Model Output Discussion 18z 28/07/13

[Frosty.]

The Gfs 06z operational run shows some warm, occasionally very warm and fine weather next week but with a few cooler and fresher days and next monday shows a mass of heavy rain spreading from the southwest across england and wales before it clears into the north sea, scotland escapes the deluge and looks dry and sunny for monday, for most of next week it's sunshine and scattered heavy slow moving showers with thunder in a very slack pattern with temperatures in the very comfortably warm range of 22-25 celsius, nearer 17-19 celsius for n.ireland and scotland but occasionally warmer in eastern scotland (aberdeenshire) to the lee of the mountains where low 20's celsius looks likely at times, so, next monday would be relatively cool due to the persistence of the heavy rain but then warmer and brighter with a showery theme, later next week the 6z shows the south and west drying up with longer sunny spells as pressure rises a little but it remains breezy and showery across northern uk. Into FI, the azores/atlantic anticyclone tries to build in but soon gets flattened by low pressure sweeping in off the atlantic but in general, the further south you are, the drier and warmer it would be and the opposite for the north (scotland & n,ireland) Looking at the temperatures through low res, it shows them returning to average across the uk and a little below across more northern areas at times but 20-21c in mid august for the south is not that bad in my opinion, plus the fact that the gfs may have overdone the atlantic influence in lala land so mid august could end up being warmer than currently shown.

yeah ill give you that one karl

cheers mushy.

Edited August 2, 2013 by Frosty039

[UV-RAY]

The Gfs 06z operational run shows some warm, occasionally very warm and fine weather next week but with a few cooler and fresher days and next monday shows a mass of heavy rain spreading from the southwest across england and wales before it clears into the north sea, scotland escapes the deluge and looks dry and sunny for monday, for most of next week it's sunshine and scattered heavy slow moving showers with thunder in a very slack pattern with temperatures in the very comfortably warm range of 22-25 celsius, nearer 17-19 celsius for n.ireland and scotland but occasionally warmer in eastern scotland (aberdeenshire) to the lee of the mountains where low 20's celsius looks likely at times, so, next monday would be relatively cool due to the persistence of the heavy rain but then warmer and brighter with a showery theme, later next week the 6z shows the south and west drying up with longer sunny spells as pressure rises a little but it remains breezy and showery across northern uk. Into FI, the azores/atlantic anticyclone tries to build in but soon gets flattened by low pressure sweeping in off the atlantic but in general, the further south you are, the drier and warmer it would be and the opposite for the north (scotland & n,ireland) Looking at the temperatures through low res, it shows them returning to average across the uk and a little below across more northern areas at times but 20-21c in mid august for the south is not that bad in my opinion, plus the fact that the gfs may have overdone the atlantic influence in lala land so mid august could end up being warmer than currently shown.

cheers mushy.

So all in all it's standard August weather really, showers or longer periods of rain interspersed by periods of warm sunshine with temps around average for most of the time. I'll bank that now frosty!

[draztik]

ECM wants HP back, and its trying its best to nudge northwards..

Edited August 2, 2013 by draztik

[Milhouse]

The ECM 0z mean does seem to indicate high pressure building across southern England at T+168 bringing warmer air with it.

 

[DTHFCJ]

looks fairly good mid week onwards atm,just waiting for the last ECM chart,

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

http://www.wetterzentrale.de/pics/Recm1441.gif

http://www.wetterzentrale.de/pics/Recm1681.gif

http://www.wetterzentrale.de/pics/Recm1921.gif

http://www.wetterzentrale.de/pics/Recm2161.gif i wonder where this will lead us....

 

http://www.wetterzentrale.de/pics/Recm2401.gif .here

Edited August 2, 2013 by DTHFCJ

[Captain Shortwave]

The ECM has gradually moved low pressure further north, and this run it's removed any real blast of very cool air from the north west. Not much to say about the output, looks pretty standard fair, not to say the temperature could not get back into the mid-high twenties, as the ECM shows with a broad warm sector.

The middle of next week still looks quite messy so that might evolve to something a little more interesting if the trough drops into the Bay of Biscay.

[Milhouse]

A mixed ECM 12z it has to be said with a fairly dry and warm weekend with temperatures a little above average, althouth there will be a scattering of showers on Saturday. On into next week it looks like it will start off cool and wet on Monday but there looks to be a drying and warming trend throughout the week with next Friday once again seeing temperatures into the mid 20s. Hopefully the trend to a warmer end to the week will be reflected in the ECM mean when it comes out. Next weekend it turns cooler from the northwest but FI has shown a cooler spell many times since late June and it has never come off.

[Frosty.]

