Model Output Discussion - 1st June 2015 12z--------->

[knocker]

hi knocks - not drawn to the upper azores trough on the extended gefs?  thats the same feature that is driving this weeks heat ............

 

I did look at it ba but it's a pretty weak feature on the anomaly and the ECM doesn't make much of it although having said that the NOAA 8-14 is not adverse to the idea, I appreciate one needs to take into account the time scale but you are right an eye needs to be kept.

Edited June 28, 2015 by knocker

[Iceaxecrampon]

Don't usually post in Summer too much - more of a viewer as it comes up to the holiday season,

 

But,

 

Kerboom.....

 

 

 

 

 

 

 

 

[mushymanrob]

im not buying the gfs 06z by day 9,




the anomaly charts knocker posted, plus the noaa 6-10 day dont agree with a strong greenland high with a west scandi trough the gfs 06z suggests.

Edited June 28, 2015 by mushymanrob

[Frosty.]

Well, it's almost here and nothing can stop it now, the Gfs 6z shows the spanish plume surging northwards during Tuesday and wednesday, temperatures by tomorrow reaching 24c 75f in the south and nearer 28c by Tuesday and 30-32c in the hottest spots midweek, once again, the core of the plume is pushed east but it stays very warm / hot and very sultry, the heat rises further as the plume returns for an encore later Friday and into Saturday, things go crash, bang wallop on saturday before gradually freshening up from the west by this time next week. This will be a stonking week with plenty of scorching sunshine and increasing risk of thunderstorms, very muggy nights from tues/sat. Looking further ahead, staying warm in the south with the best of the fine weather, very warm at times. Northern UK becoming cooler but still pleasantly warm and occasionally fine but most of the rain throughout low res is across the north, especially Scotland...enjoy the heat

[Captain Shortwave]

im not buying the gfs 06z by day 9,

Rtavn2281.gif

the anomaly charts knocker posted, plus the noaa 6-10 day dont agree with a strong greenland high with a west scandi trough the gfs 06z suggests.

610day.03.gif

The development and movement of that cold pool looks rather extreme and to be honest even that doesn't really succeed at dislodging the warmth over a good part of the UK.

I suspect we will keep a SW/NE trajectory to the jetstream once the pattern breaks down during Saturday (timing still in question). Already looking at the output I would suggest Monday might see the return of 80F temperatures to the south though I suspect the following week will be mixed with periods of warm/very warm weather separated by bands of rain or showers.

Back to the nearer timeframe, the 06z pushes the second push of heat through quicker which in simple terms increases the temperatures on Friday by a degree or two and drops the temperatures on Saturday as the heat departs quicker during the day. Swings and roundabouts though to be honest with the same story of 30C possible between the 1st and the 4th of July being the headline along with the risk of thundery downpours, lowest risk likely being Thursday under a slightly cooler and more stable airmass.

Edited June 28, 2015 by Captain shortwave

[William Grimsley]

This is only a theory, but surely being nearer the coast during the night is going to be more oppressive than inland due to the temperature falling near the dew point/sea temperature hence higher humidity than inland?

[Methuselah]

I, for one, cannot entirely get to grips with the anomalies: if, on any particular day, there's a transient Greenland HP, will that day's anomalies be smeared-out into an overall mean? If that is so it might explain how some HPs, though they appear on individual charts, do not appear to be reflected in the anomaly predictions...?

[nick sussex]

Forecasters here in France  suggest a chance the June record might go on Tuesday, likely area for this to happen is se of Bordeaux .

 

The current record stands at 40.7C for Mont De Marsan. Actually its Gourdon in se France, I was looking at some other records! lol I think the heats already getting to me!

 

For the UK theres still a chance that a renewed surge of heat from the south could see temps rocket again Friday/Saturday much depends on how far east that Atlantic low gets before phasing with another exiting the USA.

Edited June 28, 2015 by nick sussex

[summer blizzard]

Aside from GEM which now wants to maintain the plume through Monday it now looks like the GFS and Euro have agreed that Weds-Sat could see 30C+ and that Weds and Sat especially look extremely wet for some places as thundery fronts move through, no doubt delivering some mammoth rainfall totals in the north west. 

 

Something to please the heat and storm lovers then..

 

[mushymanrob]

I, for one, cannot entirely get to grips with the anomalies: if, on any particular day, there's a transient Greenland HP, will that day's anomalies be smeared-out into an overall mean? If that is so it might explain how some HPs, though they appear on individual charts, do not appear to be reflected in the anomaly predictions...?

 

yep..... transient ridges or troughs will be smeared out. the anomalies predict the upper mean pattern and (as john holmes has said after several years of research) are (when in consistent agreement) are around 70% accurate. so currently the anoms suggest a sw upper airflow, that doesnt mean there will be 2 weeks of southwesterlies, it means the mean upper flow is strongly expected to be from the southwesterly quadrant. that allows for breif westerlies and breif southerlies.

what i do is view the anomalies first, then see which ops are closest, the ops will give the detail like transient ridges, but its really not very often that the ops 'beat' the anomalies 6-14 days out.

i think that right

[Timmytour]

I was referring more to the original comment by Timmytour, with which you agreed, that appears to me to be dismissive rather than lighthearted.

