Hi all,

Here's todays video update;

High Pressure To Dominate The First Half Of September;

http://www.gavsweathervids.com/

Looks like High Pressure all the way to be honest.

http://www.wetterzentrale.de/pics/Rtavn6017.png

http://www.wetterzentrale.de/pics/Rtavn8417.png

Warmer up nicely

Thanks Gavin A lot of useable weather ahead and even signs that HP could build on into Europe and allow hotter air to reach us. If the Tropical Atlantic wakes up as also suggested, then we could find ourselves enveloped in a lot of imported sub-tropical air. It's often got soemthing to do with of those early September heatwaves coinciding with the start of the new school year

We had quite a few of those in the late 1990s and early 2000s. It gave some very nice autumns indeed.

Long may it continue and for us to save on heating and stop putting on an extra layer 

Exactly - and in the meantime - No compliants about this lot from GFS.

http://www.jp2webdesign.co.uk/ds/gfs.htm

Good evening folks. Here is the report on the noon outputs from GFS, UKMO, GEM, NAVGEM and ECM for today Friday August 23rd 2013.

All models show a cold front crossing the UK tonight and tomorrow slowing down over Eastern areas. Some heavy rain will fall in places with others seeing less. A cool NW flow is shown to follow tonight over SW Britain and easing into central areas tomorrow. The pressure then builds from both the NE and SW late tomorrow and Sunday with a couple of largely dry and bright days with some warm sunshine especially on Bank Holiday Monday. A few showers are possible mostly in the East on Sunday. By Tuesday a new front crosses SE across the UK with a band of cloud and occasional mostly light and showery rain with clearer skies following from behind. By Wednesday pressure is shown to be building strongly from the West.

GFS tonight shows High pressure holding firm though slipping South a little late in the week to allow a brief incursion of cloud and a little rain to the North before the weekend. The remainder of the run then shows High pressure anchored over the UK with fine, very warm and settled early September weather for all.

The GFS Ensembles show a dry couple of weeks with just very occasional rain and temperatures close to average for the time of year. The operational is a crazy run tonight with a locked in pool of very high uppers over the UK in the second half.

The Jet Stream shows the flow flying high to the north of the UK after the weekend around the Northern periphery of an Atlantic or UK based high pressure area.

UKMO tonight shows a strong ridge across Southern Britain with a cloudier Atlantic Southwesterly over the North where a little rain is possible. In the South though there would be plenty of reasonably warm and settled conditions in very light breezes.

GEM tonight shows the anticyclone building across the UK next week with fine, bright and warm weather likely for all before the High temporarily slips more towards the West with a light Northerly drift bringing cooler air South for a time towards the end of the run.

NAVGEM shows a ridge of High pressure holding firm over the UK next week in what would be fine and pleasant conditions across the UK with plenty of warm sunshine by day and some mist and fog overnight.

ECM is a peach tonight building High pressure across the UK next week and keeping it over the UK for the rest of the run with warm air entrapped over the UK meaning some very warm and sunny days for the middle and end of next week and for some time thereafter coupled with some cooler and Autumnal nights with mist and fog in places.

In Summary the pattern remains unchanged from this morning overall. High pressure looks like building strongly across the UK behind next Tuesday's weak trough, a pattern supported by all models which then shows no signs of High pressure losing grip within the outputs time limits tonight. So we can all expect some warm or at times very warm days with sunny spells and some calm and chilly nights in rural locations with mist and fog patches becoming commonplace.

2013 seems to be the summer that just keeps on giving doesn't it? Cant help feeling that we must be due an extended period of zonality sometime this coming Autumn : the weather always balances itself out in the long run.

http://www.wetterzentrale.de/pics/Recm1201.gif

http://www.wetterzentrale.de/pics/Recm1921.gif

HP is the order of the day from ECM, so much dry weather around IMBY

http://www.wetterzentrale.de/pics/Rtavn541.png

http://www.wetterzentrale.de/pics/Rtavn5417.png

http://www.wetterzentrale.de/pics/Rtavn781.png

http://www.wetterzentrale.de/pics/Rtavn7817.png

Sunday and Monday looking very nice

Believe it or not we're currently seeing a lot of classic summer zonality where the jet tracks either across the north or more towards Iceland, leaving  a lot of reasonable weather across much of the UK. It also featured in July for a large part of the month. Back in June the jet wasn't tracking so far north and actually spent about half the time splitting somewhere to our west, with a lot of energy going right down towards Africa. This allowed for some blocking to our NE at times.

In fact, looking at the synoptics in general since around mid-April, we're due an extended period of -ve NAO

In the 12z GEFS tonight, there are some signs of HP pulling back west and possibly heading NW. I think that this is more likely to occur after a period of HP displaced from the Azores and lounging about across the UK or just to the east - more in line with the GFS and ECM operational runs.

