Monthly retrospective for August 2016

The month was slightly above average temperature wise but rainfall was again variable due to the showery nature of the precipitation although very dry in places, and sunshine was near or somewhat above average- especially in the SE- but almost everywhere away from the far north.

The (Hadley) CET mean temperature was near 17.1C, about 1.3C above average with the mean minimum about 1.5C above.

Most parts of the north were about 0.5C above average but the south was generally a degree or more above average. The pressure was 2-3mb above average across the UK as a whole.

The warmest mean maximum was at Heathrow (Middsx) with 24.7C and the highest daily maximum was 33.9C at Gravesend (Kent), which was also the highest this summer.
The coldest mean minimum was at Aviemore (Highlands) with 8.9C, the coldest absolute minimum by night was at Dalwhinnie (Highlands) with -1.0C though some spots in this area were certainly a degree or so lower.

August was generally a rather dry month in the south & east, and generally wettest in the north & north west, but it was a month of 'exceptions'. It was mainly drier than average in the south certainly where Manston (Kent) saw 39% of its average rain but both Portland (Dorset) & Plymouth (Devon) were near average. These places -in England especially- saw near average amounts where heavy showery rain fell on a few occasions despite a rather dry month otherwise.

However in the north & NW amounts were generally rather above average almost everywhere ranging from 110-160% and Warcop Range (Cumbria) saw 198% of its average, but even parts of the Scottish east & west coast saw exceptions and were below average, like West Freugh (Wigtownshire) with just 65%.
Sunshine was somewhat below average in the north (Lerwick on Shetland saw 77% of its average) but much of the south was slightly above its expected amounts, with Manston (Kent) seeing 127%. Kirkwall (Orkney Isles) saw one day with as much as 14.3 hours.

It was not a particularly stormy month but the one exception was around the 20th as a deep low ran across the northern UK with a 69mph gust reported at the Needles (Isle of Wight). Thunder was generally rather below average.
By the end of August sea temperature anomalies were about 1-2C above average around most UK coasts, similar to July but almost 3C up in the SE and some east Anglian coasts. Generally the central Atlantic was now nearer average but remained above average elsewhere in the Atlantic especially off the coast of the NE'ern USA and around Iceland & Greenland.

Soil temperatures were almost uniformly slightly above average in the south & Midlands partly due to dry ground but generally nearer average in the north and soil moisture again fell in the south during the month, this being especially noticeable in parts of the SE but mainly rose in the areas that received well above average rainfall due to convective activity.

Now looking at August in more detail.

On the 1st August, as fronts encroached into the west and stalled it became very wet in places in south & west Wales, where The Mumbles (Swansea) saw 38mm in the 24 hours to 21Z. The 2nd saw a cold night for early April in parts of N Scotland and Kinbrace fell to -0.8C. In the SW it was wet however as the fronts moved a little further east with Liscombe on Exmoor seeing 30mm in the 24 hours to 21Z. On the 3rd it became very wet in part of north west England, Blencathra (Cumbria) saw 42mm in the 24 hours to 21Z. The Channel Isles was also very wet with over an inch of rain falling but the east stayed dry. Towards the start of week 2 on the 6th it became very warm in places in East Anglia, with Cavendish (Norfolk) reaching 27.0C and the 7th was again very warm in parts of the SE and East Anglia, Cavendish (Norfolk) again reached above 80F with 27.9C. However wet and windy weather affected the far north & NW with a rather deep low tracking off the NW of Scotland. Kinlochewe (Wester Ross) saw 29mm in the 24 hours to 21Z and Loch Glascarnoch (Wester Ross) gusted to 68mph, and Inverness Airport gusted to 65mph. A high level gust of 112mph at Cairngorms summit was the highest on record there in August. The 8th was still rather wet in parts of NW Scotland where Cluanie Inn saw 35mm in the 24 hours to 21Z. Localised thunder & hail affected parts of the Home Couties (eg in Bracknell,Berks) in the evening. Any warm weather cleared away eastwards and was replaced by a chilly polar airmass on the 9th where clearing skies enabled Dalwhinnie (Highlands) to fall to -1.0C and unofficially a station at Carrbridge near Aviemore recorded -3.1C. -4C was recorded on the grass at Aboyne (Aberdeenshire), cold for early August. The cooler weather was then swept away east by the 11th as fronts moved in from the Atlantic again and it became very wet in parts of NW Scotland, Achnagart (Ross & Cromarty) saw 47mm in the 24 hours to 21Z. The 12th was then very warm, & sunny & locally hot in parts of the SE & east Anglia, esp London & east Norfolk, Cavendish reached 28.8C. It continued wet in parts of NW Scotland though, Achnagart in Glen Shiel (Ross & Cromarty) saw 32mm in the 24 hours to 21Z making a 48 hour total of 79mm.The 16th was warm in the Scottish Highlands, Kinlocheve reached 26.9C with a lot of sunshine in the area too. By the 17th with a high pressure ridge from Norway right across the UK, Northolt & Heathrow topped the synop maxes with 26.7C but remarkably, in the far northern Highlands, Altnaharra was only just behind with 26.4C. Outbreaks of showery rain moved in from the SW later in the day however, locally heavy & thundery across SW Wales and parts of Devon, signifying the start of a breakdown to more unsettled conditions again in the northern & western UK. The 19th was wet in parts of SW Scotland where slow moving fronts gave Dundrennan (Dumfries & Galloway) 35mm in the 24 hours to 21Z.

