Model Output Discussion 01/09/17

[Frosty.]

Some will moan but I'm looking forward to this warm up from the sw / s  later this week shown by the Ecm 12z this evening and other output today, there is plenty of time for cool, wet and windy weather...I'm going to enjoy this late taste of summer as I'm sure will the majority!

Edited October 10, 2017 by Frosty.

[cheeky_monkey]

4 minutes ago, Frosty. said:

Some will moan but I'm looking forward to this warm up shown by the Ecm 12z this evening and other output today, there is plenty of time for cool, wet and windy weather...I'm going to enjoy this late taste of summer as I'm sure will the majority!

Looks lovely..nothing to moan about with these charts 

[Ice Man 85]

6 minutes ago, cheeky_monkey said:

Looks lovely..nothing to moan about with these charts 

Erm...low diurnal range which to me indicates high humidity, which equals uncomfortable nights. I could go on...

[Ross Andrew Hemphill]

55 minutes ago, Frosty. said:

Some will moan but I'm looking forward to this warm up from the sw / s  later this week shown by the Ecm 12z this evening and other output today, there is plenty of time for cool, wet and windy weather...I'm going to enjoy this late taste of summer as I'm sure will the majority!

All I need is two dry days to do the last cut of the grass but the models aren't delivering! 

[Summer Sun]

In between this warm up some western parts are in for some persistent torrential rain tomorrow which could well lead to some flooding in places

[ANYWEATHER]

Evening All ! Im still excited about our forthcoming weather ,not just some high temps for this time of year but also a tropical storm to really complicate things. I Think we need a couple of more days at least to sort out the synoptics but this tropical storm needs to be watched as both ecm and gfs bring it in striking distance of the uk  at T+144. There will be lots of changes during the next few days but perhaps this is the "Calm Before The Storm"!

[damianslaw]

Further uncertainty abounding again courtesy of unknowns regarding ex tropical storm activity. In the reliable we have a long fetch southwesterly to look forward too, those in the south and east will enjoy very pleasant calm conditions, with locally warm conditions, and sunny spells. The north west quarter though will see very different conditions, rain, low cloud at times, limited sunshine - though Thursday promises some drier conditions. Indeed next 24 hours set to bring a deluge to these parts - and further heavy rain on Friday, and weekend. 

Next week - all to call for, but generally probably unsettled nearer average temps for all.

I'd like to shake things up a bit synoptic wise at the moment, instead of just looking to the west all the time..

[ANYWEATHER]

Hi, To be honest I don't see any record breaking temps from the gfs  Perhaps Next Monday with the highest temps , this just goes to show how complicated this set up is ...Just watch this space..

[Man With Beard]

GFS 18Z is a direct hit both for the plume and the storm. Monday is quite remarkable as 25C looks well on the cards for central areas, and then the storm nearly makes the Cornish coast in full glory, probably a force 10 or 11 at landfall but weakening very quickly afterwards. It's still what you might call a cat 1 hurricane not a couple of hundred miles off our shores.

Edited October 10, 2017 by Man With Beard

[summer blizzard]

1 hour ago, Man With Beard said:

GFS 18Z is a direct hit both for the plume and the storm. Monday is quite remarkable as 25C looks well on the cards for central areas, and then the storm nearly makes the Cornish coast in full glory, probably a force 10 or 11 at landfall but weakening very quickly afterwards. It's still what you might call a cat 1 hurricane not a couple of hundred miles off our shores.

Ophelia will be extra-tropical by that point but not fully barlonic which is very rare for the UK (Katia 2011 probably the last time). That means we will get fronts like a normal storm but it will be unusually strong for a system of its pressure value due to efficient mixing and we may see stronger winds closer to the center. 

Moves through quickly though so a good gale but a one evening affair. 

[Ice Man 85]

Just when you think the model outputs can't get any worse.

[Geordiesnow]

3 hours ago, damianslaw said:

Further uncertainty abounding again courtesy of unknowns regarding ex tropical storm activity. In the reliable we have a long fetch southwesterly to look forward too, those in the south and east will enjoy very pleasant calm conditions, with locally warm conditions, and sunny spells. The north west quarter though will see very different conditions, rain, low cloud at times, limited sunshine - though Thursday promises some drier conditions. Indeed next 24 hours set to bring a deluge to these parts - and further heavy rain on Friday, and weekend. 

