Model output discussion - hot spell beckons but then what?

[chrisbell-nottheweatherman]

34 minutes ago, knocker said:

This evening's ecm for next week is a pretty good example of a fluid Atlantic with a fairly strong westerly upper flow with  phasing of the airmasses leading to changeable detail for the UK on a day-to-day basis. This is merely an example as this is still subject to change at that range

Fascinating stuff, Malcolm, and, though I am aware we're not supposed to discuss forecasts here, this makes a contrast to MeteoGroup's prognostications for the weekend and early next week for the East, which is almost entirely dry.

[knocker]

[knocker]

2 minutes ago, chrisbell-nottheweatherman said:

Fascinating stuff, Malcolm, and, though I am aware we're not supposed to discuss forecasts here, this makes a contrast to MeteoGroup's prognostications for the weekend and early next week for the East, which is almost entirely dry.

Not sure I quite follow that Chris as my post isn't really within that time zone. Just taking three spot charts from the ecm I suppose one could argue the south east will be the driest

[Frosty.]

Tonight's Ecm 12z ensemble mean suggests a changeable outlook with a mix of settled / unsettled conditions, something of a N / S split with the north showing more emphasis on unsettled, the south doing better with some decent ridging at times and longer term indicates increasing azores high / ridge influence. We get our first, albeit short burst of polar maritime air on sunday into early next week but there is then a tendency towards a gradual recovery in temperatures, especially further south towards the end of the run as the 850's (uppers) show!.

 

Edited August 29, 2019 by JON SNOW

[ANYWEATHER]

Good Evenight Folks! Hope everyone is getting there Boiler primed  and serviced because  there is some very cold nights in some locations and even Jack Frost making an appearance in one or two prime locations a very early start to the meteorological Autumn. A semi settled spell coming up but the jet stream is too strong to allow pressure to build strongly across the nation..   Watch this space..?

[kumquat]

4 hours ago, ANYWEATHER said:

but the jet stream is too strong to allow pressure to build strongly across the nation

I think you're spot on. However, I'm holidaying down near Plymouth next week and I'm pleased to see that I'll be in the right place at the right time at least for a couple of days midweek. The Azores wants to pay a meagre visit to the South West and I will tap into that as a beach/BBQ day, possibly... albeit a tad windy but pleasant in the sunshine.

Tues 3rd

ECM

UKMO

GFS Pub Run

Most of next week seems relatively dry in between the weekends (a bit imby) and away from the far NW (sorry about that ppl in  NW Eire, NI, NW Wales and Scotland) but with showers and decent early autumnal sunshine interspersed.

I will raise a (first of the summer wine) glass to you all and see you post equinox. With Dorian looking like it will go nastily into Florida / Georgia I also wish our international visitors and friends well.

Edited August 30, 2019 by kumquat

[Robbie Garrett]

16 hours ago, knocker said:

Current sat for Dorian

Coldest place on Earth, the eye of Hurricane Dorian.

[knocker]

The North Atlantic 500mb and surface analysis for midnight and the 700mb precipitate water

There is a fair bit of medium cloud around over England and Wales at the moment but generally to day will be quite sunny and quite warm in the south east. Different picture in the north west. Already moderate persistent rain is effecting western Scotland associated with the frontal system which stretches way back to the south west and this will continue through the day, expanding to cover N. Ireland and NW England as pulses of heavy rain run along the almost stationary front. (see chart above)

Through this evening and overnight there will be heavy rain over N. Ireland and Scotland as a wave forms on the front as it begins to edge east and thus by dawn the rain will also begin to effect western regions of England and Wales. Elsewhere a clear night with maybe the odd mist.fog patch

The front and band of rain will continue to track east across the country through Saturday leaving clearer and cooler weather i it's wake  but quite breezy with frequent showers, mainly over N. Ireland, Scotland and NW coastal regions of England. And by now a lot of rain has fallen on regions in the NW that have been under the slow moving front.

