Model Output Discussions 12z 03/05/2016

[knocker]

Looking a bit further afield than this week there is a pretty good agreement between the anomalies this evening that indicates a return to an old familiar pattern of upper westerly streamlines which portends our usual N/S split regarding the weather weather over the UK with systems tending to travel NE and chances of the Azores HP impinging further south with temps overall about average. En passant the EPS has the transition to this this weekend so it's still touch and go whether the south hangs on to any hot weather for the whole period.

In short high Pressure over N. Canada/Greenland with low pressure over the eastern Pole troughing down to the Atlantic where the pattern has become much flatter as the HP declines and tracks east.

NOAA and the ECM pretty much in agreement in the 10-15 period with no great anomaly and retaining the flat zonal pattern but the GEFS reintroduces a tad more amplification.

Edited August 22, 2016 by knocker

[knocker]

Today

Quite wet and cool in N. Ireland and Scotland but in England and Wales dry and warm, hot in places.

GFS this morning

For the rest of the week until Friday dry and warm/hot in England but much cooler north of the border. One proviso being a belt of thundery showers effecting the south on Thursday although the GFS is not making much of it this morning.

Saturday sees a change with an unstable low tracking north from Iberia that phases in with the filling Atlantic low to the west and introduces some very wet and thundery outbreaks, more particular to the south and west. This low pressure area gradually moves east, then a transient ridge, before the next system arrives from the Atlantic. Of course all bets are off in the medium if 90L/Gaston sticks it's nose in.

Temps Weds. SE of a line the Wash to Lyme Regis possible 30-32C in places. Thursday similar. Friday similar area but cooler.

Edited August 23, 2016 by knocker

[Polar Maritime]

Temps and Cape for the next few days from Netwx-SR

Edited August 23, 2016 by Polar Maritime

[Gordon Webb]

10 minutes ago, Polar Maritime said:

Temps and Cape for the next few days from Netwx-SR

Going by those charts the SE is the place to be for next couple of days , I did wonder why the met office had today as the warmest day at my location , now I know

[knocker]

The ecm incorporates the Iberian with the Atlantic low quite early and runs the convective area north on Saturday and mainly effecting the western half of the UK. The whole depression then moves NE to be west of Stavanger by 00z Monday and bringing some quite inclement weather to Scotland in it's travels.Thereafter it's good morning Atlantic

But wait..................

[Summer Sun]

We're going to have to keep a close eye out in the Atlantic over the next week to 10 day's

ECM and GEM have a deep low getting very close at D10 it's just whether the high will force it north enough to miss us or not

GFS at the same time

Right at the end of GFS's run it develops another deep low

[Man With Beard]

8 minutes ago, knocker said:

The ecm incorporates the Iberian with the Atlantic low quite early and runs the convective area north on Saturday and mainly effecting the western half of the UK. The whole depression then moves NE to be west of Stavanger by 00z Monday and bringing some quite inclement weather to Scotland in it's travels.Thereafter it's good morning Atlantic

But wait..................

Looks scary but the most likely result after that is yet more hot weather for the UK. Though I imagine we're going to see a lot of variations in the coming days.

The ECM at T120 is eye-catching. It would promote warmth - and storms - across much of the country. It may also mean Sunday joins the hot bracket in the SE - outside chance of 30C on 6 consecutive days, fair chance of staying in the 80s till then.

 

[Man With Beard]

For Saturday: A closer look at the ECM 00Z using the Icelandic Met shows it is reasonably good for northern Scotland but a little fresh, warm and stormy from Central Scotland down to about Manchester, and a sizzler for all areas south of that, quite possibly being the hottest day of the week with temperatures between 30C and 34C fairly widely in this area, according to this one run:

    

Edited August 23, 2016 by Man With Beard
Forgot to mention day - thanks Gordon!

