Model Output Discussion 01/06/2012

[Backtrack]

There is absolutely zero chance 30c-33c would be reached looking at that chart. You're taking the 850's into account without considering other variables such as rainfall, cloud cover, wind and surface temperature. Going by that chart 18c - 22c.

.. It was raining today under 5C uppers and the SE managed 20C.

The chart is not on the present run anyway, so both our points are not valid at the minute, I didn't bother to look at any other charts either, but in any sunny spells, with 20C uppers, you're talking high 20's.

[Snowy Easterly]

GFS 18z looks good for next week, but who wants to bet the warmth will get shunted south and we end up with some sort of cool cloudy northerly again.

FI but hope this comes off http://cdn.nwstatic.co.uk/gfsimages/gfs.20120621/18/168/ukmaxtemp.png

[Slowpoke]

Best chart of the summer so far in my opinion, BANK!

[Snowy Easterly]

yep look at all that heat in europe for next week it will be a kick in the balls if we end up with the cool rubbish again

the heat don't last long anyway but its better than nothing

Edited June 21, 2012 by Snowy Easterly

[I Cumbria Marra I]

GFS 18z looks good for next week, but who wants to bet the warmth will get shunted south and we end up with some sort of cool cloudy northerly again.

FI but hope this comes off http://cdn.nwstatic....8/ukmaxtemp.png

15c for me

Best chart of the summer so far in my opinion, BANK!

me and you are too far north and west

[Slowpoke]

Yeah I know but it'll be cool to see what happens around the country. Possibly the most intense thunderstorms for years.

[Snowy Easterly]

it is the 18z though and you know what people say about that, its probably leading us up the garden path

[Robbie Garrett]

Best chart of the summer so far in my opinion, BANK!

I've replied in the Convective thread. Clicky

[Trackback]

I've replied in the Convective thread. Clicky

Looks warm, possible pressure increase aswell on us?

Also GFS looking a bit mixed some rain, sun and interestingly it looks like the wind will blow from time to time aswell.

Edited June 21, 2012 by Trackback

[Robbie Garrett]

Looks warm, possible pressure increase aswell on us?

Also GFS looking a bit mixed some rain, sun and interestingly it looks like the wind will blow from time to time aswell.

I think any warmth may be shortlived, it's encouraging but it's only step 1 of 10,000 needed before we get into any decent spell of weather. I am sure there will be a decent spell of weather, it might not be anytime soon though. But settled in British Weather doesn't mean 40*C heatwave, -10 can be settled during a winters day under clear skies.

[shedhead]

ECM and UKMO paint a much warmer picture for next week, with LP stalling in the Atlantic and allowing a S flow to develop for a time. GFS goes with a similar type evolution, but ultimately fails to move any warmth much farther north than southern England. No denying some better looking prospects this morning though, which makes it all the more surprising that this thread is so quiet.

[picog]

Quite a difference in the amount of rain forecast for London versus Manchester — the SE might start to dry out!

http://www.wetterzentrale.de/pics/MT8_Manchester_ens.png

http://www.wetterzentrale.de/pics/MT8_London_ens.png

[ANYWEATHER]

ECM and UKMO paint a much warmer picture for next week, with LP stalling in the Atlantic and allowing a S flow to develop for a time. GFS goes with a similar type evolution, but ultimately fails to move any warmth much farther north than southern England. No denying some better looking prospects this morning though, which makes it all the more surprising that this thread is so quiet.

Yes warmer and apart from better conditions for most on Mon/Tues it looks as though things turn distinctly unsettled from mid-week onwards although probably turning warm and humid in the south ahead of the low moving slowly in. Might be something for storm lovers too from weds onwards, anyway longway off but somrthing worth watching!

