Model output discussion 14/04/18

[I remember Atlantic 252]

EC decent at 192, good FI on both now, GFS and EC

[Frosty.]

38 minutes ago, Gordon Webb said:

well the first 16 words were realistic

That's high praise coming from you Gordon..thank you

Looking at the Ecm 12z..it's not in any great hurry to bring in the cooler, unsettled atlantic airflow next week unlike the gem.

Edited June 5, 2018 by Frosty.

[Matthew.]

Much more of an active Atlantic by mid June it seems. Looks like that easterly burst in the tropics is being shown now. Does look like being short lived though 

[Mike Poole]

ECM looking much better to me, here at T240, yes westerlies, but no trough stuck right over the UK:

I think it's clear now the weather will get more unsettled, the question is how unsettled and for how long.  The GEFS ensembles seemed to have quite a strong signal for ridging back in by T384, and usually the ensemble mean is an averaged out mess at this timescale, it wasn't today.

[Andy Bown]

All this talk of it becoming more unsettled is rather subjective. I think the term 'pattern change' is more applicable, if indeed the flow begins to come more from the Atlantic than the Easterly quadrant. It hasn't been 'settled' in this region for just over a fortnight, we have had drizzle/rain/thundery downpours on 11 of the last 15 days!

[Frosty.]

Yes mike, the GEFS 12z mean shows promising signs beyond mid june for the azores high to become more influential, at least across southern uk following the more changeable / unsettled atlantic westerlies which may mostly affect the north with the south not doing too badly at all.

Edited June 5, 2018 by Frosty.

[Singularity]

An impressively broad trough for mid-June but the idea of allowing ridges into Europe looks sensible enough.

Possibly I should pay more attention to GFS' briefly very strong jet stream though. On the other hand, it's not the only model that overreacts to tropical signals such as the trade wind burst.

Imagine the overall pattern trending westward beyond day 10 (but not smoothly so - a little back-and forth for a few days I imagine) and you can see where the interest for the final third of June has its roots.

[Mike Poole]

27 minutes ago, Frosty. said:

Yes mike, the GEFS 12z mean shows promising signs beyond mid june for the azores high to become more influential, at least across southern uk following the more changeable / unsettled atlantic westerlies which may mostly affect the north with the south not doing too badly at all.

 

Yes, I think what is clear is that the high latitude block's days are numbered, but what comes next I think there are two front runner scenarios, one the UK trough washing machine one, or secondly we fall back on a ridge from the Azores which while probably only giving decent weather to the south, allows development to a more UK wide settled spell later.  My money is on the second, as per ECM, and let's throw in the latest from the JMA (T192) and FIM9 (T222):

I think the 2018 'return of the westerlies' will be a massive damp squib!  (My iPad froze on selecting emoji and that's what got inserted, honest, so I'll just leave it there!)

ECM ensemble mean at T240, probably a blend of both scenarios:

[ANYWEATHER]

Good Evening Folks .....! Well the ops models both ecm and gfs show a major pattern change into next week , with the jet stream firing up across the Atlantic and making a Bee line for the Uk.  After weeks and yes at least three months of mostly continental weather ,which don't forget brought us a severe freeze in March, is now starting to change , But before next week look for more continental weather.....

[Frosty.]

I wouldn't really call it a major pattern change..it could just be a blip..plus, it takes most of next week to even get here!

[h2005__uk__]

Tweet from meteorologist Simon Lee:

Quote

This is one to watch. The CFS is continuing to project anomalously strong ridging centred over the British Isles in July, which would bring persistently warm & dry conditions. Follow daily updates here: https://t.co/rjApNooXyv

https://twitter.com/SimonLeeWx/status/1004079867846152199

Edited June 5, 2018 by h2005__uk__

[Man With Beard]

Nearly game set and match now on the clusters - it's probably going to be less settled around mid month 

All kinds of possibilities for the final third of June - spot the plume clusters in there too

[knocker]

A quick look at the GEFS NH analysis at the beginning and end of the short range  from last night’s 1800 run which continues to signal  the start of a major transition with the amplification of the ridge over North America and displacement of a vortex lobe/trough into the north west Atlantic whilst at the same eroding the block that has been so influential in recent weeks in dictating the weather over the UK.

Back to this morning

Overnight most of the cloud that persisted yesterday in the south has disappeared as the drier air moves south resulting in a clear start to the day. but in eastern Scotland the north east of England low cloud and mist from the North Sea has once again encroached inland. So today will be a reversal from yesterday with a generally sunny day and warm in many areas, particularly in the south but the cloud could well hang around in the north east.eastern areas and thus depressing the temp. But by late evening more humid unstable air is once again pushing north from France into the south.

The humid air will continue to push north overnight and through Thursday whilst also initiating showery, perhaps stormy, outbreaks along the south coast and the south east. Despite this another warm day in these parts and elsewhere with the usual caveats vis the north east/east although it should be less cloudy.

So the overview on Friday sees the upper low to the south encircled by the ridging of the Azores and European highs thus a fairly quiescent period beckons with the surface low and moist air continuing to push north with more showery outbreaks in the south but generally tending warm and sunny with the possible exception of the usual areas in the north and east.

