Model output discussion 14/04/18

[Frosty.]

46 minutes ago, northwestsnow said:

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

Brighter and warmer for the east once this what I consider to be a fairly short-lived pattern change arrives around next midweek..no more north sea filth rolling inland making for cool cloudy days..like today across parts of northern / eastern england!...like I said, I don't think the atlantic spell will last long as the longer term signal is potentially a return to very summery weather later in june and into july..fingers crossed.

Edited June 6, 2018 by Frosty.

[Scorcher]

1 hour ago, northwestsnow said:

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

Indeed, awful these northeasterlies aren't they- yet another warm, cloudless afternoon here in Manchester!

[weatherguru14]

I think it would be better for all if we have the pattern we had in most of May where the jet was way north and we didn't have an easterly.Its not cold here today but very cloudy. was nice yesterday so can't really complain.

[cheese]

48 minutes ago, Scorcher said:

Indeed, awful these northeasterlies aren't they- yet another warm, cloudless afternoon here in Manchester!

And a very dull, 16C afternoon in Leeds. And you wonder why some of us are hoping for a pattern change..

[Frosty.]

8 minutes ago, cheese said:

And a very dull, 16C afternoon in Leeds. And you wonder why some of us are hoping for a pattern change..

Indeed, I can't wait for the wind and rain from the west

Anyway, the models are firming up on a change from around the middle of next week but as I've said before, I don't think it will amount to much further south or last long for that matter.

Edited June 6, 2018 by Frosty.

[cheese]

6 minutes ago, Frosty. said:

Indeed, I can't wait for the wind and rain from the west

Anyway, the models are firming up on a change from around the middle of next week but as I've said before, I don't think it will amount to much further south of last long for that matter.

Looking at the weatheronline forecast for Leeds, we go from generally 0-1 hours of sun a day with this northeasterly, to 7-8 hours of sun a day with the forecast westerly. So yes, bring it on. I will happily take a bit more rain and wind in exchange for far more sunshine.

Edited June 6, 2018 by cheese

[IanR]

This pattern has been good for the north west of england, its been mostly dry sunny and warm for the past 3 weeks or more with just odd cloudy days, but even those cloudy days have been the rare ,

just wish we got  a few storms thrown in though  

[Frosty.]

Looking at the GEFS 6z mean...yes we are on course for a more changeable / unsettled atlantic incursion / intrusion from around next midweek, especially for northwest uk but it doesn't take long before the azores high starts to ridge in towards southern uk bringing with it more settled and warmer weather.

Edited June 6, 2018 by Frosty.

[Mike Poole]

OK so an unsettled period looks to be on the cards, has done for a few days.  But the hypothesis seems to be that this will be short lived, that needs testing against the model output. GFS and GEM 12z at T240 show us in this period of westerly winds, with generally unsettled weather, particularly on the GEM run:

Earlier than that things appear to start to go down hill about T168 on GFS:

But if longer range models, and indeed the Met Office contingency planners forecast for the summer as a whole are on the money, we should continue to see output like this in the later stages - obviously FI for the detail, but so long as the trend is there it's all good.  GFS at T300 and T384, we want to see this signal retained on future runs:

[Frosty.]

Looking at the Gfs 12z, first thing to say is there's plenty of warm weather across the uk until and including next wednesday, this weekend in particular looks very warm for the s / se with temps around 80F in places, there's plenty of fine sunny weather but also some heavy thundery showers scattered around and some persistent heavy rain for the south next monday. Later next week it becomes cooler and more unsettled from the atlantic and it stays unsettled for a while with plenty of rain around but towards the end of the run high pressure builds in strongly...despite this more unsettled run, I still think it will just be a nuicance blip before the azores high / high pressure generally returns!

[Frosty.]

Looking at the GEFS 12z mean, as with the 6z it turns more unsettled from the atlantic during the second half of next week, again it looks like northwest uk would bear the brunt with southern uk generally less affected. Beyond that the mean indicates a gradual improvement from the southwest / south as the azores high starts to build towards southern uk but it's fair to say it's less bullish about the eventual influence of the azores high compared to the 6z, there is more of a split between settled / unsettled members towards the end of the run.

I'm keeping positive about late June / early July very warm / hot potential though..hopefully Exeter will continue to see that too from GloSea5 / mogreps..ec32 etc!

