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Lets be honest, it's never going to be anything near a 'hurricane' anyway in the first place ;)

 

Models over the next 24-48 hours will be key to see how this storms changes etc

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Update on the 12z runs,

 

GFS - Has it crossing over Northern England down to 992mb during Sunday. It shows winds around 35 to 45mph across England and Wales with very heavy rain moving over Ireland and Southern Scotland.

 

post-6686-0-90265200-1407267988_thumb.pn

 

GEM - Similar track to the GFS but further South missing out most of the UK. The low passes over Northern France at first but then it heads into the English Channel and deepens a lot bringing strong winds to the South East of England.

 

post-6686-0-85177300-1407268169_thumb.pn

 

NAVGEM - Almost the exact same track as the GFS but it is slightly further North over Northern England and into Southern Scotland and deeper as well.

 

post-6686-0-05900600-1407268275_thumb.pn

 

ECM and UKMO - Both don't seem too interested in it and don't really form anything at all.

 

Overall the GFS along with some other models form a low and have it cross over England and Wales or near it bringing lots of rainfall and strong winds during Sunday. However the ECM and UKMO don't show this and show the system die out before it reaches our shores.

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Well, I thought I would participate in this discussion. Currently, I'm not expecting too much from Bertha but I am expecting some gale force winds and a large amount of rain at least. I think in the ideal situation, we could see severe gale force wind gusts but nothing much higher. However, if that happens, it could be one of the strongest summer storms to hit here for many years. Also, due to trees being in full leaf and large amounts of rainfall making the ground saturated, trees could easily uproot and there could be some travel disruption particularly on roads and railways. It just would be lovely to have a St Jude type storm here again but will it happen is the question.

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I think rain will be more of an issue than the wind. I can't see it interacting with the jet stream to give it the cyclogenesis.

Breezy up the channel but the western flank of low pressure giving heavy and perhaps convective rainfall. That's my shout from this far out anyway.

The GFS could be over-doing a ridge of high pressure which is quite clear at T+96hrs (GEFS mean at least) over Spain and up in to France. The UKMO has it, but substantially weaker. On the ECM, it is nonexistent. A lot of factors involved, but that is one which makes me feel as though the GFS could be the red herring.

Edited by Mapantz
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I think rain will be more of an issue than the wind. I can't see it interacting with the jet stream to give it the cyclogenesis.Breezy up the channel but the western flank of low pressure giving heavy and perhaps convective rainfall. That's my shout from this far out anyway.The GFS could be over-doing a ridge of high pressure which is quite clear at T+96hrs (GEFS mean at least) over Spain and up in to France. The UKMO has it, but substantially weaker. On the ECM, it is nonexistent. A lot of factors involved, but that is one which makes me feel as though the GFS could be the red herring.

I don't mind non-damaging wind if there is a lot of rain to the point of getting interesting, it's just that the GFS, as you say, wants to suggest one hell of a summer storm.

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The NHC's latest track has the centre to the SW of the UK. It looks like it'll head up through the channel and send the winds across France.

post-15177-0-48954400-1407322797_thumb.g

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The NHC's latest track has the centre to the SW of the UK. It looks like it'll head up through the channel and send the winds across France.

http:////f1.nwstatic.co.uk/forum/public/style_images/tctc91_simplify/attachicon.gif083625W5_NL_sm.gif

Yes, the GFS also agrees with this theory, the wind seems to be more SE when it reaches here and not as strong, we could still see a lot of rain though but for gale force winds, this is looking a little saddening.

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Thankfully it looks as though bertha will now head down into france. Just grazing the south coast. Looking at the latest gfs 6z run it now looks as though next week could turn out not too bad over much of the uk. Hopefully this trend continues.

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Looks like we'll miss Bertha with it tracking south of the UK as a weak low pressure system

 

Ex Bertha more likely to miss UK

 

Tropical Storm Bertha is currently off the north east coast of the US and is likely to become an ‘extra tropical storm’ on Thursday. It’s then expected to track across the Atlantic – and while there are still a number of possible outcomes, it looks increasingly likely that the UK will miss any serious impacts from ‘ex Bertha’. The Met Office has been assessing the likelihood of the UK seeing any effects from Bertha by using our own forecast model alongside models from other world-leading forecast centres.

 

At the moment the majority of forecasts from those models suggest ex Bertha will track to the south of the UK as a relatively weak low pressure system. In fact it’s debatable whether this is even ex Bertha, as the storm declines to such an extent as it comes across the Atlantic that it fragments.

 

http://metofficenews.wordpress.com/2014/08/06/ex-bertha-more-likely-to-miss-uk/

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Yes, the GFS also agrees with this theory, the wind seems to be more SE when it reaches here and not as strong, we could still see a lot of rain though but for gale force winds, this is looking a little saddening.

Do we really want gales in August with all the foliage?