There is a nice little fine, sunny and very warm spell on tonight's Ecm 12z towards the back end of next week which brings the 564 dam line into the uk again, it doesn't last but it might signal that the outlook won't be as average as first thought, for the south of the uk it would bring very warm continental air up from france again with temperatures into the high 20's celsius for a few days, it should be noted that the continental heat is never far away in the week ahead and the southeast is in the best position to hold on to residual warmth during the coming days. As for the week ahead as a whole, this weekend starts on a bright and breezy fresher note with sunny spells and a scattering of sharp showers and a risk of thunder but some areas will miss the showers altogether such as southeast and northern england, a warm day tomorrow but with lower humidity although temperatures into the low to mid 20's celsius, warmest in the southeast corner. Windier and less warm for n.ireland & scotland with a band of rain pushing east followed by sunshine and scattered blustery showers, there could be gales across western scotland but they should ease later. Sunday looks drier than saturday in the north and east but rain will be encroaching into the southwest of the uk as time goes on, this rain is associated with a trough weakness which will bring a thoroughly wet and miserable day on monday to a large part of the uk before eventually clearing into the north sea, tuesday and wednesday look rather warm with lighter winds and sunny periods but heavy, slow moving showers then breaking out, and then later in the week the southern half of the uk becomes drier, sunnier and warmer which may last through to the end of next week but continuing more changeable across northern uk with average temperatures.

[Frosty.]

I'm going to be down south next week so I would take that.

Let's hope the Ecm 12z is right then, since it's only 6 days away it has a fair chance and the earlier Ecm 00z ens mean also brought ridging across the south in the same timeframe so there are grounds for optimism.

[Milhouse]

ECM this morning has moved further in the settled direction with warmer and drier conditions developing as next week progresses. Even the plunge of cooler air from the NW in FI is being toned down.

[phil nw.]

Morning all.

 

Some off topic posts from last night have been removed.

Please remember to post general chat about the weather to the other threads to save cluttering this one up.

 

Thanks folks.

[Methuselah]

Morning all.

 

Some off topic posts from last night have been removed.

Please remember to post general chat about the weather to the other threads to save cluttering this one up.

 

Thanks folks.

I wondered why it appeared to be so quiet!

 

So, anyway, some interesting weather can be expected during the coming week?

[draztik]

ECM seems to be on its own this morning, certainly in terms of having the Azores high nudge itself further north eastwards into the UK. GEM and GFS promote the idea of a more Atlantic driven trend, with low pressure in and around the north of the UK. GFS does show that the best of any weather will be in the SE, as normal.

long range ensembles (GGEM, GFS Ens, NAEFS) for the 12z runs still shows LP over the UK / to the north, so it'll be interesting to know where the 0z updates take us.

However, as runs pass by, there are signs of the Azores trying more and more to push its way northwards, with the ecm being most progressive with this.

[Summer Sun]

We haven't got full ensemble support from ECM yet for another rise in pressure but at this stage I think the further south you are the drier and brighter it will be this could and will all change if the high decides to move north like the Op suggests giving most of the UK another dry settled period albeit not as hot as the previous ones

 

ECM ensemble

 

 

The further out we go the more disagreement we get between the Op and ensemble

 

Edited August 3, 2013 by Summer Sun

[Captain Shortwave]

I wondered why it appeared to be so quiet!

 

So, anyway, some interesting weather can be expected during the coming week?

Plain average weather or......

"Perfect" conditions according to government and BBC officials. 

South east will probably get naff all rain with the North west wet and windy at times.

People in the North would take the ECM output as the GFS has a secondary feature which pushes wet and windy weather through Scotland, whilst the ECM doesn't and holds the main trough well north of the UK. Good agreement on pressure being fairly high in the south.

Edited August 3, 2013 by Captain shortwave

[Frosty.]

It's good to see the Ecm 00z operational has improved with the PFJ further to the northwest and high pressure ridging in more and more as time goes on with warm or very warm and sunny weather returning after a more unsettled blip.

[phil nw.]

Indeed we are now into our more typical westerly pattern with the low pressure to the north and the sporadic ridging from the Azores high between the fronts.

 

Monday looks quite wet for much of England and Wales as another frontal system moves across.

 

 

but as ever in this pattern there will be some dry and fine interludes with some warm days,especially the further south and east where temps.will continue to max out in the low 20's.

 

 

[Frosty.]

More good news, the Ecm 00z ensemble mean has built on the encouraging signals from yesterday with a nice pressure rise for the southern half of the uk and especially further south with a spell of warm and settled weather returning later next week (as ecm 0z op) which may last through next weekend into the start of the following week, temperatures probably into the mid 20's celsius, a little higher for the southeast, further north, probably more changeable with a westerly flow and a mix of fine and warmer spells alternating with unsettled and cooler periods. In the meantime, this weekend starts with sunshine and sharp showers with thunder risk but some areas staying dry with sunny periods, tomorrow less showers and more sun but clouding over across the southwest of the uk with rain spreading slowly northeastwards, the trough (weakness) spreading a period of heavy rain north and east across a large part of the uk during monday before clearing into the north sea, feeling relatively cool in the persistent rain. Tuesday and the midweek period show slack shallow trough conditions with warm sunny spells and light winds but unstable air with heavy, slow moving showers with thunder breaking out, but then later next week, the shallow trough fills and the azores/atlantic anticyclone begins to ridge towards the south but further northwest, an atlantic depression heads towards nw scotland bringing a spell of wind and rain across the north of the uk but once that has passed through, a stronger rise of pressure follows across the south with very summery weather returning for several days.

