Model Output Discussion 00z 19/07/13

[Methuselah]

aye, the charts scream potential, but more runs needed, otherwise it's nailed on for a pattern change, providing of course that we're not clutching at straws, after all it is only one run, and thus should be taken with a pinch of salt, otherwise it's a rinse and repeat....so my hunch tells me...

 

 

In the meantime, how's about we all stick to the reliable time frame?

[A.J]

In the meantime, how's about we all stick to the reliable time frame?

absolutely, never believe f1 charts that show a displaced bartlett or phantom easterly!

Edited July 19, 2013 by ajpoolshark

[OldMetMan]

Interesting although subtle changes in model output so far today.

There seems to be a reasonable consensus now of falling pressure over the UK as we head into next week with LP moving into our area accompanied by hot, humid air and thunderstorms, at least for a time. Currently, the air over France is becoming increasingly unstable, with storms breaking out as far N as Brittany, so the SW of the country could be at risk of storms already. What seems quite likely to happen, I think, is the development of a more organised trough, even a frontal zone, heading N across the country with much thundery activity embedded in it. The cloud pattern over France at present suggests this is already starting to happen, albeit slowly.

The trickiest and most intriguing part of the output is what the development is likely to be later next week. As I have mentioned before, the N American jet is the thing to watch:

Today, it looks somewhat livelier than hitherto. The latest GFS 12Z run shows a much more vigorous jet heading E and then SE with developing LP along it, which will feed into the thundery low over the UK. Yes, it has been saying something similar for some time, as it likes to do, but there are now hints that the other models are developing along similar lines. The latest 500mb has some clues.

An active shortwave near the Great Lakes is intensifying the upper vortex over the E of Canada. Downstream, we now have a more noticeable upper high right over us whereas previously it has been quite flat. If the jet proves to be as strong as the GFS suggests, then it would seem more likely for it to propagate E and then SE as the GFS depicts. Along with this, we would have an upper trough extending eastwards at our latitude, with the upper high weakening and heading NE. This injection of energy across the Atlantic would, I think, break down the block, at least for a while.

But I must stress, there is a big question mark over this happening as far as I am concerned. It's quite possible that the whole development could just run out of steam and we could remain in a slack pressure field with gently rising pressure towards the end of next week.

In any event, there remains still the possibility of some record temperatures in the early part of next week and some interesting thundery activity. Perhaps by the end of the weekend, we will have a clearer idea.

[chapmanslade]

The problem with this 'breakdown' is that it isn't a strong Atlantic pushing through but more a weak cut off low wibbling and wobbling about to our SW with lots of small differences having a big impact. Indeed inter-run variations are quite large once the 'breakdown' starts. Once we get some MCS developments to 'create their own weather' then there is a lot of uncertainty how it will all pan out. At least it gives something to look at rather than a static blocking high.

Don't get excited about some of the possible 2m temps as cloud will become much more significant as pressure falls next week rather than the gin clear skies we have got used to.

Edited July 19, 2013 by chapmanslade

[tinybill]

http://www.meteociel.fr/modeles/gfse_cartes.php?mode=2&ech=204

 

well all i  say  is  f1  the  start  of  our monsoon season!!!

[Swave Snow]

http://www.meteociel.fr/modeles/gfse_cartes.php?mode=2&ech=204

 

well all i  say  is  f1  the  start  of  our monsoon season!!!

 

 

And SNOW in Greenland 

 

yipee

Edited July 19, 2013 by Swave Snow

[Barry12]

ECM 96 and GFS 96

 

 

ECM 120 and GFS 120

 

 

ECM 144 and GFS 144

 

 

ECM 168 and GFS 168

 

Edited July 19, 2013 by Barry95

[draztik]

The 'king' of the models, doesn't look so regal tonight, as it falls in line with the GFS! So, the second tier model leads the way. How refreshing

[Methuselah]

ECM 96 and GFS 96

 

 

ECM 120 and GFS 120

 

A cool-down is certainly on the cards...But, I can't see any indications, anywhere, of anything that I'd call 'cold'...yet!

[Milhouse]

The ECM does bring low pressure in sooner than the 0z showed but it parks it to the west of the UK through the middle of next week which would keep the heat building northwards. It would mean a much greater chance of some thundery downpours but also some sunny spells in the east.

[Steve C]

What a great and balanced post by OldMetMan.  The kind of post that 95% of people reading this thread want to see.

