Model Output Discussion - Into Autumn 2019.

[LRD]

1 hour ago, Ed Stone said:

With a 75mb spread in SLP and an 18C spread in T850s, one could hardly refer to the GEFS 06Z ensembles as 'tightly knit bunch'...It all looks like a forecaster's nightmare...?

   

   

Not suggesting any link between now and December, but I did see two hedgehogs behaving strangely, yesterday!

Those Suffolk 850hpa temps look to be on a downward trend, long term, over the last few GFS runs compared to previous sets. The cooler ones were the minority a few days back. Now they're not. Let's see if that firms up or reverses again

[Frosty.]

The GEFS 6z mean longer term is suggesting a NW / SE - N / S split with some decent spells of weather across the S / SE... and for those of a cold persuasion there is a bit of interest from the 6z members, as there was from the 6z operational.

 

[NorthernRab]

That's quite an unpleasant looking chart for the Azores, taking a direct hit from Lorenzo. 

[summer blizzard]

Ironically recent runs have had Lorenzo strong enough to pummel the high such that we get westerlies rather than a proper build.

The models githeth and they taketh.

[carinthian]

Just wondering if ECM will upgrade a potential Sunday storm for Southern England. Some thought over here could develop on a further southerly latitude.

C

[shaky]

Ukmo and gfs cold at 144 hours with a greenland/icelandic block!!!

[knocker]

The gfs has Lorenzo tracking along the eastern flank of the Atlantic trough and then merging whilst reinforcing the downstream ridge

Edited September 25, 2019 by knocker

[ICE COLD]

GFS 12z going for quite cool conditions around day 10 onwards . Not often you see a low in the Atlantic move west towards the USA they usually head east towards the uk  , very strange run . 

[feb1991blizzard]

Big undercutter here, -8c poised in Norway.

[shaky]

What is going on with gfs 12z!!puts us in the heart of winter from early october❄?!!disrupting lows and a block to the north east!!

[knocker]

This is going on so anything post t120 needs to be scrutinized with great care

Edited September 25, 2019 by knocker

[SouthLondonCold]

ECM makes the low on sunday quite deep at sub 985, would bring quite strong winds to England and Wales.

[Methuselah]

Aye knocker, scatter past T120 is literally all-over-the-place; following a day or two when the Op was on the warm end of the pack, it's now very much at the opposite extreme...?

   

   

Far too many 'ifs', 'buts' and 'maybes' for my liking...MOOB!

Edited September 25, 2019 by Ed Stone

[knocker]

According to the ecm Lorenzo starts engaging with the major trough that has drooped down into the western Atlantic at T126 and 30 hours later there are major impacts downstream of a very strong jet.

And 24 hours later the trough has split. How all this pans out in the Atlantic  will obviously impact downstream

 

 

 

Edited September 25, 2019 by knocker

[January Snowstorm]

Lorenzo is potent and comes very close to Ireland. For now remains a fish but it wouldn't take much for things to change!!

[I remember Atlantic 252]

uncertain times,with ex hurricanes etc, but do like the end of the EC, improving from next Wed, on GFS too, but good chart this, upper teens maybe, higher SE?

[MATTWOLVES 3]

50 minutes ago, I remember Atlantic 252 said:

uncertain times,with ex hurricanes etc, but do like the end of the EC, improving from next Wed, on GFS too, but good chart this, upper teens maybe, higher SE?

Yes mate, the ECM mean also toying with a pressure rise towards the end of next week, and warming temos.... Perhaps low pressure at this stage becoming anchored to the NW again... So perhaps some rain pushing SE at times towards the end of the run! All along way off and subject to much change with all the current going ons though. 

[knocker]

The mayhem that ex hurricanes can cause in five days

[knocker]

lorenso GEFS and EPS

 

[knocker]

The North Atlantic 500mb and surface analysis for midnight

Still some rain around in some areas, particularly the east and north, from the fronts crossing the country but this should clear through the morning leaving the UK within the circulation of the low to the west, thus a day of blustery showers. These could be heavy and slow moving, particularly in northern areas where it will be less windy. Quite warm in the sunny intervals in the south

Little change overnight, with the showers more inclined in western regions

During Friday the showers will pep up a fair bit with thunder entering the mix as a little frontal wave swings around in the circulation and thus some longer spells of rain as well. Also quite windy in the south with perhaps coastal gales. A cooler day than today

Over Friday night and through Saturday overall pattern changes are underway which have previously been discussed and there is a brief interlude for the UK with plenty of sunshine and scattered showers as the winds abate. But the next frontal system is waiting in the wings to the south west

The aforementioned low tracks across England and Wales on Sunday thus some heavy rain and strong winds before the system clears into the North Sea

On Monday the UK is pretty much in no mans land between the upper trough to the north east and Atlantic troughs tracking east below the Greenland/Iceland block. All resulting in a much drier and sunnier day apart from Scotland where a cold front slipping south will result in quite frequent showers

Edited September 26, 2019 by knocker

[knocker]

According to the gfs another wet and windy day on Tuesday as another low tracks east across the country

But as can be seem Lorenzo is arriving on the scene out west in the Atlantic and it tracks up the eastern flank of the Atlantic trough as a very intense surface low which just impinges on Ireland with most of the UK in a col.

 

Edited September 26, 2019 by knocker

[ItNeverSnowsInWindsor]

It’s looking increasingly cool and unsettled according to latest GEFS run 0z.

Perhaps a good sign for proper winter ?

[knocker]

The ecm has Lorenzo merging with the Atlantic trough resulting in a very deep low in mid Atlantic

[ItNeverSnowsInWindsor]

GFS also merges the Atlantic low with Lorenzo but has a much colder pool ahead of the encroaching low next week.

Edited September 26, 2019 by prolongedSnowLover

[Yarmy]

1 hour ago, knocker said:

The ecm has Lorenzo merging with the Atlantic trough resulting in a very deep low in mid Atlantic

Yes, an absolute beast:

Fortunately, it stalls and fills out mid-Atlantic otherwise it would be a headline maker.