Edited August 3, 2013 by Frosty039

[Frosty.]

Can't complain really frosty, beats relentless cool or cold, cloudy grey and wet! We've been there too many times before

Yes it's a great summer overall, July being EPIC...with more good weather on the way soon, I think i'm right in saying that thursday 1st august was the hottest august day since 2003 when heathrow reached 34.1 celsius 93 F.

[Scorcher]

The GFS 06Z is an improvement in terms of warmth for the week ahead, once tomorrow and Monday are out of the way. It looks like a pretty decent week after Monday and there are signs of pressure building from the south later on, although it's less bullish than the ECM about this. The kind of week (after Monday) that most fans of warm weather would have bitten your hand off for in many previous summers.

[Milhouse]

If the GFS 6z is correct then its a continuation of the warm/very warm weather with Monday the only day to provide a cool and wet blip. Tuesday will see a scattering of showers but in any dry sunny spells it should feel very pleasant with temperatures slightly above average peaking at 24c. From Wednesday until Friday, showers will still feature but these should be well scattered and temperatures still doing well, into the mid 20s in the south. Summer continues.

[Milhouse]

Next weekend starts with high pressure still strong over southern England with most of the southern half of the UK dry with average temperatures. Furthern north we will have to watch that low pressure closely. The 6z looks to be sending cooler air southwards at T+186.

 

[johnholmes]

comments on the 500mb anomaly charts, for the change from upper ridge dominating to the upper trough becoming the dominant feature and the next 10 days or so?

 

 

500mb anomaly charts-july to august 2013 on sat 3 august.pdf

 

copying into other thread also

 

[Tamara]

I posted the other day about possible options in terms of where the weather patterns would be headed and expressed humble little doubts about the proximity to the UK of a low pressure anomaly as indicated by NAEFS at the 10 day period. This now being assessed at how it looks at about 8 days. I think that we can see from current model evidence that this signal the other day has been shown to be overly progressive in terms of being nationwide as appeared to be suggested. If we take a look at the latest overnight NAEFS anomaly charts for approx the same period (now at 8 days) we can see that whilst there is indeed low pressure still to the north of the UK maintaining the westerly pattern, the jet stream is further north than suggested the other day and we have relatively high pressure to the south as a result of ridging from the Azores. This has also been well illustrated by regular members like Karl and Phil this morning with the ensemble means etc for GFS and ECM and means that at the very least a split in the weather pattern is most likely with the more unsettled conditions shifted further north and still some very pleasant weather to be had within a slightly changeable theme

 

 

The EPS individual members up to day 7, mostly, support this evolution with the atlantic high pressure evident to the west and south west in most all cases and although there is a variety of suggestion in terms of how amplified the jet stream might be as sandwiched between low pressure to the north and the Azores high pressure ridge, there is reasonable enough support there to suggest that the jet stream will be far enough north to assure that temperatures are always going to stay reasonable, and warm in the longer sunnier spells, especially further south.

 

So although a few spells of rain or showers are likely from time to time almost anywhere, most especially in the north west, I think that after a more generally unsettled blip to start the week, there is enough summer weather still on offer for many, most especially further south and south west.

Edited August 3, 2013 by Tamara Road

[DTHFCJ]

I posted the other day about possible options in terms of where the weather patterns would be headed and expressed humble little doubts about the proximity to the UK of a low pressure anomaly as indicated by NAEFS at the 10 day period. This now being assessed at how it looks at about 8 days. I think that we can see from current model evidence that this signal the other day has been shown to be overly progressive in terms of being nationwide as appeared to be suggested. If we take a look at the latest overnight NAEFS anomaly charts for approx the same period (now at 8 days) we can see that whilst there is indeed low pressure still to the north of the UK maintaining the westerly pattern, the jet stream is further north than suggested the other day and we have relatively high pressure to the south as a result of ridging from the Azores. This has also been well illustrated by regular members like Karl and Phil this morning with the ensemble means etc for GFS and ECM and means that at the very least a split in the weather pattern is most likely with the more unsettled conditions shifted further north and still some very pleasant weather to be had within a slightly changeable theme

 

 

The EPS individual members up to day 7, mostly, support this evolution with the atlantic high pressure evident to the west and south west in most all cases and although there is a variety of suggestion in terms of how amplified the jet stream might be as sandwiched between low pressure to the north and the Azores high pressure ridge, there is reasonable enough support there to suggest that the jet stream will be far enough north to assure that temperatures are always going to stay reasonable, and warm in the longer sunnier spells, especially further south.

 

So although a few spells of rain or showers are likely from time to time almost anywhere, most especially in the north west, I think that after a more generally unsettled blip to start the week, there is enough summer weather still on offer for many, most especially further south and south west.

Yet another top post from a clever Lady,cheers Tamara.