Model Output Discussions 12z 01/06/2017

[Singularity]

 

I was a little concerned by the continued presence of the deep low at +144 on the ECM run, but less so than I could have been thanks to the ridge looking stronger - closer to GFS than the 00z run was.

 

Happily this has proved sufficient to fend off that vigorous low and keep the run tracking satisfyingly close to the GFS 12z - though a more straightforward NE motion to that system in the first place is actually more important here. Less and less support for trying to dig that trough down close to the UK so that's encouraging .

 

Edited July 11, 2017 by Singularity

[knocker]

As it turned out the ecm, although varying in the detail, is in the same ball park as the gfs vis the sequence. It too develops the breakaway upper trough over the weekend which develops into a more pronounced feature by midday Tuesday. This does two things. It helps to create a very slack pressure area south west of the UK and at the same time boosts the Iberian low which is free to track ENE and perhaps bring some convective activity to the south Weds/Thurs. but it's really nonsense to speculate about that at this range. Temps trending above average during next week.

 

 

Edited July 11, 2017 by knocker

[Singularity]

So the ECM 12z really did stick close to the GFS 12z! 

Odd how that makes it three 12z ECMs in a row with this general progression - but improved this evening - with both the 00z runs between being more aggressiveresive with the Atlantic low.

I daresay the latest effort is setting up a mighty heatwave. Notable how a bit more of the higher uppers finds its way in compared to GFS - a typical difference with GFS often undercooking this factor.

[Frosty.]

I think most of us would be very happy with what the Ecm 12z shows this evening for next week and beyond, especially since the Gfs 12z looks equally good..indeed, from where we are right now with torrential rain in the south, south-east, next weeks charts are Beautiful from the Big Guns (Ecm / Gfs)..Bank

Edited July 11, 2017 by Frosty.

[damianslaw]

As we enter high summer (roughly mid July-mid August) when we expect our warmest weather of the year and generally the make or break time for the summer as a whole (an average even relatively poor first half can be cancelled out by a fine four week period coinciding with the start of the school holidays, and vice versa the other way around as well - but this year at least in the south its been a very good first half..) and what are the models showing, a possible widespread very warm settled sunny dry spell for all, with a classic azores-scandi high combo.. Too early to bank on such synoptics verifying but there are very positive signals that this current slightly more unsettled average spell of weather will progress into something much warmer and drier, and not just for the SE this time around.

Always think of the last third of July as the peak summer period, before a gradual turn towards late summer through the first half of August largely due to loss of light levels, so lets hope we could be about to see another late July 2003 or 2013 / 2014 perhaps. Last year delivered that one day summer heat wonder on the 19 July, but I think this year we will see something far more robust akin to the months mentioned. I'm not though too sure it will hold out long into August though.. 

Edited July 11, 2017 by damianslaw

[Scorcher]

It's happening...wonderful charts from both the GFS and ECM for a sustained nationwide very warm, sunny spell. I haven't seen charts like this in July since 2013 in terms of the potential longevity and scale of the high pressure.

It's not 100% nailed on yet but I'm pretty confident given the data we have available.

[Fourty Point Three Degrees]

Models already suggesting 582DAM over Spain and then spreading into France. This could turn into a very severe heat wave on our side of the continent and with the right wind flows and dragging up some heat from the SE then 40C is not out of the question. Interesting times ahead.

[Frosty.]

6 minutes ago, Scorcher said:

It's happening...wonderful charts from both the GFS and ECM for a sustained nationwide very warm, sunny spell. I haven't seen charts like this in July since 2013 in terms of the potential longevity and scale of the high pressure.

It's not 100% nailed on yet but I'm pretty confident given the data we have available.

Agreed, what's so great about it is the potential longevity, usually warm spells in the uk last 3 days and then break down..what we are seeing from  most of the output today is a major pattern change nationwide..hope it continues to firm up..I think it will! 

Edited July 11, 2017 by Frosty.

