Model Output Discussion 31/07/14 onwards.

[IDO]

All change from ECM this evening; from a non-event this morning's run it is now showing Bertha exiting the jet next Monday, reacting with the trough and by D8 at its deepest:

D6: D7: D8:

Much like GEM though timing issues, D7:

UKMO looks like it may also reinvigorate on D7 and D8 as it heads up the North Sea:

ECM at D10 is very messy:

But having been keeping an eye on the Pacific storms and their after affects it does reflect those more than GFS's smooth transition to higher heights.

Looks like a very wet 10 days or so upcoming.

Edited August 4, 2014 by i'm dreaming of...

[Captain Shortwave]

So let's get the reliable out of the way,

Conditions will turn increasingly unsettled towards the end of the week as the upper trough slowly edges east wards with shortwaves moving north east along it's eastern flank, these will bring showers or longer outbreaks of rain on Wednesday and late Friday.

The weekend itself has a lot of uncertainty, Saturday looks showery with most of the showers in the north.

Sunday heralds a lot of uncertainty considering how quickly Bertha arrives and where it strikes, UKMO/GEM and ECM all go for the south of the UK to bear the brunt of this system.

 

GFS is further north, though it does seem to be shotgun spreading the outcomes, so not sure how reliable it's run is.

 

I feel bold tonight and I am going to personally disagree with all the output here on the track of this system.

I may be very wrong and only time will tell, but I think this is going to be a channel runner, probably affecting the south east (Hampshire eastwards) and Northern France with the rainfall being more of an issue afterwards. I feel the models might be over-blowing the storm a bit when it hits the UK at the moment, hence the correction south and reduction in intensity of my prediction.

 

After this, well it does look like we see the Atlantic jet ease somewhat so perhaps the path beyond Bertha is towards something more atypical for the time of year, AKA a north/south split with the Azores high sitting just to the south west of the UK.

Edited August 4, 2014 by Captain shortwave

[tinybill]

So let's get the reliable out of the way,

Conditions will turn increasingly unsettled towards the end of the week as the upper trough slowly edges east wards with shortwaves moving north east along it's eastern flank, these will bring showers or longer outbreaks of rain on Wednesday and late Friday.

The weekend itself has a lot of uncertainty, Saturday looks showery with most of the showers in the north.

Sunday heralds a lot of uncertainty considering how quickly Bertha arrives and where it strikes, UKMO/GEM and ECM all go for the south of the UK to bear the brunt of this system.

 

GFS is further north, though it does seem to be shotgun spreading the outcomes, so not sure how reliable it's run is.

 

I feel bold tonight and I am going to personally disagree with all the output here on the track of this system.

I may be very wrong and only time will tell, but I think this is going to be a channel runner, probably affecting the south east (Hampshire eastwards) and Northern France with the rainfall being more of an issue afterwards. I feel the models might be over-blowing the storm a bit when it hits the UK at the moment, hence the correction south and reduction in intensity of my prediction.

 

After this, well it does look like we see the Atlantic jet ease somewhat so perhaps the path beyond Bertha is towards something more atypical for the time of year, AKA a north/south split with the Azores high sitting just to the south west of the UK.

reg  Bertha   track   cat 1  at the  moment

 

http://www.nhc.noaa.gov/graphics_at3.shtml?5-daynl#contents

Edited August 4, 2014 by tinybill

[knocker]

The ECM ops 12 anomaly has a deep upper trough west of the UK stretching eastward over the the same.

 

Surface analysis for the weekend has low pressure just to the north of the UK which influences the whole of the latter. The jet is running south of the UK that facilitates this set up. Basically ubsettled weather with average temps, possibly below average in west. The ECM is not dealing with Bertha along the same lines as other models and seems to having it dying a slow death iin the Bay of Biscay Sunday.

Edited August 4, 2014 by knocker

[summer blizzard]

Worth a note that Bertha may be stronger than expected as it has deepened faster than forecast and is now a hurricane (30KT strengthening in 24 hours). The 18z will be the run initialised with the new, stronger data so watch for any impact change once it hits the jet from that run on.

 

As for the models, GEM still goes very wet in the coming days and i expect flood warnings in some places..

