Model output discussion - hot spell beckons but then what?

[knocker]

In the latter half of the ten day period the gfs has the high pressure setting up shop to the north west with a trough conduit along the path of the jet to the south to the TPV and trough over Europe.Thus we are looking at a low pressure unsettled sunshine and showers regime with temps varying around the average.

Edited July 31, 2019 by knocker

[knocker]

The ecm in the same ball park as the gfs in the latter half of the run

Edited July 31, 2019 by knocker

[mb018538]

No getting away from the fact that it’s a very poor outlook beyond the weekend. Low pressure dominated with plenty of rain.

I guess we shouldn’t be surprised - the 4th autumn month doing its thing yet again.

[knocker]

The frontal system to the south west is currently bringing some rain down here

Edited July 31, 2019 by knocker

[Frosty.]

14 minutes ago, mb018538 said:

I guess we shouldn’t be surprised - the 4th autumn month doing its thing yet again.

Hardly autumnal temperature wise for the first 10 days or so of august according to the Gfs 0z operational with temps into the low to mid 20's celsius, warmest for the s / se...Too much moaning as usual!!!

[DIS1970]

The old Cheshire Gap event could make itself present this morning, IF the wind speed and direction maintains its current angle, not that we need any more rain after yesterday's downpours.

[danm]

UKMO actually slowing down the advancement of the low on Monday/Tuesday allowing further ridging ahead of it into southern and eastern parts of the UK. This is something to keep an eye on. The Atlantic is very sluggish:

Edited July 31, 2019 by danm

[Methuselah]

The GFS 00Z ends on an interesting (though it is of course at the far-reaches of NWP usefulness?) still persists in having LPs sandwiched somewhere between HP near Greenland and ever-present hot air situated over Southern Europe...?

   

The GEFS 00Z ensembles show temps falling, as the main centre of LP heads toward Scandinavia, for a stay of indeterminate (though hopefully short) duration...

   

   

[Man With Beard]

The situation between now and D6 is close to being settled:

    

With a trough almost stalled in the Atlantic for several days, the UK will be on the warmer side between now and then with a WSW or SW flow predominant, and temperatures in the afternoon widely low 20s through the weekend and early next week, mid 20s further south with possibility of 26-28C as the max in the SE corner by Sunday/Monday. Not a bad start to August.

However, with the lack of high pressure close by, it is unlikely to be completely dry even after today's rain in the midlands/north - showers look possible on any day - though occasional rather than organised and unlikely to spoil a good day out. 

In the 24 hours from the charts above (Tuesday/Wednesday), the weather is forecast to gradually become more unsettled from NW eventually through to the SE. Given the slow movement of the trough, I wouldn't take this as an absolute certainty - this prognosis seems reliant on a few other things such as the intensity of the trough to the NE being modelled correctly and heights in Europe failing to build on the E flank of the Atlantic low. So although the second half of next week looks more unsettled, I'd hold fire before writing the period off, especially in the south where a small pulse of extra heights into Europe could divert the worst of the frontal activity.

It's a rather odd period, just as it has been a rather odd summer - dominated by heights to the north, but the almost complete lack of ability of heights to form in the Eastern Atlantic has meant the colder air up north has only occasionally managed to influence our shores - normally with northern heights, even the simplest of ridges forming in the Atlantic would provide a trigger to pull colder air south. The coming 7 days are perhaps the best example of all - strong northern heights, yet still slightly above average over the UK. 

And the clusters this morning suggest this may well continue into week 2 of the analysis, here's D11 and D15:

 

Same old same old ... strong heights NW, troughing mostly stuck ever so slightly to our west, hints of ridging over Europe - the UK again in the warmer sandwich of a WSW or SW flow with occasional Atlantic incursions but no knockout blow particularly further S and E, where another of the well above average periods cannot be ruled out.

[mb018538]

41 minutes ago, Jon Snow said:

Hardly autumnal temperature wise for the first 10 days or so of august according to the Gfs 0z operational with temps into the low to mid 20's celsius, warmest for the s / se...Too much moaning as usual!!!

Many areas in northern England and Scotland are going to see over a months rain in the next 10 days....on top of what’s already fallen. Looks pretty bad to me anyway£.

[Frosty.]

Looking at the GEFS 0z longer term, there is some support for the azores high building in but also some unseasonably cool unsettled members too...obviously I hope the azores high idea gains more support!!

Edited July 31, 2019 by Jon Snow

[Frosty.]

Patience grasshoppers, the chocolate fireguard system..cfs for short is showing a warm anticyclonic late august!!!!

Edited July 31, 2019 by Jon Snow

[Methuselah]

At least this thread has reverted to its usual summertime stampede!

Anywho, the GEFS 06Z ensembles have arrived, and the model is still suggesting a gradual cooldown as we approach mid-month:

    

   

Could wandering TS-remnants be about to make their presence known, and shake things up a bit?

[Frosty.]

Looking at the GEFS 6z mean I would say there's a window of opportunity for the azores high to ridge in from the end of next week into the following week, at least across southern uk and in the meantime there's a ridge extending down from the NW  which will significantly reduce the showers risk for a few days with plenty of dry and warm, even very warm sunny weather, especially further s / se.