Edited June 6, 2018 by Frosty.

[Frosty.]

Well at least there's no shortage of warmth on the Ecm 12z run, especially across southern uk with uppers (850's) like these and given some decent sunshine, temperatures will rocket into the mid / upper 20's celsius, especially this weekend further s / e and there should be a lot of fine weather but with increasing humidity comes an increasing risk of scattered heavy showers / thunderstorms..then as per other output, it becomes generally more unsettled and cooler from the atlantic but day 10 would be warmer, especially given any sunshine but ending with quite a deep low to the NW by mid june standards!

Edited June 6, 2018 by Frosty.

[Fourty Point Three Degrees]

The GFS and ECM 12z are both quite frustrating next week. Back to a progressive Atlantic. But it can be expected in mid-June, the european monsoon "return of the westerlies".  But how long it lasts for is the main question. I have a good feeling that the Azores will meet up with Scandinavia just in time for July then we can settle into a decent summer pattern for high summer.  

[Matthew.]

9 minutes ago, 38.5*C said:

The GFS and ECM 12z are both quite frustrating next week. Back to a progressive Atlantic. But it can be expected in mid-June, the european monsoon "return of the westerlies".  But how long it lasts for is the main question. I have a good feeling that the Azores will meet up with Scandinavia just in time for July then we can settle into a decent summer pattern for high summer.  

The unsettled return does just like a blip. There’s many signals out there saying we may be in for the warmest summer of the decade. ECM 240 sees a quick return of the Azores ridge. Because we’re at solar minimum the meridional jet looks like continuing and high pressure looks non existent around Greenland. A few similarities to the Ssw year of 2013

[mb018538]

It’s to be expected in any year in the UK, you can’t just run through 3 months of summer weather without any unsettled spells, even the best summers have them. The only issue you have is when we start an unsettled spell and it rolls into a second...third....fourth week in a row it seems to set the tone and ruins the summer. I’m optimistic that this won’t be one of those long waits for the return of summer.

[Frosty.]

Looking at tonight's Ecm 12z ensemble mean there's plenty of warm fine weather to enjoy in the reliable timeframe, indeed becoming very warm / humid further s / se with an increasing risk of a few thunderstorms..it stays warm although not as warm next week but freshens up with increasing atlantic mobility, more so further n / nw with the s / se generally less affected..

[MP-R]

This 'return of the westerlies' or 'European monsoon' so many bang on about sounds interesting. It happens so rarely I can't actually think of any examples off the top of my head.

The irony is that many places would probably dry up a bit if there was snore westerly flow given the jet moves north during the summer. Fewer low pressures hugging the south with rain there. 

I can't see anything that suggests more than an Atlantic blip so far. Returning from Rio de Janeiro in winter, it should feel quite similar in the UK.

[mb018538]

Morning,

Differences abound today. The Atlantic influence is creeping ever closer, GFS goes full on tilt mode, really ramping up the unsettled weather:

http://modeles.meteociel.fr/modeles/gfs/runs/2018060700/gfs-0-192.png?0

ECM somewhat calmer at the same timeframe:

http://www.meteociel.com/modeles/ecmwf/runs/2018060700/ECM1-192.GIF?07-12

Plenty to be resolved.

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

Ensembles still all over the place, those very warm/hot runs are still there which is a plus.

[Djdazzle]

The 18z showed a big plume post 240 but the 00z is unsettled. However, both runs built strong HP over the continent so building blocks still there.

[johnholmes]

I cannot see anything other than a more westerly influenced upper air pattern. The 500 mb anomaly charts, all 3 I use, show this type again in the past 24 hours, now 4 in a row.

It would be very surprising if they prove to be wrong in the 6-14 day or so outlook in my view.

Others may disagree.

Beyond that, well not my area of expertise so I leave this to others. Myself I would be surprised if there is another major change within, what, say 15-18 days at least.

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

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

the 14 day chart is not much different either

Edited June 7, 2018 by johnholmes
spelling

[Guest]

Have to say I see little in the way of positive signs that the weather will return to anything settled, warm/hot and sunny before at least the 20th June, yes the models can flip and flip but once a pattern change such as the one we are seeing forecast in an ever more reliable time frame starts to set in with a flatter jet its generally a minimum of a couple of weeks for the jet to buckle and deviate enough to either along substantial ridging from the Azores or blocking to become re-established near the UK.

