Model Output Discussion 31/07/14 onwards.

[IDO]

ECM 12z from yesterday had 6 clusters at D5 highlighting the uncertainty for Friday before we even get to how Bertha will react when it hits our locale. So no surprise to see the last three ECM runs being all over the place, from Bertha going SW and sending up a plume, to pumping up the core low in the trough, to this morning, where it blows itself out on the jet.

 

Like the GEFS members, agreement on Bertha heading towards the UK but this morning the GEFS mean suggesting more support for last night's op, where Bertha leaves the jet to the west of the UK and heads NE towards the NW of the UK:

 

Mean  

 

No point looking beyond that, as the disruption to the jet and pressure flow, has the GEFS all over the place by D10.

 

ECM has a very cool, unseasonal upper flow from D6-D9:  

 

GFS similar though not quite as cool.

 

Before Bertha arrives it looks like the SE/E/S having the worse of the rain this week: Totals till late Friday: 

 

This is due to a shortwave on Wednesday and a LP system with a cold front on Friday:

 

 

 

Uncertainty on Friday's low in the GEFS, similar clusters as the ECM variety from last night's 12z. No doubt once Fridays short wave flow is firmed up on this will aid the models for Monday's storm.

[Frosty.]

Yes PM you have called this upcoming unsettled weather very well...spot on mate

[knocker]

Yes some quite unsettled/cool & Autumnal charts showing again this morning by the GFS, With Ex Hurricane Bertha still Model'd to cross the UK around the 11th.  I'm sure we will see many adjustments N/S over the next day or so, Interesting times ahead.

 

 

 

Sorry PM I'm a bit lost here. Modeled by whom to cross the UK around the 11th? Forget that I see this is the GFS interpretation.

Edited August 4, 2014 by knocker

[knocker]

The ECM ens is not a million miles away from the ops, perhaps a tad cooler. It's downplaying Bertha in comparison with some.

Edited August 4, 2014 by knocker

[Frosty.]

Ecm 00z op run looks pleasantly warm but increasingly unsettled, very warm uppers occasionally flirting with the south & southeast importing some continental air at times, generally  +5 T850 hPa covers the uk which means surface temperatures around and about 20-22 celsius which is warm enough, occasionally mid to upper 20's c for the southeastern corner with a risk of thundery activity. For most of us it shows a good old mix of sunshine and sharp showers with a risk of thunder and occasional bands of more persistent rain..feeling cooler under prolonged rain. :-)

[Summer Sun]

Friday into Saturday could be very wet for most parts as a band of heavy rain moves south to north

 

 

Then the 10th and 11th shows more heavy rain moving in with the heaviest rain shown hit the south, Ireland and the central belt of Scotland

 

 

A lot to keep an eye on over the next few days but we have the real prospect of some very high rain totals for parts of the country between the 8th and 11th

Edited August 4, 2014 by Summer Sun

[Stormyking]

There is indeed alot of unsettled weather to come this week with alot of rain! Got a feeling fridays rain could be followed by thundery downpours behind, thats what the GFS is hinting at by the looks of it, and it could be quite warm behind the main band of rain.

 

Does genrealy look quite unsettled as the run goes further on...

 

This could be potentially quite warm and thundery though

Further into FI shows High pressure coming back which would looks warm/very warm! Especially in the South/South East of the UK

End of FI seems to finish with Northerly which looks rather cool and kinda horrid with some rather cool uppers as well

[IDO]

I personally don't think ex-Tropical Storm Bertha will be all that severe to be honest. It appears to be quite threatening when it's off the coast of Canada, but it will quickly fill as it moves across the Atlantic. I think it will be breezy, but it certainly won't be as bad as those winter storms earlier this year. The rain doesn't look exceptionally heavy either.

 

So as of now, I don't think it will be anything substantially different to a regular extratropical cyclone.

 

(I don't know why Netweather has decided to mess up the order of the images)

 

A possible outcome but if the 06z GFS control comes to fruition then maybe not:  

 

That's not the only member going for something more potent: 

 

 

 

  

 

  

 

 

What the 06z suite has moved to is that Bertha leaves the jet to the west of the UK next weekend, but 24-48 hours later that energy interacts with the low(s) in the trough and the net result is a deepening low(s). Too early to know if this is a one off bias suite but this type of interaction will have the Pros rubbing their heads for a few days to come.

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

[Summer Sun]

GFS 06z shows some significant rainfall totals for parts of the UK upto the 12th some parts of the south west are shown to get almost 120mm of rain, west wales and eastern Scotland also looks very wet

 

 

The 00z totals were not so extreme

 

 

A lot to be resolved yet but its well worth keeping an eye on

Edited August 4, 2014 by Summer Sun

[carinthian]

Not sure how the UKMO is viewing the forecast beyond Friday. I think there is a fair amount of uncertainty today regarding the distribution of rainfall on Sunday or Monday and indeed how stormy it will get. Presently, exposed parts are mentioned in the latest forecast. They seem confident of warmer more settled conditions to prevail during next week in the Southern half of the British Isles and unsettled up North. So how do we view the all important forecast as far as I am concerned, that's for the Manchester test match  ? Maybe, with a bit of luck it will miss any rainy spells ! Hope so, I am travelling out there this coming weekend.

[legritter]

looking at current charts and Data its certainly looking like a very interesting time coming up for us weather enthusiasts and every new run of the Models im sure will give us plenty to talk over and put plenty of Meteorological uncertainty in the further outlook for the uk .I,V said this many times before [we have the best Forum for weather in the world ].this coming week and probably into next as well many places could see high rainfall totals with models now firming up on general detail but as always in a very complex synoptic situation detail will increase with each day ,Energy from the Atlantic and still a strong sun could produce some news worthy weather .i,m pretty sure the papers or some of them will be ramping up the weather stories over the coming days ,but here on Netweather we are more level headed and never Ramp up the weather ,[all agree ]lets pour out a STella sit back and enjoy what Mother Nature May throw our way .