 

 

 

[ANYWEATHER]

An unseasonable weather pattern coming up, more like Autumn charts than August! Looks like Bertha will continue to give models a headache right down to the wire. Certainly no detail to be attached to late week and into the weekend but some folks will get a real soaking which may be a news maker. If the system really winds up as the models at times been hinting, it could well be a very windy spell coming up. At day ten ,ecm and gfs disagree on pressure rise, after all its FI and its certainly premature to be thinking post Bertha as  models cant decide  Pre Bertha........    

[Frosty.]

The Ecm 12z op run stays unsettled for longer next week compared to the Gfs 12z, however, the ecm delays the worst of the weather and by T+240 hours, a large mass of high pressure is lurking just to the west, waiting for that pesky trough to clear off, worth noting, it never gets cool, temperatures stay in the low 20's celsius, occasionally warmer than that in the southeast.

[Man With Beard]

The ECM idea of deepening Bertha in situ over the north sea is very novel. Never seen that happen - been watching weather charts for 31 years and have only ever seen them develop as they are moving. Any thoughts as to why the ECM allows this to happen?

A further thought tonight - some charts don't look so severe but most have it deepening over us - and a deepening low can be more dangerous than a fully developed one.

[knocker]

This is way above my pay grade but here we have a dissipating tropical depression popping along on a southerly tracking jet hitting a pretty deep and extensive established upper low. Now assuming Bertha retains a fair whack of energy some complicated meteorological processes will then ensue possibly leading to a deepening of the in situ depression. That's my simplistic theory but await input from those who know a thing or two.

[Frosty.]

All things considered, this week isn't bad at all, it's warm, lots of sunshine for the northeast of the uk tomorrow, wednesday looks the wettest day of the working week by far, thursday looks fine and sunny, as does friday but the weekend does look like becoming a washout for many areas with torrential rain around and stronger winds eventually.

[bluearmy]

anyone confident that the models have a handle on bertha yet ?

[Man With Beard]

This is way above my pay grade but here we have a dissipating tropical depression popping along on a southerly tracking jet hitting a pretty deep and extensive established upper low. Now assuming Bertha retains a fair whack of energy some complicated meteorological processes will then ensue possibly leading to a deepening of the in situ depression. That's my simplistic theory but await input from those who know a thing or two.

Thanks - A bit like a bomb then ... also sounds like the kind of thing that won't be accurately forecast until very late, as it will depend on the initial point of contact ... wow.So to answer your question Bluearmy, I don't think confidence could be lower, just that 'something' is coming! Edited August 4, 2014 by rjbw

[Polar Maritime]

Aye B.A, Very uncertain reg the track and strength of Ex Bertha. Leaving beyond that even more so.

Edited August 4, 2014 by Polar Maritime

[knocker]

anyone confident that the models have a handle on bertha yet ?

 

Not me and the METO isn't either.

[East_England_Stormchaser91]

Bertha could end up anywhere West of us from Scotland to Iberia, all it will take is a slight slip South or north to end up somewhere completely different to what some models are showing. Much much much more runs will be needed to pin down a more accurate track of the little mistress!

[Frosty.]

 Very uncertain reg the track and strength of Ex Bertha. Leaving beyond that even more so.

Yep that's right, the track & intensity is nowhere near nailed yet, however, the weekend does indicate potentially severe weather but hopefully we will see a BIG improvement by the second half of next week as per the Gfs 12z.

[ANYWEATHER]

Yep that's right, the track & intensity is nowhere near nailed yet, however, the weekend does indicate potentially severe weather but hopefully we will see a BIG improvement by the second half of next week as per the Gfs 12z.

Why  post these BIG letters when none of us no the pre burtha weather, let alone the post burtha    

[phil nw.]

A couple of posts have been moved here

http://forum.netweather.tv/topic/79882-model-banter-moans-and-ramps-springsummer-2014/

 

as they were not adding to model discussions- rather questions about high tides and travel plans because of the possible storm.

[IDO]

With Bertha hitching a ride on the jet stream and the jet running through the UK I would be confident of the track of Bertha.  The problem is seven days out the models struggle with this type of scenario with regard to surface conditions. If for instance there is a degree of explosive cyclogenesis, then as this usually happens within 24 hours, its going to be hard for the models to nail this till closer to the time. 

 

Looking at the Atlantic forecast for +T96 it shows that Bertha has little choice but to ride over the Azores High: 

 

It will then interact with the trough over the UK. Anybodies guess on where it interacts and the timing and its intensity pre and post mixing.

