening somewhat as we move deeper into next week.UKMO today shows a strong ridge of high pressure building in from the West early next week replacing the cool and unsettled weekend with better drier and sunnier conditions with temperatures recovering out of the rather cool values of previously.GEM too brings High pressure in towards Western Britain through next week with dry and bright weather developing with spells of sunshine. Most places would stay dry beyond Tuesday but a cool breeze would affect the East and SE of England blowing down from the North.NAVGEM builds High pressure in from the west but more slowly maintaining a cool Northerly feed down over the UK perhaps with scattered showers at times still in the East.ECM finally brings High pressure into the UK too next week giving several days towards the middle and end of the week of fine and dry weather with broken cloud and sunshine though never notably warm. The pattern then flattens towards the weekend with unsettled weather feeding down from the North again at the end of the run with rain developing for all at times.In Summary today the weather looks like becoming briefly more settled next week as High pressure situated over the Atlantic spawns a strong ridge which is shown by most models to move over Western areas at least early next week. Before that ridge arrives though we are staring down the barrel of a windy and cool weekend with rain and showers for all before this moves away NE over the first days of the new week. The ridge then moves in but if only we could get the ridge across to the East and feed Continental air over the UK I would be more optimistic for a sustained spell of settled weather. As it is the ridge looks like holding slightly too far West maintaining an Atlantic feed gently blowing down from the North, especially in the East which would hold temperatures down somewhat. Also without the High pressure ridge migrating to the East of the UK the door is once more left open to further Low pressure areas to drift around the top of the Atlantic High and down towards the UK and once more this is where ECM ends up today so in all honesty despite better conditions again for a time next week a pattern change it is not and with GFS endorsing this in a more extreme form this morning we still have some way to go before we can get a nationwide warm and sunny period that we can all share and not the 1-2 day regional spells we have seen so far this summer. Nevertheless, with such difficult synoptics some places may fair well while others not so, and as I keep enthusing things are a multitude better than at most times last summer.

[shedhead]

Gibbys summation this morning looks pretty much on the money to me. Higher pressure should bring a spell of less unsettled weather next week, but the pattern touted by both main models suggest there are questions over both the strength and longevity of any ridge, with LP again looking favourite to sweep back in off of the Atlantic later in the period. This at best looks like a pattern tweek as opposed to a pattern change, with things actually looking worse than they are currently as we go into July.... IF the longer term GFS evolution is to be believed that is.

Edited June 19, 2013 by shedhead

[Weather Boy]

Hi Gibby, and thanks for another excellent update.

 

However, I disagree with your line: "if only we could get the ridge across to the East and feed Continental air over the UK I would be more optimistic for a sustained spell of settled weather. "

 

 

 Many members (including me) would probably like to see the High drift east of the UK, but that's not conducive to a sustained spell of settled weather, because it leaves the door open to the Atlantic and/or a hotter breakdown from the south, neither of which fits your desc

 

In situations like this, the orientation of the high is of crucial importance.  I think it's unrealistic to expect the models to have a handle on that kind of detail at this point, especially later on next week and therefore it is very hard to predict what the surface weather is going to be like.

 

For my money, I'd say that (especially in the south) we are looking at a 'quiet' spell of weather.  If the HP is close to, but not over the SW of the UK, that would produce a flow from the W/NW which would be slack in the south, a little more brisk in the north meaning that showers and longer spells of rain can be expected up there, over the top of the high, whereas rainfall in the south is likely to be significantly below average, with the SW possibly experiencing little or no rain.  However, sunshine could be locally very variable and temperatures are likely to be subdued with that kind of flow, probably no more than 20 at best. 

 

However, that may alter as the week goes on an inevitably the High's position changes, although it could be a change for the worse if the High pulls back into the Atlantic, allowing the development of a UK trough, rather than progress towards Denmark leaving us in the more continental flow that you are alluding to.....but that is all miles ahead.

 

I think all we can say for now is that we have a short and unfortunately time spell of cool and wet weather over the weekend, followed by relatively settled weather next week which is unlikely to give us any real heat in the short term.