Thank You Martin.

A mixed bag this week..

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Good evening. Just rescuing this thread from the very rare event of it nearly falling off of page 1 of the forum here is the evening model report taken from the 12 noon output from GFS, UKMO, GEM, NAVGEM and ECM for today Sunday September 15th 2013.

All models show High pressure returning to the British Isles tonight. Before that happens though we have to get rid of the current deep depression close to Northern Scotland first as it transfers slowly SE and fills through the week. Further wave depressions look like crossing the South on Tuesday and troughs most places on Thursday with Wednesday being somewhat showery while Friday becomes more generally dry as pressure builds up from the South with sunny spells and cool nights.

GFS shows next weekend as a warm and fine one as High pressure builds across all of the UK and with winds inherently having blown up from the SW it will be warm by day but with some mist and fog night and morning. The latter half of the run shows fine weather largely persisting across many parts but things will slowly cool down day by day to become somewhat chilly by the end of the run with some mist and fog night and morning throughout and the chance of a ground frost late in the run.

The GFS Ensembles show the operational was a warm outlier in part 2 of the run and was not very representative of a rather changeable rest of the pack. Rainfall amounts look close to average for the most part though many areas look like having a drier interlude coinciding with next weekend.

The Jet Stream tonight shows the flow continuing to flow SE across the UK as further troughs and disturbances come through the UK over the next few days. It then ridges north of the UK in response to the drier period next weekend before it settles in a West to East flow across the Atlantic and Scotland through Week 2.

UKMO has High pressure elongated across the UK from a centre over Northern Norway. The weather would be dry and bright with some sunshine and daytime temperatures close to average but cool nights with mist and fog.

GEM is a little more reluctant and less extensive in its spread of High pressure across the UK next weekend. Nevertheless the South at least would see some decent weather with any rain and attendant cloud restricted more towards the North and west at first and towards the SW in the far end of the run.

NAVGEM has High pressure developing over the top of the UK next weekend and lasting into the following week. The weather would settle down with sunny spells and light winds by day when it will feel quite warm but cool nights with mist and fog problematical night and morning.

ECM shows quiet Autumnal weather developing from early next weekend with a light westerly breeze at first before High pressure builds over the UK with fine and quiet days with some sunshine but cool and misty nights with dense fog in places, slow to clear in the mornings.

In Summary the trend towards High pressure building back over the UK shown in previous output of late has gathered pace tonight with all areas looking like settling down next weekend at least for a time as High pressure builds across the UK from centres to the SW and NE. Though some warm uppers are shown by some output others show cooler conditions with all models that show High pressure over Britain next week likely to bring mist and fog problems overnight as well as making it feel chilly in the morning's.

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Models struggling with the behaviour of Humberto as the storm goes ex-tropical and heads to higher latitudes while west of the UK.

Interesting new idea on the 12z runs is for Humberto to drop a little energy towards the Azores. This is then supported by further energy streaming NE from the GOM and through Florida (being discussed on tropical weather blogs and looks like an interersting setup coming along). The result for the UK is a ridge being propped up to give a run of settled days for some, many or all (depending on specifics). It could turn rather warm for the time of year thanks to a flow from the south... but only if the Atlantic troughs don't push through to our NE as per GFS. That seems to come down to Humberto's track as well so... uncertain times.

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I like the sound of this

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Looks like after an unsettled and chilly week, high pressure builds in to bring a spell of settled, pleasant weather with temps into the high teens come Sunday or into the early part of next week for a while at least.

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Good morning. Here is the report on the midnight outputs from GFS, UKMO, GEM, NAVGEM and ECM for today Monday September 16th 2013.

All models show a changeable week to come with the weather being driven primarily by Low pressure to the North and NE of the British Isles with a showery WNW flow over all areas today. This pattern is then complicated on Tuesday and again later on Thursday or Friday with more organised bands of rain crossing East in the flow in what will remain quite cool conditions through to the weekend.

GFS then shows the weather settling down steadily as High pressure builds up from the South and SW across Southern areas next weekend with some fine and warmer conditions if rather cloudy. The NW will stay windy and wet for a time as troughs brush by to the NW. Through the following week a new High pressure builds to the West and extends a slow moving ridge across the UK with fine and bright weather by day and chilly misty nights. This weather type then persists for some time with High pressure filtering slowly away from the UK at the end of the run as shallow Low pressure and occasional rain develops for many.