[ANYWEATHER]

Both Ecm  and Gfs agree at T+240.....Strange

[Scorcher]

1 minute ago, damianslaw said:

Always think of the last third of July as the peak summer period, before a gradual turn towards late summer through the first half of August largely due to loss of light levels, so lets hope we could be about to see another late July 2003 or 2004 perhaps. 

I don't recall the end of either of those months being particularly special to be honest- not bad perhaps but 2003 was more notable for heat earlier in July and then in August. 2004 was pretty underwhelming all round, apart from a short hot spell in early August. Nothing remarkably warm or settled. I see more potential similarities with July 2013: 

 

A large area of high pressure extending from beyond the Azores into Eastern Europe, which was typical of that month.

[Ice Man 85]

1 minute ago, Frosty. said:

You could say the same thing about extreme cold in winter but it doesn't stop most of us chasing it!

Well the long range charts are going for wet and stormy this year from the look of things. Those in cumbria and flood-prone areas might want to invest in insurance if they're right. We'd run out of alphabet letters before we hit november.

[Frosty.]

Just now, Gordon Webb said:

what kind of heat are we on about then ?

Realistically next week, low to mid 20's celsius, perhaps reaching high 20's c across the s /se during the second half of next week..based on current output from Ecm / Gfs.

[Gordon Webb]

Just now, Frosty. said:

Realistically next week, low to mid 20's celsius, perhaps reaching high 20's c across the s /se during the second half of next week..based on current output from Ecm / Gfs.

well that's not unusual for this time of year and really shouldn't cause any problems to infrastructure or peoples health as long as proper care is taken

[Man With Beard]

14 minutes ago, 40*C said:

Models already suggesting 582DAM over Spain and then spreading into France. This could turn into a very severe heat wave on our side of the continent and with the right wind flows and dragging up some heat from the SE then 40C is not out of the question. Interesting times ahead.

If you wanted a set up at D10 that could allow for such a situation by D15, the GFS and ECM are pretty close to perfect tonight. But I suspect that's still hunting for the needle in the haystack even if it does get to that stage.

The GFS/ECM have brought the settled conditions forward a little tonight. They may be overdone but the great thing this time round is that the margin for error is quite big, if it's a more gentle heatwave (25-28C) you're after anyway - more major heatwaves (33C-37C) as ever need perfection. 

Of course the runs are dreadful if you need to stay cool, and after the scorching start to summer down here, actually I'm nearly in that boat myself given I have little ones to keep asleep at night

[damianslaw]

29 minutes ago, Scorcher said:

I don't recall the end of either of those months being particularly special to be honest- not bad perhaps but 2003 was more notable for heat earlier in July and then in August. 2004 was pretty underwhelming all round, apart from a short hot spell in early August. Nothing remarkably warm or settled. I see more potential similarities with July 2013: 

 

A large area of high pressure extending from beyond the Azores into Eastern Europe, which was typical of that month.

Yes I edited it to say 2013 and 2014, not 2004. 

[Frosty.]

Another absolute peach of a GEFS 12z mean this evening, heights extending from the azores to scandinavia with a prolonged period of anticyclonic domination for the whole of the uk..at last!.. it looks wonderful to me..gets better and better the further it goes!

Edited July 11, 2017 by Frosty.

[Polar Maritime]

Post have been hidden, Please use the model banter thread for more general chit chat.

Thanks please continue. 

[Singularity]

Given the similarities being drawn between the mid-to-longer term model output and July 2013, it's of considerable interest to compare the two Junes in terms of preconditioning for high temperatures;

On the one hand, June 2013 was much, much cooler over western Europe than 2017, but on the other hand, it wasn't as wet, particularly across France. 

On balance, though, the far greater mean temperatures outweigh the wetter conditions due to being both more widespread and capable of driving extreme rates of evaporation and transpiration (i.e. evapotranspiration) which quickly remove moisture from the surface soil layers. Even in 2013 this will have mitigated the restraining effect on heatwave preconditioning, but still, I expect 2017 is leaps and bounds ahead of that year in most if not all areas of Central and Western Europe.