[Gordon Webb]

4 minutes ago, Man With Beard said:

A closer look at the ECM 00Z using the Icelandic Met shows it is reasonably good for northern Scotland but a little fresh, warm and stormy from Central Scotland down to about Manchester, and a sizzler for all areas south of that, quite possibly being the hottest day of the week with temperatures between 30C and 34C fairly widely in this area, according to this one run:

    

As it hasn't been mentioned the day been referred to is Saturday and just for contrast my local met office forecast has it at 21c

Edited August 23, 2016 by Gordon Webb

[stodge]

Morning all

A more complex evolution than seemed likely a few days ago - this morning's models have the heat in two phases - a first phase on Wednesday and Thursday with a respite through Friday and a second phase coming through on Saturday and into Sunday before the whole lot is shunted away to the east.

The shallow HP which forms and draws in the second flow of S'ly or SE'ly air is displaced by the rapid movement of the LP from SW to NE sweeping the Atlantic back in.

GFS is more bullish with temperatures and incursions of the 20c 850 HPA than ECM but Thursday looks the only 30+ day for the south as far as I can see. It may be we'll see the warmest air come through overnight Saturday into Sunday.

Oddly enough, GEM 00Z is if anything more bullish than the GFS with a wider spread of heat on Saturday.

Plenty still to resolve and more runs will (you know the rest).

 

 

[coldcomfort]

1 hour ago, Man With Beard said:

For Saturday: A closer look at the ECM 00Z using the Icelandic Met shows it is reasonably good for northern Scotland but a little fresh, warm and stormy from Central Scotland down to about Manchester, and a sizzler for all areas south of that, quite possibly being the hottest day of the week with temperatures between 30C and 34C fairly widely in this area, according to this one run:

    

Couldn't disagree more MWAB....pretty much zero chance of verifying as shown, indeed outside the far SE the very average weather will continue across the weekend, much as it will across the remainder of this week after today. There really is unworthy amount of hype surrounding the weather atm, with the vast majority of us well outside the heat zone - take Camborne for instance where 20c looks a push on any day after today..... and Camborne as Knocker will attest is a long way south of Manchester. Things have to be kept in context here imo.

Edited August 23, 2016 by coldcomfort

[Evening thunder]

2 minutes ago, coldcomfort said:

Couldn't disagree more MWAB....pretty much zero chance of verifying as shown, indeed outside the far SE the very average weather will continue across the weekend, much as it will across the remainder of this week after today. There really is unworthy amount of hype surrounding the weather atm, with the vast majority of us well outside the heat zone - take Camborne for instance where 20c looks a push on any day after today..... and Camborne as Knocker will attest is a long way south of Manchester. Things have to be kept in context here imo.

I don't think he said that it would necessarily verify.. just that as he stated that's what this one run appears to show?

Edited August 23, 2016 by Evening thunder

[knocker]

1 hour ago, Man With Beard said:

For Saturday: A closer look at the ECM 00Z using the Icelandic Met shows it is reasonably good for northern Scotland but a little fresh, warm and stormy from Central Scotland down to about Manchester, and a sizzler for all areas south of that, quite possibly being the hottest day of the week with temperatures between 30C and 34C fairly widely in this area, according to this one run:

    

I rather like your :quite widely in this area MWB. The temps in the Midlands are 24C-26C  There is a narrow stretch of temps 28C, possibly touching 30c running from Bristol to Kent.

Edited August 23, 2016 by knocker

[johnholmes]

31 minutes ago, coldcomfort said:

Couldn't disagree more MWAB....pretty much zero chance of verifying as shown, indeed outside the far SE the very average weather will continue across the weekend, much as it will across the remainder of this week after today. There really is unworthy amount of hype surrounding the weather atm, with the vast majority of us well outside the heat zone - take Camborne for instance where 20c looks a push on any day after today..... and Camborne as Knocker will attest is a long way south of Manchester. Things have to be kept in context here imo.

you are showing your cold bias mate, the phrase was 'according to this one run' You are, in my view, being a bit OTT in your assessment using Camborne, only my view though.