UKMO today shows High pressure building slowly North across Southern Britain at the weekend with fine if rather cloudy conditions while many Northern and Central areas see the ridge disected by a weak front delivering cloudier weather with occasional light rain and drizzle in places.

GEM shows High pressure building across to the East of the UK with a warm Southerly feed, quite strong in the extreme West. The Low pressure driving this flow will see it's energy split to the West both North and South with the void being filled by a strong High pressure area over the UK in 10 days time with fine and warm weather by day likely with potentially foggy nights.

NAVGEM shows the South being influenced by High pressure at the weekend and the start of next week with more Northern and NE parts more likely to continue to be affected by cloudier weather in a Westerly flow with occasional rain.

ECM shows High pressure building strongly North over the UK at the weekend and the start of next week away from the far NW and later NE as it jostles it's position before gaining total domination over the UK weather centred up to the NW of the British Isles. So from the weekend most areas can expect dry and fine weather and with uppers high daytime temperatures could be respectable for many. The inversion at night though will encourage mist and fog to form in places and this may be slow to clear in the morning's.

The GFS Ensembles show the operational as a milder outlier under it's second half under the High pressure while there is considerable spread between the members from the second half of the output. While a fair amount of members opt for an anticyclonic regime it s by no means all and some show more changeable conditions at times especially in the North.

The Jet Stream shows the flow maintaining it's WNW to ESE flow through this week before being lifted further north clear of the UK through Week 2 as High pressure builds.

In Summary the weather looks like settling down again for many by the weekend and more especially next week. High pressure from the South or SW is again responsible as it moves in and locates somewhere close to the UK and could lead to a spell of pleasant and tranquil Autumn days next week with gentle warmth but cool and potentially foggy nights which could become slow to clear in the mornings. There is though a somewhat lesser chance of things staying or becoming somewhat more changeable again as the pattern from the operational's above does not have complete and universal support from all members of the ensemble data. 

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Thank You Martin..

Very changeable.But would like some tranquility.

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I like the sound of "gentle warmth by day, and cool & foggy nights", typical Autumn fair in fact.

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If the retrogressing High scenario that keeps cropping up in the GFS carries on doing so during the winter, we could have a very interesting season to discuss....

It's fascinating (albeit FI) to see run after run retrogressing a UK high to the mid-Atlantic and then up towards Greenland....

If that happens, and does so in winter, we could well be shivering sooner rather than later!

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Funny, I said a few weeks ago on my Facebook page that a fine spell of weather could develop for late September but then the other day I said I'd got it wrong. Bugger.

Welcome back

The only real difference in a broadscale sense between summer and many other months this year was the ability of the Atlantic/Azores HP to ridge across the UK rather than retrogress, hence a much warmer spell was realised. The continuing warmer patterns in the high Arctic interest me as it was those that appeared to have at least some effect on our cold winter and spring synoptics. Fascinating times

Thanks... I've still been here, but I've been out enjoying the summer, and can't often think of much to post in the hot weather....I am more a winter poster and a summer lurker!...Yes the pattern setting up at the moment is fascinating, and this September has really felt like Autumn, which makes a change from previous years.

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Hi all,

Here's today's video update;

Cold November And December?

http://www.gavsweathervids.com/

Also has a look at the warmer/drier weather on the way for the weekend.

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Cheers Gav

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Summer on the way back. We could be looking at 25c again!

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

http://www.wetterzentrale.de/pics/Recm1441.html

http://www.wetterzentrale.de/pics/Recm1681.html

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

http://www.wetterzentrale.de/pics/Recm2161.html

http://www.wetterzentrale.de/pics/Recm2401.html

 

 

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High teens low 20's more like an less we tap into some very warm air at the surface and pull it north.

Settled does seem to sum things up from the weekend onwards.

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With Uppers approaching 15c i reckon we could squeeze out a 25c or two. Some very impressive heat for the time of year whatever happens.  

http://www.wetterzentrale.de/pics/Recm2162.html

 

 

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Looks like summer is on the way back if GFS and ECM are right.

Good evening folks. Here is the report on the midday output from GFS, UKMO, GEM, NAVGEM and ECM for today Monday September 16th 2013.

