Model Output Discussion - 17th Oct Onwards

[Bobby]

Nasty winds on that low at +144 on GFS

 

 

Can't be specific about detail at this range but the setup we're moving into is ideal for an intense windstorm - with a strong jet and plenty of cold and warm moist air mixing over the Atlantic. So I'd bet on at least one storm over the next week or two.

 

Wet too with perhaps another 100mm in places by the end of the month, so flooding concerns considering the ground is already saturated in the wettest areas.

 

[summer blizzard]

Looks like the sun is at the end of the rainbow. Both the Euro and GFS models do suggest a cold front sweeping through at days 6 and 7 bringing colder air.

[BLAST FROM THE PAST]

Not much of a chart reader but what are the chances of this coming off thankyou im still learning.

Once in a 100 year period? It is very extreme....so  'extremely' unlikely

BFTP

Edited October 22, 2013 by BLAST FROM THE PAST

[Zenarcher]

The GFS hasn't been consistent with the low yet its changed its mind every run, it does seem to want to have a low pressure system but it doesn't know where to put it yet and how deep it will actually go. The UKMO and ECM last two runs haven't shown anything like what the 06z GFS this morning is showing.

 

Some stormy ensemble runs this morning from the 06z GFS but for those who don't know the ensembles run in a lower resolution to the main output and start with different conditions. There aim is to tell us if the run has support or not. It does seem to have some support from its ensembles and the GEM model itself.

[itsnowjoke]

Once in a 100 year period? It is very extreme....so  'extremely' unlikely

BFTP[/quote

Thankyou BFTP

[shedhead]

For me GEM shouldn't be discounted, it picked up quite early the very unsettled pattern developing.  Below shows precisely the sort of track I envisaged with an impactual storm or two.  I'm not discounting severity either....wow that would be some event.

 

 

BFTP

 

 

 

 

If that's the case Blast then it should never be discounted, but the truth is in general it only gets trawled up when it's showing something interesting or something we want to see. 

 

Not saying the LP's will not ultimately end up this far south, indeed the GFS +144hrs below bring the LP across central area, but at the kind or timescale involved I don't think any track or any intensity (within reason of course) could be genuinely 'discounted'.

 

Edited October 22, 2013 by shedhead

[Nick L]

Let's not get too carried away with what the ensembles are showing. I think we get 87-esque storms showing every year, but as they approach the reliable they either weaken considerably or completely disappear. Yes, if it happens it could be concerning, and if it remains that way in a few days with decent support then is the time to worry. But for now - I'm certainly sceptical, the GFS is well-known for it's exaggerated lows at times.

[draztik]

 

The 6-10 day Height anomalies from the GFS 6z continue to be dominated by low pressure, with copious amounts of rainfall expected, with 4+ inches expected towards the West, most prone in areas of Wales, the SW, South West Scotland and the Eastern side of N.I.

Edited October 22, 2013 by draztik

[pip22]

Some of those ensembles, eh? Yikes...

 

What a beast!! If have to name that storm, it would be called ''the mother of all storms'' or ''the Beast of the West''.

Edited October 22, 2013 by pip22

[Skullzrulerz]

Some of those ensembles, eh? Yikes...

 

If it happens it will be one bad storm.

[tight isobar]

Stunning output from gfs......tight isobars...understatment!!!!!!!

GEFS (

[stainesbloke]

Not much of a chart reader but what are the chances of this coming off thankyou im still learning.

Hiya, there is potential for some stormy weather over the next week or two for sure. The strong jet and temperature contrasts in air masses over the Atlantic could result in some 'explosive' development of low pressure. The chart posted however, does look a bit extreme! Unlikely to verify but there's always a small chance of something really nasty brewing up. Will be watching the charts intently for the next week!

[radiohead]

What a beast!! If have to name that storm, it would be called ''the mother of all storms'' or ''the Beast of the West''.

 

And 940mb on a chart with that scale and resolution would probably be more intense in reality, 930mb maybe lower.

 

Luckily it's only one ensemble member, in one run, of one model, a model thats known for overblowing storms.

[Heisenberg]

so IF (however unlikely) that came off, what sort of wind speed and gusts would we be looking at?

