Model Output Discussion 31/07/14 onwards.

[SteveB]

Yes, Sunday's low yet to be resolved, which I don't think the exact track will be until tomorrow/Saturday. It does look as though somewhere in the UK  will get a direct hit, currently GFS has it running up the West of the UK.

 

 

After the low passes through it looks to cool things down next week.

 

 

[knocker]

The ECM is running a vaguely similar scenario to the GFS but not deepening Bertha as much and certainly not the resultant low pressure to the north.

 

Edited August 7, 2014 by knocker

[Polar Maritime]

Yes Bertha still to be resolved on detail, GFS Shows it pushing N/E over the Irish Sea this morning.. And Yet another unsettled & cool run, Showing a slack Northerly towards the end of the run, With High Pressure over Greenland and the Jet buckled well South..

 

Edited August 7, 2014 by Polar Maritime

[Captain Shortwave]

The ECM this morning is about the best we can hope for, the weaker system stemming from Bertha does result in low pressure being centred further north which means conditions might be a little better than the other models for the first half of next week.

GEM this morning also builds in this high, if anything more strongly later on

The GFS also wants to improve things after midweek

 

 

 

So there are signs of an improvement in the second half of next week. But before then conditions will turn increasingly unsettled with the first widespread unsettled weather for quite a while. Temperatures look around average this weekend and dipping a little below next week.

Edited August 7, 2014 by Captain shortwave

[johnholmes]

One has only to look at the changing Fax charts or the Met forecaster on BBC1 to see how much of a headache both the track and depth remain to their forecasts.

[Summer Sun]

UKMO's looks unsettled and cooler through-out this morning by mid next week things slowly improve from the south west but quite frankly until the track of Bertha is sorted next weeks weather is anyone's guess

 

 

t96 850's unavailable at the time of posting

 

[IDO]

Last night's ECM members were 55% in favour of a deepening low and 45% a shortwave running along the south coast/Channel. Only two clusters so ECM were narrowing down the impact. At least ECM is consistent, this morning it is again around the same split: http://old.ecmwf.int/samples/d/inspect/teasers/samplers/banner/mean_sea_level_pressure_and_temperature_at_850hpa!96!pop!od!enfo!enplot!2014080700!!/

 

Interestingly by D5 the op is in cluster 3 so it does still look like the op may not represent its ensembles re Bertha.

 

The ECM op has the low on Sunday in France so we avoid the worse of the rain: 

 

The GEFS on the 0z have 60% development of Bertha and 40% like ECM. The London pressure graph highlights this: 

 

Temps look around average for SE next week and probably below the further NW you move: 

 

So even if Bertha does not disrupt the trough then a less warm spell is on its way. This is partly due to an extended period of lower uppers. The average for London is 9-10c but we are heading for a week or so of around 5c:

 

 

ECM mean keeps lower pressure in charge for most post Bertha: D10 

 

It may not be till tomorrow's 12z before a consensus for Bertha's track is established.

 

 

[knocker]

JOMEC's take on Bertha is a little different. It appears to have Bertha leaving the cold side of the jet on Sunday and then moving NE and deepening into quite intense low in the North Sea by Monday.

[johnholmes]

JOMEC's take on Bertha is a little different. It appears to have Bertha leaving the cold side of the jet on Sunday and then moving NE and deepening into quite intense low in the North Sea by Monday.

 

An interesting version there-certainly IF it did, as Nick F made comment about a day or so ago, and engage the cold side of the jet, that is the left exit, then a chart as shown is possible.

Keep watching folks, very interesting to see how Bertha does end up in/over/around the UK.

 

looking at the very latest Fax charts issued this morning and they are keeping it south of this thus only slight deepening.

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

Edited August 7, 2014 by johnholmes

[knocker]

Regarding the middle to the end of next week the ECM upper anomaly still has an intense trough dominating the UK. Cyclonic conditions prevail with perhaps a nudge from AZ high from the SW by Friday. Generally unsettled with the temps below average. The split jet would seem to mitigate against a more stable regime at present.

Edited August 7, 2014 by knocker

[IDO]

The 06z run has a deeper low: 

 

Though the control is less developed: 

 

55% of the GEFS are like the op; 33% support for this morning's ECM and 12% support for the control.

 

Latest Met track:  

 

Bertha will be riding a strong jet and this no doubt will not make the forecast easy:

 

Warning for Sunday now but still indicate uncertainty: here 

 

 

[mushymanrob]

a few runs might give some optimism for another warm spell via the ridging azores high. i dont think though the noaa anomaly charts would agree, keeping the mean high out to our west as the current trough drifts east.to my eyes this is looking pretty cool, or on the cool side of average as the uk is locked in a northwesterly airflow. whether or not the azores high ever gets close enough to bring something warmer is anybodies guess, and IF the trend for the eastward drift continues, then just maybe there might be one last shot of something much warmer evolving , (like frostys chart he 'banked' yesterday). but until theres anomaly support id be very scepticle about pining hopes on the odd run here or there. but if these charts are accurate, there will only be 1 week left of 'summer' for anything much warmer to evolve.

 

[Methuselah]

Whilst the projected uppers may be on the cool side, SSTs are still pretty high; it may turn out to be a tad warmer than would usually be the case?

