UK Weather - Autumn 2011

[Simon Culling]

New thread as the season of Autumn is now upon us......with the beautiful colours to look forward to as the trees get ready for winter.

A nice start to Autumn as September has started with a warm SE to S flow and two days of sunshine for those of us in England. Not so good further north and west.

Yesterday (Friday 2nd) was a suuny day over most of England + Wales with some decent temperatures for early autumn. Maxes reoprted include:

27.0*C at London Heathrow
26.9*C at Cavendish (Suffolk)
26.8*C at Gravesend (Kent) + Olympic Park South
26.4*C at Cambridge NIAB
26.1*C at Holbeach (Lincs)

Temperatures should get close to these levels again today in SE England and E Anglia, but cooler and more unsettled weather is on the way for next week. Forecasting will be difficult due to all the TS and Hurricane activity Stateside and the uncertainties as all this warm moist air gets advected east across the Atlantic.

[stepr]

26C the top temperature today.

[Simon Culling]

It was another warm day on Saturday (3rd Sept), but only in the east of England, with max temps of:

26.7*C at RAF Manston (far east of Kent)
26.4*C at Gravesend (Kent)
25.4*C at Santon Downham (Suffolk)
25.3*C at Shoeburyness (Essesx)

It was much cooler in the west, with maxes of 15.5*C at Sennybridge (Wales) and 16.9*C at Camborne (Cornwall).

CET up to the 3rd of September is 16.6*C (+1.7*C) but this will start to fall from today.

Much cooler and unsettled for the new week.....I got absolutely soaked on the golf course this morning (Sunday) as nigh on half an inch of rain + drizzle fell, and guess what, it stopped as soon as we reached the 19th.

[stepr]

Some interest for Monday night into Tuesday perhaps. The first significant storm for the UK.. potential gusts up to 60 or 70mph on Irish Sea coasts, potentially up to 60mm rain on western hills too.

That's just a normal storm, however The parameters for storm relative helicity are showing some potential for tornadoes over the wide area of England.. it'll be very interesting to see what TORRO come up with.

[stepr]

Currently there is a system moving over us, and I wonder is cyclogenesis is possible? If so it could being some big problems.. the models aren't forecasting it to 'bomb', but I think the possibility is there.

[Simon Culling]

I think a 'bomb' is unlikely as the conditions for rapid cyclogenesis are not there. However, we do have a deepening depression approaching the UK at present. At 1800GMT today (Monday 5th) it was at 984mb and located approx 500 miles west of the NW tip of Scotland and it is forecast to be at 978mb by 1200GMT tomorrow (Wednesday 6th) and located over the Western Isles. An 'ana' style cold front is likely to sweep across the UK tonight and tomorrow morning, clearing the SE of England in the afternoon and this feature may have sufficient lift to create some line convection and perhaps the odd small tornado. These 'ana' fronts are not uncommon in autumn and can give rise to 10 or more tornadoes along their length in the right conditions, but perhaps not this early in the season.

The models are struggling with what Hurricane Katia will do when it recurves NE past the States and then crosses the Atlantic....some outputs suggest a very deep depression close to the UK.....but that is not until the begining of next week. A lot can happen in that time span.

[stepr]

It didn't bomb in the end, it was something I saw in the near term evolution that alerted me as to question whether it might undergo cyclogenesis. There was, on the 0z last night a rapid insurgence of dry cool air, I thought this might act to allow the rapid deepening, however on this mornings 6z it was gone... it was unlikely anyway but interesting. Even had it, though there probably wouldn't have been time to develop a baroclinic leaf.

[Simon Culling]

No bomb or ana cold front. The cold front did show some line convection in the early hours of Tuesday 6th over NW England and N Wales but appears to have become a split cold front and the rain became more disorganised (although still heavy at times) as it spread SE. The low crossed Northern Scotland at around 975mb, so was well forecast.