Edited July 31, 2019 by Jon Snow

[MATTWOLVES 3]

Just how is August shaping up so far? Some seem certain it's heading in the same direction has many previous Augusts! Perhaps there is now a stigma associated with this month, to the point some just can't shake it off! Because a fair few previous August months have been poor, we shouldnt conclude that this one is guaranteed to follow suite. To my knowledge the rest of the week looks decent with less in the way of showers, and in sunny spells it's likely to feel warm. The problem with next week at this stage is the current models output to park low pressure to the West of us!! So some frontal activity and showers looks the order of the day! Obviously prone areas will be the usual suspects towards the North and West! Places further SE could still end up with a fair bit of usable conditions. Interesting to me is the fact that low pressure could still aid in the distribution of a more Southerly feed at times, meaning much warmer conditions pushing into the South!!! One to watch for sure.... Looking at the extended ensembles out to day 14 from ECM, shows a mean around 8c...with seal level pressure around 1013mb..worth noting again that there is indeed a huge amount of scatter... Many runs bringing higher pressure and temps, and many runs bringing lower pressure and temps! So again confidence and any clear signals are fraught with danger.... Certainly nothing to suggest we should draw the curtains on a month that only officially starts tomorrow.. Onwards and upwards folks... And if all else fails we have winter to look forward to, and perhaps this time, it will deliver. 

[Frosty.]

22 minutes ago, Mattwolves said:

 Interesting to me is the fact that low pressure could still aid in the distribution of a more Southerly feed at times, meaning much warmer conditions pushing into the South!!! One to watch for sure....

You make a very good point there Matt, I noticed on the GEFS 6z mean there's potential for some very warm tropical maritime / continental air to encroach into the S / SE at times next week.

Edited July 31, 2019 by Jon Snow

[MATTWOLVES 3]

6 minutes ago, Jon Snow said:

You make a very good point there Matt, I noticed on the GEFS 6z mean there's potential for some very warm continental air to encroach into the S / SE at times next week.

Cheers Karl... Yes I pointed out after the icon run a few days ago, that if low pressure sits favourably we could start to import much warmer conditions into the South. The longer range models appear to be parking low pressure the the NE with cooler and wetter conditions further North and perhaps high pressure ridging to the SW, which would entail warmer more settled conditions there.. The EC46 is hinting at this, and I've noticed exeter are too. But at this range for me, confidence would be low.. Small little factors like where low pressure sets up shop could make the world of difference to the weather type we get here in the UK.. Anythings possible mate.

[Frosty.]

My thoughts on the Gfs 12z operational are tomorrow warm with sunny spells and less showery as a ridge becomes more influential, even less showery on friday and a tad warmer..the weekend warms up further, especially further south by southeast, saturday the main risk of showers further west, drier and sunnier away from the west, sunday there are more showers generally but it's certainly a warm weekend and early next week, feeling really nice where it stays fine and sunny for any length of time. Next week becomes very showery again as a trough moves in from the west but with warm sunny spells too although there is a decline in temperatures compared to the weekend and next monday, especially further n / nw but I've seen worse..most of June for example!

[knocker]

A overview of next week with tonight's gfs

The NH profile is much as been described previously so suffice it to say low pressure is dominating the Atlantic but there is no rapid eastward trough movement across the UK as the jet is too far south. Thus rather static low pressure is the order of the day portending a week of sunshine and showers, with the odd front. and temps varying around the average.Nothing lurking as Sidney would say.

 

[Methuselah]

I would much prefer it, if the LP would stay centred out west!

   

Sure beats the Scandinavian option?

[feb1991blizzard]

35 minutes ago, Ed Stone said:

I would much prefer it, if the LP would stay centred out west!

   

Sure beats the Scandinavian option?

I would much prefer if it sat slap bang over us for 2 weeks with a lovely cold pool aloft!

[Methuselah]

Anywho, apart from some fluctuation at the end, the GEFS 12Z ensembles are similar to the 06Zs. Though, the 2m temps seem a tad warmer?

   

   

[knocker]

An unsettled week as expected with the ecm but temps a tad above average, particularly in the north

[Captain Shortwave]

Hmm, I guess a few elements of interest tonight, firstly the successful push of Atlantic fronts might take until Tuesday night to achieve and to be honest the trough isn’t overly cool so probably mixed from the middle of next week.

perhaps the chance of a plume type set up occurring at the back end (end of next week), though this is low risk at the moment and dependent on the behaviour of that low upstream.

Edited July 31, 2019 by Captain Shortwave

[MATTWOLVES 3]

It's not a bad ECM at all if you ask me. Firstly we have plenty of settled Conditions between now and the weekend, and quite warm. The weekend itself looks OK, there could be some showers in places, but it's very hit and miss. Next week we have low pressure to the West, but this could stall at some point, so far from certain... Rain and showers likely in areas mainly to the North and West. Of more interest to me is low pressure helping to import some very warm conditions in by the end of next week. Winds becoming more Southerly is quite a possibility in my opinion.... One to watch for sure..