Just calling it as I see it Knocker. I don't know what the EC32's verification stats are past 10 days and I do accept that there might be more worth to it than I see. But in the times of my greatest interet in the longer term weather, winter and summer, I don't often see it leading the way successfully to any significant pattern changes

Edited June 28, 2015 by Timmytour

[summer blizzard]

12z rolling out. 

 

Wednesday and Friday look hot, Wednesday night and Friday night look wet. All over by sunday. 

 

[Summer Sun]

A weekend breakdown than a new area of high pressure building on the 6th from this afternoons GFS but not as hot

 

Edited June 28, 2015 by Summer Sun

[Man With Beard]

A weekend breakdown than a new area of high pressure building on the 6th from this afternoons GFS but not as hot

 

Amazing, the 20C 850 mark hitting the UK and hardly any posts, indicates to me just how excellently this hot spell has been modelled from a long way out!

Summer Sun's charts make me think "Breakdown what breakdown?" The 30C degree mark leaves us on Saturday, but I bet it will be back the following Tuesday if tonights charts are right.

UKMO fairly similar to GFS but perhaps with High Pressure building back from the SW even faster. Friday now looking a very hot day too on their charts. Saturday looks "banging" if you see what I mean

[Scorcher]

Amazing, the 20C 850 mark hitting the UK and hardly any posts, indicates to me just how excellently this hot spell has been modelled from a long way out!

Summer Sun's charts make me think "Breakdown what breakdown?" The 30C degree mark leaves us on Saturday, but I bet it will be back the following Tuesday if tonights charts are right.

UKMO fairly similar to GFS but perhaps with High Pressure building back from the SW even faster. Friday now looking a very hot day too on their charts. Saturday looks "banging" if you see what I mean

 

What you'll find rjbw is that it's the same few posters who don't want this spell to happen who have been continually playing it down and talking about a breakdown- it seems to me that they have succeeded in their aim of dampening down enthusiasm in this thread for what is going to be wonderful spell of summer weather if you enjoy heat and interesting conditions.

 

Another brilliant run from the GFS tonight, the likes of which we have been crying out for over many of the previous summers. Wednesday is looking a really hot one for many, and it will certainly feel very warm indeed with the BBC predicting lows of 19C overnight for much of England on Tuesday night, which will give the temperature every chance of rising above 30C for much of central England and higher in the SE. It looks to me like Thursday could be cooler for most, before it hots up again on Friday (although not quite as hot as Wednesday).

 

Then we appear to get a rebuild of high pressure over the weekend with temperatures again rising for the start of the following week. It's certainly going to be a very warm first week of July.

[matty007]

I won't pretend to be experienced with reading charts. What are the chances of us getting a reload of heat next week possibly setting us up for a July 2006 repeat? 

 

It's wonderful we're getting some real heat again, but would love it to continue past this coming week. 

[A.J]

What you'll find rjbw is that it's the same few posters who don't want this spell to happen who have been continually playing it down and talking about a breakdown- it seems to me that they have succeeded in their aim of dampening down enthusiasm in this thread for what is going to be wonderful spell of summer weather if you enjoy heat and interesting conditions.

 

Another brilliant run from the GFS tonight, the likes of which we have been crying out for over many of the previous summers. Wednesday is looking a really hot one for many, and it will certainly feel very warm indeed with the BBC predicting lows of 19C overnight for much of England on Tuesday night, which will give the temperature every chance of rising above 30C for much of central England and higher in the SE. It looks to me like Thursday could be cooler for most, before it hots up again on Friday (although not quite as hot as Wednesday).

 

Then we appear to get a rebuild of high pressure over the weekend with temperatures again rising for the start of the following week. It's certainly going to be a very warm first week of July.

I agree with the gist of your post, tues, wed fri & sat look particularly warm/hot....thursday warm/very warm in the south with the plume destabilizing friday into saturday, with a reload of warmth as we move into next week....after that and into FI the GFS goes into 'hyper-progression' mode plonking the atlantic trough over the UK with much cooler NWerlies, far too progressive to my eyes.....after all FI is called FI for a reason

[stodge]

Afternoon all

 

I saw a few slightly inaccurate posts about the NAO last evening and its relevance to the impending much warmer spell:

 

http://www.cpc.noaa.gov/products/precip/CWlink/pna/nao_index.html

 

The NAO is now negative and getting more so - this means in effect there is a negative pressure anomaly to the west and south-west of the British Isles (i.e: pressure is lower than it should be). This indicates the trough digging south and creating the plume of warm/hot air coming out of Iberia, over France and into the south of England (and possibly further north).

 

In tandem with the lower pressure anomaly, pressure may be higher to the west or north-west of the British Isles - in this instance it isn't so the NAO, though negative, isn't sharply so.

 

http://www.cpc.noaa.gov/products/precip/CWlink/pna/nao.sprd2.gif

 

Going forward, the NAO remains negative for several days suggesting this plume set up isn't going to shift too far too fast. What it doesn't reflect is the extent to which lower pressure might approach the British Isles and trigger storms.