The strongest winds were in South Wales and along the south coast of England with gusts recorded to:

87mph at Needles Old Battery - an exposed lighthouse on the Isle of Wight
71mph at Hurst Castle (Hampshire coast)
69mph at Portland Bill (Dorset coast) + Mumbles (S Wales coast)
66mph at Aberdaron (Lleyn Peninsula, NW Wales)
61mph at Pembrey Sands (S Wales coast) + Langdon Bay (Kent coast) + Solent MRSC (Hants coast)

Inland over southern England gusts rached between 40-50mph, enough to remove a few branches from trees.

Forecasters are still struggling with the path of what will be ex-hurricane Katia when it gets near the UK this coming Monday (12th), but it will be windy wherever she goes! Warming up tomorrow (Friday) and into the weekend as we develop a southerly flow.

[stepr]

NOAA have this storm as a 'tropical storm' right up to Scotland, but that's debatable. The Met-office fax charts have Katia as a Post-TS up to roughly Ireland.

Windy it will be though, GFS going for 50 knot sustained winds off the Hebrides..

[Richard]

Interesting point Stephen,i suppose a tropical storm is classed as such because of there origin maybe ??

You fellas be carefully with all that wind

[stepr]

Well when it hits the UK it will be extratropical/post tropical, but this allows the potential for Barolinic development. At the moment it should hit NW Scotland meaning damage will be kept to a minimum. Was the storm to take a different track, for example, over England and Wales, things could be more problematic.

NOAA forecasting 1 minute mean wind speeds over 70mph off the coast of NW Scotland, with gusts in excess of 100mph. This will obviously decrease as it hits land and loses energy.

[Simon Culling]

There has been the usual over the top hype in the media about the coming storm, with many tabloid sources claiming a hurricane is going to smash into Britain. The truth is that Katia has completed the transition to an extratropical storm system and is now taking the more typical guise of the Shapiro-Keyser model for temperate lattitude storms with the wrap around occlusion evident on the 0600GMT (Sunday 11th) map, where the storm is located at 31*W 49*N at 960mb, i.e. in the centre of the Atlantic. Forecast charts have it approaching NW Scotland (still around 958/960mb) by 1200GMT on Monday 12th. Strongest winds are for the north of the UK with means of 50kts gusting as high as 70kts in exposed areas, i.e. typical of a normal depression in Autumn/Winter.

Very mild night for September o/night Friday into Saturday (9th/10th) with a low of 16*C here in Milton Keynes, but as high as 17.8*C at Crosby (nr Liverpool) and Trawscoed (W Wales) and 17.5*C at Chivenor (Devon) and Pershore (Worcestershire). Humid and breezy yesterday, Saturday, with highs of 25.0*C at Leconfield (E Yorks) and Weybourne (Norfolk) and 24.6*C at Marham (Norfolk).

CET is 16.1*C (+1.6*C) up to the 10th and EWR 22mm (av 78mm) up to the 9th.

[Simon Culling]

The low duly passed over the north of Scotland at around 968/970mb yesterday, somewhat higher than predicted and gave the north of the UK a wet and windy day, but nothing unusual. Max gusts at Met Office sites were:

82mph at Capel Curig (Wales)
76mph at Lake Vyrnwy (Wales) + Edinburgh Blackford Hill (Lothian, Scotland)
74mph at Catlederg (Co Tyrone, N Ireland)
72mph at Glasgow Bishopton
71mph at Loftus (Northumberland)
70mph at Drumalbin (South Lanarkshire, Scotland)

Wet as well, with 48hr totals to 0600GMT this morning (Tues 13th):

58mm at Eskdalemuir (Dumfries + Galloway, Scotland)
45mm at Tulloch Bridge (Highland, Scotland)
42mm at Lusa, Isle of Skye
33mm at Glasgow Bishopton

Damage reported in places, see BBC link:

http://www.bbc.co.uk/news/uk-england-14887875

Weather will calm down for the next few days with a transient ridge passing over the UK and should give us a couple of sunny days, but with cool nights and the first of the autumn mists. It was cool coming back from the pub this evening at 11pm (after watching Champions League footie) with a lovely clear bright moon, but a cool breeze at just 10*C.