Day to day forecasts clearly impossible to predict currently but it doesn't look at the moment as through slow moving troughing will not be anchored over the UK (good news) so probable conditions look like a combination fronts passing west to east, followed by showers and weak ridges of high pressures between lows giving slightly better conditions, although infill and cu development likely to be a pain inland. Temps probably mid teens in the north west to 20-21C in the south east. Clearly stuck under rain during any frontal passages (which always seems to happen in the daytime) temps likely be held at 14-17C almost anywhere.

Far from great and what the majority of us want, but could be worse (likely to be 4 out 10 summer weather IMO)

Edited June 7, 2018 by Alderc

[mb018538]

4 minutes ago, Alderc said:

Have to say I see little in the way of positive signs that the weather will return to anything settled, warm/hot and sunny before at least the 20th June, yes the models can flip and flip but once a pattern change such as the one we are seeing forecast in an ever more reliable time frame starts to set in with a flatter jet its generally a minimum of a couple of weeks for the jet to buckle and deviate enough to either along substantial ridging from the Azores or blocking to become re-established near the UK.

Day to day forecasts clearly impossible to predict currently but it doesn't look at the moment as through slow moving troughing will not be anchored over the UK (good news) so probable conditions look like a combination fronts passing west to east, followed by showers and weak ridges of high pressures between lows giving slightly better conditions, although infill and cu development likely to be a pain inland. Temps probably mid teens in the north west to 20-21C in the south east. Clearly stuck under rain during any frontal passages (which always seems to happen in the daytime) temps likely be held at 14-17C almost anywhere.

Far from great and what the majority of us want, but could be worse (likely to be 4 out 10 summer weather IMO)

It's not disastrous yet - I don't think anyone expected just a day or two of low pressure then an immediate rebuild of high pressure - the prognosis was always towards the last third of the month for the next window of opportunity.

[Guest]

18 minutes ago, mb018538 said:

It's not disastrous yet - I don't think anyone expected just a day or two of low pressure then an immediate rebuild of high pressure - the prognosis was always towards the last third of the month for the next window of opportunity.

Its the how long is a piece of string question where we are now. Will it just be 7-10days of more unsettled conditions or will it be a pattern that really digs in for 2, 4, 6 weeks etc. The thing I find concerning is that in recent years things appear to get stuck in a rut irrespective of season and while there is absolutely nothing at this time to suggest it would not surprise if in a months time we are sat here searching the depths of FI for hints of warm sunny weather.

[Singularity]

 

...and on the MJO keeps chugging into the Pacific, right in the face of the models which, with each new update, continue to insist that it will suddenly collapse.

This makes the drastic fall in GLAAM currently being predicted by GFS/GEFS look highly improbable. As a result, I'm inclined to put aside what it produces beyond a week's range for the time being - such as the 00z and 06z runs, which have suddenly started showing an MJO phase 6 + Nina-like pattern in the later stages, due to it thinking that the MJO will suddenly decay without getting beyond phase 6 (this seemingly also entirely removing the subsequent positive GLAAM response).

ECM is likely having similar issues but perhaps without such negative GLAAM bias.

 

This does not, however, change the prognosis of recent days; that we're heading for a more changeable spell prior to (hopefully!) a recovery toward more settled conditions by/within the final third of the month - it's just the positioning of troughs and ridges during the changeable period that the above has an impact upon.

[mushymanrob]

7 hours ago, johnholmes said:

I cannot see anything other than a more westerly influenced upper air pattern. The 500 mb anomaly charts, all 3 I use, show this type again in the past 24 hours, now 4 in a row.

It would be very surprising if they prove to be wrong in the 6-14 day or so outlook in my view.

Others may disagree.

Beyond that, well not my area of expertise so I leave this to others. Myself I would be surprised if there is another major change within, what, say 15-18 days at least.

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

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

the 14 day chart is not much different either

i guess im clutching at straws, but doesnt the 8-14 day chart suggest the azh shifting a bit further eastward with slight pressure rise to our south and indeed across the uk in comparison to the 6-10 day chart?  so maybe not quite as unsettled ?. (or wet lol)