Model Output Discussion - Into Autumn 2019.

[feb1991blizzard]

Sliders always an indication that the atmosphere is preparing to be disposed towards a long spell of a Southerly tracking jetstream.

 

[The Eagle]

Well, we'll certainly look forward to that!  

[Frosty.]

There's certainly some wintry potential at times on the Gfs 6z operational which is a recurring theme, there's some impressively low dam thicknesses there for so early in the season and october could be a very interesting month with, dare I say, a few early snowy surprises..fingers crossed!!❄

winter is coming!

Edited September 28, 2019 by JON SNOW

[emmett garland]

still a way off but looking ominous for Ireland

[Mr Frost]

4 minutes ago, emmett garland said:

still a way off but looking ominous for Ireland

Looks a tad windy here in the West of Scotland also on that - love a severe gale/storm force wind event! (Extreme weather enthusiast)

Last September Storm Ali arrived at the bottom of my street packing some decent wind gusts - bit choppy on the water. (Video attached at bottom of this post taken by me)

In the short term Tuesday to Thursday will be chilly for quite a few of us with some frost about! Lovely stuff! (Latest GFS charts below - Tuesday to Thursday 03:00 for each day)

So frosts and a potential stormy period of weather for Ireland and parts of the UK...now that is what Autumn is all about for me! 

Have a good weekend everyone! 

 

[Methuselah]

Winter is most definitely coming...But, as the GEFS ensembles show, the GFS Op. is once again almost a cold outlier, late in its run...? Should this continue, winter proper could see a huge number of unrequited 'BOOM' charts!?

   

   

So, what's new about that? I hear myself thinking...?

[Zak M]

Hurricane Lorenzo is currently a Category 4 Hurricane and is going to travel across the Atlantic and potentially hit us. It won't be a hurricane when it arrives here although it could be a powerful storm. Some of the FAX is hinting a sign of Lorenzo travelling across the Atlantic.

The GFS 06z is showing Lorenzo to hit SW Ireland and NW of the UK, and then later some parts of the SW/SE could still get winds of over 40mph.

[The Eagle]

Lorenzo latest track. Slightly west of earlier but will fluctuate over coming days.

 

[SMU]

ICON with a swing to the west of Lorenzo -

however 12z shows a solution not on offer this far of the initial ridge ahead of Lorenzo holding firm supporting a pretty substantial cold pool over Central & Northern Europe- UK on the periphery- Either way no sign of the zonal train chugging along !

 

[feb1991blizzard]

Yes - that is a beautifully aligned block with perfect WAA, If that was a month later it would be having a huge effect on the PV.

[feb1991blizzard]

6 hours ago, feb1991blizzard said:

I would be very surprised if there isn't a significant correction towards the ECM IMO, it would be unusual in these type of setups for the GFS to trump all other models and not over-deepen and track too far North.

And  right on que - the usual GFS coffee smelling southward correction - didn't expect the correction all in one go though.

[Sir Mim]

Latest GFS op run showing a completely different track for Lorenzo, taking a much shallower system towards northern France.  Still lots to play for so far out but the swing in GFS output surprised me considering how consistent the few previous runs were.

 

Edited September 28, 2019 by Sir Mim

[Jordan S]

6 minutes ago, Sir Mim said:

Latest GFS op run showing a completely different track for Lorenzo, taking a much shallower system towards northern France.  Still lots to play for so far out but the swing in GFS output surprised me considering how consistent the few previous runs were.

 

That's what ex hurricanes tend to do they cause models to rapidly change output as they grasp what energy goes where expect it to change a few more times a lot of uncertainty. 

[SouthLondonCold]

While gfs backs off its theme of Lorenzo hitting the UK, the GEM jumps on board.

Edited September 28, 2019 by SouthLondonCold

[carinthian]

6 hours ago, carinthian said:

Most of the main models show colder polar maritime airmass over much of NW Europe by the middle of next week. Eventually a cut off low to form over Adriatic. So heavy rainfall amounts expected in the Alpine Region with snowfall on the North Alps by Thursday. Still lots of doubt about the track of the ex tropical hurricane, so further changes in the model outputs can be expected soon, especially as it has now being downgraded during the past few hours with the eye eroding. Anyway first frosts of the season this coming week for some of you and from my view will be looking carefully at our snow model predictions on Monday morning.

C

Further runs from the various models continue to show the uncertainty of the affect ex tropical storm has on the forecast for much of NW Europe. ICON and UKMO models do not really go with its full associated connection with the main North Atlantic trough .. Oscillation changes in the flow still out with jury at this instant. Will see what ECM run shows. Current GFS run engages full Atlantic trough with ICON consistent with some sort of undercut scenario and the Russian model maintaining strong heights to the NE. All very interesting viewing.

C

[I remember Atlantic 252]

1 hour ago, Sir Mim said:

Latest GFS op run showing a completely different track for Lorenzo, taking a much shallower system towards northern France.  Still lots to play for so far out but the swing in GFS output surprised me considering how consistent the few previous runs were.

 

Aye, miles better chart, looks decently warm too, but of course due to setup deepest FI, whatever EC shows makes not much difference

and pardon me, but few days ago, thought members were meaning the NW forecaster lorenzo

Edited September 28, 2019 by I remember Atlantic 252

[Mapantz]

11 minutes ago, carinthian said:

and the Russian model maintaining strong heights to the NE

Could you provide a link to the Russian weather model, please? It's one i've not seen.

[feb1991blizzard]

4 minutes ago, Mapantz said:

Could you provide a link to the Russian weather model, please? It's one i've not seen.

https://www.meteociel.fr/modeles/wmce_cartes.php

[MATTWOLVES 3]

Just looking at the extended ECM mean from this morning, shows the op and the mean were miles apart during the 1st few days of October. The op was well under a 100mb,with the mean being quite a bit above. Further ahead the mean shows some sign of improving further.... So for me I think we could be looking at a settled spell towards mid month.... And perhaps a few visits from Jack Frost come the night's! 

[Methuselah]

Some mid-month beach-time, a la 1978?

   

[feb1991blizzard]

7 minutes ago, Ed Stone said:

Some mid-month beach-time, a la 1978?

   

And we all know what happened 2 months later.

[Methuselah]

Not much in the way of consistency in the GEFS 12Z ensembles, yet...Lorenzo is still playing silly buggers?

   

   

More runs needed!

 

[MATTWOLVES 3]

ECM shows a decent spell around mid week, with temps on the up... One last plume attempt! Low pressure deepens to the NW by next weekend.... And we could have some fun and games!!! Towards the end we are lining up our 1st cold shot of the Autumn!!! Some impressive cold uppers lurking with intent by day 10.......get in there my son..... 

[feb1991blizzard]

Impressive early cold pooling from the CFS - record breaking for the time of year on the continent.

 

[halny]

1 hour ago, feb1991blizzard said:

Impressive early cold pooling from the CFS - record breaking for the time of year on the continent.

 

I haven't seen the reanalysis, but is it really record-breaking? There was 5 cm of snow on 12 Oct 2015 in Krakow, (following 35C heat in September and average daytime August highs a shade under 30C.) And I was 70 miles north of Krakow in the snowstorm of Oct 2012 when for three days it failed to rise above freezing. The continent can get very cold, very quick. And yet it'll still rain on Christmas.