[Manukau heads obs]

still respectible windspeed those though!
(75 mph is 65 knots)

[Simon Culling]

Fair point Brian. Some of the stations listed are rather exposed or hill sites, such as Capel Curig, Lake Vyrnwy and Blackford Hill. The site at Loftus is on the east coast of England but is to the east of the Pennines (N to S running hills) and gets downslope enhancement when winds are from W-SW as they were on Monday.

The Glasgow site is not particularly exposed, but is in the W to E running Clyde Valley and W or W-SW winds tend to be funnelled and increased along this valley.

Here in Milton Keynes in the south midlands (of England) the winds averaged 20kts+ all day, with gusts up to 40-45kts, for example top gusts at stations near me were:

46kts at Wellesbourne Aerodrome (Worcestershire)
42kts at Cranfield Airport (Bedfordshire)
40kts at Bedford
38kts at RAF Brize Norton (Oxfordshire)

[Simon Culling]

Showery couple of days over the weekend, with a flabby low (around 998mb) passing slowly eastwards over central Scotland and into the N Sea by late Sunday. Winds gradually swung round from SW to NW and were gusty around the heavy showers. We actuallly managed a decent thunderstorm here in Milton Keynes on the Saturday lasting over three quarters of an hour around tea-time and producing 10 c-c or c-g strikes and some decent rumbles of thunder. Plenty of heavy rain for the garden too and some hail up to 8mm. This marks only the 6th day with thunder this year at my site, which is well down on the yearly average.

CET for September up to the 19th is 15.2*C (+1.1*C) and the EWR up to the 18th is 42mm, a smidgeon below normal....but heavy rain over the midlands and southern England this evening (Tuesday) will bump that figure above average.

Longer term the Met Office are going for a cool and dry but sunny first half of October for England with more frosts than normal, after a warm but unsettled end to September. This implies a pattern shift to high pressure but still dominated by the so called anomalous NW flow.

[Simon Culling]

Fairly quiet here on the weather front...although much fun and games in Euroland as we all wait for the inevitable of a Greek default.

CET up to the 23rd is 14.9*C (+1.0*C) and is likely to increase until the end of the month as we enjoy and 'Indian Summer' here in the UK....our last taste of warmth + sunshine before 6 months of winter gloom.

EWR up to the 22nd is 50mm, just below the average and not much rain expected before the end of the month.

Met Office has changed its mind and is now going for a decent end to the month and start to October, with sunshine and warmth...with temperatures expected to reach 25*C+ by thursday and friday this coming week. These are not record breakers, but will be very welcome. The latest date that 30*C has been recorded in the UK was on the 27th September way back in 1895 at Stratfield Turgis in Hampshire. In recent times, 29.4*C was reached in March, Cambridgeshire on 1st Oct 1985.

[Simon Culling]

Beautiful clear sunny day today (Weds 28th Sept) here in Milton Keynes with a light SE zephyr and a max of 25*C, following a sunny day yesterday (max 21*C).....although with a foggy start to Tuesday.

A big high pressure has taken up residence over central Europe (1032mb at 1200GMT today + centred over East Germany) and this pulls warm air up from the south over the UK and it is set to remain in place until at least the weekend. Sunny and warm over much of the UK, with highest temperatures from synoptic stations today:

27.3*C at Jersey (Channel Islands)
27.1*C at Gravesend (Kent)
26.4*C at RAF Northolt (Gt London)
26.3*C at Hawarden (N Wales) + Church Fenton (North Yorkshire)
26.2*C at Bedford + Pershore (Worcs)
25.5*C at Crosby (nr Liverpool) + Trawscoed (W Wales)
24.3*C at Altnaharra (far N Scotland)
24.0*C at Edinburgh

Likely to see a 28*C or 29*C somewhere in the UK over the next few days as it remains warm and sunny over England and Wales, although N Ireland and the west of Scotland will see rain at times coming in off the Atlantic. The record October high of 29.4*C at March in Cambridgeshire on 1st October 1985 might be under threat on Saturday.

Satellite image of the UK today (courtesy of NOAA) showing the lack of cloud....a rare occurance.

[Manukau heads obs]

I like it
that cloud moving onto Ireland looks very streaky...whats up with that?

[Simon Culling]

Brian, the 2 stations reporting on the south coast of Eire were in fog for much of the day, so I presume the streaks could be sea fog.....they do not look like cloud.

