Model output discussion - summer rolls on

[Leo97t]

Really promising GFS. At least 7 days in the mid to high twenties in the south on just raw output. Definitely some thundery potential which we have lacked this summer. I think we may be heading in the direction of the hottest year on record which seemed improbable after March although the one month which may stop this is December which the signals are slightly more suggesting colder weather but I guess this is still quite a time to go before then. Wouldn't surprise me if this would be the hottest September on record but probably too early to say. This Summer has gone remarkably similar to 2006 - interesting but I hope the similarities end after September as I would want a repeat of that tragic winter which I believe included a 7-degree January on the CET

[northwestsnow]

Hi everyone, not posted much recently but hope all my NW friends are well, i was wondering if anyone knows if there are issues with WZ as GFS is consistently late in updating.

UKMO looks very anticylonic this evening,hope we get a late summer burst of heat.

:)

[Frosty.]

15 minutes ago, northwestsnow said:

UKMO looks very anticylonic this evening,hope we get a late summer burst of heat.

Indeed, the Ukmo 12z does look settled away from the far NW and would continue settled beyond T+144 hours.☺

[Frosty.]

Lovely Ecm 12z also with high pressure / strong ridging and potentially very warm at times, especially for the s / e / se..I think another taste of summer is just around the corner! ☺

Edited August 29, 2018 by Frosty.

[Mike Poole]

I'm not going to post charts from the early part of the evolution tonight, because they are all seemingly pointing to the same thing.  High pressure extending across the UK to the east with reloads following on behind.  So settled weather, warm at least to start with, then as we head further into Autumn, warmth dependent on the position of the high pressure systems.  

As we move into early and mid September, the CFS AAM charts are showing a rise in atmospheric angular momentum which should reinforce this pattern (would normally post chart but I can't find it! it's saved on my work PC).  

As we move towards mid September, one wild card is ex-tropical storms.  Here's one on the FV3 at T276:

This one doesn't impact us, but if one came our way (it happened last year with Ophelia) it could change our prospects, but otherwise, return of summer for a significant period for many based on today's 12s.

 

Edited August 29, 2018 by Mike Poole

[Frosty.]

Nice Gem 12z too, lots of high pressure / strong ridging away from the far n / nw and a very strong finish with a large intensifying area of high pressure building in from the west over the uk..very good cross model agreement from the 12z runs that high pressure is going to become the dominant feature and any atlantic crud will mostly just occasionally brush across the far NW..a summery end to summer / start to autumn for most of us with predominantly pleasantly warm settled conditions but with some cool nights under clear skies in rural areas !

Edited August 29, 2018 by Frosty.

[Mike Poole]

Well if anyone wants warm settled conditions as we go through September then the ECM 12z ensemble mean has it all settling down nicely:

The warm late summer is finally falling into place, only 3 weeks of normal average summer weather to detract from this great summer, and, good news, the decent weathers back and probably extended for another month. 

Edited August 29, 2018 by Mike Poole

[Frosty.]

A nice looking Ecm 12z ensemble mean tonight with heights extending from both the azores / scandinavia strongly influencing the uk with settled and at least pleasantly warm surface conditions being the result but as it's nearly september, expect some chilly nights where skies clear, especially in rural spots..another thing we can't rule out is a v warm humid continental incursion which the Gfs 12z shows in the mid range which would mean some sticky nights and a risk of thundery rain / showers.☺

[summer blizzard]

Firm agreement out to day 8 from the Euro and GFS on high pressure over/east of the UK. 

Although i'd normally be wary of September heat (often far too humid) this setup looks more like May/June with reasonable uppers so like today, i imagine it will be nice. 

[I remember Atlantic 252]

6 hours ago, summer blizzard said:

Firm agreement out to day 8 from the Euro and GFS on high pressure over/east of the UK. 

