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Posted
  • Location: st albans
  • Location: st albans
its in its 'gestation' period and soon to be issued Nick.

Yes NOAA seem not too happy at the models suggesting a wave change over their area. 6-14 days it covers in their chat. Their own 500mb anomaly charts, first hint at a Euro high then, and this is the third day its happened, they then take it away.

sorry to distract you JH but that is more support for my thoughts that ECM is indicating a euro/sceuro high of sorts, dragging up a southerly. the fact that the 8/14 day output magically removes the high 3 days on the bounce must mean that GFS and GEM, in contrast, have no appetite for it. (ECM is absent from the 8/14 day musings on cpc)

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Posted
  • Location: just south of Doncaster, Sth Yorks
  • Location: just south of Doncaster, Sth Yorks

No 15-Update on Tuesday 24 June for 27 June – 6 July

For links/average temperatures for the period please see the usual links given in earlier posts.

Nothing I have seen from any data source, from either Europe or elsewhere suggests there is much to change from the Friday issue.

To put some detail on this: There remains doubt, at the end of the period as to whether the southerly will develop. From about the end of this month then quite high afternoon temperatures seem likely for the southern areas of England, less so the further north you go, and the more unsettled, although there will be showery outbreaks in the south and central areas in that period.

From T+192 to about 240(4 th July) then the higher values seem to be supported by both ECMWF and GFS outputs, albeit if you look at the normal 500mb-msl charts they show rather different methods of arriving there. (I personally think the GFS dartboard is a bit OTT, how OTT will become clearer as time goes on). If it is real it may in fact, thanks to the warm air advection ahead of it, be a bonus for the European upper ridge thus helping build the surface high GFS keeps dabbling with.

Post 240 hours then it would seem that the major teleconnections including the AO and NAO will pull the temperature levels back again to just about where we are at the moment. As GP has posted elsewhere the ending of La Nina, (according to NOAA its going to be a neutral position through the summer), could help the upper trough to remain in the Atlantic, time will tell?

Both the ECMWF and GFS on their hemisphere 500mb anomaly charts flirt with the idea of a Euro upper ridge but keep dropping it. I'm not sure if this is because of the teleconnections. The NOAA equivalent shows a similar thing, as one might expect, with the –ve arriving over the UK area from around 20W during the period 1-7 July.

From these and the signs of the AO and NAO trying to go +ve I would conclude that any marked change in the present set up, including the temporary increase in afternoon temperatures mentioned above, is unlikely to occur before about the end of the first week in July, the period end of this lrf. So the verification on that date will be interesting, the other verification will be 27 June (assuming I remember them both!).

Next update on Friday 27 June for the period 7-14 July.

sorry to distract you JH but that is more support for my thoughts that ECM is indicating a euro/sceuro high of sorts, dragging up a southerly. the fact that the 8/14 day output magically removes the high 3 days on the bounce must mean that GFS and GEM, in contrast, have no appetite for it. (ECM is absent from the 8/14 day musings on cpc)

if you look at the 500mb ECMWF and GFS outputs its the GFS that brings it in takes it away, ECMWF has shown little interest in putting it there in the first place!

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Posted
  • Location: st albans
  • Location: st albans

http://www.meteo.psu.edu/~gadomski/ECMWF_12z/hgtcomp.html

granted its from the op run, but the location of the negative atlantic anomoly is the same as the cpc chart which is derived more from ens data rather than operational (only just today though)

http://www.cpc.ncep.noaa.gov/products/pred...y/610day.03.gif

though its more south west/north east axis rather than south/north

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Posted
  • Location: just south of Doncaster, Sth Yorks
  • Location: just south of Doncaster, Sth Yorks

the first charts you show are for 12z, I took a decision, when I first started with lrf ideas, to just use one set, it happened to be the 00z, so its that I use each time. The 12z, I think 2 days ago was as keen as the one you show on building the upper ridge over Europe.

