Model output discussion 14/04/18

[Man With Beard]

39 minutes ago, Frosty. said:

For the rest of this week the Ecm 12z ensemble mean indicates plenty more of what we've seen today..i.e..high pressure bringing beautiful blue skies and hot sunshine. As I've mentioned a few times today there is a risk of T-Storms spreading up across southern / southeast england from France from around sunday into the start of next week as it does look like becoming more humid further south during that period but then the mean shows a gradual change from the west from around next midweek as cooler / fresher atlantic air spreads in but of course that could change. 

The ECM mean is getting rather consistent about a westerly breakthrough mid-next week - though I agree it is a way off, when the mean does this, it's rarely a million miles away. 

But I also drawn to heights to the NE. Which may mean the Atlantic doesn't break in for long before the next draw from the south? 

Edited June 25, 2018 by Man With Beard

[Leo97t]

I have a feeling that the breakdown will lead to either a Classic Summer with a July CET above 18C or a disgusting Atlantic destruction à la 2015 with a CET of around 15C. With what 2018 has brought already I just don't see an average/mixed summer. Now I say that it's probably gonna come out bang on average 

[mb018538]

Well the BBC long ranger tonight is going full guns with the unsettled Atlantic breakthrough into next week...

How exactly does that fit in with this from noaa?? Completely different there surely?!

[Man With Beard]

3 minutes ago, mb018538 said:

Well the BBC long ranger tonight is going full guns with the unsettled Atlantic breakthrough into next week...

How exactly does that fit in with this from noaa?? Completely different there surely?!

It might fit in if the breakdown is D9/D10 - the NOAA 8-14 day chart is completely different, much flatter

[summer blizzard]

BBC probably go largely with the Euro ensembles though both GFS and Euro tonight go for an Atlantic win at days 8 and 9. 

[Mike Poole]

Not had much time to look at the models today, but with ECM and UKMO so different at T144, there's no clarity at all beyond the weekend.  So it's in that spirit I post the first half of the GFS 18z:

That cut off low starting to cause issues into the weekend.  But uncertain where we go from there.  The GFS parallel 12z seemed to side with ECM take on things, actually decent through to T192:

Edited June 25, 2018 by Mike Poole

[Cheshire Freeze]

53 minutes ago, summer blizzard said:

BBC probably go largely with the Euro ensembles though both GFS and Euro tonight go for an Atlantic win at days 8 and 9. 

GFS with a more concerted effort to turn gradually more unsettled into July on this evening's run. Could be some thundery activity initially, before the troughing takes hold to a greater extent

[Cheshire Freeze]

Wow, some actual rainfall spikes

[bluearmy]

The eps clusters days 8/10 onwards continue to look a bit more mobile but we’ve seen the extended outlook quite wrong several times already this spring/summer. 

Note the ec 45 is pretty troughy last third July and beyond. First time I’ve seen this outlook so Monday nights forecast awaited with much interest. 

Edited June 26, 2018 by bluearmy

[Guest]

It’s a shame such a memorable spell of weather will go out with such a whimper, it deserves so much more. It certainly starting to look as through over the weekend temperatures will start to ease off and by the time we get into the middle of next one of those rare events ‘a front’ might starting crossing the country. At this range those like me who love sun and warmth will be hoping it’s just a blip and not a longer term pattern change however our luck can’t go on forever especially given May and June here will both of clocked up 250hrs of sun, the first instance of two months doing so on the bounce in 15years, so the chances of the third reaching that figure are tiny really with it only happening in 1976. 

[Uncle_Barty]

End of June/beginning of July change from settled to mobile not a good time for a pattern change as it often sets the tone for the rest of the summer. Await the next missive from Tamara to see what the teleconnections are saying.

[Guest]

32 minutes ago, Uncle_Barty said:

End of June/beginning of July change from settled to mobile not a good time for a pattern change as it often sets the tone for the rest of the summer. Await the next missive from Tamara to see what the teleconnections are saying.

Yes I would agree however the majority of times gfs has introduced the Atlantic it’s only been briefly.

another thing to watch is the huge thermal gradient that will exit the eastern seaboard of the US in the coming few day, could be enough to really fire the jet up

[mushymanrob]

9 hours ago, Man With Beard said:

It might fit in if the breakdown is D9/D10 - the NOAA 8-14 day chart is completely different, much flatter

exactly, which fits perfectly imho with what you previously posted

9 hours ago, Man With Beard said:

The ECM mean is getting rather consistent about a westerly breakthrough mid-next week - though I agree it is a way off, when the mean does this, it's rarely a million miles away. 