Although i'd normally be wary of September heat (often far too humid) this setup looks more like May/June with reasonable uppers so like today, i imagine it will be nice. 

but hopefully be no north sea mist, as seas warmest in Sept

Edited August 30, 2018 by I remember Atlantic 252

[mb018538]

Looks fairly benign again on this mornings output. Generally quite settled, but with upper air temps no great shakes, looks like staying in the 20-24c range....which at this time of year isn't bad at all. In high summer we'd have been seeing mid to upper twenties from the same thing, but with the lower sun, and shorter days we need a bit of oomph now for any heat. Not that i'm complaning, beats wind and rain any day for me!

[Singularity]

So yes, here we are, 7-10 days later than originally anticipated, getting into the continental flow regime, with the Atlantic trough well-suppressed at least for the first week of the month as the seasonal wavelengths support the ridge in our vicinity. Room for the trough to present more of a fight toward mid-month, perhaps, which could lead to some interesting results.

Temps wise, low-mid 20s indeed a safe bet for large parts of the UK during the easterlies, but if the flow turns south of that, high 20s are achievable. 

As for a direct southerly draw, well that can bring the 30s even in the late stages of the month, so it's also worth keeping an eye on any signs of such a thing. Especially if it looks long-fetch... remember the final days of September 2011? It was pretty much the optimal setup for maximising temps, so far from something to reasonably anticipate this year, but still... it's fun to entertain what it would be like if it happened sooner in the month .

[Paul_1978]

On 29/08/2018 at 09:57, Paul_1978 said:

Interesting to see an intense system to the south west of Portugal within the T+160 range on the 00z GFS. 

By T+240 it has moved north further into the Atlantic and after that (FI) starts to move towards the UK.

The same system is also on the ECM well to the west of Portugal at T+216.

Will be interesting to keep an eye on this in the next few days. 

Presumably it's an ex hurricane or tropical storm, and if so won't get named by the Met or Irish weather services. I believe the next named storm on the list is Iona. Storm names for the new season are usually issued in the first week of Sept and I believe the names take immediate effect, so it perhaps looks unlikely that we'll get "Storm Iona" this year. 

Met Office tweeted this morning that the modelled intense pressure system could be the first tropical storm to develop this season, and it’s in the far eastern side of the Atlantic. Unusual to develop so far East?

Will be interesting to see how this could effect the UK.

[johnholmes]

Mixed messages from the anomaly charts

EC is now more ridge dominated than before with GFS showing strong heights but in a general westerly flow.

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

NOAA shows smallish +ve heights over the UK  and little 500 mb flow south of the country.

Wil this be enough to allow any sufficient build of a surfave high in a position to allow for additional warmth from France? Hard to tell, and as S posts above it does seem as if the teleconnections that some talked of are the most likely from model outputs of various types, so well done got this linkage being shown. Way beyond my level of expertise but the 6-10 and the 8-14 from NOAA do lend a fair level of confidence in those time scales for much of the UK having generally dry settled weather, just how much sun and how high the temperature levels will be is beyond anomaly chart interpretation. What can be deduced from them is that the Atlantic still seems not to be a major player, at least away from the NW.

Just one caution, we moving into the major part of the hurricane season. No model, long or short term, is vary good at predicting just where any major storm will track or its possible effects in the UK area.

http://www.cpc.ncep.noaa.gov/products/predictions/610day/500mb.php

[summer blizzard]

4 minutes ago, Paul_1978 said:

Met Office tweeted this morning that the modelled intense pressure system could be the first tropical storm to develop this season, and it’s in the far eastern side of the Atlantic. Unusual to develop so far East?

Will be interesting to see how this could effect the UK.

Not the first and not highly abnormal at peak season (we usually do get a few developing pretty early in their travels). 

[summer blizzard]

Not a bad outlook from the current pressure build with fairly cool minima likely sat-mon aside. 