Which will be right we have to wait and see.

the second chart you show is this evening from NOAA, the last one I had seen before publishing was last evenings pair of charts, there are always two 6-10 and 8-14 days. Usually the 8-14 day one is less dramatic looking in terms of +ve and -ve anomalies. This has been the case almost without fail over the 4-5 months I've been doing them.

lrf work is just as fraught, indeed more so, than 24-120 hours forecasting as there is so much more to try and use to attempt as clear a view as possible. At the end, no matter whether its a professional or an amateur, old man weather can still take xxss, if you see what I mean!

one of the checks I'm just starting is looking at the predicted AO and NAO and seeing how it looked for that time on the actual charts. Then to see how the UK weather, courtesy of R Met Soc and their Monthly Summary, itself courtesy of Philip Eden, to see if there is a viable and forecastable connection.

Edited by johnholmes
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Posted
  • Location: just south of Doncaster, Sth Yorks
  • Location: just south of Doncaster, Sth Yorks

No 16- Update Friday 27 June for period 7-14 July

Average temperatures across the UK for early July are(Met O 1971-2000 data)

Northern Isels(14), Scotland and N Ireland (19), England and Wales (20-21) with London on 23C

Met O temperature criteria is

+6-7C above average is described as hot and +4-5C as very warm with +2-3C is warm.

Looking first at the AO and NA shows that both are predicted to rise but not by that much so I would suspect that blocking to the north of the UK will remain a feature through that period.

The 10 day outlooks from the ECMWF and GFS 500mb charts, see below, show a pattern that has been developing over the past few days. That is for a +ve area to begin to show over Europe towards Scandinavia as a –ve area edges closer towards the UK. The overall 500mb flow showing a south of west direction into the UK.

ECMWF and GFS for 4 july

post-847-1214601663_thumb.jpg

Turning to NOAA and their assessments of how the models are showing out to 14 days(10July-based on their Thursday resume) shows a mark of 4 out of 5 for their area; not that often that a 4 is given for the end period. Perhaps we should have a look at what they believe is such a good idea of what the upper air pattern will be over them.

As we can see the chart shows where the +ve and –ve areas are along with the overall 500mb flow. A trough between Russia and Alaska with a flattish flow into the west coast, a ridge in mid USA and a trough over the eastern side. Looking upwind of that we see another flattish flow over the Atlantic into a trough over the UK with some signs of +ve anomalies south of Iberia and also north of Greenland(NAO perhaps?)

post-847-1214601703_thumb.jpg

The latest ENSO update comments that tropical winds and convection continue to show La Nina conditions although the negative departures on the SST's have continued to weaken since February. Their prediction is for neutral ENSO conditions through August. (La Nina seems to refuse to die in spite of it predicted demise some time ago!)

Summary

All the above suggests to me that the major 500mb trough will be over or near enough to the UK for our weather to be not settled but with a flow mainly from a southerly rather than a westerly point. Surface pressure is likely to be generally relatively high, especially in the south east. The surface high pressure is probably going to be in two areas, and they may at times tend to link. The Azores high and high pressure well to our north east. In the time scale of this lrf I really don't see any major hot spell of several days or more. Much as the short term seems to indicate, a few such days for the south and east. Equally some unsettled weather from time to time, especially for the north and west and also possibly on a wider scale as the southerly warmth is replaced at times by a rather showery possibly even thundery 500mb trough before it warms out and resettles west of the UK. That would seem to be the most likely sequence of events to me. Nor is there any sign of any major Atlantic jet flow causing any more of the windy weather of relatively recent times, although rather breezy from time to time, again especially the further north you are, in association with lows as they track east north east towards the Iceland area.

Returning back to my comment about any major hot spell. It is a possibility, that a warm rather than hot spell may develop towards the end of the period and this may locally put temperatures into the hot category for some southern and south eastern locations but it is far from clear whether this may happen. Perhaps by next Tuesday, when the next update is due it may be clearer?

Next Update Tuesday 1 July.

Verification dates will be 7 and 14 July

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Posted
  • Location: just south of Doncaster, Sth Yorks
  • Location: just south of Doncaster, Sth Yorks

No 17 Update on Tuesday 1 July for period 7-14 July

I closed by saying Tuesday might give a better idea of any hot weather! Well, in a way it does, there is none, or none that I can see.