But I also drawn to heights to the NE. Which may mean the Atlantic doesn't break in for long before the next draw from the south? 

 

[Uncle_Barty]

12 minutes ago, Alderc said:

Yes I would agree however the majority of times gfs has introduced the Atlantic it’s only been briefly.

another thing to watch is the huge thermal gradient that will exit the eastern seaboard of the US in the coming few day, could be enough to really fire the jet up

Yes, thats what concerns me. I think it was that scenario that kicked in the summer of 2015 from the start of July onwards. Continent hot and settled while we were under the influence of the jet caused by a large thermal gradient in the W Atlantic.

This might just be a blip similar to what we had a couple of weeks ago, we shall see!

Edited June 26, 2018 by Uncle_Barty

[shaky]

First signs of things turning a lot more unsettled with much needed rainfall from sunday onwards!!ecm joins the gfs and bringing the biscay low northwards!!still.dont think this is nailed down for another couple of days or so!!turns a lot.more humid very briefly for the weekend before turning freshee next week!!

[Frosty.]

The models are looking a lot more unsettled next week which is bad news for the first week of Wimbledon.. but at least centre court has a roof

[mb018538]

Indeed. Make the most of this week folks, things are on the slide into next week!

the ecm actually looks decent again at 240, looks like the Azores high is buildings once again.

[I remember Atlantic 252]

6 minutes ago, Frosty. said:

The models are looking a lot more unsettled next week which is bad news for the first week of Wimbledon.. but at least centre court has a roof

Court 1 too next year, but yes, full model agreement of turning more showery from the south, staying warm though, good news for many

[mb018538]

7 minutes ago, Frosty. said:

The models are looking a lot more unsettled next week which is bad news for the first week of Wimbledon.. but at least centre court has a roof

If they hadnt moved wimbledon forward a week, then this week would have traditionally been the first week! Think how good it could have been!

[Nick F]

The models, IMO, have not been particularly reliable in the medium range with placing the blocking and subsequently handling the Atlantic trough disruption to the west. The cut-off low between the Azores and Iberia and potential for it to phase (or not) with broadscale troughing further north over the N Atlantic has been causing some medium range uncertainty.

For a while the models have been inclined to keep the closed low off Iberia away from the upper westerlies further north, which has maintained blocking over / near the UK. But recent runs seem to be converging on the idea of pulling the upper low off Iberia moving NE toward Bay of Biscay and phasing it with upper troughing digging down from the NW Atlantic next weekend. This in turn leads to a breakdown of the heatwave from the SW, though details of how this occurs and when remains elusive for now. 

Have used the 00z ECM charts to illustrate what's potentially happening by the weekend, GFS broadly similar at 500mb, by the weekend in merging the upper low moving NE and trough digging down from the NW to the west though, but it differs at the surface by blowing up a fairly deep low to the SW then filling it without moving it much.

Although I like warm or hot weather, not a great fan of weeks of blue skies, prefer a few hot days accompanied by thundery breakdowns a few cooler days then heat building again. So I'm glad to see what the charts are showing this morning and the garden desperately needs some moisture too.

[Frosty.]

20 minutes ago, mb018538 said:

 

the ecm actually looks decent again at 240, looks like the Azores high is building once again.

Indeed, beyond T+240 hours would go on to show fine weather returning.

Edited June 26, 2018 by Frosty.

[Leo97t]

I think people are being a bit pessimistic. While I now don't think July will beat 2006 as I did a few days ago, I think their is still the possibility of this being a classic summer. Let's just wait and see. ECM amongst others are rebuilding the high within a week. 

[johnholmes]

Not time to post links to anomaly charts but all three I use now have some kind of troughing in the UK area rather than ridging, that is 6-10 day period from now. This has been a rather uneven transition from the ridging set up.

[Man With Beard]

Interestingly the ECM mean is unchanged from yesterday, with warm air holding on in the SE until midweek. 

No clusters last night were as progressive as this morning's GFS or ECM op - so I still don't think we've reached resolution yet for the weekend. 

[summer blizzard]

Although it would stay warm to hot for some time it would appear that a marked downgrade has occurred overnight with both the Euro and GFS backing yesterday mornings solution of a thundery low moving north and then letting the Atlantic move through. Day 5 is when this process all begins to occur.