On the 20th as a deep low of around 985mb moved NE across the northern UK, rather wet and windy weather affected many southern & western parts. There were mean storm force winds & gusts to 69mph at the Needles (Isle of Wight) around 0900 and similar gusts later in the day around 1800 too, with 68mph at Capel Curig. Unofficially Prawle Point (Devon) recorded a maximum gust of 63mph. Around 50mm of rain fell in 24 hour period in parts of NW Wales, Cumbria and SW Scotland with Capel Curig the wettest place officially, seeing 58mm of rain in the 24 hours to 21Z. A windsurfer in his sixties died in a Colchester hospital after being rescued by RNLI lifeboats off the coast of West Mersea, in Essex, at around midday. An Essex police spokesman said there were trying to establish the events leading up to his death. A man was drowned off Sandbanks, Poole after getting into difficulties in strong seas and a man was swept into the sea and drowned at Newquay, Cornwall on the previous day, Friday afternoon due to high waves and swell whilst two people, a mother and child also died after being swept into ther sea at Aberdeen. Later on Saturday, a woman’s body was recovered from treacherous seas off Jersey. Rescue boats from Jersey fire service and the RNLI were launched at about 8.20pm after two swimmers were reported to be in difficulty near Green Island beach. A male swimmer was rescued by a member of the public. The woman, who was in her 20s, was later recovered from the water and transported to hospital, where she died, Jersey police said. Key parts of Bournemouth airshow were called off due to the winds and swell caused by high tides. The low seemed to have a trapped wave train, (meaning the speed of the low and the speed of the waves were very similar), thus keeping the largest of the waves within the area of strongest winds within the circulation of the low, and effectively generating a long 'fetch'.

The 22nd was very warm in parts of London & the SE, Kew Gardens reached 28.6C. Wet however in the north west of England as slow moving fronts affected these parts with Levens Hall (Cumbria) seeing as much as 48mm in the 24 hours to 21Z causing localised flash flooding in places. On the 23rd as a plume of very warm air moved up from the continent it became very warm & sunny & locally hot in the south east and East Anglia where Cambridge (Cambs) reported 31.0C and hot in the Channel Isles where St Helier (Jersey) recorded 31.5C. By the 24th as the plume of very hot air moved across the south & SE especially, it became the hottest 24th August on record with 33.9C at Gravesend (Kent) and only the fourth example in 117 years of 33.9C or higher being recorded as late as the third week of August, (the others being 1906, 1930 and 1942).

The 25th was very warm or hot in parts of the east & SE where Writtle (Essex) reached 29.9C. Heavy thundery showers affected the north of England locally though, High Mowthorpe (N Yorks) saw 30mm in the 24 hours to 21Z. The 26th was very warm in places, esp in east Anglia where Writtle (Essex) reached 28.1C. The 27th was again very warm in parts of the east & SE where Frittenden (Kent) saw 28.0C reached. Thundery showers broke out mid afternoon in central south & moved NE across parts of the central south & the East Miidands later as a mesocyclone giving some heavy rain in places, Church Lawford (Warwickshire) saw 32mm in the 24 hours to 21Z. A lightning strike at Tisbury, west of Salisbury, damaged rail signalling equipment causing closure of the Salisbury/Yeovil junction route. The First Division match between Swindon and Bristol Rovers at Swindon was abandoned due to a waterlogged pitch. Hailstones the size of grapes were reported to have affected Oxford, smashing green house glass locally, setting off car alarms and forcing people to run for safety.
The 28th was quite wet in parts of the NW of Wales and central northern England where Capel Curig (Conwy) saw 33mm of rain in the 24 hours to 21Z. The 30th was a very warm & sunny day in parts of the SE with Gravesend (Kent) reaching 27.2C and the 31st was similarly warm & sunny esp in the south & east.

David Wiseman disclaimer – Issued as a non commercial ‘Not for profit’ forecast. The user assumes the entire risk related to its use of this data. I am providing this data "as is" and disclaim any and all warranties, whether express or implied, including (without limitation) any implied warranties of merchantability or fitness for a particular purpose. In no event will I, David Wiseman, or any related contactors be liable to you or to any third party for any direct, indirect, incidental, consequential, special or exemplary damages or lost profit resulting from any use or misuse of this data . Climate stats have been compiled with the partial use and help of UKMO news page data , with thanks. Other news data was compiled from many sources including UKww reports, news papers & some BBC local news reports.