[bluearmy]

following on from the 00z runs, the 12z naefs spread continues to show the monday shortwave crossing the uk whilst the ecm 12z spread has picked up a small shallow but discreet system at the same juncture. this is at odds with much of the operational output for monday 25th which at this time looks pretty reasonable. this will be a good test of whether the ens spreads are a better bet than the fi ops. (although a week tomorrow shouldn't ordinarily be seen as particularly fi). the possible ridge for the thursday has dropped off naefs 12z run. it looked a bit of a 'stretch' but we should continue to look out for it on subsequent runs.

i note WB's post above re the may warm spell. it wasnt a surprise to all - many of us were trailing this event at least 10 days before it arrived. it showed up consistently on naefs fi as a high anomoly, initially as a sceuro block at two weeks range and then it began to show as a retrogressing high moving nw towards iceland and ultimately greenland, where its been ever since !!

just coming back to this, the sat night into sunday shortwave is the one that the spreads had picked for monday. evidently, the modelled rise in pressure ahead of this feature failed to verify and it will zip through 24 hours earlier than the spreads showed. what is looking like an even better pick from the sunday morning naefs run is the plumey ridge next thursday. again, this may be a bit faster coming through and thursday may be less settled than wednesday.

[Weather Boy]

Quite a difference in the amount of rain forecast for London versus Manchester — the SE might start to dry out!

http://www.wetterzen...chester_ens.png

http://www.wetterzen..._London_ens.png

Interesting, the ensembles are very dry for London. However I recall that the ensembles were surprisingly dry when the LP was approaching a couple of weeks ago and my location received over 30 mm of rain which was not uncommon in the region. This therefore suggests that ensembles can under-do rainfall events, or are at present.

This does support my NW/SE split theory, although the current Meto long range doesn't seem interested in it.

[Carl46Wrexham]

Exactly what I was thinking. It's true to say that, at present, there is absolutely no sign of any long-term settled weather for the UK.

However, at the beginning of the month the jet was essentially over the channel. Last weekend's weather, which for where I was at least (the south) was nowhere near as bad as forecast, the Low was much further north than earlier in the month. This weekend's low (not liking the good weather being in the week and bad weather at weekend) looks to be generally further north with the jet nearer its more usual position. There are hints of a high nudging into the channel pushing the low further north.

I conclude from this that the trend is gradually improving for the south, but for the north, if anything the position is worse, because northern Scotland at least was a long way from the jet earlier in the month, now the jet gets closer to that location, allowing more settled weather in the south, although that is not to say that the south will be immune from showers or frontal systems from time to time and indeed, as I said at the start, heatwaves and the like are very much for far FI, if at all.

In short, still not brilliant, but a gradual two steps forward one back type improvement compared to the start of the month.

Good old SE/NW split anyone? Likely solution for 30 June onwards, IMHO.

No thanks. That sort of set up would just continue the crappy weather we've had more than enough of up here.

[Summer Sun]

Another dreadful run from GFS this morning summer remains firmly on hold with July starting just how June has been

http://www.null/ds/gfs.htm

[Thundery wintry showers]

NW/SE split scenarios are most often associated with a strong northerly tracking jetstream and a persistent belt of high pressure to the south. In summer this is typically associated with ridging from a strong Azores High. Typically we get a zone of mostly dry but cloudy weather on the northern flank of the high pressure, with dull wet weather to the north-west of it and sunny dry weather to the south-east of it, and the positioning of the three zones depends on how far north the high pressure is able to extend.

The above scenario is the reason why I am reluctant to embrace settled spells associated with a ridging Azores High and the jet in its usual position, for north-east England quite often ends up in the area of cloudy nothingness in between the two zones, and we often get to hear about the comparitively warm sunny weather down in London, expressed as if it's occurring over the whole of England and Wales.

I think this NW/SE split scenario is actually unlikely to arise in the near future. The models still have low pressure systems taking a generally southerly track and the Azores high is still displaced to the south and west of its usual position. The current model outputs suggest that the jet will slow down somewhat, allowing an emphasis on warmer brighter weather with rainfall mostly of a convective rather than frontal nature, but note that this looked likely last week and then we found out that the models were underdoing today's autumnal depression.

