Model Output Discussion 00z 19/07/13

[mushymanrob]

Despite the weather warnings for Tues and Weds!!

 

... the gfs had huge cape readings and widespread heavy rain for those charts mon/tues, the met office has issued weather warnings and the bbc graphic show some heavy storms.... but not for everyone in the way the gfs rain graphic suggests. theres the difference.

 

now i have no idea who will be right, but i strongly suspect a large part of the uk wont be under one large area of heavy thundery rain in the way the gfs suggests but will be under the scattered thunderstorm/sunnier hot regime the bbc currently predicts.

 

so yes, weather warnings for torrential rain and localised flooding doesnt contradict the bbc graphics suggesting scattered heavy showers.

 

looking like a messy week ahead, starting hot and humid, becoming increasingly unsettled as thunderstorms/heavy thundery showers start to break out as early as tomorrow. temps then gradually coming down, sunshine becoming less prevalent as cloud increases and bands of rain/ areas of rain, some very heavy, cross the uk.

 

no sign of any quick return to hot sunshine, looking like 'normal' weather will return afterwards.

[Supacell]

good morning everyone, fasinating reading here already this morning, plenty of predictions to get excited about regarding storm potential this comming week, although cold damp and cloudy here this morning, is there a chance these storms could produce some tornado activity, with the high dewpoints and temps that are being forecast

 

Not a great deal of shear or helicity for the early in the week storms but still, with the amounts of CAPE being forecast along with convergence zones then I would say there is the risk of some convergence funnel obs and maybe a tornado (although i would put the risk as low). 

 

I am no expert but I would imagine the chance of them increases later in the week as the plume engages further with the upper jet stream which looks to move south.

 

 

Probably better asked in the convective thread though which is where all the storm enthusiasts and experts will be hanging out over the next few days 

[Summer Sun]

Here is the latest analysis summary from Gibby

 

In Summary the weather still looks like cooling down this week. We have to get through a hot and humid phase first when thunderstorms will be scattered about though not widely. Then after a band of thundery rain moves NE over the UK midweek it looks like all areas will come under a more changeable pattern with a mix of sunshine and showers with temperatures descending to much nearer the average for late July and early August as Low pressure remain close to or over the north of the British Isles.

 

The full analysis as ever can be found here - http://www.norton-radstockweather.co.uk/Model-Analysis%282859336%29.htm

Edited July 21, 2013 by Summer Sun

[NorthNorfolkWeather]

The latest fax charts show the thundery breakdown starting in the southwest and then spreading out further north and east in the week ahead, troughs swinging northeast, fronts grinding to a halt, some big storms are on the way as the current heatwave intensifies tomorrow and tuesday with 34 celsius 93 F for the southeast tomorrow, any storms tomorrow look isolated but from tuesday the storms and thundery rain look more widespread and even though the heat will moderate as the heavy rain sets in, it still looks very warm and muggy all week or at the very least it will be warm, even by next weekend the temperatures are likely to still be in the low to mid 20's celsius but the next 3 days look very hot and sultry with storms becoming more frequent and widespread but still with some hot milky sunshine at times, by the end of the week it looks warm and cyclonic with sunshine and thundery showers. There is a risk of localised flash flooding in the next 7 days after such a hot dry spell and if fronts do grind to a halt there could be more widespread flooding if you are stuck under torrential downpours for many hours.

 

Thanks for all the work you put into those posts Frosty.

 

Looks like a tough week for sleeping.  Maybe we'll see storms track west to east instead of south west to north east.

[Summer Sun]

After a prolonged period of drier than normal weather the starts of the 6 week school holidays will be greeted with rain

 

 

The ensembles also show an increase in the rain spikes though temperatures should hold out at around average so when its not raining and the sun is out it will still feel quite warm

 

[nanu]

I dont mind this break down saves me going out and watering the garden, but just want to know one thing, the height these storms may climb to for our homegrown ones to the ones over in northern france?? if the ones over in france climb higher then may drift north and still impact us due to the size of them,, storms seem better that cross the water to our our home ones down here due to a higher cape they may have.

[Man With Beard]

Latest GFS: Cool down now looks virtually certain for Western areas after Wednesday, but the far south-east remains perilously close to the hot stuff even until Sunday, could we see some high temperatures being reported in Gravesend come Friday, Saturday, Sunday?

