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

[mushymanrob]

Rob, here are the Naefs 00z anomolys (days 8 and 14) which is where today's CPC chart will come from

There will definitely be a high anomoly across the UK but it won't be very strong. My point is that run by run, the upper ridge is becoming less marked as we head through week 2 and those weakish anomolys provide for some uncertainty although a positive anomoly of any kind over Europe is going to mean decent heights where they are shown.

image.jpg. image.jpg

 

fair play

[mushymanrob]

Just going to drop this in here as it is relevant to the period 5-6 days down the line as to what the weather pattern may be.

 

hope it makes for an interesting read, and please make comment about it.

 

http://www.netweather.tv/secure/cgi-bin/premium.pl?action=gfs;sess=4834d1b1a7637fd8eb7444d53e16fe81

 

some this up as

will the ridge be NW of the UK 6-10 days from now or over the UK or even somewhere over east/SE of us.

 

very interesting john, but not what i was hoping to read!

[Cheshire Freeze]

I view all runs. The 12z and 0z runs have also been somewhat leaning away from a UK high until well into FI. 

 

Your right. In this instance i don't think the wider pattern supports a hot spell developing. Now some have disagreed and i could be wrong but right now we have somewhat atypical patterns globally in my opinion. 

 

It's not due to not wanting a UK high though. 

 

Don't worry mate, if you don't tow the 'a hot spell is just round the corner' line you'll get called out and told you're being negative. I agree with your assessments, at no point has this month looked like it would threaten any prolonged heat and significant N blocking has been a feature of a fair proportion of the output (though it hasn't always come to fruition to the extent as modelled).

 

The GFS has been touting a return to a N'ly based airmass in the mid range for a couple of days now so it's foolish to just simply ignore it if you ask me.

Edited June 14, 2015 by CreweCold

[stodge]

Don't worry mate, if you don't tow the 'a hot spell is just round the corner' line you'll get called out and told you're being negative. I agree with your assessments, at no point has this month looked like it would threaten any prolonged heat and significant N blocking has been a feature of a fair proportion of the output (though it hasn't always come to fruition to the extent as modelled).

 

The GFS has been touting a return to a N'ly based airmass in the mid range for a couple of days now so it's foolish to just simply ignore it if you ask me.

 

This time last week, the NAO was looking to go very negative so as you say while the possibility of northern blocking has been raised by GFS, it has so far backed away once we get into high-res. Even now, there's a lot of uncertainty:

 

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

 

From Thursday or Friday, there's no clear signal with a lot of options (including both northern blocking and the maintenance of the Azores HP on the table). The "col" option probably the favourite with no strong signal for anything which might mean no Atlantic influence and the weather coming from the east or north.

[Scorcher]

Don't worry mate, if you don't tow the 'a hot spell is just round the corner' line you'll get called out and told you're being negative. I agree with your assessments, at no point has this month looked like it would threaten any prolonged heat and significant N blocking has been a feature of a fair proportion of the output (though it hasn't always come to fruition to the extent as modelled).

 

The GFS has been touting a return to a N'ly based airmass in the mid range for a couple of days now so it's foolish to just simply ignore it if you ask me.

 

Negative all depends on your perspective- it seems many would actually be quite happy for what you suggest to occur. Just as I and a select few others would be quite happy to see mild conditions during winter- and would likely be shot down instantly if we tried to suggest that a mild solution without a great deal of support would be the likely outcome.  Can you post a chart that shows any northern blocking that has actually occurred in the last couple of months?

[Cheshire Freeze]

Negative all depends on your perspective- it seems many would actually be quite happy for what you suggest to occur. Just as I and a select few others would be quite happy to see mild conditions during winter- and would likely be shot down instantly if we tried to suggest that a mild solution without a great deal of support would be the likely outcome.  Can you post a chart that shows any northern blocking that has actually occurred in the last couple of months?

 

Maybe- but then again by the same token I've personally gone against the grain in winter too and downplayed progged cold spells if I can't see them materialising. You say about me posting charts which show N blocking but where are the heatwave charts? Other than a couple of days we've been experiencing sub 5C upper air and sub 0C on a couple of occasions. When all said and done it has actually been a fairly standard June, which, if you look back at the post I made early last week is what I said looked likely i.e a battle between Azores high and Atlantic trough.

 

The long term? Well I think it will turn wet for a period of time but that doesn't preclude an upturn to summery conditions in July or August.

[mushymanrob]

Fortunately theres more to summer then air temps. We have had a lot of strong sunshine and good air quality, many dry days too.

