model discussion Model output discussion 11th July onwards

[Frosty.]

20 minutes ago, Mike Poole said:

Maybe there’s a badge for that, Karl? 

Nah mate it has to be a gold cup with encrusted diamonds..nothing less is acceptable!  

on a more serious note, I noted that an ex tropical storm is having an impact on the Gfs 12z operational longer term!…I think all bets are off regarding long term predictions when there are those in the mix!  

Edited September 16, 2021 by jon snow

[Frosty.]

1 hour ago, Mike Poole said:

Maybe there’s a badge for that, Karl? 

You were right, I did win a badge! yay!  

Meanwhile, back at the ranch, the GEFS 12z mean does trend more unsettled (cyclonic) and cooler during the second half of next week and into the following week although conditions do then gradually improve again?…broad brush as it’s the mean but there is certainly scope for a polar maritime or even something more meridional with a direct arctic shot towards the end of next week..daft as that may sound?!

 

 

[Mike Poole]

ECM looking good for a hold against the Atlantic T120, here compared with the other models, UKMO looks the odd one out:
 

[Mike Poole]

Well that was a good call!  NOT!!  ECM T168:

[mb018538]

Very unsettled ecm at day 8 tonight - cool with gales and rain on the menu if anyone fancies that?!

[I remember Atlantic 252]

2 minutes ago, mb018538 said:

Very unsettled ecm at day 8 tonight - cool with gales and rain on the menu if anyone fancies that?!

Nearly always is on that date, anniversary of horrendous rain 9 years ago

[Mike Poole]

ECM horror show T240:

JMA goes the same way but not so deep, so there’s a high building at T264:

I really think the ECM op is off on one. But life is weird sometimes, isn’t it?

[Frosty.]

What has happened to that prolonged benign blocked bore fest the models were showing as recently as last night?…answers on a postcard please!   

 

[sheikhy]

Jheez the ecm will feel cold with 0 degree 850s and a showery northwesterly from next week!!aint had that for ages!!defo feel refreshing at night

[lassie23]

Hopefully no early frosts on show in the models as my garden is full of veg that needs 3 more weeks and it's done

[mb018538]

26 minutes ago, jon snow said:

What has happened to that prolonged benign blocked bore fest the models were showing as recently as last night?…answers on a postcard please!   

 

Just hurricanes obliterating forecasts as usual! That spell of 30c weather earlier in the month wasn’t well forecast until quite close either. Always very volatile in September, and this year is no different. Global patterns actually favour a NW Europe trough at the moment anyway, it’s just taken longer to get there than expected.

[Eagle Eye]

Snaw

[Mike Poole]

ECM clusters T192 - T240:

6 clusters.  Yesterday the ensembles strongly favoured the blocking (red border) solution. This morning on the 0z they all favoured the Atlantic.  Now it is a mix.  But with 26 members going for blocked, this is no done deal that the Atlantic is going to come blazing through.  

[Penrith Snow]

Come on guys, summer is over so let's see some wild interesting weather in late September compared to the boring semi summer conditions of recent weeks. Its now autumn so let's have some proper autumn weather, come December let's have wintry weather, its simple really!

[Mike Poole]

10 minutes ago, Penrith Snow said:

Come on guys, summer is over so let's see some wild interesting weather in late September compared to the boring semi summer conditions of recent weeks. Its now autumn so let's have some proper autumn weather, come December let's have wintry weather, its simple really!

Actually it isn’t that simple!  I think if we get standard autumn fayre from now on in, there isn’t a cat in hells chance we will get winter in December.  Which is why I’m holding out for the blocks that have been there since last December….

[Mike Poole]

GFS pub run T150:

Again, GFS going for the glancing blow with the LP.  Getting to the time of year that you need to look on NH view too…

Anyway T240 on pub run, all’s good in the hood!

Edited September 16, 2021 by Mike Poole

[Weather Enthusiast91]

16 hours ago, damianslaw said:

Did September 2006 not do this as well a very warm dry first third, cooler wetter end.. once we go past the equinox the tables often turn.. 

I remember September 2003 being like that as well. First few weeks of September was essentially a continuation of the warm and very dry August. But on the 22nd (a day before the equinox) the weather suddenly changed. It was a wet day and many people welcomed the rain by that point. After this, temperatures were back down to average for the time of year.

[Frosty.]

I’m on snow watch again! …the Gfs 0z operational becomes temporarily meridional towards the end of next week as it shows quite a cold plunge again with (albeit modified) arctic air sweeping south, would certainly feel like we are deeper into autumn should this transpire and across some of the Scottish mountains, like winter has arrived…for a time! ? 

 

 

[Methuselah]

Another day, another GFS 00Z. But will the blocks reestablish?:

    

    

    

[mb018538]

Just to show how much the forecast and models have changed in the last 4 days and why September can be an absolute pain to forecast...

Monday's update had a ridge over the UK for the end of September and into October



Last night's update for the same period? Troughing over the UK for the next 2 weeks




Output this morning very much along those lines too. Very unsettled by the end of next week:

[mushymanrob]

Its turning more Autumnal... after previously predicting high pressure (albeit weak) would dominate over the next two weeks, the latest NOAA charts have shifted as they sometimes do, and now suggest low pressure dominance for the rest of the month.

 

[carinthian]

Well the GFS produces an astonishing chart way out in its latest run ( almost Feb 47 looking with Scandinavian High and with upper low locked over France ) The length in time of the Atlantic zonal flow blocked over Western Europe has become a noticeable feature for much of the past 9 months and as we move into the winter season a increasingly amplified set up could hold sway if the jet does not break through as  normally at this time of the year. Interesting times, I think.

C

Edited September 17, 2021 by carinthian

[Frosty.]

Stunning day 10 ECM 0z operational, certain to warm the cockles of any coldies heart?!…it’s one of those situations when day 11 is desired as that low tracks further east and opens the floodgates to a potent arctic blast (for the time of year)!  

 

[Cambrian]

It’s really getting going now according to the 0z ECM. Rapid deepening of the low near Iceland between 96h and 120h, from 984mb to 948mb.

 

A secondary low starting to form off Greenland at 120h has Scotland in its sights by 168h, another low forming off Greenland by then.

 

Rinse and repeat by 216h but this one is deeper, 968mb.

That could be a bit rough! Socked rather than blocked. 30mb difference between Aberdeen and Penzance - we couldn’t get that from the whole height of the chart just a few days ago. Looks like the switch has been well and truly flicked.
 

The ensuing northerly would be a welcome respite. All along way off but plenty of interesting little precursors to keep an eye on, particularly around Greenland.

[mountain shadow]

33 minutes ago, jon snow said:

Stunning day 10 ECM 0z operational, certain to warm the cockles of any coldies heart?!…it’s one of those situations when day 11 is desired as that low tracks further east and opens the floodgates to a potent arctic blast (for the time of year)!  

 

I thought it would have backed down from that scenario this morning, if anything, it has increased the risk. 

 

Will certainly wash the cobwebs away.