[johnholmes]

a few runs might give some optimism for another warm spell via the ridging azores high. i dont think though the noaa anomaly charts would agree, keeping the mean high out to our west as the current trough drifts east.

to my eyes this is looking pretty cool, or on the cool side of average as the uk is locked in a northwesterly airflow. whether or not the azores high ever gets close enough to bring something warmer is anybodies guess, and IF the trend for the eastward drift continues, then just maybe there might be one last shot of something much warmer evolving , (like frostys chart he 'banked' yesterday). but until theres anomaly support id be very scepticle about pining hopes on the odd run here or there. but if these charts are accurate, there will only be 1 week left of 'summer' for anything much warmer to evolve.

http:////f1.nwstatic.co.uk/forum/public/style_images/tctc91_simplify/attachicon.gif610day.03.gif

 

http:////f1.nwstatic.co.uk/forum/public/style_images/tctc91_simplify/attachicon.gif814day.03.gif

 

the source as well as the direction of the 500mb contours can give some idea of surface temperatures. In the 6-10 day time frame NOAA are suggesting an origin around the Gt Lakes area with heights of about 564DM, not that warm for early August. The 8-14 warms it up a touch, that is for the contour over the far south of the UK.

In winter some on here would be already showing signs of excitement!

[TonyH]

Whilst the projected uppers may be on the cool side, SSTs are still pretty high; it may turn out to be a tad warmer than would usually be the case?

Exactly what I was about to post, even NW flows around 6c uppers have given warmth provided we get sunshine this Summer.

Today being kind of a good example, uppers not so warm, winds WNW yet it is warm and sunny, max 21c so far.

Edited August 7, 2014 by TonyH

[Staffordshire]

Obviously a very short widow of certainty about Bertha but can anyone give a quick answer as to what it is like to be the week after Bertha (particularly next weekend) I'm going to be very busy outdoors that week and could do with some warm or if not at least dry weather, thanks in advance

[knocker]

Exactly what I was about to post, even NW flows around 6c uppers have given warmth provided we get sunshine this Summer.

Today being kind of a good example, uppers not so warm, winds WNW yet it is warm and sunny, max 21c so far.

 

Perhaps it's worthwhile remembering that the 850mb temps on some charts are pretty broad brush. The 00z ascent for Nottingham has an 850 temp of 9.5C which easily gives STs in the low 20s even assuming something close to the environmental lapse rate.

[IDO]

Latest press release by the Met; no nearer to a resolution: http://www.metoffice.gov.uk/news/releases/archive/2014/bertha?utm_source=twitterfeed&utm_medium=twitter

[mushymanrob]

Exactly what I was about to post, even NW flows around 6c uppers have given warmth provided we get sunshine this Summer.

Today being kind of a good example, uppers not so warm, winds WNW yet it is warm and sunny, max 21c so far.

 

tricky one.... seems to me like 'warm in the (strong) sunshine' , but noticably cooler when it goes in. chilly nights too. maybe a time of a larger diurnal range so whilst temps might get to c 21c , theyll only be there a short while so the rest of the day wont feel so good as what the actual max says... if you get my drift..

 

eg, the other friday at the begining of the hot spell, locally we got 28c.... but for most of the day we were plagued by cloud and temps around the low 20's. when the sun broke through temps rocketed...but it was for a short space of time and statistically it suggests the whole day was 'hot' whilst in fact it was only a breif (but welcome) hour or so.

[terrier]

even out to next tuesday were looking very unsettled. think next week is a right off in my opnion

[Bristawl Si]

tricky one.... seems to me like 'warm in the (strong) sunshine' , but noticably cooler when it goes in. chilly nights too. maybe a time of a larger diurnal range so whilst temps might get to c 21c , theyll only be there a short while so the rest of the day wont feel so good as what the actual max says... if you get my drift..

 

eg, the other friday at the begining of the hot spell, locally we got 28c.... but for most of the day we were plagued by cloud and temps around the low 20's. when the sun broke through temps rocketed...but it was for a short space of time and statistically it suggests the whole day was 'hot' whilst in fact it was only a breif (but welcome) hour or so.

It's been beautiful here the last 2 days; low 20s, sunny.

 

the summer goes on here and typical August really, with slightly cooler showery days in between.

[Summer Sun]

Big differences between UKMO and GFS with UKMO keeping pressure between 1005mb and 1015mb

 

 

Where as GFS goes for a much deeper low

 

Edited August 7, 2014 by Summer Sun

[h2005__uk__]

What happened to the model run that showed hot weather coming in about 10 days' time? Is that well and truly off the cards for now?

[IDO]

GEM keeps Bertha in the jet stream longer and it is not till late Sunday that it breaches the trough, reinvigorates and creates a new low that deepens:

 

This hangs around for 2-3 days and is windy: 

 

GFS Control similar to op in track: 

 

The GEFS are now about 55% support of the op and about 45% more like ECM. That is a small shift away from this morning so maybe trending towards ECM???

 

NAVGEM is now on the ECM song sheet: 

 

Out of the ops the JMA is the wildest: 

 

Though the NNM 5km gives it a run for its money: 

 

I can see why warnings have gone out. Still chances of a stormy period, though no nearer resolving this evening.

[Panayiotis]

Can anyone give a suggestion why the North Sea lowers the pressure of a storm? Looking at Saturday on the EURO4 and a small shortwave deepens over the North Sea to form quite a potent low pressure system. Now if Bertha follows there could be some unexpected strong winds recorded for the east of the UK:

Edited August 7, 2014 by Panayiotis