If anything the pattern looks more cyclonic and more unsettled than it did on Friday through the period of this lrf. Most indications from various sources is that low pressure and a 500mb trough are going to be the dominant features of the weather over the UK.

The two major models are not consistent in their advice. This is not surprising given the effects that events much further afield seem likely to have. We keep a slight La Nina (in spite of regular forecasts of its demise). ENSO is predicted to be neutral, now until the northern hemisphere ‘fall’ (American for autumn). Both AO and NAO stubbornly refuse to do more than show some tendency towards the zero line but not much else. The wavelength of the major troughs and ridges around the northern hemisphere shows little sign of any marked change. Both NOAA 500 mb anomalies and those a bit less far down the line from ECMWF suggest –ve height anomalies over or near the UK with +ve ones to the north.

Thus the forecast has to be for no sign of any ‘hot’ weather(as per the Met O definition-see previous links), and for a generally unsettled spell with rain or showers from time to time, some of it on the persistent side now and then, along with temperatures more akin to late spring than mid summer. There will be some warm days but they will be just odd ones with the south generally doing best. Breezy at times as any low gets near the UK and there may be more than one case of this occurring.

Looking at the latest AO and NAO there may be just a chink beginning to show, acka the developments around the equator right at the period end – no more than a glimpse though.

This will be validated on 7 and 14 July and the next update will be Friday 4 July for the period one week further, 14-21 July, taking us to the half way point of official summer

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Posted
  • Location: st albans
  • Location: st albans

NOAA cpc are discussing upstream changes over N america in their chat tonight JH. doesn't seem to work its way to any changes in our neck of the woods before mid month though which is where your thread looks out to. lets hope for those over the next few days.

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Posted
  • Location: just south of Doncaster, Sth Yorks
  • Location: just south of Doncaster, Sth Yorks

yes, their comments are always read daily and incorporated into my summary when it seems relevant.

Hence my comment about wavelengths as their idea fits with other data I've been watching.

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Posted
  • Location: just south of Doncaster, Sth Yorks
  • Location: just south of Doncaster, Sth Yorks

No 18 Update on Friday 4 July 2008 for 14-21 July 2008

Average temperatures are shown below

Average temperatures across the UK for early/mid July are (Met O 1971-2000 data)

Northern Isles (14), Scotland and N Ireland (19), England and Wales (20-21) with London on 23C

Met O temperature criteria is

+6-7C above average is described as hot and +4-5C as very warm with +2-3C is warm.

Links for those new to this are in previous Friday issues.

This outlook takes us half way into the official summer. Nights are already, believe it or not, drawing in!

The last forecast suggested that there was little to suggest any marked change in the pattern we have had for so long. That is a 500mb trough too close to the west of the UK for any settled weather. This being caused by various factors, most emanating from the tropics. Not surprising really as the area either side of the equator is the heat engine of the earth, courtesy of the sun of course. Events in these areas do have an impact on the weather for more northern regions, links like the AO and NAO stemming, partly at least, from ENSO-La Nina, El Nino etc.

NOAA currently expect neutral ENSO conditions into our autumn. The latest charts predicting AO and NAO can be seen at this link

http://www.cpc.ncep.noaa.gov/index.php

Both show a rise almost into +ve before later showing signs, especially the AO of a return into –ve values although nothing like as low as it currently is. The NAO has a wider spread and tries to sit near the zero line but with a few below. How much can we believe these forecasts? Are they any more reliable than what many see dailyX4 with GFS? They are certainly more reliable than watching on each GFS run and are, so it seems to me, over the past 3-4 months of regular use, quite often a fairly good indicator of the basic weather pattern for the UK area. Will it be cyclonic or anticyclonic and generally good guidance on how much so of these which in turn gives a reasonable picture of the type of weather we can expect?