Next week - all to call for, but generally probably unsettled nearer average temps for all.

I'd like to shake things up a bit synoptic wise at the moment, instead of just looking to the west all the time..

The trend seems to me a wet Friday in the North West but a drier weekend? Where the front actually waves is yet to be decided but hopefully the Northward trend will continue so we are underneath the influence of high pressure if albeit we may be under cloudy skies anyways.

Its an interesting period coming up I feel, just how much rain will fall in some western areas,  just how warm will it get this weekend and what influence will the tropical storm have on our weather? Its such an unusual track as tropical storms that far South in the Atlantic usually head westwards and not Eastwards and I don't think we can rule out totally Spain/Portugal feeling some affects from this storm?

[knocker]

Without too much waffle the 6-14 day out look from last might's NOAA, GEFS and EPS anomalies is for it to remain unsettled with the usual NW/SE bias in this pattern and temps returning to around normal.

But the nearer time frame is far more important at the moment. Today sees a complex frontal system across north west England and Wales dominating affairs with significant rainfall amounts expected. Perhaps 120mm in Cumberland and 60-80mm in north west England and Snowdonia. To the south and east of this partly cloudy, particularly in the south west but clearing for not a bad day but deteriorating later. N. Ireland and Scotland showery, perhaps thundery in Scotland.

Quieter day tomorrow with a transient ridge

On to the morning delight's of the gfs. Early Friday morning sees the next deep Atlantic low 958mb just south west of Iceland with associated front lying across N.Ireland and Scotland bringing more rain in these areas , The front itself stretches all the way SW to the Azores along the eastern flank of the  large upper trough with TS Ophelia at the end. Over the next 48 hours the front will stall and tend to dissipate so still intermittent rain over the regions already mentioned. Further south remaining dry in the S/SE drift with temps reaching the low 20sC in England which is in marked contrast to central and northern Scotland where they will be around 12C  But to the south west the front is certainly not inactive with waves forming on it and Orphelia on the move as can be seen on the Sunday midday chart.

What happens from here is a long way from settled and this morning's version has Ophelia deepening to 953mb west of Ireland by 12 Monday with the weakening front pushing east across the the UK. It continues to track north then NW and the whole process organises the major trough in the Atlantic with more fronts crossing the country on Tuesday along with other developments in the flow. Absolutely no point in looking further ahead because I'm sure this is will be subject to change in future runs.

Keeping the TS out west would obviously best case scenario vis the UK and the more worrying aspect is short term rainfall amounts in some areas and the possibility of flash floods.

 

 

Edited October 11, 2017 by knocker

[knocker]

Compare the area of unseasonably warm ocean with the forecast track of Ophelia. H/t Stephen Rahmstorf

[knocker]

The ecm very similar to the gfs and takes Ophelia as an intense extra tropical depression just west of Ireland on Monday. Lets hope they are both correct.

[snowbunting]

Models having fun and games with this ex tropical storm. Looks like force 10 possibly 11. Track switches position Cornwall, South Coast. Western Ireland. NW Scotland. Sunday/Monday could be interesting. 

[snowbunting]

38 minutes ago, knocker said:

Compare the area of unseasonably warm ocean with the forecast track of Ophelia. H/t Stephen Rahmstorf

Has the blue blob of the North atlantic moved a little further West?

[knocker]

10 minutes ago, snowbunting said:

Has the blue blob of the North atlantic moved a little further West?

Really just the natural variations that occur over time for various reasons

[Frosty.]

Great charts these, while there is still potential for low to mid 20's celsius, I say welcome it with open arms!..

Edited October 11, 2017 by Frosty.

[Nick F]

So the models generally agreeing, for now, on taking ex-Ophelia north close to the west side of Ireland early next week, a close call for Ireland though, with a track further east threatening potential widespread severe gales. 00z UKMO takes this deep low NE toward western Scotland, rather than north toward Iceland like the other models, so western Scotland could come into the frame for strong winds too if this NE track were to transpire.