All models show a cool and showery NW flow across the UK with a deep Low pressure area to the North of Britain. Further fronts are approaching Western Sea areas at present and will move SE over the SW half of the UK tomorrow with a spell of heavy rain and strong winds in the extreme South. This feature is whisked away before Wednesday leaving a dry, bright and cool day for many with just scattered showers. Winds then are shown to back Westerly on Thursday with fronts delivering rain from the West through the day. It will slowly feel less cool as warmer air is mixed in with this system. By Friday and more especially over the weekend the weather settles down for many as High pressure builds up from the SW with some fine and gently warm days on light winds but with the potential for some mist and fog patches overnights. The far NW seems likely to be the only exception to this rule as cloud and a little rain remains possible here.

GFS then shows High pressure in control for some time as a new centre moving in from the Atlantic takes over from the one to the SE next week. Fine and dry days but chilly nights will be commonplace across the UK through the middle and end of next week before an area of very cold air for September feeds down across the UK with showers and sunny intervals for all with some wintriness in the showers over the Scottish mountains and ground frost increasingly likely. Things turn milder then towards the end of the run before a change to an unsettled SW airflow is shown at the very end of the run.

UKMO tonight shows High pressure down to the SE early next week with fine and somewhat warmer weather than of late for most while the North and West becomes at risk of more cloud and some rain again late in the day next Sunday.

GEM tonight also shows High pressure building for a time at the weekend and beginning of next week with the South likely to see some fine and bright weather with the North and West seeing much more cloud. By the latter stages of the run High pressure slips away East and a depression edges in slowly from the West with some rain or showers at times in temperatures a little above average.

NAVGEM has High pressure building North across the UK at the weekend and into next week with fine and dry weather for most parts of the UK before this is slowly eroded from the North and West early next week as the High begins to slips away East and SE.

ECM has High pressure building North across the UK at the weekend and extending to all areas next week. A typical fine and anticyclonic early Autumn weather pattern will develop with fine and sunny days with gentle warmth across the UK. Nights could well become chilly under clear skies with fog and mist a potential hazard to conditions night and morning as High pressure remains anchored near the UK with warm air aloft creating a sharp night time inversion pattern.

The GFS Ensembles show a growing trend for a strong warming from the weekend and into next week. as has been the case a lot of late the operational was an outlier at some point and tonight it is a cold one towards the second half of the run with most other members showing a slow moderation of warmth to more average levels late in the run. The South becomes dry over the weekend and start to next week before several members indicate a light increase in the incidence of rain in the South late on while the north sees occasional rain after the 21st.

The Jet Stream flows across the British Isles in a SE direction weakening later in the week as it moves further North to be clear of the mainland by the end of the weekend and start to next week as High pressure takes hold to the South.

In Summary there is still a lot of evidence of High pressure building North across the UK this weekend and next week. Most models do now show that most of the UK will be affected by this at least for a time before some ingress from the Atlantic is shown by some output from the Atlantic later in the runs. With warm uppers aloft it looks like the weather could be quite warm by day while night's could become very foggy if night's stay clear and given we are approaching the end of September now this could be slow to lift in the mornings.

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Well then. The signs of warmer than average conditions are back in the mid-range model output. After the letdown back at the start of September, I'm wary... but support is on the up and even the least rewarding runs still offer a spell of warm, settled conditions for many of us, so there's good reason to be hopeful if you're looking for what would qualify as an Indian Summer given that we've seen frosts in a few places during the past two weeks.

As Martin points out, the fog risk is the main potential spanner in the works. That said, I can remember some September days of times past where it was chilly in fog (single-digit temps) until noon and yet the afternoon saw temps soaring into the 20's thanks to the insulating effects of atmospheric moisture (allows shortwave solar radiation through but then reflects back the emitted longwave radiation from the surface to a great extent - more so than Carbon Dioxide).

Fog usually clears by noon in late September, but I'm sure exceptions can and do occur... here's hoping we avoid that until October (I enjoy the odd foggy day in October, for my own absurd reasons ).

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Thanks for that excellent description there. I often wondered how the heat holds and builds when fog clears.

 

 

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Oh please no

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Oh come on Gooner , you mean you would be happy with the weather as it has been for the next 7 months ( next April) , as im sure 98% of us would not

the other 2% are yourself and Retron 

We are into Autumn let's see some Autumnal weather before we hit into Winter.

 

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