[Captain Shortwave]

The metoffice/bbc must be thinking there will be a lot of cloud around on Tuesday given predicted maxima of 26/27C, compared to the GFS which is predicting 32C.

I do feel this is very conservative as given uppers of 16C over the south east, in any sunshine the temperature inland will get into the 30s surely. Especially as we will be stating the day at around 20/21C.

The UKMO also has 16C btw.

Edited July 21, 2013 by Captain shortwave

[I Cumbria Marra I]

Latest GFS: Cool down now looks virtually certain for Western areas after Wednesday, but the far south-east remains perilously close to the hot stuff even until Sunday, could we see some high temperatures being reported in Gravesend come Friday, Saturday, Sunday?

yes, certainly wouldnt call it a major breakdown which 'draztik' was banging on about all week, just looks cooler for the west although still slightly above average temps and still above average temps for the south and east with thunderstorms/showers.

[NeilN]

Not suprised the South West is the first to cool down. A welcome relief I may say.

 

Is August due a good start or the same pattern as other years?

[shaky]

The 06z shows that england and wales will still have temps of 25-26 till the weekend!!nothing like the cool down it was showing a couple of days ago and infact it will probably feel quite hot!

[Weather Boy]

Only time to look at the ops, but they are interesting and not too different.  I think they support my little theory of wet in the west; drier and warmer in the east (although with some downpours.  Take this chart:

 

See how the warm uppers are trying to cling on as the low sits over or just to the west of Ireland without substantial progress east as you might expect.

 

The ECM is similar.  After a lot of going nowhere fast, the low eventually goes to the north of Scotland by the weekend, suggesting the best weather in the south, although not what you'd call settled weather anywhere.

 

No hint whatsoever at this point of an Azores high rebuild, but probably remaining warm in the east for now, although few places will stay dry.

[draztik]

yes, certainly wouldnt call it a major breakdown which 'draztik' was banging on about all week, just looks cooler for the west although still slightly above average temps and still above average temps for the south and east with thunderstorms/showers.

if you're going to quote me, at least be accurate. I never used the word major, i stated a breakdown was rather likely, as gfs was showing low pressure consistently near us just after the reliable time frame last week. To be honest, nothing really has changed. A breakdown by midweek, with cooler freaher weather sweeping in to all parts thereafter. Sure, the SE may hold onto some warmth, but the days of 30C wont be repeated by the weekend! Gfs FI then shows the Azores high being flattened for the remainder of its run!I remember many members questioning this flow to cooler fresher weather, and by midweek, this heatwave that has left many exhausted and feeling unwell will be gone. Look forward to fresher weather Edited July 21, 2013 by draztik

[Gordon Webb]

if you're going to quote me, at least be accurate. I never used the word major, i stated a breakdown was rather likely, as gfs was showing low pressure consistently near us just after the reliable time frame last week. To be honest, nothing really has changed. A breakdown by midweek, with cooler freaher weather sweeping in to all parts thereafter. Sure, the SE may hold onto some warmth, but the days of 30C wont be repeated by the weekend! Gfs FI then shows the Azores high being flattened for the remainder of its run!

I remember many members questioning this flow to cooler fresher weather, and by midweek, this heatwave that has left many exhausted and feeling unwell will be gone. Look forward to fresher weather

 

I am also looking forward to the cooler weather just not the storms I may have to put with to get there but it's happening early in the week so hopefully get the worst of it out of the way by midweek

 

I'm Assuming due to the nature of storms I might not see any at all ?

[Mini tiger]

if you're going to quote me, at least be accurate. I never used the word major, i stated a breakdown was rather likely, as gfs was showing low pressure consistently near us just after the reliable time frame last week. To be honest, nothing really has changed. A breakdown by midweek, with cooler freaher weather sweeping in to all parts thereafter. Sure, the SE may hold onto some warmth, but the days of 30C wont be repeated by the weekend! Gfs FI then shows the Azores high being flattened for the remainder of its run!I remember many members questioning this flow to cooler fresher weather, and by midweek, this heatwave that has left many exhausted and feeling unwell will be gone. Look forward to fresher weather

Hi are we looking at an active cold front sweepingEast pushing all the warm and hot air away or couldIt be a slow moving front that takes a whole to move north eastWith warmth hanging on in the east and south ?

[NO LONGER POSTING]

Why would you argue over the weather? Very sad.. Debate it not rant at each other!