[pip22]

And 940mb on a chart with that scale and resolution would probably be more intense in reality, 930mb maybe lower.

 

Luckily it's only one ensemble member, in one run, of one model, a model thats known for overblowing storms.

Its a good job its only a one run. Otherwise we be screwed by facing power cuts by the storm, let alone a potential energy crisis, which is bad for our economy.

Edited October 22, 2013 by pip22

[Frosty.]

http://www.youtube.com/watch?v=uqs1YXfdtGE

Ladies and Gentlemen..I have at no expense dug out this classic from the archives, a absolute Blast from the Past...this is really all that needs to be said about the risk of storms this weekend or next week... or ever, a warning from history from the legend himself

Edited October 22, 2013 by Frosty.

[radiohead]

Its a good job its only a one run. Otherwise we be screwed by facing power cuts by the storm, let alone a potential energy crisis, which is bad for our economy.

 

It's the most extreme example, but still worth remembering that 7 out of the 20 ensembles (plus the control run) are showing a storm with 955mb or lower, and the op run got down to 960mb, that has sustained winds reaching 75 mph in the Bristol Channel.

 

So worth keeping an eye on for sure.

[Nick L]

Can we try and keep things model related please folks? There are other threads for more casual discussion.

[lorenzo]

so IF (however unlikely) that came off, what sort of wind speed and gusts would we be looking at?

 

50-70 mph wind and 60-80 mph gusts. Massive caveat being as others have mentioned the GFS tendency to ramp up features like this, truth is we won't know until nearer the time if the system will bomb as projected on the 06z run. Certainly providing some good model watching at present though !

 

 

 

[carinthian]

Let's not get too carried away with what the ensembles are showing. I think we get 87-esque storms showing every year, but as they approach the reliable they either weaken considerably or completely disappear. Yes, if it happens it could be concerning, and if it remains that way in a few days with decent support then is the time to worry. But for now - I'm certainly sceptical, the GFS is well-known for it's exaggerated lows at times.

 

Certainly looks like some speedy developments over the coming days. To repeat the bomb of 87, the formation under the strongest upper level winds would be nearer to the tropic zones at 40N. Looks like present formations are going to be around 50N in the sub maritime zone.Stormy weather on the horizon, but 87 repeat not likely. However, the exit of the jet streak is going to produce some powerful winds over the Uk. To early to be exact with location but my feeling is the south could get a battering.

C

[summer blizzard]

Personally i do rate the GEM model so whilst i would discount sub 950mb i do think it may well be correct in a strong storm on a southerly track.

[lorenzo]

The 00z ECM Ensembles are worth a look, would be nice if these were slightly easier on the eye to look through.

 

144 / 156

 

A fair few troublesome solutions in the 156hr run, so not without support from the ECM either.

 

[Iceni]

Personally i do rate the GEM model so whilst i would discount sub 950mb i do think it may well be correct in a strong storm on a southerly track.

 

Our friend and mentor John Holmes has just given me an interesting piece of information... apparently when depressions deepen quickly, they veer off track to their left.

 

And I remember a storm which did just that several years ago. It was approaching from Brittany heading NE and expected to affect West Dorset to the Isle of Wight area, when it suddenly headed due North and hit Teignmouth Devon. If anyone could supply the date - must have been about 9 am and either late autumn or early spring as I got up in the dark around 7 am to watch its progress.

Edited October 22, 2013 by Iceni

[pandit-scholar]

If that deep low appearing on the GFS & ECM verifies, it seems we could have been a bit harsh on that guy on that YouTube video who predicted that category 3 hurricane & the worst storm for 300 yrs would hit the UK at the end of October!! But still plenty of time for a big downgrade!

[nick sussex]

Some very depressing output shown by both the GFS and UKMO with a deepening low forming off the main troughing and running east/ne in towards the UK.

The ECM doesn't make much of this for the timebeing and I sincerely hope it stays that way, with trees still in leaf this could be very worrying and coming on top of already saturated ground it really is a very poor outlook if that storm verifies. In terms of track and as alluded to by JH, the deepening motion normally leads to that turn to the left or in this case a more northerly track.

Overall its a pretty horrid outlook with this conveyor belt of depressions lined up to effect the UK.