[Summer Sun]

Early next week is looking hot

 

 

By mid week the thunderstorm risk increases for the west with low pressure in the Atlantic

 

[Captain Shortwave]

If a trough is going to limpet somewhere, that spot isn't too bad

 

[Scorcher]

It hasn't come into line really at all, Barry95 has shown a nice comparison there of how the GFS is far more progressive and the ECM looks considerably hotter to me for Monday and Tuesday than the GFS. At 144 hours that low stalls out to our west as opposed to going straight over the top of the UK.

[Milhouse]

The GEFS mean indicates that Wednesday will be the last of the very warm/hot days before temperatures fall and it turns more unsettled later in the week. From then on it looks 50/50 with some members bringing in a warm southerly and others going for a cooler low pressure outcome.

[summer blizzard]

Lovely FI to the GFS, cool and showery by the looks of it.

[Scorcher]

The ECM is certainly warm right out to the end of the week, it's less hot after Tuesday but many would still see the mid 20s even after that. Areas further south and east would probably hold onto fairly settled weather right to the end of the week.

[Milhouse]

ECM looks very warm and thundery with some very warm nights likely with winds coming from a southerly direction. East is best closest to high pressure. I would compare the ECM to the warm spell of August 2011. Hot in places but showers breaking out.

[Summer Sun]

By Thursday the trough remains in the same place so the further east you are the sunnier, drier and warmer it could be

 

[Milhouse]

The Atlantic breaks through at T+216 with a NW/SE split and cooler for all but still warm in a southwesterly.

 

Edited July 19, 2013 by Milhouse

[nick sussex]

Quite a big downgrade in 850 temps over the last few ECM operational runs. Thankfully those 25s shown for down here have disappeared, that would equate to upper 30s here which is far too hot!

I think the recent outputs across the board show the difficulty in forecasting those plumes with any degree of certainty,the ECM has another go at drawing some hotter air further north once again as it drops that low to the sw of the UK but I'd have little confidence at this range.

Overall there is a strong signal for more unsettled conditions with troughing near or over the UK in the outlook, it still looks generally warm though after the hot weather recedes, hard to put too much detail on conditions on the ground until we see exactly where this troughing sets up.

[bluearmy]

ukmo's recent progressive troughing now looks a tad more reasoned although it remains progressive by day 6.  for many days now, next week has looked very complex. nothing has changed and detail looks very tricky to pin down. the only safe statement would be that three weeks of dryness will be relieved next week from the south. how far north and east this gets is open to question. how much the heat relents is also unknown though by the time we get past tuesday, i think we will all be begging for it to.  i'm off to eastern china where it will be 38c and cloudy. monday will be good acclimatisation !

[Swave Snow]

By Thursday the trough remains in the same place so the further east you are the sunnier, drier and warmer it could be

 

 

 

I agree with you, however on meteociel it looks strange as the trough seems to be going south westward, is the Pressure too strong?  Is the Ridge in the Azores coming back again?  

 

Not a total breakdown.  Many will see this as the ECM being dragged back in Line with the persistent recent GFS signal.  But it isn't clear cut or true, as the GFS was an outlier at on its 06z run and it seems ECM has been signaling a stalling of this low for days now, but where it goes and stalls ior gets cut off is the confuser here.

 

 

We need to see more models runs as others have suggested as things are getting murky now the run has completed as the low just swings back into SW UK, cant buy that evolution.  

 

 

Just maybe GFS is right.  

 

 

But it is a difficult call.  A lot of pros including the met office won't get of the fence yet.  Others are almost adamant that cyclonic weather will take over throughout the UK  

Edited July 19, 2013 by Swave Snow

[Summer Sun]

ECM ends with the low strengthening where we go from here is anyone's guess more runs are needed before things turn more clear longer term

 

What we do know tonight is;

• [*]The heat will return for the first part of next week UK wide before slowly easing from the west as we enter the 2nd half of next week but its a slow process with the SE keeping the heat till at least Friday [*]From Wednesday there is an increased thunderstorm risk with low pressure coming in from the Atlantic though the further east you are it may stay drier and warmer for longer [*]By a week Saturday the low is shown to cross the UK on ECM pushing the heat eastwards though this is open to debate as GFS shows a different set up
  

 

Edited July 19, 2013 by Summer Sun

[ANYWEATHER]

Plenty of energy in the atmosphere for the chart below to result in some scattered very heavy downpours with hail and thunder by as early as Monday..