Model Output Discussions 12z 01/06/2017

[karyo]

43 minutes ago, phil nw. said:

This mornings models show just how frustrating the pattern is for any chance of getting anything more than brief spells of something warmer and brighter.

The NH view at days 4 then 5 show how the Azores ridging is quickly flattened by the next surge of the Jet from upstream-UK charts here but they all show the same.

which just returns us to a rather uninspiring westerly upper flow.

The continual feed south east off the Canadian/Greenland trough has done us no favours these last few weeks that's for sure.

I have to say that deep Arctic low is worrying as it may cause a lot of damage to the already fragile ice.

[Man With Beard]

This morning's ECM ensembles, op at T144 was in the smallest cluster, and last night there was no cluster like it. All others this morning and last night more settled.

Edited August 6, 2017 by Man With Beard

[Matthew.]

The latest UKMO actually holds out some hope for Wednesday and Thursday with the high edging in. By Friday the Low extends south with quite an autumnal feel in the air with strong winds.

[Summer Sun]

Thursday looks the best day of the coming week thanks to a weak ridge of high pressure

Unsettled on Friday but the low looks like it won't hang around too long so improving in the west for the start of the weekend

Edited August 6, 2017 by Summer Sun

[knocker]

If you want an example of amplification look no further than North America this evening. Deep trough down the north west coast and strong ridging central Canada and some extraordinary WAA

[Frosty.]

An encouraging end to the Gfs 12z with high pressure building in

[CK1981]

3 minutes ago, Frosty. said:

An encouraging end to the Gfs 12z with high pressure building in

Always at the end of the run. I think it may be time to throw in the towel  

[Frosty.]

29 minutes ago, CK1981 said:

 I think it may be time to throw in the towel  

I wouldn't do that, although the runs today have lowered the mood in here, especially for those in northern uk, the latest met office update still sounds pretty good for the south of the uk generally speaking with a lot of settled and warm weather beyond the cool, windy unsettled day on wednesday..not good all the time but still some very decent august weather is indicated during the mid-longer term further south, even a chance of some very warm continental incursions across the s /se but for northern UK its been a truly abysmal summer so far but they will be put out of their misery when this God-awful meteorological summer ends in scotland in 3 weeks time..roll on winter!

Edited August 6, 2017 by Frosty.

[mb018538]

Problem is we've been waiting for this settled spell since mid July now....it's nearly mid august and it hasn't got any closer. Tonight's output doesn't fill you with any confidence that hints are about to change either.

[Frosty.]

I honestly think most of the rest of august will be a generally north-south split with continual waxing and waning of the azores high and lower heights to the north-west / north with the northern half / third of the uk being generally changeable / unsettled and atlantic driven with a more pronounced broadly westerly upper flow keeping temps on the cool side of average for most of the time with the central swathe of the uk a little better and southern uk having spells of largely settled and warmer weather interspersed with occasional cooler changeable incursions from the NW but on the other hand, the south / south-east has the best chance of tapping into late summer continental heat at some stage beyond mid month.

[summer blizzard]

I have not been around to compare run to run but if we are seeing a less settled picture then it's probably because the GFS has strengthened the Pacific trades vs it's previous forecasts. 

 

[CK1981]

1 hour ago, Frosty. said:

I wouldn't do that, although the runs today have lowered the mood in here, especially for those in northern uk, the latest met office update still sounds pretty good for the south of the uk generally speaking with a lot of settled and warm weather beyond the cool, windy unsettled day on wednesday..not good all the time but still some very decent august weather is indicated during the mid-longer term further south, even a chance of some very warm continental incursions across the s /se but for northern UK its been a truly abysmal summer so far but they will be put out of their misery when this God-awful meteorological summer ends in scotland in 3 weeks time..roll on winter!

The met office updates have been useless so far, even at short range, so I won't count on them!

[Frosty.]

1 minute ago, CK1981 said:

The met office updates have been useless so far, even at short range, so I won't count on them!

That's harsh, anyway, they are the best we have and they are only human.

[CK1981]

19 minutes ago, Frosty. said:

That's harsh, anyway, they are the best we have and they are only human.