 

Into the week following and most of the members suggest a return to a more neutral value which would suggest rising pressure to the south-west and a return of the Azores HP. The problem with that for fans of heat is the orientation of the Azores HP generally brings air in from the SW rather than S or SE or warm rather than  hot would be the outcome.

 

Just glancing at the AO (also negative at the moment) and it's following the NAO which again suggesta a return to a more "normal" spell of weather in the medium to longer term with the Atlantic becoming more influential and that seems to coincide with the 12Z Op run going into and through FI which does, in all fairness, look much more unsettled.

 

That's a very long off at present and there's plenty of heat and storms for us all to enjoy or endure (delete as appropriate).

 

http://modeles.meteociel.fr/modeles/gfs/runs/2015062812/gfs-1-72.png?12

 

That really looks quite warm but as I said yesterday the initial intrusion of heat isn't what matters - it's getting the heat in place and building successive waves or plumes.

[Milhouse]

I won't pretend to be experienced with reading charts. What are the chances of us getting a reload of heat next week possibly setting us up for a July 2006 repeat? 

 

It's wonderful we're getting some real heat again, but would love it to continue past this coming week. 

 

This is what the GEFS 12z mean is showing at the moment. So its likely to remain on the warm side even after the main heat has passed.

 

[stodge]

What you'll find rjbw is that it's the same few posters who don't want this spell to happen who have been continually playing it down and talking about a breakdown- it seems to me that they have succeeded in their aim of dampening down enthusiasm in this thread for what is going to be wonderful spell of summer weather if you enjoy heat and interesting conditions.

 

Another brilliant run from the GFS tonight, the likes of which we have been crying out for over many of the previous summers. Wednesday is looking a really hot one for many, and it will certainly feel very warm indeed with the BBC predicting lows of 19C overnight for much of England on Tuesday night, which will give the temperature every chance of rising above 30C for much of central England and higher in the SE. It looks to me like Thursday could be cooler for most, before it hots up again on Friday (although not quite as hot as Wednesday).

 

Then we appear to get a rebuild of high pressure over the weekend with temperatures again rising for the start of the following week. It's certainly going to be a very warm first week of July.

 

It's not a question of "playing it down" - it's more about those who think getting above 30c in England is some incredible event worth getting hyper-ventilated about (not a good idea in the heat).

 

I think we achieved 30c last year - we certainly did in the 2013 July heatwave which peaked on August 1st at 34c in west London I believe. We've hit 30c more often than not in recent summers. It isn't that unusual to be honest.

 

Some of the more outlandish forecasts of 40c suggested by NAVGEM and others were just that - in essence, we're getting a fairly typical Spanish Plume with some very warm or hot air sitting briefly over the southern and eastern parts of the British Isles. Yes, it will be hot, humid and unpleasant especially in the cities but it's not unusual. As to whether it marks the beginning of a prolonged spell of hot and humid weather, I don't know - it might - the GFS 12Z Op suggests not but the point is the jury is out on that at this time.

 

Four or five days with the mercury hitting say 30-32c in London are on the cards but again we had this just two years ago so not exceptional at this time. The possibility of a serious storm event with localised damage and flooding is there and one to be aware of.

Edited June 28, 2015 by stodge

[Scorcher]

It's not a question of "playing it down" - it's more about those who think getting above 30c in England is some incredible event worth getting hyper-ventilated about (not a good idea in the heat).

 

I think we achieved 30c last year - we certainly did in the 2013 July heatwave which peaked on August 1st at 34c in west London I believe. We've hit 30c more often than not in recent summers. It isn't that unusual to be honest.

 

 

I disagree with this- yes the SE achieves 30C quite often, but it will be reached over a much wider area than usual on Wednesday. Here in NW England it is not a yearly thing- we managed it a couple of times in 2013 but it has not been common at all over recent summers. There is every chance of it getting above 30C here on Wednesday, and I don't say that too often.

[Frosty.]

The Gfs 12z is very easy on the eyes this evening, what a super week ahead of us, lots of sunshine with temps / humidity soaring, especially further east / southeast and with the heat comes an increasing chance of catching a thunderstorm. Normally charts like these would be deep in FI but not this time..hope you all enjoy it.

Edited June 28, 2015 by Frosty.

[sunnijim]

Well the BBC news forecasts are now calling for 35c possible on Wednesday,so any talk of an 'average' 30c looks way out.Possible July record breaker ?

[h2005__uk__]

Well the BBC news forecasts are now calling for 35c possible on Wednesday,so any talk of an 'average' 30c looks way out.Possible July record breaker ?

 

I wonder what model they're basing that on? Only NAVGEM is being that bullish at the moment.

[matty007]

Well the BBC news forecasts are now calling for 35c possible on Wednesday,so any talk of an 'average' 30c looks way out.Possible July record breaker ?

 

 

Can't see 36.2c being beaten. 

 

It's not records I'm interested in, although 35c will be lovely. Longevity is more important. I'd take a month of 25-28c over a day of 35c and four around 28c anyday. 

Edited June 28, 2015 by matty007