In fact not only is this the case on land, but also out at sea;

 

I very much recall thinking about how July 2013 could have brought day after day reaching into the 30s *C across a wide swathe of the south had it not been for those well below average SSTs (largely a result of the exceptionally cold March).

So it would seem that all that remains is to achieve a similar pattern again this year and things are going to get very toasty this year. 

Well, I say all... 

Plenty of ground to cover before we can really start concerning ourselves with the possible impacts - but I figured this assessment would be entertaining anyway .

[bluearmy]

 

still looking pretty summery going forward! 

[Level1]

1 hour ago, 40*C said:

Models already suggesting 582DAM over Spain and then spreading into France. This could turn into a very severe heat wave on our side of the continent and with the right wind flows and dragging up some heat from the SE then 40C is not out of the question. Interesting times ahead.

Eek! I'm going to the Loire on Saturday for a week. These charts are making me nervous as I wilt in the heat. It couldn't hit mid 30s/40s that far north could it? (I ask hopefully)...

[knocker]

The anomalies this evening are pretty much on the same page despite a rather complex upper pattern

The essential features are a quite intense vortex lobe over northern Canada with associated trough, A strong east European ridge into the Arctic, The Azores nudging slightly north in mid Atlantic and a weak upper trough to the south west of the UK. As it gets towards the end of the period the Azores becomes more active and ridges NE.Thus the frame work is here that would support to some extent  this evening's det runs.

The westerly upper flow will tend NE due to the combination of the orientation of the trough and ridge and the Azores thus systems will be diverted to the north of the UK with the area to the SW/S of the UK becoming a slack shallow low pressure area with some very warm air south of central France Now comes the tricky bit that the det runs will need to sort as the days tick by. Two basic questions. Will the Azores ridge far enough NE to disconnect any link to the major trough to the NW and curtail any major WAA from the south or ridge just far enough for a two pronged attack from the W and the south. The tricky bit is if we get a combination of the two.

Edited July 11, 2017 by knocker

[knocker]

This morning's gfs illustrates once again that the evolution next week should be treated with caution. A quite significant difference in the twelve hours.

Prior to that the weekend typifies the N/S split in this pattern with wet and breezy in the north and dry and less so in the south. Temps around average, perhaps a little above in the south. From this point the changes occur.

The development of the previously mentioned upper trough still occurs but although it doesn't now develop to any great extent it does disrupt the ridge. This allows the next trough emanating from the faithful vortex lobe in N. Canada to develop and adopt a more easterly route and setting up the next intriguing position.

As the trough nears Ireland it disrupts and fills the space to the SW created by the earlier trough which on the surface activates the Iberian low pressure and pushes it north along with some quite warm air into the south of England. In fact by the end of the week the slack area of low pressure covers the whole of the UK with all having temps above average. As stated previously this is a long way from being a done deal as there are a few options on the table and the devil is in the detail

 

Edited July 12, 2017 by knocker

[mushymanrob]

12 hours ago, mushymanrob said:

stunning gfs 12z.... absolutely stunning, and its not totally impossible either , ok its probably over estimating but its consistency is there, all we need now is a slight shift in the anomaly charts to support this and itll be game on!
 

..... and there you go, another step in the right direction that supports the general developing 'heatwave' synoptic pattern that at its worst still looks pretty decent with a lot of decent warm dry summery weather, at its best we would be in for a decent lengthy spells of hot weather . 
 

[knocker]

The ecm dies not disrupt the trough next week quite so effectively as the gfs so no new upper low is formed to the south west of the UK but the original trough is still influential west of Portugal and this activates the Iberian low which tracks north over France and introduces a very slack southerly drift over the UK which makes the latter part of the week quite warm with temps above average, if not excessively so, before the Azores ridges NE by the end of the run. All quite interesting stuff and certainly this morning just illustrates the options within the framework suggested by the anomalies. As previously stated this a long way from a done deal and the devil  remains in the detail.

Edited July 12, 2017 by knocker

[Summer Sun]

UKMO and ECM have different ideas at D7

Thundery rain moving into the SW if UKMO is right?