September can either bring in autumn at pace or extend the summer for many more weeks. My own instincts are telling me that in 2013 it will have a good go at the first and then switch quite rapidly to the second.

The big question being - How long does the nice extended summer last.

http://www.wetterzentrale.de/pics/Rtavn1621.png

http://www.wetterzentrale.de/pics/Rtavn16217.png

HP looking to dominate all week

All models show a weak area of Low pressure close to SE England with a trough linked to it stretching NNW across Eastern Britain. A cool and blustery NW flow is affecting the far SW. Showers or spells of potentially thundery rain will affect the East today slowly dying away tonight while the far West sees brighter skies with a little sunshine but more cloud too for a time as a weak warm front slides SE just to the West. Tomorrow will see things simplify as Low pressure slips away SE from SE England with a ridge sinking South over the UK giving fine and dry conditions for many over the extended weekend before a weakening trough follows it SE on Tuesday with a band of decaying rain and cloud. By Wednesday all areas will see rising pressure from the West with sunny spells and average temperatures in a cool North drift especially in the East.

GFS then shows slacker pressure over Britain towards the end of next week on this run with dry and fine weather still most likely but with the risk of a few showers, perhaps more especially towards the SE but relatively pleasant conditions overall. Then beyond next weekend a spell of solid High pressure is shown to bring 4-5 days of potentially very warm and sunny weather for all before a thundery Low drifts North from France towards the end of week 2 to advance somewhat cooler uppers in from the West to the North at least.

The GFS Ensembles continue to show a warm outlier as an operational in it's latter stages among a pack that show an agreed trend towards rather warm and High pressure conditions beyond this weekend through to the end of the run. There are members that show cooler interruptions to this overall pattern in the North though. Rainfall is a scarce commodity in the South with nothing to write home about in the North either.

The Jet Stream continues to be projected to move North of the UK next week and the week after though there are some occasional outflows South over the UK from the main flow on occasion.

UKMO today has shifted everything further South next week which has implications for the North with Low pressure near Iceland having a definite influence over Scotland and Northern Ireland next week with some cloud and rain in places. The ridge does hold good though for Southern areas with mostly dry and reasonably warm conditions holding here with some sunshine.

GEM today is also less inclined to bring full blooded High pressure over the UK later next week. What it does show is a spell of winds from the North with a period late next weekend when a really cool Northerly Autumnal blast gets perilously close to Northern and Eastern regions with as it is a spell of cool and bright weather with scattered showers in the NE. Towards the close of the run a further incursion of unsettled weather is shown to arrive from the NW as a High pressure ridge is sucked away South at the expense of Atlantic Westerlies.

NAVGEM too makes hard work on this morning's output of building High pressure across Britain late next week with a ridge holding for a time before a deep Low near Iceland pushes stronger Westerly winds and troughs across the North and West later next week.

ECM completes the set this morning keeping pressure quite slack later next week but maintaining largely dry, bright and warm conditions across all areas before it takes the GFS operational route in building High pressure solidly across the UK at the end of the run with fine and sunny weather for all with cool  misty nights in places.

In Summary there is some hesitation shown throughout the output this morning in the speed of the build of pressure later next week. Many models wish to keep a slack period of pressure over the UK which could result in a shower or two late next week rather than the extensive High pressure shown last night. Thereafter things diversify rather with GFS and ECM building pressure strongly as shown on previous runs with prolonged fine and settled weather UK wide while GEM, NAVGEM and UKMO look more tentative with the door ajar to the NW for Atlantic Lows to make some inroads towards the North of the UK next weekend and beyond. It will be interesting to see whether this is the start of a new trend or just natural variability from run to run. Hopefully I can throw more light on it after tonight's output.

Thanks. Martin

Thanks Martin.

A warm output is nice.

Indian Summer perhaps on the way? Looks very dry after Sunday.

http://www.wetterzentrale.de/pics/MT8_London_ens.png

I reckon UKMO is still taking the jet more to the NE on day 6 as per ECM and GFS, but GEM is certainly different. While that model often over-amplifies (even more so than ECM), it's ideas can never be fully discounted because there are times when the models end up correcting to a more amplified solution - that was often seen prior to this summer. I think that over the past 3-4 months, the state of the Arctic (+ve AO) might be the reason behind the models tending to correct towards flatter jet patterns instead.

All that said, the majority vote is still in favour of the jet angling SW to NE, tracking N of the UK and allowing HP to displace from the Azores and move across the UK as a distinct cell

Isn't an Indian summer a warm spell of weather in October ? 

I know what your saying but considering the last few summers if weather balances itself out like this, then we wont even get a winter.  Looks lovely as we end August and move into September. No sign of autumn.

Temps look good for the week IMBY

24c 23c 22c 24c 23c 23c

Happy with that