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The Met Office today have an update on it,

 

More likely to track South at the moment,

 

Posted Image

 

 

Tropical Storm Bertha is currently off the north east coast of the US and is likely to become an ‘extra tropical storm’ on Thursday.

 
It’s then expected to track across the Atlantic – and while there are still a number of possible outcomes, it looks increasingly likely that the UK will miss any serious impacts from ‘ex Bertha’.
 
At the moment the majority of forecasts from those models suggest ex Bertha will track to the south of the UK as a relatively weak low pressure system.
 
In fact it’s debatable whether this is even ex Bertha, as the storm declines to such an extent as it comes across the Atlantic that it fragments.
 
A much smaller number of model outcomes suggest ex Bertha will move across the UK as a more distinct feature which could bring some strong winds and heavy rain. Because these outcomes are in a minority, however, they are less likely.
 
While there remains a good deal of uncertainty about the weather on Sunday, it currently looks as if it will be fairly unsettled with some rain and breezy conditions – but nothing too unusual for the time of year.

 

For More http://metofficenews.wordpress.com/2014/08/06/ex-bertha-more-likely-to-miss-uk/

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Still some uncertainty with the models.Still ranges from wash outs to no events.So really we will find out nearer the time what is really happening soon enough.

Yeah, really I'm not going to look into any detail until later tomorrow/Friday onwards, it's just too uncertain. However, the BBC want to support the idea, so things are looking up.

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As a student to this fine science, that has got to be one of the most informative post I have had the pleasure of feasting my eyes over ( and I have feasted them over many other informative posts)Thank you!

Edited by Supacell
Removed quote as rather long. Agree with this post though.
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From the looks of the models it is likely that Bertha will hit the uk.

 

But the how deep the low gets (Bertha that is) and where it hits is still up for grabs through 

 

The ECM looks the have the least deep low out of them all.

 

Some others have it deeper.

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for my idea see latest post in the model thread and also the link to UK Met Fax charts below

http://www.weathercharts.org/ukmomslp.htm#t96

and just to echo the compliment above for the post last evening by vorticity, as an ex professional it is well worth reading in my view-thanks v

Edited by johnholmes
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Have started a blog re: ex-Bertha's track in a blog here, which will be updated when I can:

 

http://www.netweather.tv/index.cgi?action=news;storyid=6068;sess=

 

Current thoughts:

 

The T+00 Met Office fax chart for 6am Thursday 7th August shows Bertha has now become associated with a frontal system south of New Foundland and has acquired ex-tropical characteristics. The centre of the low appears to be on the cold side of the frontal zone now and on the forward side of an upper trough extending south from Quebec down towards the Carolinas. The ex-tropical low is also under an upper-level westerly jet stream. The low pressure system will continue its track NE at 20knts, before tracking more eastward later today, as the steering flow and jet stream above it becomes more westerly along the base of a large upper (long-wave) trough extending south from Greenland across the Atlantic.

 

Now Bertha doesn't deepen a great deal on the model guidance over the next 48 hrs as it crosses east over the Atlantic under an unusually low latitude zonal jet stream, but a shortwave trough in the strong upper westerlies coming out of NE Canada over the weekend looks to 'sharpen' as catches up with the low by then in the southwest approaches later on Saturday. However, the models have been struggling with how the shortwave trough 'engages' with the low pressure system as it approaches UK waters and whether the low falls under the cold side of the jet and in developmental 'left exit' region of the jet where maximum upper divergence takes place. These factors will have an impact on whether the low deepens quickly to our SW and moves NE across Ireland then northern UK on Sunday, as per 00z GFS model output, which would bring a spell of very wet and windy weather to Ireland, England, Wales and S Scotland - with gales around coasts and hills. Or, the low doesn't interact so favourably with the shortwave and jet streak in the southwest approaches as per 00z ECMWF model, thus not deepening and rather continuing on a more southerly track northeast as a shallower open wave through the English Channel and across far north of France, before deepening later on.

 

The updated t+84 fax this morning from the Met Office, drawn by the Duty Forecaster using a combination of model 'raw' output and their ensembles, agrees more with the track of 00z ECM, though the low a tad further north across SE England, with centre of 995mb at noon Sunday in London area. 00z GFS, on the other hand, has low centre at noon Sunday over southern Scotland around 985mb! So you can see the uncertainties for now. Whatever the track, large scale ascent of very warm and moist sub-tropical air getting drawn into the low's circulation from the southwest and strong baroclinic zone created between this air and cold air sinking south from Greenland area - is indicated to produce large rainfall totals from some of the models, perhaps 20-30mm widely according to GFS and NMM over northern and western areas, 40mm+ according to NMM over S/E EIRE and Irish Sea, similarly large totals further south if the low tracks further south.

 

All in all, a risk of some unseasonably wet and windy weather during the second half of the weekend. I will endeavor to bring updates on these thoughts over the next few days.

Edited by Nick F
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