[Cheshire Freeze]

Fortunately theres more to summer then air temps. We have had a lot of strong sunshine and good air quality, many dry days too.

 

Indeed there is. It's been fairly pleasant IMO other than a nagging NWly which has made it feel rather cool at times.

[BlueHedgehog074]

Just going to drop this in here as it is relevant to the period 5-6 days down the line as to what the weather pattern may be.

 

hope it makes for an interesting read, and please make comment about it.

 

http://www.netweather.tv/secure/cgi-bin/premium.pl?action=gfs;sess=4834d1b1a7637fd8eb7444d53e16fe81

 

some this up as

will the ridge be NW of the UK 6-10 days from now or over the UK or even somewhere over east/SE of us.

Thanks for this post John - a good read.

 

 

As is usually the case with your reports, a lot of thought has been put into this document. Provides a valuable insight regarding what the upper pattern could be like in the next 6 to 10 days, especially for those new to those new to those kind of anomaly charts. Still learning to use those anomaly charts effectively, but it's worth taking a little while to study them to build up a picture in your mind. Not to mention, using them (almost) everyday to work out where the upper 500mb ridges and areas of higher than average, and lower than average, heights could move to as well as spotting the general long-wave pattern. Also, as you demonstrated, using the NOAA anomaly charts in conjunction with the ECMWF-GFS mean charts does seem to help provide a more wider picture and seeing what the overall confidence is like. It's interesting to find from this that using the GFS mean chart, in particular, has started becoming a match for the NOAA 500mb anomaly charts. It's as though the accuracy of the NOAA anomaly charts has made the GFS jealous and is now trying to take the No. 1 spot away from it. 

 

While they are at day ten, most of the long-range operational models (the 06Z GFS, 00Z ECMWF and the 00Z GEM) go for ridging to be close by over the UK, or just to the West/North-West of the UK in the Atlantic. Some differences clearly evident as you would assume from the operational models at that time-frame, such as the GEM having a strong mid-Atlantic Low, rather than the mid-Atlantic High Pressure the GFS has. (though, personally, I do feel the GEM is kinda overdoing the build up of High Pressure to our North even though the possible undercutting of Atlantic Lows could make it possible). 

 

 

The 00Z ECMWF 500hpa Height and Sea Level Pressure ensemble mean (using the 192, 216 and 240 hour charts), while looks a little messy, seems to keep surface ridging over the UK and extends to our North through the East of Iceland. Perhaps not a particularly strong ridge, however.

 

 

Does look possible it could be a varied mid-latitude and/or high-latitude block sort of situation with heights either setting up close by to our North/West (or perhaps even to our North-East should High Pressure get drawn towards Scandinavia), or somewhere over the UK. Personally can't see a proper Greenland High developing - doesn't look like heights and ridging will set up far enough North-West for blocking to establish directly over Greenland. Having said that, it will certainly be amusing to see the 500mb anomaly charts from the NOAA tonight to see whether it keeps ridging over, and just to the West of, the UK.

 

I know it's not worth going into too much detail for 8 days beyond, since the overall trends are more crucial, but if you're looking for further settled or warm weather after this week, then would perhaps need to hope the GFS doesn't keep troughing over the UK/Eastern UK too stubborn as it could hold back ridging of High Pressure to our West/North-West (or at least delay the ridge moving Eastwards) and keep the UK locked into a less settled and cooler set-up:

 

 

...although the GEFS air pressure ensembles (for London) shows the GFS operational model (bright green line) a bit of a outlier for the period 22nd to 25th June, which suggests the GFS could indeed be underestimating the strength of pressure over the UK for that time-frame.

 

 

The GEFS ensemble postage stamps at 192 hours using the 500hpa Height and Sea Level Pressure charts, on the whole, shows High Pressure being a fairly dominant feature for the British Isles. Ridging over the UK, in the mid-Atlantic or a flatter area of High Pressure to the South-West of the UK. What would seem apparent on this is the best of the brightest, driest conditions would generally be towards North-Western/Western and Southern UK, where High Pressure is more in-control.

 

 

In a way, those ideas do seem to fit along with what a number of anomalies are showing with blocking occurring around the UK/Atlantic/Iceland/Eastern Iceland areas. 

 

For the next few days, it looks as though the Azores High will throw a ridge towards Southern UK and keep the weather mostly dry and bright at times, with areas of Low Pressure to the North and North-West of the UK. The best of the warmest and sunniest conditions looking to be towards the South and South-West, though some rain, showers and overcast conditions could affect North-Western and Northern areas at times from the Atlantic, where the coolest and windiest conditions are likely to be. Though some showery weather could then spill down from the North later in the week to affect more areas of the UK as Low Pressure travels South-Eastwards to the North-East of the UK introducing a cool flow from the North-West.   