I'll keep it simple to cause less stress:

Monday: very hot few t storms (maybe)

Tuesday: very hot more showers/t storms

Wednesday: hot/warm Tuesday into Wed maybe storms?

Thursday: ain't going that far not worth it

[London Ed]

The interesting part of the models is will the trough that's developed out of the US stall, and if so where. I looks likely that it wont the models push it through over the next 10 days bringing us the breakdown with the jet flattening over nothern britain thereafter. If it was to stall over us (which is probably unlikely now) I think it could really take some shifting and we'll be in for a cool wet August.

 

Interestingly there a hint that heat building in the 500's over Canada towards the end of the model runs appears to be feeding into the Azores high and strengthening it. esemebles for Paris show pressure rising steadily from the end of the week to the end of the model runs. This could indicate a late burst of summer sun middle to the end of August.

Edited July 21, 2013 by London Ed

[stainesbloke]

Why would you argue over the weather? Very sad.. Debate it not rant at each other!I'll keep it simple to cause less stress:Monday: very hot few t storms (maybe)Tuesday: very hot more showers/t stormsWednesday: hot/warm Tuesday into Wed maybe storms?Thursday: ain't going that far not worth it

Ha! Far too many petty little ego's in here so the ranting will continue. As for your forecast it looks very accurate. I can't see a dramatic cool down this week, at least in the S, with temps staying above average. Good stuff

[nitro_deluxe]

^ a pretty bumpy transition between hot to very warm then eventually warm ^

Egos aside hopefully..

Edited July 21, 2013 by triple_x1

[mushymanrob]

the nature of this breakdown was never expected to be a sudden dramatic change esp in temps. but there is going to be a breakdown and the higher temps are expected to deteriorate as the week goes on. the gfs has been very consistent in showing this, the ecm now agrees broadly. theres no sign of anything hot again in the forseeable after this has gone, but going it is, and itll become much cooler eventually assuming the model predictions currently progged becomes reality.

pity.

[Bristawl Si]

the nature of this breakdown was never expected to be a sudden dramatic change esp in temps. but there is going to be a breakdown and the higher temps are expected to deteriorate as the week goes on. the gfs has been very consistent in showing this, the ecm now agrees broadly. theres no sign of anything hot again in the forseeable after this has gone, but going it is, and itll become much cooler eventually assuming the model predictions currently progged becomes reality.pity.

how much cooler though?if they fall to, and settle, around 21/22c for the foreseeable and into early August that will be just fine for this time of year and in any sunny periods will be just dandy.Personally i'm more interested in it becoming settled again, after what looks like will develop this week.Models seem to be suggesting pretty changeable conditions after this coming week's 'fireworks'; just hope it stays reasonably warm and we get sunny spells. Edited July 21, 2013 by Bristle boy

[Swave Snow]

the nature of this breakdown was never expected to be a sudden dramatic change esp in temps. but there is going to be a breakdown and the higher temps are expected to deteriorate as the week goes on. the gfs has been very consistent in showing this, the ecm now agrees broadly. theres no sign of anything hot again in the forseeable after this has gone, but going it is, and itll become much cooler eventually assuming the model predictions currently progged becomes reality.pity.

 

 

Yes you are correct, however , there is still a lot of things to happen.  And for one, Sunday last week down graded  the temps, let see what they paint tomorrow 

[Methuselah]

This breakdown reminds of one that occurred in 1995: because the LP was anchored away to our west, and the weather was basically 'unsettled' temps in Inverness still reached the mid 20s on most days...And remember, the PFJ will be bumping into a large mass of very warm air, still be resident over the near continent...

[legritter]

Where have all the posters gone or have we a new thread and i cant find it .just done a tour of data and modells from different so urces and its certainly going to be a very interesting week and nail biting for some .more runs needed as usual to give us more of an idea on where any action will be ,and i dont think GFS as nailed it yet ,its going to be along humid couple of days but certainly worth the wait if the holy grail of storms turns up in your location .so im eagerly awaiting tonights main runs and later faxes .

[Captain Shortwave]

Tomorrow aside, next weekend lots very hot just across the channel

 

 

I wonder if the models might correct and direct that huge plume towards us *hopecasting*  

UKMO looks interesting too

 

The models are starting to dig the trough further south at the end of the week and the weekend, increasing the chances of another plume

Edited July 21, 2013 by Captain shortwave