 

ECM op is in Cluster 1 of 6 with about 25% support at D5, so at least at the moment, the op represents the most likely option according to ECM.

 

Looking at the GEM ensembles most of the members are similar to the GFS op, though the Control supports the GEM OP.

 

I don't see the jet destabilising from its current position pre-Bertha so UK looking like a direct hit.

[knocker]

With Bertha hitching a ride on the jet stream and the jet running through the UK I would be confident of the track of Bertha.  The problem is seven days out the models struggle with this type of scenario with regard to surface conditions. If for instance there is a degree of explosive cyclogenesis, then as this usually happens within 24 hours, its going to be hard for the models to nail this till closer to the time. 

 

But that is still dependent on the position of the jet. At the moment the GFS has it north of the ECM which has it going into France. I'm not quite sure how people know that models struggle with this type of scenario, although no doubt they will, because I don't remember too many scenarios of this nature.

 

[Scorcher]

With Bertha hitching a ride on the jet stream and the jet running through the UK I would be confident of the track of Bertha.  The problem is seven days out the models struggle with this type of scenario with regard to surface conditions. If for instance there is a degree of explosive cyclogenesis, then as this usually happens within 24 hours, its going to be hard for the models to nail this till closer to the time. 

 

Looking at the Atlantic forecast for +T96 it shows that Bertha has little choice but to ride over the Azores High: http:////f1.nwstatic.co.uk/forum/public/style_images/tctc91_simplify/attachicon.gifA_96hrbw.gif

 

It will then interact with the trough over the UK. Anybodies guess on where it interacts and the timing and its intensity pre and post mixing.

 

ECM op is in Cluster 1 of 6 with about 25% support at D5, so at least at the moment, the op represents the most likely option according to ECM.

 

Looking at the GEM ensembles most of the members are similar to the GFS op, though the Control supports the GEM OP.

 

I don't see the jet destabilising from its current position pre-Bertha so UK looking like a direct hit.

 

You seem to be a lot more confident about this than the Met Office, who have said that they are still far from certain about the track of this storm, or indeed the timing if it actually hits the UK. The Met Office are even saying there is a chance that it will miss the UK to the south.

[Panayiotis]

This storm for around the 10th/11th needs watching closely, if it develops/tracks like it does on the GFS then it could be damaging for the UK especially for exposed areas in the west. We have had quite good weather in the past few weeks so most people might see this as a shock and may not be prepared, hopefully it gets downgraded in the near future...

Edited August 5, 2014 by Panayiotis

[SteveB]

Unsettled for the foreseeable is the only way I can sum up the charts this morning. Temp look very low for the time of year as well next week.

 

Edited August 5, 2014 by SteveB

[Captain Shortwave]

^As the later output is determined by what Bertha does, then I think we shouldn't take any output after this too seriously as it will change around a lot.

GFS is the most aggressive this morning with Bertha

 

Meanwhile the UKMO and GEM simply dissipate the energy which results in a non-event for the UK

 

Remember my prediction yesterday? The ECM is pretty close to that

Runs quickly across the south of England before pushing towards Denmark. Still thinking that something close to this will be the correct outcome.

 

Still looks like the Azores high will likely nose in to bring improving conditions to the southern half of the UK after this. Well, going by the ensembles at least.

Edited August 5, 2014 by Captain shortwave

[IDO]

Every one of the GEFS ensembles has Bertha on a direct hit for some part of the UK, most suggest it will mix with the trough to the west of the UK and deepen but lots of variety from there:

 

op and control:   

 

ECM keeps Bertha in the jet longer and sends it through the Channel and it is a small feature clipping the south/SE coast:

 

 

 

GEM does it's own thing and splits the energy and the main thrust is delayed: 

 

The effect of that is the storm dissipates by the time it reaches the UK but prolongs the UK in the trough, so by D10: 

 

UKMO at T84 Fax: 

 

It does look like Bertha is not a run of a mill Hurricane. The current satellite image does indicate GEM could be right in splitting the energy as Bertha looks like it is more than one energy source:

 

 

Will see what the ensembles indicate but still lots of variety as to what force it will be when Bertha hits the UK locale.

 

 

Edited August 5, 2014 by i'm dreaming of...