 

 

Overall, quite a reasonable week, especially for Southern UK with Summer-like weather at times.

 

Just quickly going back to the idea of blocking to the North-West, I suspect should the GFS go all mad and build a strong High over Greenland again like it did on the GFS 06Z yesterday, the next run could just shoot it away...    

 

[Methuselah]

I quite like the prospect of a weakish high: plenty of opportunity for LP down to our S or SSW to break through. Straw-clutch!

[Summer Sun]

t144 we have 2 differences between UKMO and GFS

 

GFS has a small area of low pressure just south of Iceland mostly dry in the UK, but the risk of some showers breaking out

 

 

UKMO doesn't have that low, thus high pressure is over the UK

 

[Mokidugway]

Doesn't look to bad to me , typical summer fayre ....

Edited June 14, 2015 by Mokidugway

[summer blizzard]

GFS12z is semi unsettled days 6-9 but then builds pressure quickly for a 3 fine days and thunderstorm affair. 

 

GEM12z is more progressive and gets ever worse.

 

Edited June 14, 2015 by summer blizzard

[Polar Maritime]

GFS continues to show some very strong Heights push up over Greenland around the 21st, With a week Low sat over or close to the UK.

 

[Milhouse]

The GFS for next weekend onwards has been all over the place lately. The GEFS 6z mean was a bit of a let down for warmth and high pressure but there are some pretty eye catching members amongst the 12z ensembles. The control run being one of them.

 

 

 

[knocker]

A quick look at the last three 12z GEFS anomalies just out of interest.

Just shows slightly more influence from the Scandinavian trough and movement west of the ridge. After that it's all a bit nondescript although weakish HP remains with a suggestion of a weak ridge to the east and with temps around average, maybe slightly above by the end of the month.

http://www.tropicaltidbits.com/

Edited June 14, 2015 by knocker

[ANYWEATHER]

Evening , and I hope every one has had a good weekend. Gfs is showing changeable conditions for the north especially this week whilst pressure rises across southern  Britain , gently the gfs lowers pressure right through to T+240 later this week, I think we are on to a big pattern change , but models are really struggling with the outcome......

[summer blizzard]

Euro tonight has capitulated to the GFS and sporadic GEM runs, well done GFS i suppose. 

 

Can't call it unsettled as such but the high pressure looks like losing at day 6 and then we get the edge of a trough and more cool air for the time of year. 

 

[Polar Maritime]

Yes ECMWF not to dissimilar to GFS now, With Heights pushing up into Greenland and a week Low sat around or over the UK by the 21st.

 

 

Edited June 14, 2015 by Polar Maritime

[Costa Del Fal]

Euro tonight has capitulated to the GFS and sporadic GEM runs, well done GFS i suppose. 

 

Can't call it unsettled as such but the high pressure looks like losing at day 6 and then we get the edge of a trough and more cool air for the time of year. 

 

Well done for something that has far from happened yet?

Deary me.

Certainly doesn't look a washout anyway these charts albeit somewhat cool at times. But at about a week away I'm not worrying about that and will be outdoors enjoying the sun and warmth this week here.

[Polar Maritime]

Well done for something that has far from happened yet?

Deary me.

 

S.B was pointing out that the ECMWF/Gem has picked up the blocking signals the GFS has been showing on in-trim runs over the last day or two. 

Edited June 14, 2015 by Polar Maritime

[Penrith Snow]

Shocking ECM!

Those people still going on about what a great June this is should stop taking the tablets.

Apart from a few nice days last week I have know higher temperatures in many a recent April.

Great winter charts but for summer they are nothing short of dire.

Andy

[Methuselah]

Eh? 18-25C?

[Milhouse]

Shocking ECM!

Those people still going on about what a great June this is should stop taking the tablets.

Apart from a few nice days last week I have know higher temperatures in many a recent April.

Great winter charts but for summer they are nothing short of dire.

Andy

 

Its truly dire but what is also disappointing is when the ECM 12z draws more focus than the 0z which happened to show a settled end with high pressure and warmth at 240h. As ever, the ensemble mean will give the overall picture.

[Skullzrulerz]

Shocking ECM!

Those people still going on about what a great June this is should stop taking the tablets.

Apart from a few nice days last week I have know higher temperatures in many a recent April.

Great winter charts but for summer they are nothing short of dire.

Andy

 

Please explain how they are "Shocking" for us?