The 500mb anomaly charts from NOAA alone and those showing both GFS and ECMWF are generally showing less sign of +ve anomalies near the UK, especially north of the UK. Several days ago they were still showing anomalies which suggested out to about 7-10 July that some kind of surface and 500mb blocking would persist north of the UK. Their change over the past few days seems consistent so it may indicate a change about to start. Certainly not something that you could easily pick up on if just using the major model control run. Watching the T+240 for GFS and ECMWF has seen more or less a change a day with one or sometimes both models. This ‘switching’ has also been referred to by GP, (far more experienced in lrf attempts than me). It does seem to me, and they have shown this before just prior to a fairly major change in pattern, that it is ‘perhaps’ a sign that a change is about to show?

Links to see both the combined ECMWF-GFS 500 mb anomaly charts out to day 10 and the NOAA link for their charts right out to day 14 are below

http://www.meteo.psu.edu/~gadomski/ECMWF_0z/hgtcomp.html

I have kept almost 2 months of these charts if anyone is interested although I have no idea how they might be copied to anyone!

http://www.cpc.ncep.noaa.gov/products/pred...10day/500mb.php

So my forecast

Little change in the present type of pattern well out into the period. A 500mb trough is going to be the main player with surface low pressure continuing to affect the country from time to time. Most of the activity will be in the north but even the south will not be immune at times. There is, currently, no sign of another low like the one this weekend but they seem to have a habit of appearing at relatively short time scales (in comparison to lrf issues some 2-3 weeks ahead). Towards the end of the period under review then, references above, there are rather more definite signs that a change may be starting by then. This would tend to give more settled weather, working up from the south, and with afternoon temperatures starting to rise to more reasonable values for mid summer.

Tuesday may give more such indication, or it may not!

Next update Tuesday 8 July and verification of this will be 14 and 21 July.

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Posted
  • Location: Lincoln, Lincolnshire
  • Location: Lincoln, Lincolnshire

Long range forecast Summer '08 and early autumn '08:

OK I don't claim to use any scientific methods but let's see anywy

July 2008

Generally about average temperatures, wet at times, warm at others while slightly unsettled and showery, this remaining through to the early 4th week, then brief high pressure from the east will develop, giving some settled days with average to slightly above average temperatures

CET: 16.0c

August 2008

Starting slightly settled seeing highest temperatures in the first week. However, becoming quickly unsettled with north westerly winds dominating, showery with longer outbreaks of heavy rain at times and depressions tracking one by one over the UK. Much cooler than normal.

CET: 14.3c

Before any one jumps on me let's say nobody really "knows" anything when it comes to Long Range Forecasting. Doing it this way is no less accurate than using scientific methods in my opinion these days, that will soon change of course, but there's my forecast, you can take it at face value and just see what happens, like we all have to do.

Some of the most meticulously thought out scientifically based forecasts for the long term turn out to be the most dramatically incorrect of all!

Edited by richarddx7
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Posted
  • Location: just south of Doncaster, Sth Yorks
  • Location: just south of Doncaster, Sth Yorks

No 19 Update on Tuesday 8 July for 14-21 July

As usual on a Tuesday its a relatively short update

Has anything changed materially since the last main update for this period last Friday?

This is what I wrote then:-

Little change in the present type of pattern well out into the period. A 500mb trough is going to be the main player with surface low pressure continuing to affect the country from time to time. Most of the activity will be in the north but even the south will not be immune at times. There is, currently, no sign of another low like the one this weekend but they seem to have a habit of appearing at relatively short time scales (in comparison to lrf issues some 2-3 weeks ahead). Towards the end of the period under review then, references above, there are rather more definite signs that a change may be starting by then. This would tend to give more settled weather, working up from the south, and with afternoon temperatures starting to rise to more reasonable values for mid summer.

Tuesday may give more such indication, or it may not!

The answer has to be very little with the data up to Tuesday providing no more solid evidence of any marked change. There is, as yet, no real sign of the major ‘players’ forcing a major change in the pattern for the UK area. As I mentioned on the model thread just what effect hurricane Bertha may have has yet to be seen. It will most likely curve north east well clear of the USA and may create more problems from its effect further north than any precipitation or wind problems. By that I mean it may just add to the –ve sign for the NAO which still shows reluctance to make any mega change. There is some indication of both the NAO and AO showing change but not enough for me to predict anything major in the continuing pattern as suggested above.