Just what may happen over the Friday into next Monday is going to give all of us lots of interest and differing emphasis from run to run on all the models.

Edited August 23, 2016 by johnholmes

[stodge]

Afternoon all

Have to say (and one shouldn't really do this at all) the 06Z OP changes the game once again.

30c in London tomorrow and Thursday quite likely but Saturday perhaps not as hot as the 00Z offered.

The T+105 chart would be useful if one existed.

 

[northwestsnow]

12 minutes ago, johnholmes said:

you are showing your cold bias mate, the phrase was 'according to this one run' You are, in my view, being a bit OTT in your assessment using Camborne, only my view though.

Just what may happen over the Friday into next Monday is going to give all of us lots of interest and differing emphasis from run to run on all the models.

LOL John, dont worry, in winter he will show his mild bias

Anyway, looks very good for the SE over the coming 4 or 5 days, although Saturday holds the potential to be a bit on the wet side as the low to the SW becomes the more dominant feature.

TBH i think thats one thing the models agree on at the moment, some more inclement weather spreading in saturday

[Kentspur]

All this talk of the heat with possible 30c to come from tomorrow or thursday never mind that it's already 28c here now so surely will reach that today my accuweather is showing hourly forecasts up to 31c at 4pm!

Edited August 23, 2016 by Kentspur

[MR EXTREMES]

1 hour ago, coldcomfort said:

Couldn't disagree more MWAB....pretty much zero chance of verifying as shown, indeed outside the far SE the very average weather will continue across the weekend, much as it will across the remainder of this week after today. There really is unworthy amount of hype surrounding the weather atm, with the vast majority of us well outside the heat zone - take Camborne for instance where 20c looks a push on any day after today..... and Camborne as Knocker will attest is a long way south of Manchester. Things have to be kept in context here imo.

well then jo forecast must be ready for the bin!

with all the expertise on here then id say coldcomfort that u seem to be the minority going against everything the models and experts are suggesting.

the ecm pretty much says low 30s 

gem pretty much the same low 30s

navgem to suggests low 30s

could be some fireworks to imported heat unstable air could be some spectacular storms although hit and miss cool down out into fi so things likely to change in later model runs the low 30s i feel is a done deal as always beware of fi.

ive noticed how the gfs progressive in sweaping away the heat although it does keep things humid into the weekend bank holiday well could be fine or could be a washout.

and mid to high 20s for almost half uk

 

 

Edited August 23, 2016 by MR EXTREMES

[stodge]

One of the problems, I fear, is that people are extrapolating temperatures from the 850 HPA lines. On a clear, sunny day like today high temperatures can be realised as there's nothing to stop the sun warming the air but warm air can exist under cloud - high humidity but the actual mercury value not as high.

Likewise, if the warmest air crosses at night all we get is an uncomfortable night in the south.

If we can get warm unstable air that means high humidity and thunderstorms but not necessarily very high temperatures.

A lot of detail to be resolved in my view especially for Saturday/Sunday as you'd expect.

 

[coldcomfort]

17 minutes ago, MR EXTREMES said:

well then jo forecast must be ready for the bin!

with all the expertise on here then id say coldcomfort that u seem to be the minority going against everything the models and experts are suggesting.

the ecm pretty much says low 30s 

gem pretty much the same low 30s

navgem to suggests low 30s

could be some fireworks to imported heat unstable air could be some spectacular storms although hit and miss cool down out into fi so things likely to change in later model runs the low 30s i feel is a done deal as always beware of fi.

ive noticed how the gfs progressive in sweaping away the heat although it does keep things humid into the weekend bank holiday well could be fine or could be a washout.

and mid to high 20s for almost half uk

 

 

Maybe if you read my post correctly you would understand the point I'm making...that said I'm happy to clarify it for you once again. I said 'outside the far SE (for clarity based on the UK this means roughly southeast of a line from the Wash to the IOW, not just Kent and Essex) the very average weather will continue across the weekend, much as it will across the remainder of this week after today.