Little change from this scenario on Saturday

And the north/south split continues to be the percentage play on Sunday with showery/thundery outbreaks likely in the south and west whilst sunnier and drier in the north with the usual proviso vis eastern coastal areas. But still generally remaining warm over the weekend with temps a little above average

Edited June 6, 2018 by knocker

[knocker]

MODS could you delete the above as I posted it in the wrong thread.

[Man With Beard]

1 hour ago, knocker said:

MODS could you delete the above as I posted it in the wrong thread.

Would you be happy if it was just copied over, and kept here too? Cracking post. 

[mb018538]

Morning,

Although it still looks likely we will enter a period of unsettled weather very soon, there are plenty of reasons to be optimistic that it won't last too long.

https://www.theweatheroutlook.com/charts/gefs/gefsens850london0.png

http://modeles.meteociel.fr/modeles/gfs/runs/2018060600/gfs-0-288.png?0

1) There are recurring themes of high pressure showing up in latter parts of the GFS runs (288 chart shown above)

2) Ensembles become increasingly dry into the last third of June, and there are a significant number of very warm/hot runs appearing. 8/20 runs this morning are above average by the end of the run, with quite a few well above. Of course this means there are around the same number below average, but the general average trend is upwards)

3) ECM long rangers showing some pluming, as well as the MetO extended text & knowledgeable posters such as Tamara cautiously backing high pressure to return later in the month.

Plenty to be positive about!

[knocker]

12 minutes ago, Man With Beard said:

Would you be happy if it was just copied over, and kept here too? Cracking post. 

No problem

[Matthew.]

The easterlies are well and truly gone at +240

[carinthian]

23 hours ago, carinthian said:

Well make what you want of this one from GFS at t240.. Quite a change in the upper air profile over Europe with the Atlantic jet into the heart of Euroland replacing weeks on end  of the flabby atmosphere dynamics that have been the dominant feature of UK/ Euro weather . Obviously changes ( slower evolutions ) will occur but I doubt to the speed of this extent, so I remain very wary of the latest GFS output for day 10.

C

This mornings GFS 300mb jet profile already changes 24 hours on from the above. Gone is the winter jet profile as shown above ( as being highly unlikely see @Singularity post yesterday.)  Subsequent runs taking it further north and will  eventually end up in its usual resident high summer position and thats much further north. A change in flow is now being widely forecast by day 10 by all models but at varying intensity. GFS brings back the Azores ridge into play very quickly, especially the south of Britain. So based on the strength of its influence so far this year, especially with its strong ridging to all vectors north, I feel that any westerly intrusion may only have minimal effect.

C

[mb018538]

44 minutes ago, Matthew. said:

The easterlies are well and truly gone at +240

Good! I think it was virtually agreed that we needed to get rid of this Iberian trough and easterly flow. Get a good Azores high building, all of our best summer weather comes from this sort of set up. Wipe the slate clean and rebuild something better.

[Frosty.]

12 hours ago, Frosty. said:

promising signs beyond mid june for the azores high to become more influential, at least across southern uk following the more changeable / unsettled atlantic westerlies which may mostly affect the north with the south not doing too badly at all.

 

 

 

I agree with carinthian above and think my post from last night still applies following the 00z runs, especially the Gfs 00z.

[northwestsnow]

Well i guess those who have been hoping for an end to the continental feed will be happy with the 00z runs.

From my POV  i think one has to be careful what one wishes for.. westerlies once they become established can be very resiliant.. lets hope this isnt the case this time round!

[Guest]

53 minutes ago, northwestsnow said:

Well i guess those who have been hoping for an end to the continental feed will be happy with the 00z runs.

From my POV  i think one has to be careful what one wishes for.. westerlies once they become established can be very resiliant.. lets hope this isnt the case this time round!

Yes agreed, better the devil you know really but to be fair it doesn't look like an extended spell of Atlantic dross, there is nothing worse in mid to late June than having 16hours of day light and only a hour or two of sun per day. It quite possibly a small pattern shift will aid blocking to develop slightly further south and east of its current location in about 10-14days time. We can but hope.

[Man With Beard]

EC clusters really firming up on a more unsettled period of weather mid-month, only a small cluster disagrees now.

I'm noticing a trend between D11-D15 towards maintaining the Atlantic trough closer to our shores for a bit longer than we were hoping for a couple of days ago. This morning's D15 chart shows potential for a NW/SE split, not impossible to get a plume out of cluster 2 but it's not screaming with that potential though. As ever, early days on this period.

 

[northwestsnow]

1 hour ago, Man With Beard said:

EC clusters really firming up on a more unsettled period of weather mid-month, only a small cluster disagrees now.

I'm noticing a trend between D11-D15 towards maintaining the Atlantic trough closer to our shores for a bit longer than we were hoping for a couple of days ago. This morning's D15 chart shows potential for a NW/SE split, not impossible to get a plume out of cluster 2 but it's not screaming with that potential though. As ever, early days on this period.

 

Precisely why i was not one of those hoping for a pattern change!