[Man With Beard]

I see the latest GEFS mean has the magical 1030mb Scandi high out at T264. If we were 6 weeks down the line some people would be wetting their pants, but for now it means we're more or less nailed on for a 2 week Atlantic shutout, with more of an easterly component for the UK rather than a southerly one - such a flow still just about in the warm category for now, but that would quickly become cooler after mid month, after which a S or SEly is needed for heat. 

Just a thought - I note some suggesting cool nights ahead - I imagined the same but the ensembles suggest above average minima all the way through - I wonder if the anomalously warm seas to the east may play a part here - the North Sea is doing fairly well, but the Baltics must have smashed all records this summer for sea temps. 

Edited August 30, 2018 by Man With Beard

[Leo97t]

Exceptional end to the Gfs 12z. Constant southerlies after about +240 with daily raw maxes in high 20s over most of England for 10 days. Hope this comes off as I'm very much missing the heat. 

[Fourty Point Three Degrees]

Well after the usual August it looks like High pressure is set to make a big come back over the next few weeks with a big ridge across N Europe and dragging up some Spanish delight. Major models seem to be reaching agreement on this.  

If this September can reach 28C I cant think of a year where 28C has been hit every month since April.

Edited August 30, 2018 by 38.5*C

[Mike Poole]

Evolution to settled high pressure dominated weather is across the suite now, has been since yesterday really.  So looking a little further, ECM 12z is the pick running to this at T240:

Nice! 

[summer blizzard]

5 hours ago, Man With Beard said:

I see the latest GEFS mean has the magical 1030mb Scandi high out at T264. If we were 6 weeks down the line some people would be wetting their pants, but for now it means we're more or less nailed on for a 2 week Atlantic shutout, with more of an easterly component for the UK rather than a southerly one - such a flow still just about in the warm category for now, but that would quickly become cooler after mid month, after which a S or SEly is needed for heat. 

Just a thought - I note some suggesting cool nights ahead - I imagined the same but the ensembles suggest above average minima all the way through - I wonder if the anomalously warm seas to the east may play a part here - the North Sea is doing fairly well, but the Baltics must have smashed all records this summer for sea temps. 

GFS op has had minima around 10C here for a while in the forecast albeit that's to a week or so out. 

[Allseasons-Si]

Well some upgrades today regarding +ve height's to our NE including the uk with the hp cell growing even bigger than was showing yesterday,this is turning out to be a lovely outlook indeed and hopefully some thrown in to boot

lets have a look at the 500mb outlook from cpc days 6-10 and 8-14,we have +ve height's over Scandinavia inc the uk  and one over Alaska with trough over Northern siberia through to Greenland being squeezed by the two +ve height's hence forcing/deflecting the SW'lies to our NW

cpc teleconnections AO&NAO

the Arctic Ocsilation(AO) looks to go negative as it has been showing for a few days now,this neg phase slows the westerly winds in the northern hemisphere(pv from ramping up),the North Atlantic Ocsilation(NAO) shows mixed signals in the forcast,the NAO if neg slows the westerly winds in the north atlantic and the pattern would be more of a meridial flow or blocked scenario

so putting the two togeather there is no ramping up of the westerly winds as such like a bowling ball pv(round) but more of a deflated one at the moment...pffft!!!

a look at this evenings models from the gfs and ecm mean at 240 shows some pleasent warm weather to be had and i don't mind it at all,it is still summer

and the 500mb mean geopotential height anomoly's

shift that Atlantic

 

 

 

 

Edited August 30, 2018 by Allseasons-si

[mother nature rocks]

GFS 0z run = settled pretty much right thru’ the run with potential plume event at the end with + 16/18*c uppers. Summer is back in autumn lol!! 

MNR

[Man With Beard]

Well if the ensembles have any credibility then we can bin the ECM 00Z this morning. It's the complete opposite for Scandinavia. 

[shaky]

54 minutes ago, Man With Beard said:

Well if the ensembles have any credibility then we can bin the ECM 00Z this morning. It's the complete opposite for Scandinavia. 

As a result is it warmer for the uk?!!