Edited by user 06 September 2012 07:11:52(UTC) | Reason: Not specified
Overall, Mostly Cool & Wet with Warmer bits
Remember it well - I had 3 weeks off in July - good call
http://www.cpc.ncep.noaa.gov/products/people/wwang/cfs_fcst/images3/glbz700Mon.gif
http://www.cpc.ncep.noaa.gov/products/CFSv2/htmls/glbz700e3Mon.html
The two versions of the CFS show markedly different patterns dominating June. v1 delivers a pattern which could easily deliver some hot spells of weather but also some major thundery breakdowns. Perhaps we might see a spell or two of fine weather lasting 5 days or so... with some luck.
v2 just has high pressure dominant at the mid to high latitudes right across the Atlantic and through NE Europe. The strongest positive anomaly in that lot signals a mid Atlantic ridge trying to extend through the UK. I'd say a decent spell of high pressure right across the UK is quite possible next month based on that output, but either side of that we look to be facing rather chageable conditions.
For July, the two versions agree on positive anomalies over Greenland - not a good sign - and then they show a month dominated by westerlies but with the Atlantic tracking south of normal... potentially rather rubbish for the north and nothing special in the south... although there is some scope for the GH to be more to the west of Greenland, allowing some finer conditions in the SE at least, and v1 actually shows positive anomalies centered over the UK as well as to our NW, indicating that a spell of fine weather for many or all of us is quite possible.
The indications are rather weak for August... high pressure looks like it could be close by and northern blocking has been taken off the menu, so you never know...
Given all the above, it appears that this summer could see some notable swings between runs of fine weather, potentially with some decent plumes of heat in June, and runs of particularly dissapointing weather, the latter more frequent across the north than the south.
Frankly, that's not really calling for anything much beyond June, which is why I hesitate to make a long range forecast that looks more than a month ahead. Sure, looking at the other available models and composites could allow for a fair stab at what July might bring, but I simply don't have the time for that sort of thing
Who knows whats gona happen this summer and thats my forecast.
Edited by user 11 May 2012 09:12:09(UTC) | Reason: Not specified
Well, that is a typical summer in Scotland and Northern Ireland.
My last model based summer outlook video in April actually suggested the summer might be OK. You can see it (and the March summer video) here:
http://gavsweathervids.com/seasonal.html
I'll be doing another one in a week or so's time. It'll be interesting to see where this months model updates take us.
As for my own view, I'm thinking possibly the unusual combination of warm and wet. Frequent plumes, with frequent breakdowns.
So maybe a lot of thunder?
Edited by user 11 May 2012 12:53:13(UTC) | Reason: Not specified
I just dread the thought of another summer with HP in charge over eastern Eurpoe and Russia and LP stuck near the UK. I recall some of the 850hpa temp charts from last summer showing endless cool air spilling down from the north.
Looking at some charts from summers gone by there were cases where HP was dominant over Russia but it didnt scupper the chance for settled weather to come our way.
I had a 'feeling' on the Winter thoughts thread that it wouldn't be that snowy or cold. I had feeling on the Spring thoughts thread that April would be wet and cold.
I think there will be a 2 or possibly even 3 week period between early July and mid August that will see temps reach over 30c in the South, possibly even temps like 32c or 34c in some spots! This will be the best spell of summer weather for a number of years. Wont be a 1976 or a 1983 or 1995, but will be a very nice spell.
I think June will dry things out and temps will recover to normal or even slightly above values, but nothing spectacular.
My thoughts would be for a possible hot last week of July / first few weeks of August followed by a spectacular breakdown mid August with an early taste of Autumn just in time for the August bank holiday weekend
Veiwing various 'CFS 9 month' runs through to the end of July has revealed an interesting theme; the weather becomes very poor on numerous occasions, but between those spells there are decent periods of high pressure, often positioned such as to waft considerable quantities of continental heat across the UK... although the south is quite often plauged by troughing, meaning that while it would be warm, it would probably also be wet at times. There are a few UK-wide spells of fine weather too.
If you like considering years with similar patterns, 1983 is a hopeful one! Mild Jan, Cold Easterly spell Feb, Dry March, rubbish April-May. Thereafter an average but dry June, exceptionally warm and thundery July with a warm August thrown in. Of course all patterns have to end somewhere, and maybe the similarities will stop at the end of May. However I can't help thinking that such a dreadful spell will be counterbalanced by more summery weather. (Hopefully this year!)
Looking at the last few years of warm springs and poor summers we may well be in with a chance,who knows? nobody does thats the fact of the matter.
That fat blob of HP is still anchored over Russia on the 6z. Why has it become such a regular accurence over recent summers to see it there.
From MVH on twitter.
"Latest seasonal EC data signalling a +ve pressure anom to the W of the UK through summer, with a likely trough over the UK... In essence this model is signalling a rather 'blah' summer, nothing special, no signs for any significant, sustained heat or dry weather."
Still plenty of time for that to change...
Just to carry on from that tweet the other day, whilst I don't officially issue a summer or winter forecast, the middle of May is usually the cut-off point in terms of looking at the summer prospects and from what I have seen I am going with;
A predominantly unsettled summer with temperatures generally slightly below average and precipitation totals slightly above average. Obviously you could call this a 'forecast', but it's not official. This is simply based around a variety of features I have seen and looked at in recent weeks and months and there seems to be a clear sign for high pressure to be influential to the north and west of the UK with perhaps mid-atlantic ridging and a trough over the UK leading to predominantly unsettled conditions.
Clearly even in a poor summer some hot weather is likely/possible at times, but I expect this summer to be in-keeping with the last couple, overall relatively poor, which if it is would certainly make the year 2012 up to the end of August a particularly cyclonic one!...
As ever, it'll be interesting to revist this come September to see what the outcome was.
Regards, Matt.
So the prospects are there for a poor summer than...
Last summer was one of the driest since 1976 though not the warmest I'ed add.
As usual I've read conclusions predicting all manner of dominant weather types during June and July. August has had less mention - all I've seen is some expectation that it'll be a very westerly dominated month.
If you look at the CFS v1 and v2 outputs you'll see that they paint very different pictures for June - with the former showing high pressure most often close to our east and the latter most often close to our NW - before coming into close agreement for a cool July with blocking to our NW. Both have very weak signals for August.
What follows is just a bit of fun speculation...
Considering everything I've seen, including the predicted May anomalies when the month is said and done, I'm thinking we might see a warmer pattern from late in May through to about mid-June, perhaps widely settled for a week to ten days of that time, before the pattern switches to an somewhat cool and changeable one that persists from then until late in July at the earliest... during that time there could well be some more settled interludes but any warmth is likely to be of the home-grown sort during that month if the pattern evolves as envisioned here.
You only have to look through the early spring prediction thread to see how inaccurate virtually all the predictions turned out to be.