On the shorter time scale, beyond this week, T+240, both major models continue, if not to chop and change, then to show variations with each other and indeed from one day to the next with their own output. An indication I feel of the possible changes much further afield that seem sometimes to indicate some change and then fail to firm up on that. So we watch and wait for things like MJO, and nearer events affected by such matters, to give more solid grounds for any real sign of a summery spell of several days at last. Maybe come Friday, hope springs eternal!

post-847-1215545153_thumb.jpg

Just for a spot of light relief, here is the CFS chart for Xmas Day, although its not really got any support from the monthly output. Its version (monthly one) for July shows below average temperatures for most areas away from the western and northern extremities with average to above average rainfall for many.

Next update will be Friday 11 July for 21-28 July, No 20; with validations being done for this lrf on 14 and 21 July and for No 20 on 21 and 28 July

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Posted
  • Location: Brixton, South London
  • Location: Brixton, South London

John thanks for the update.

Would you please set out the mechanism by which ex-hurricane 'Bertha' might intensify the -NAO signal?

Doubtless some excitedly await the August CFS Christmas synoptic update for signs of 'upgrades/downgrades'...

regards

ACB

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Posted
  • Location: just south of Doncaster, Sth Yorks
  • Location: just south of Doncaster, Sth Yorks

as Bertha is 'warm' cyclone once it gets into the northern Atlantic it tends to push warm air aloft which in turn causes pressure rises due to the warm air advection(WAA you will see some people using).

equally depressions on their rear show CAA(Cold air advection), all very complex but its what causes lows and highs put very simply.

I'll look for a better explanation on the web and, if I find one, or someone else does, then I/they could post that link in here.

hope that helps anyway.

not sure if this link is any help

http://www.theweatherprediction.com/habyhints/18/

Edited by johnholmes
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Posted
  • Location: Worcestershire
  • Weather Preferences: Forecaster Centaurea Weather
  • Location: Worcestershire

....

1) WAA in the North Atlantic;

2) increased storminess and surface mixing helping to upwell colder water from below in the sub-tropical Atlantic;

3) negative OLR and greater cloud fraction over the sub-tropical Atlantic preventing surface heating during the Summer leading to colder SSTAs over the sub-tropical Atlantic in the winter.

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Posted
  • Location: North Yorks, prev West Essex
  • Location: North Yorks, prev West Essex

Thank you for the update John. Have just ordered a sledge!! :)

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Posted
  • Location: Brixton, South London
  • Location: Brixton, South London

JH/GP many thanks for the explanations.

JH: I had a quick look at the link and it seemed to me useful.

regards

ACB

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Posted
  • Location: Castle Black, the Wall, the North
  • Weather Preferences: Spanish Plumes, Blizzards, Severe Frosts :-)
  • Location: Castle Black, the Wall, the North
post-847-1215545153_thumb.jpg

Just for a spot of light relief, here is the CFS chart for Xmas Day, although its not really got any support from the monthly output. Its version (monthly one) for July shows below average temperatures for most areas away from the western and northern extremities with average to above average rainfall for many.

Good chance of a white christmas then :)

Signs of hope in fantasy land for a bit of high pressure but today's rain is now advancing north east, could be 50-75mm in places with flooding a probability as the front responsible will be very slow moving for much of daylight hours before shifting the bad weather further north for wed night and thursday. Friday could see more torrential downpours in the north and east and the weekend looks showery as does the first half of next week. Temps not too bad and after the deluge on wednesday the sunshine levels look adequate for england and wales.

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Posted
  • Location: just south of Doncaster, Sth Yorks
  • Location: just south of Doncaster, Sth Yorks

No 20 on Friday 11 July for period 21-28 July

Average temperatures for end of July are below

14C (N Isles)-19C for Scotland and N Ireland-20-21C for much of England and Wales with 22/23C for London

Reviewing the evidence, (please excuse the lack of charts as I’ve had my pc away for 24 hours and whilst I made copies of what I felt relevant I have not time this evening to upload them), there is very little, at least for the first part of the period to suggest any real change from the last couple of lrf summaries.