The high is still centred over Germany today (1030mb at 1800GMT Thursday 29th) and England and Wales enjoyed another warm and sunny day. Here in Milton Keynes I didn't see a cloud from dawn to dusk and the mercury reached 27*C. Highest temperatures recorded include:

28.5*C at RAF Northolt + St James Park (both Lonodon)....a new date record for the 29th
28.4*C at Coleshill (nr Birmingham)
28.3*C at Gravesend (Kent)
28.0*C at Watnall (nr Nottingham) + Cranwell (Lincs) + Weybourne (Norfolk)

It is predicted to remain warm + sunny in the south until at least Sunday.

Edit: The max temperature recorded on Thursday 29th was 28.8*C at Kew Botanical Gardens, London

[stepr]

A quite amazing spell of weather currently.

There is an outside chance month record for October could be broken tomorrow, but it is an outside chance.

The met-office predict 29C over a wide area tomorrow, the record just happens to be 29.4 (I think), so any higher than that will top off one of the most impressive spells of weather ever witnessed in early Autumn.

I would go as far as to say it may have rivalled (and beaten) 1985, due to it's longevity.

[Simon Culling]

Friday (30th Sept) was clear and sunny again today......I have not seen a cloud since mid-afternoon Wednesday, with the temperature reaching 27*C again here in Milton Keynes (morning low was 11*C).

The high pressure has remained in the same place over Germany and maintained the feed of warm southerly winds over the UK. Max temperatures on Friday include:

29.2*C at Sutton Bonington (Nottinghamshire)...another date record
29.1*C at Gravesend + Monks Wood (Cambridgeshire)
29.0*C at Church Fenton (N Yorks)
28.9*C at Cranwell (Lincs) + Watnall (Notts)
28.5*C at Coleshill (Warwickshire) + London Heathrow
28.3*C at Bedford + Marham (Norfolk)

The highest tenmperatures were north of London and up through the East Midlands. it will be touch and go for the October record to be broken today because there is a fair bit of cirrus over England today, but the wind is very light this morning (Saturday 1st). Highest temperatures will be in the same area again today, but will need the cirrus to thin to test the record. We shall see.

[stepr]

It's official October has seen it's highest temperature on record in both England and Wales.

These are still pending however, as the temperature will finish higher still.

The England record was confirmed when Gravesend hit 29.5C in early afternoon, by the time I'm writing this it has almost certainly breached 30C.

In Hawarden, Wales, just down the road from me, the temperature has reached 27.3C at the time of measuring, which makes this Wales' hottest October day since records began. At last measurement, it was reading 28C at Hawarden so the evidence suggests Hawarden is now over 28C.

Here locally speaking, the record has been shattered, the original temperature of 24.6C replaces by a much higher figure of 27.6C (although that may have levelled out, depends how high cloud interacts out to the west)

[Simon Culling]

Yesterday saw the October record broken, although there are some reservations about the site at Gravesend, even from the operator, the Met Office. The high pressure is still in situ over Germany (1029mb) but is declining and has elongated more to an E-W shape, with the ridge holding over southern England until tomorrow (Monday).

Max temperatures yesterday included:

29.9*C at Gravesend.....possibly a new Oct record
29.4*C at Charlwood (Surrey)....equalled the old record
29.1*C at Coleshill + St James Park
29.0*C at Monks Wood
28.7*C at Bramham (N Yorks)
28.2*C at Hawarden (Flintshire).....a new Welsh record

Spare a thought for Scotland and Ireland where it was cool and cloudy. For example, at Aviemore, 18mm of rain fell with a max temp of just 12.2*C and 31mm + a max of 14.7*C at Prestwick (SW og Glasgow).

Two more warm and sunny days here in the south (Sunday + Monday), but autumn will progressively arrive this coming week, with the chance of ground frosts by friday.

[stepr]

There is a further chance of the record being broken today Simon.. RAF Mildenhall is on 29C at the moment.

It should be broken, as the cloud is forecast to stay west, however some station have reported a strengthening breeze, which may prevent temperatures from rising much further.