July has gained a reputation recently, especially with all the discussion about global warming, of being a very warm settled month but it is interesting how our memories can deceive us. Even in relatively warm summers there can be some very unsettled periods and as recently as July 2004 this proved to be the case.

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The latter part of June 2004 had been unsettled and the month of July also began in the same vein but by the 6th as pressure built to the south west it seemed that perhaps some fine dry weather was at last on the way. However, it was not to be. Although winds swung to the south by the end of the first week a deepening depression moving up across Biscay intensified quite rapidly and brought a spell of unseasonably strong winds and wet weather to the southern parts of the UK.

An area of heavy rain developed to the south across Northern France early on the 7th and tracked slowly north across England and Wales

October is traditionally the month when with the harvest safely gathered in and long dark nights ahead, we expect to experience the first of the true Autumn gales. September can hint at this with blustery winds and heavy rain but by mid October we may well experience the first true autumn gale with the leaves really coming off the trees and lying in deep drifts.

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Whilst one of the infamous October storms occurred on 16th- 17th October 1987, with the severe storm that crossed the south east of the England, several in more recent years have caused local damage.

The storm of the 27th October 2004 is one such example, for which the event itself did full justice to the warnings of severe weather that were issued by various agencies, up to five days beforehand. This also ran up from Biscay deepening rapidly, like the 1987 storm, but there the similarities end.

The 26th October was actually a pleasant sunny Autumnal day for most parts, with a weak

On the 24th September a very active cold front worked east across the UK in the early morning. As it did so there were some very strong winds reportedfrom various places, as well as a lot of localised damage, especially to trees which were still in full leaf. It seemed that whilst some of the damage was caused by strong winds (or straight line winds -SLW- as meteorologists tend to call them) there were also some tornadoes involved but the difficulty can be sorting out what damage was done by the SLW and which were actually caused by a tornado.

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Something similar happened on the 4th October 2004 as well, when a system with some impressive line convection developed, again during the early morning hours. The convection was associated with a marked veering of the wind from south-south-west to west and some very strong gusts on a cold front. You can see the synoptic set up on the surface chart, as the cold front developed a few hours before the event just here

During the summer months we sometimes see a plume of very warm air adverted north from the region of Iberia, which becomes unstable as it moves up across France, into the UK and can give parts of the country some very unsettled thunder outbreaks. Sometimes though, the most severe weather can be restricted to a relatively narrow ‘corridor’, as in this case, across north eastern England and parts of the north and west Midlands.

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During the 18th of June 2005, high 'theta-W' values moved north over Biscay and France and up across England. The values peaked on the 19th at or over 19C across the West Midlands and into NW England. These figures are very high and are not often exceeded across the British Isles. The lower levels of this air mass were also very moist from air that had originated in the deep tropics several days earlier.

Although the period was initially rather cloudy, with a considerable amount of mist and low cloud persisting across many

Although it's been rather unsettled at times in August, it has seen nothing like the unsettled weather than can set in by mid September across parts of the UK. As the Atlantic jet starts to develop, warm sea temperatures contribute to the development of warm air masses coming up from the south at the surface and as the upper air cools, it allows more vigourous low pressure systems to develop and then the usually stronger jet rapidly transports them across the UK with their attendant frontal systems, rain and strong winds.

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Whilst we have heard a lot about Hurricanes Dean and Felix this season in the Caribbean, one of the problems that can sometimes occur in September and October is that tropical moisture can get wrapped up in our own low pressure  systems and this can cause some exceptionally

This is probably the key month when sometimes ex-hurricanes can make it across the Atlantic as they wind up. One example was in September 2006. A small but intense depression, associated partly the remains of hurricane 'Gordon' brought heavy rain and strong winds to western parts of the UK between the 21st and 22nd of September 2006.

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Hurricane Gordon lay over the Azores at 00Z on the 20th http://www.wetterzentrale.de/archive/2006/brack/bracka20060920.gif and then by 00Z on the 21st its remnants were located at about 15 degrees west, west of Lisbon, 990mb and then it moved north and deepened again, so that by midday on the 21st the deep low was located over SW Ireland, with gales in the SW approaches and through the Western Channel. Slow moving fronts were located over Scotland and showery troughs moved NE across England and Wales. By 00Z on the 22nd it was 974mb just off NW

After both the record breakingly high temperatures and sunshine amounts during July it may seem that the course of our summer is set. Whilst it certainly looks as though the summer overall will be a warm one there are some significant trends that we should carefully note.

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One of the most obvious is that our Climate has a habit of righting itself; that is for most periods when the weather has set into a warm dry pattern there will be a definitive break from this; a period of unsettled wetter weather may result. There have been several notable periods when hot dry weather has been followed by very wet unsettled weather, such as in 1947 and 1975 when standpipes had hardly been erected in the streets (and a Minister for appointed) before it was raining heavily!

Another concern is that the sea water temperatures are up to 3-4C warmer around our coasts now than they would normally be. Whilst this means our sea bathing is rather pleasant, meteorologically

Whilst it is always pleasant to have a fine dry August there is a good chance that it will not live up to our- possibly- rather heady expectations. This was certainly the case almost 100 years ago in 1912. This month stands out as an exceptionally poor month even by other poor August standards. It was the wettest (231%), dullest, and the coldest (12.9C CET) of the century. As this is the only month that holds all three worst records, as Dr Trevor Harley points on his excellent 'British Weather' site (http://www.personal.dundee.ac.uk/~taharley/britweather.html) it is undoubtedly the worst summer month in the last century. For example there was just a single day all month in London when the mercury rose above 70F (21C) and plenty of days when it didn't make 60F (15.5C) even.

It is notable for the 'Great Norfolk flood' event on the 26th when 206 mm fell at Brundall in 24 hours and the pressure as low as 978mb

The second week of October 2005 saw an extremely wet couple of days across western parts of the UK and Ireland, as some exceptionally heavy and prolonged falls of rain occurred across the North and West of the British Isles. The equivalent of a months worth of rain fell in just 48 hours in some areas,causing some significant flooding especially in SW Wales and across the Border region in Scotland. Earlier though to the east across England it was unseasonably warm, especially at night.

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During the 10th to 12th October 2005 a trough lay to the west of the UK, moving slowly SE and eventually stalling. A large blocking anticyclone extended its influence across much of Northern Europe inhibiting the movement of the trough. At the surface, a depression of  around 970mb's was moving towards the NW of Scotland with a trailing cold front that extended SW right down to the Azores. By the 11th, the cold front had moved SE through Ireland introducing

Following on from a rather dry September, the second week of October 2007 saw an extremely wet couple of days across western parts of the UK and Ireland, as some exceptionally heavy and prolonged falls of rain occurred across the north and west of the British Isles. The equivalent of a months worth of rain fell in just 48 hours in some areas, causing some significant flooding especially in SW Wales and across the Border region in Scotland. The downpours also forced one of the two main train lines between England and Scotland to close on the 12th because parts of the track were submerged.

The upper air situation through the period 10th to 12th October was that a large blocking anticyclone extended its influence across much of northern & central Europe. At the surface a depression of about 970mbs was situated south of Greenland with its warm front extending east towards Scotland and a