That is the status quo continues with a 500mb trough, along with the Azores ridge in its geographical position (for much of the time) ensures we get air from a point north of west for most areas for most of the time. Temporary backing of the flow ahead of weather systems linked to the 500mb trough will give southernmost areas the odd day of very warm temperatures.

That apart a generally unsettled picture with no prolonged dry let alone warm spell for the couple of weeks would be my summation.

Thereafter as NOAA have pointed out the effects in the tropics do suggest that things may start to change. Both the AO and NAO appear to be responding to this suggestion with a mix of rises and falls with the overall trend being a rise to around zero or a little above late in the month. Just what effect hurricane Bertha may have is open to a number of possibilities. Currently the main idea would seem that she will move south of Greenland towards the Iceland area and engage the 500mb trough to give more unsettled weather. However, that is not certain by any means and she may end up west of the main Azores ridge, or at least part of her, thus tending to build that ridge which MAY, along with the QBO, ENSO etc, cause the high to migrate to a little east of the UK and could give a more southerly, possibly, even more blocked flow.

I simply don’t know this far ahead but to repeat I see little major change out to the start of this period.

Validation dates will be 21 and 28 July

The next update will be a week today NOT next Tuesday. The work involved really is too time consuming to do it 2x weekly. It may also be a better idea as well to take a more detached view of a week of data.

Next Update No 21 on Friday 18 July for 28 July – 4 August

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Posted
  • Location: just south of Doncaster, Sth Yorks
  • Location: just south of Doncaster, Sth Yorks

sorry not been back long and too knackered to write much sense this evening, will do it, for the same period, during tomorrow morning.

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Posted
  • Location: just south of Doncaster, Sth Yorks
  • Location: just south of Doncaster, Sth Yorks

rather late but here with my latest ideas

No 21 on Saturday 19 July for 28 July - 4 August

As I've been away this will be a fairly brief summary of how I see things from the data I have been able to look at.

Events around the equator do seem to have started to move a little after a rather static period. This will in turn affect other so called drivers/teleconnections in time. Bertha seems probably to have decided roughly where she is heading. AO and NAO charts show changes occurring, or rather being predicted to occur, mind you the charts do show variations in them, just as the more routine GFS charts we all see every day, do. La Nina effects seem finally to have about disappeared with ENSO being predicted to be neutral into our autumn.

On the model fronts, from NOAA and ECMWF, for their hemispheric 500mb charts, again, as with any forecast tool, they are not constant either between each other nor indeed with one run to another of the same model. Much like many see on the GFS and ECMWF North Atlantic forecast charts.

Before we get to the time scale shown above most should experience a little bit of summer(almost hot for southern parts) before yet another trough works in from the Atlantic, possibly in the form of some storms(at least for some) through Thursday(24/07). These seem most likely for the southern half of the country although possibly not exclusively.

Thereafter into the period 28 July – 4 August, indications suggest that surface high pressure will be fairly nearby, both south west and north east, but with a trough at 500mb, not as cold as recently, with the 500mb flow from a direction south of west, so on the warmish side for many. The surface high to the north east may be fairly persistent, possibly extending south into parts of Europe at times. This is by no means a certainty but does hold the prospect of fairly warm temperatures for much of the southern half of the country for much of the time and possibly extending further north at times. I don't see a heat wave as such mind you! The upper trough is too close not to rule out unsettled weather from time to time, and this could be of a thundery nature for the south. In the north then the proximity of the 500mb trough could give rather more changeable weather at times.

Validations for 28 July and 4 August

The next update will be Friday 25 July for the period 4-11 August

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Posted
  • Location: just south of Doncaster, Sth Yorks
  • Location: just south of Doncaster, Sth Yorks

Update No 22 for 4-11 August

Average afternoon temperatures for early August are:-

14C for the N Isles to 19C for most of Scotland and Northern Ireland and 21C for much of England and Wales with 23C for London

This takes us into the second week of August so what indications are there. Will the present fairly hot if rather unsettled spell last this long?