[Bobby]

The NAEFS anomoly maps hold little hope for summer starting anytime soon.

+240 shows the trough in control:

Pressure then briefly builds but then the troughing builds again at the end of the run:

Then it looks like another soaking for most Saturday night as another system sweeps in before things settle down a little bit into next week before the next low approaches.

NAE rainfall:

ECM pressure and rainfall for Thursday:

Edited June 22, 2012 by Barb-

[Weather Boy]

If you look at my original post, Ian, I did say from 30 June on, not "in the near future". I selected that date as it's roughly the start of FI. It's only a theory though, based on the fact that the scenarios is hardly a rare one, and we seem to have a jet stream moving north, with a Euro high developing.

Looking at all three models, who could disagree with Blast's post about Groundhog day? It's amazing how similar next week is looking to this one. What is with Thurs/Fri lows so far this summer? The main difference to my eye is that the orientation of the low in a week's time looks likely to drag up some very warm air temporarily.

[phil nw.]

The mean outputs still keep the trough around the UK into week 2.

http://www.meteo.psu...0z/hgtcomp.html

the jet still running across our latitude next week.

suppressing any height rises from the south and thus will prevent anything other than brief drier interludes between further disturbances from the Atlantic.

I really can`t see any strong signal for a radical improvement yet

[Carl46Wrexham]

Sums this lousy summer up.

[Thundery wintry showers]

If you look at my original post, Ian, I did say from 30 June on, not "in the near future". I selected that date as it's roughly the start of FI. It's only a theory though, based on the fact that the scenarios is hardly a rare one, and we seem to have a jet stream moving north, with a Euro high developing. Looking at all three models, who could disagree with Blast's post about Groundhog day? It's amazing how similar next week is looking to this one. What is with Thurs/Fri lows so far this summer? The main difference to my eye is that the orientation of the low in a week's time looks likely to drag up some very warm air temporarily.

True, but I don't really see much likelihood of a NW-SE split setting up into early July either- looking at the synoptic charts at T+168 the Azores high is still a long way away from our shores and as Phil noted the jet is on a collision course with the British Isles. We are progged to have a weak high over Europe but in that sort of situation one of two things tend to happen: either lows come crashing through and push away the block (as has happened this time around) or we move into a slack regime with brighter, warmer and potentially thundery weather. At present, looking over those 8-14 day charts showing the mean trough stubbornly close to the British Isles, a sort of "Groundhog Day" looks to be the favourite to me, a brighter warmer interlude early to mid next week with scattered sharp showers for some and then a return to cloudy wet weather at the end of the week.

[bluearmy]

Interesting, the ensembles are very dry for London. However I recall that the ensembles were surprisingly dry when the LP was approaching a couple of weeks ago and my location received over 30 mm of rain which was not uncommon in the region. This therefore suggests that ensembles can under-do rainfall events, or are at present.

This does support my NW/SE split theory, although the current Meto long range doesn't seem interested in it.

http://www.meteo24.fr/fr/home/meteo-france-et-europe/passion-meteo/ensemble-de-previsions.html?eps=london

looks like dry mon and tues next week. beyond that, quite a bit of dry clustering - especially during the first week of july. i wonder if it will pan out like that ?? this is for london. puts this month into perspective when 40mm mean precip over the next fortnight is being lauded as 'optimistic'.

[Thundery wintry showers]

London's average fortnightly precipitation total at this time of year is around 20-25mm, so the implication of the ensembles is that the upcoming fortnight will probably be wetter than average but not exceptionally so.

I think a pattern of alternating dull wet interludes and slacker bright/warm interludes with scattered showers would certainly give us warmer, drier and sunnier stats than we've seen for June so far (which isn't difficult!) but chances are we're still looking at below average sunshine overall as well as above average rainfall with temperatures no higher than average. Still, early to midweek gave some reasonably comfortable weather for outdoor stuff in many places and next week may be similar.