By Sunday the country is in a cool, unstable north westerly airstream thus a sunshine and showers days and these could be prolonged and heavy with the odd trough running around in the circulation.

The ridge to the west is transient as another upper trough tracks into the Atlantic on Monday and whilst most of the country will be dry with sunny intervals another frontal system will track north east and bring more rain to N. Ireland and Scotland avvompanied by strengthening winds.

By Tuesday a complex structure of fronts associated with the low over Iceland will again bring rain and strong winds to the north west with the south east remaining dry

Note Dorian has made landfall in southern Florida

Edited August 30, 2019 by knocker

[knocker]

The gfs clears the front south east on Wednesday whilst tracking another trough east to be  near Iceland by Thursday when it amplifies the Atlantic subtropical high resulting in the trough ducking south east over the UK on Friday. Best just keep a watching brief on this

Temps a little below average in the 5-10 period

Edited August 30, 2019 by knocker

[knocker]

Current satellite

[knocker]

The ecm is not dissimilar to the gfs through the latter half of next week

Dorian

Edited August 30, 2019 by knocker

[mb018538]

Growing possibility of a nasty trough/low affecting the UK as it slides from Iceland around the flank of the high pressure close by.



Still open to much speculation at this range - Dorian will undoubtedly be throwing a very large spanner into the works.

[Methuselah]

As mb said, above, there's plenty of room for speculation:

   

   

Autumn's often good for speculation!

[knocker]

Looking at the clusters vsi the end of next week one could entertain the possibility of the amplifying ridge being of a strength and orientation that would cut off a south east plunge of the trough

[Frosty.]

Looking at the Gfs 6z operational there are the first hints of wintry precipitation on September 11th..the season's are a changing!!

[Methuselah]

It certainly looks (from the GEFS 06Z ensembles) that something substantially cooler is on the way.

   

   

However, given the latest indications from Those Who Cannot Be Named, it might not last too long...?

[JeffC]

1 hour ago, Ed Stone said:

It certainly looks (from the GEFS 06Z ensembles) that something substantially cooler is on the way.

   

   

However, given the latest indications from Those Who Cannot Be Named, it might not last too long...?

yay, proper sleep and not having to cut the grass as much. Agreed Pete, from that it looks like we're turning a tad more seasonal. My only concern looking at things generally is that we're looking at a pretty damp period overall. I know some in the SE could do with a bit of a fill up, but up here the biggest issue is trench foot.

[knocker]

A quick look at the movement of the waving cold front as it realigns and moves east, and the latest on the rain associated with it

[knocker]

The EPS on Dorian. It could park itself on the Florida coast before tracking north

[Methuselah]

27 minutes ago, knocker said:

The EPS on Dorian. It could park itself on the Florida coast before tracking north

A big hand for Dorian?

[chrisbell-nottheweatherman]

8 hours ago, Ed Stone said:

As mb said, above, there's plenty of room for speculation:

   

   

Autumn's often good for speculation!

Agreement on a wet period between the 7th and 10th.

[I remember Atlantic 252]

2 minutes ago, chrisbell-nottheweatherman said:

Agreement on a wet period between the 7th and 10th.

Yes but to not be negative, signs of high pressure coming in on GFS and EC, not great temps but at least dry

[chrisbell-nottheweatherman]

10 minutes ago, I remember Atlantic 252 said:

Yes but to not be negative, signs of high pressure coming in on GFS and EC, not great temps but at least dry

I'm not being negative - we need that rain badly down here!

[knocker]

Negative or positive is irrelevant to model discussion when the aim is to objectively assess the output as best one can. Or it should be. But of course that would rule out bias and that wouldn't do.

[knocker]

The ext GEFS is along the lines that has been indicated recently with the subtropical high ridging north east to the south west of the UK in conjunction with a positively tilted trough to the south east. Portending the south west probably in receipt of a drier interlude with any systems winging around the top of the ridge. Temps with regional variations but generally a tad below average