It seems highly unlikely that the heat will stay for the period 4-11 August. Nor do I see any especially settled spell.

The latest NAO shown below has changed quite a lot from earlier predictions whilst monitoring for this update. It now has no return to around zero but a continued fall before it later shows a rise. This would tend to favour pressure remaining high somewhere to the north of the country. Currently most charts, both those seen regularly, and others, show this is likely to be, initially, to our north east(where it is now) but then pulling back west to nearer Greenland as time goes on.

NAO

post-847-1217019650_thumb.jpg

NOAA seem fairly happy with their model interpretation and what it shows; that is much as you can see in this evenings 500mb anomaly chart for the northern hemisphere; period 2-8 August

post-847-1217019678_thumb.jpg

This has the trough-ridge-trough idea across the states with the flow as shown out into our area. Suggesting that the 500mb flow will have a trough quite close to the UK with little sign of any +ve heights to our south east but more likely to our north. This would tend to favour a 500mb vortex creating surface low pressure from east of the States across the Atlantic and east north east across the UK at times. Just looking at the GFS runs way out towards T+348-384 and this idea has been 'played around' with on most runs in some way or other over the past 5-7 days.

Why is this pattern showing? Well much of what GFS seems to be trying to suggest as a pattern and what the 500mb charts also show is being governed by the NAO in turn this by events around the equator.

ENSO is predicted to be a 75+% chance of being neutral way into late 2008 and this in turn is being affected by events in the tropics. Well demonstrated by the various posts from GP, better than I can as he has a better handle on much of these events than I have. So do read his posts.

The latest NOAA 500 anomaly charts out to 8th August is shown above; the idea of a +ve area somewhere in the Greenland area(this time into ne Canada) and a –ve area west of the UK has been a feature over the past week, so it looks reasonable to suppose something like this may be what we actually get. If you compare it to the other charts I've shown and the comments I've made based on other data and it may be not that far from its general idea=largish 500mb trough just west of the UK with surface high pressure in the Azores area and also west of Greenland.

Summary of the expected weather 4-11 August

Not settled, less hot than the next few days but, apart from possibly late in the period, not much below normal temperatures for many. Indeed still generally above for southern areas. Unsettled at times, especially away from the south and south east where mostly settled apart from an isolated thundery or showery spell early on as minor upper troughs swing across the north western half of the country. In this area then quite unsettled at times.

There is, at the moment, its impossible to be more than a 50-50 risk, of a marked flow developing from the north west late in the period. This would bring cooler conditions for all and as it developed a fairly breezy time as perhaps as one main depression ran close to the north of the country with a rise of pressure behind it giving the flow from north of west.

Verification for 4 and 11 August and the next update is scheduled for Friday 1 August for 8-15 August

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Posted
  • Location: just south of Doncaster, Sth Yorks
  • Location: just south of Doncaster, Sth Yorks

no lrf update this week due pc problems; will hope to be able to do the validations on those currently running.

Next update will begin after Monday 11 August after return from a weeks walking in the Jungfrau region, 5-10th

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  • 2 weeks later...
Posted
  • Location: just south of Doncaster, Sth Yorks
  • Location: just south of Doncaster, Sth Yorks

will restart lrf's again on Tuesday 12 August, thereafter each Tuesday evening.

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Posted
  • Location: just south of Doncaster, Sth Yorks
  • Location: just south of Doncaster, Sth Yorks

herewith the next lrf update No 24 out to 31 August;

apologies its in a link but its quicker and time is short for me this evening, I'll try and do it the usual way next time.

No_24_Update_on_Tuesday_12_August_for_the_period_12.doc

for those having a problem downloading the whole file below is the summary

A brief summary then is for no settled weather of any length or any real warmth through August. A hint, no more at the moment, that into early September may see a more settled spell developing.

Next update is Tuesday 19 August with verification of this forecast on 24 and 31 August.

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