[Rocheydub]

I'm watching the models with extreme interest (not just a weather lover) but as I was due to go camping with my family next weekend down to the SW of Ireland to county Clare. When do you resident experts here think we may have a stable solution to view how this will pan out? I like the comments above that this storm will fill out as it crosses the Atlantic. I can tolerate a windy night, but if we had anything like the winter storms of early this year, I wouldn't put the gang through that!!! I suppose at T-48 we could be relatively certain what the models say then, but not before?? It's looking quite complex at this stage with so many solutions offered on the postage stamps etc...

[carinthian]

I'm watching the models with extreme interest (not just a weather lover) but as I was due to go camping with my family next weekend down to the SW of Ireland to county Clare. When do you resident experts here think we may have a stable solution to view how this will pan out? I like the comments above that this storm will fill out as it crosses the Atlantic. I can tolerate a windy night, but if we had anything like the winter storms of early this year, I wouldn't put the gang through that!!! I suppose at T-48 we could be relatively certain what the models say then, but not before?? It's looking quite complex at this stage with so many solutions offered on the postage stamps etc...

Hi, I think the experts cannot say at the moment. The latest UKMO medium range forecast issued today indicates storms in exposed parts, so I would assume Co Clare would be in this location. However, time yet to firm up yet of this development. I would follow the UKMO forecast charts up to 92 hours and the updated fax charts from this same source. Good luck with the camping.

[Paul]

Here's Jo's latest forecast for the week ahead - with ex-hurricane Bertha coming into play there's a lot of uncertainty as we close out the week and head through next weekend...

 

 

http://www.netweather.tv/index.cgi?action=news;storyid=6061;sess=

[Summer Sun]

GFS has ex-hurricane Bertha heading straight for the UK on this afternoons run

 

 

The track is not going to be nailed down for a while yet but its something we need to keep a close eye on

 

Once that pulls away things begin to settle down

 

 

UKMO doesn't have the low as deep as GFS at t144

 

Edited August 4, 2014 by Summer Sun

[Methuselah]

Seems hot and humid enough for me Jo...

[knocker]

Is Hurricane Bertha heading for the UK? Keep an eye on METO Storm Tracker.

http://metofficenews.wordpress.com/2014/08/04/is-tropical-storm-bertha-heading-for-the-uk/

Edited August 4, 2014 by knocker

[Frosty.]

The Gfs 12z op run shows the remnants of Bertha sweeping across the uk during sunday bringing a spell of wet and windy weather to all areas, the low then hangs around on monday before filling and drifting away into scandinavia but then look what happens, it's high pressure all the way through low res with lots of sunshine and pleasantly warm temperatures.

[Lauren]

Here's Jo's latest forecast for the week ahead - with ex-hurricane Bertha coming into play there's a lot of uncertainty as we close out the week and head through next weekend...

 

 

http://www.netweather.tv/index.cgi?action=news;storyid=6061;sess=

 

Was that a tongue in cheek thing about MF or is she serious?

[phil nw.]

After tomorrow the unsettled theme starts to kick in nationwide as a couple of systems move across from the Atlantic even before the approach of Bertha due over the weekend.

 

 

Wednesday and Friday look quite wet for many with Thursday the dry and bright interlude.

 

Whatever the final track of this ex-tropical storm it does looks like extending the stay of the upper trough well into next week keeping things changeable and showery.

Of course there will be some brighter spells between the rain bands but the next 7 days do look less like high Summer.

The GFS mean indicates some improvement with pressure starting to rise again from the south around day 10 as the Azores high makes a move this way.

 

 

giving some hope of a return to warmer and brighter weather especially further south.

Edited August 4, 2014 by phil nw.

[terrier]

The Gfs 12z op run shows the remnants of Bertha sweeping across the uk during sunday bringing a spell of wet and windy weather to all areas, the low then hangs around on monday before filling and drifting away into scandinavia but then look what happens, it's high pressure all the way through low res with lots of sunshine and pleasantly warm temperatures.

what's the betting it has no support though frosty?

[Frosty.]

what's the betting it has no support though frosty?

The models have hinted at azores / atlantic high pressure trying to build in once the ex hurricane blows through, the gfs 12z op run follows through on that idea..I hope it's right

[phil nw.]

The models have hinted at azores / atlantic high pressure trying to build in once the ex hurricane blows through, the gfs 12z op run follows through on that idea..I hope it's right

Indeed Frosty prior to the appearance of Bertha the ens means were indeed looking at this..It still looks the likely outcome i think but perhaps a couple of days later.

what's the betting it has no support though frosty?

Maybe give your own views with some data terrier if you are feeling this may not be the case?

[Frosty.]

As Phil mentioned, the GEFS 12z mean shows a recovery from around T+240 hours (day 10) onwards with the lower heights retreating north and high pressure ridging in from the azores, in my opinion, the mean has improved since the 00z and if it's on the right track, we will be enjoying a return to settled and warmer weather once the remnants of Bertha clears out of the way early next week. :-)

[tinybill]

Is Hurricane Bertha heading for the UK? Keep an eye on METO Storm Tracker.

http://metofficenews.wordpress.com/2014/08/04/is-tropical-storm-bertha-heading-for-the-uk/

watching the  bbc  weather to-night they look a bit nerves  reg   BERTHA  ps  i find the best weather  forecast now is 9.55  bbc news ist extend ,and gives long rage