Perhaps using the charts above posted by yourself, you could show me why/how I'm so far off the mark with this claim, because to me the odds favour distinctly average conditions for 70-80% of the country between tomorrow and Sunday.  

 

Edited August 23, 2016 by coldcomfort

[knocker]

1 minute ago, stodge said:

One of the problems, I fear, is that people are extrapolating temperatures from the 850 HPA lines. On a clear, sunny day like today high temperatures can be realised as there's nothing to stop the sun warming the air but warm air can exist under cloud - high humidity but the actual mercury value not as high.

Likewise, if the warmest air crosses at night all we get is an uncomfortable night in the south.

If we can get warm unstable air that means high humidity and thunderstorms but not necessarily very high temperatures.

A lot of detail to be resolved in my view especially for Saturday/Sunday as you'd expect.

 

Quite you have to assume a lapse rate so taking the 850mb temp as a guide is always bound to be a tad rough and ready. The temps I quoted were taken straight from the six hour surface max chart for 18z Saturday.

[knocker]

21 minutes ago, MR EXTREMES said:

well then jo forecast must be ready for the bin!

with all the expertise on here then id say coldcomfort that u seem to be the minority going against everything the models and experts are suggesting.

the ecm pretty much says low 30s 

 

It doesn't. See my earlier post.

[Man With Beard]

1 hour ago, knocker said:

I rather like your :quite widely in this area MWB. The temps in the Midlands are 24C-26C  There is a narrow stretch of temps 28C, possibly touching 30c running from Bristol to Kent.

But I've been following the ECM predicted maximums quite closely whenever other people have given them (I don't know how to see them myself, I'm just going by what others say) and I'm finding them up to 3C out.

Let's take last week for instance. When the ECM was forecasting its hottest scenario, at one point Phil said it was giving maximums of 27C. Then there was a complete change in the forecast, the warmest air never reached us and ... it STILL made 27C! I recall you said Croydon was showing 22C as a maximum on the ECM - it ended up well past this figure.

I'm not trying to make things up or exaggerate - if anything, I think as the summer has gone on, people have got more and more cautious - but I have to call a spade a spade - my interpretation of that chart is that many areas south of Manchester would reach 30C (Cornwall won't because it has more sea influence) - IF it verifies and NOT if it doesn't!!

[coldcomfort]

4 minutes ago, knocker said:

It doesn't. See my earlier post.

And what odds do you place on that chart being similar at 7.20pm this evening Knocker.....I will say 20-30% and I suspect even that will be optimistic.

[knocker]

15 minutes ago, Man With Beard said:

But I've been following the ECM predicted maximums quite closely whenever other people have given them (I don't know how to see them myself, I'm just going by what others say) and I'm finding them up to 3C out.

Let's take last week for instance. When the ECM was forecasting its hottest scenario, at one point Phil said it was giving maximums of 27C. Then there was a complete change in the forecast, the warmest air never reached us and ... it STILL made 27C! I recall you said Croydon was showing 22C as a maximum on the ECM - it ended up well past this figure.

I'm not trying to make things up or exaggerate - if anything, I think as the summer has gone on, people have got more and more cautious - but I have to call a spade a spade - my interpretation of that chart is that many areas south of Manchester would reach 30C (Cornwall won't because it has more sea influence) - IF it verifies and NOT if it doesn't!!

Fine but whether the ecm is under cooking the max temps is irrelevant and unknowable at this stage. If you are not actually stating what the ecm is forecasting but using your own interpretation then that's fine providing you clearly state this. I had the distinct impression from your post that you were using the ecm charts that you posted. And the ecm surface chart does not agree with your interpretation.

Edited August 23, 2016 by knocker