Yes, they are only human and very knowledgeable, but their updates have not been very reliable. Maybe their new super computers need an upgrade, because just last week they were predicting high pressure from the middle of next week. I'm not having a pop, just stating what they said!

[mb018538]

Absolutely ^^^

Anyway, ECM is also tripe tonight, generally unsettled and remaining cool. Another run for the bin, and another day closer to autumn!

Lets hope trusty September delivers the goods, always seems to be better than august in recent years.

[Frosty.]

An outbreak of green slime towards the end of the Ecm 12z!

Edited August 6, 2017 by Frosty.

[Polar Maritime]

And back to sensible model output discussion please.

[Man With Beard]

There does seem a systematic problem, which is when predicting high pressure for the UK between T168 and T240 on the assumption of a weaker jet than what actually verifies. Happened a lot of last summer too.

Let's hope the ops are overdoing a reaction to something, as very little was pointing to these types of changes within the models themselves yesterday, and we have seen one day wobbles disappear before (though usually when the wobble is to something more summery before returning to something less).

By the way, signals in the EC clusters recently are for the trough to return more extensively between D10 and D15. Will that one come off??

[knocker]

Nothing much new to add this morning so keeping it brief.

Broadly speaking the anomalies are still on the same page. Low pressure in the western Arctic with associated troughs Alaska and Iceland and strong ridging in central N. America being the main key features. Thus a steady upper westerly flow over the Atlantic with the struggling to make any meaningful sustained influence with the precise strength and orientation of the trough to the north west tending to dictate matters. But it will obviously still be part of the detail that the det. will need to sort over the next two or three days and the usual comments apply. Nothing significantly different in the ext period.

Today finds the shallow low over the Hebrides with the cold front draped across central England and Wales and this marks the start of three days of cool showery conditions as another low tracks north into the North Sea and the surface wind veering northerly. By Thursday this low has cleared away east and taken the inclement weather with it and the UK has a brief respite with the Azores ridging in from the south west

brief because over the next 24 hours the next trough tracks rapidly east from south of Iceland to north of the Shetlands and in the process suppressing the ridge with fronts tracking south east across the country. A very familiar scenario.

As this deepening low swings away to the NE another feature slips in in on Saturday bringing more showery rain to most of the UK, the south east being the exception, and delaying the next burst of ridging from the Azores  This does finally occur by Sunday but, yes, you've got it..............

So essentially remaining unsettled over the next seven days with temps improving  somewhat as the time progresses but still varying around the average.

Edited August 7, 2017 by knocker

[knocker]

The ecm is much of the same

[mb018538]

It doesn't seem to matter how the N Hem profile changes, we get stuck with that pesky trough!

Today:



240:



Pressure patterns changed over the USA, but not here! I know it's far too simplistic to look at it in those terms, but that's just how it is. Even the Met have finally given up the ghost and stopped forecasting the phantom settled spell in their long ranger. I guess in this case even a stopped clock isn't right twice a day.

[knocker]

One thing to note perhaps is there could be some significant rain in the SE later on Wednesday as developments occur in the northerly flow as the low moves east

[Frosty.]

An encouraging end to the Gfs 00z with high pressure building in the perfect position.

[stodge]

Morning all

We really are grasping at straws putting up the T+384 chart from the OP but the morning output isn't brilliant for fans of heat though it's a long way from being all doom and gloom.

Here's the GEM 00Z OP at T+168:

You'll see worse charts than this with HP close to the SE corner but I do concede it's not brilliant for Scotland and Northern Ireland.

ECM 00Z at the same time:

Similar but with the LP further North-West, it's decent weather for all.

GFS 00Z OP at the same time:

Again,. settled and reasonable for all. The message is if you're after 10-14 days of fine, settled weather you won't find it for now. However, a 3-5 window of decent conditions around next weekend and early next week seems plausible at this point. Unfortunately, it doesn't last with the trough coming back.

[johnholmes]

If the anomaly charts are close to the mark then 3-5 days is more likely to be 36-48 hours I suspect. They are, all three main ones, showing a similar output, see below. The NOAA 8-14 is also not that far from a similar pattern. The amount of rain/showers/wind/coolness will be distributed generally on the often seen NW-SE split.

http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

http://www.cpc.noaa.gov/products/predictions/610day/500mb.php