The long track north of ex-Ophelia from south of the Azores will draw a deep warm southerly flow from southern Spain / western Med for the weekend into early next week, some high temps indicated for Monday from the 00z Netwx-MR showing 25-26C for eastern England, would surely threaten some date records.

Strong jet stream next week looping N to NE across the UK could pull a few shortwaves NE that could spawn some deepening secondary lows moving NE from the Bay of Biscay. Long-way off for any certainty, but 00z ECMWF and the EC control indicates potential for such a low to move NE from Biscay across NW France and perhaps on to SE UK. All coming around the 30 year anniversary of the Great Storm of 1987 as well! Worth keeping an eye on.

00z ECMWF for mid-next week

00z ECMWF control

All-in-all an interesting period of weather coming up, certainly not run-of-the-mill autumn weather, with ex-hurricane arriving from so far south and bringing unusual warmth with it too.

Edited October 11, 2017 by Nick F

[Polar Maritime]

As stated by Nick a very interesting period coming up, And how the models handle such a rare scenario over the coming days. Here's the GFS 6z take on temps & wind for next Monday. 

Edited October 11, 2017 by Polar Maritime

[Man With Beard]

22 minutes ago, Polar Maritime said:

As stated by Nick a very interesting period coming up, And how the models handle such a rare scenario over the coming days. Here's the GFS 6z take on temps & wind for next Monday. 

Remarkable to see 19C or more right through the country in the second half of September. The ex-tropical storm acting as the perfect catalyst to waft the warmth northwards.

ECM was bang on the money for this one (if it turns out as currently modelled), and now the GFS/UKMO have followed.

Ophelia looking a bit more likely to be an Ireland affair (though still low confidence) - however, the latest ECM clusters show stormy weather likely to get to the UK mainland by next Wednesday - all clusters going pretty much the same way on that:

[Nick F]

Interesting how ex-Ophelia low keeps a warm core just like a tropical storm/hurricane as it approaches to the SW of Ireland on Monday, unlike the more usual cold cored North Atlantic depressions we see. Certainly likely to be a lot of energy wrapped up in this deep low, wherever it may go.

[stodge]

Morning all

It is indeed fascinating to see TS Ophelia's impact on the synoptic development.

We've had ex-hurricanes swing past Ireland before but these have usually travelled across the Atlantic. This one is unusual given its origin and lifecycle. It does look as though it will swing NNW past the west Irish coast but it has the effect as it passes north of invigorating the Atlantic push east so the troughs break down the Azores HP and get into and (more significantly) the British Isles.

I don't see it coming far enough east to affect the British Isles in all honesty though, as others have said, it wouldn't take much for Ireland to be in the firing line.

The latter stages of 06Z FI take us into a much cooler trend moving into the last third of October and, not for the first time, we see the trough disrupt close to the British Isles with the usual tease of northern heights up and over the Pole (which we know will come to nothing, don't we ?)

[Man With Beard]

3 minutes ago, stodge said:

Morning all

It is indeed fascinating to see TS Ophelia's impact on the synoptic development.

We've had ex-hurricanes swing past Ireland before but these have usually travelled across the Atlantic. This one is unusual given its origin and lifecycle. It does look as though it will swing NNW past the west Irish coast but it has the effect as it passes north of invigorating the Atlantic push east so the troughs break down the Azores HP and get into and (more significantly) the British Isles.

I don't see it coming far enough east to affect the British Isles in all honesty though, as others have said, it wouldn't take much for Ireland to be in the firing line.

The latter stages of 06Z FI take us into a much cooler trend moving into the last third of October and, not for the first time, we see the trough disrupt close to the British Isles with the usual tease of northern heights up and over the Pole (which we know will come to nothing, don't we ?)

The ECM clusters had a go at this last week and then dropped it - the latest clusters still provide hints by D15 of more northern heights than one would expect (e.g. cluster 4 might be a Greenland High) but given their track record for delivering on northern heights, you'd probably favour a Wly or SWly outlook based upon these: