************************************************************************************** MONTHLY WEATHER REPORT JULY 1999 TEXT-ONLY VERSION Hard copy versions of this report, including graphics, can be obtained from the weather station at the following address: Pitsford Hall weather station Pitsford Hall Moulton Lane Pitsford Northampton NN6 9AX Enclosing a stamped address A4 envelope. The full register can be downloaded separately to this report from this web site. If you encounter any problems in downloading data or viewing the files, please contact the station via the answerphone on 07967 438314. For official purposes, data entries should always be double checked with the station office. ************************************************************************************** Pitsford Hall Weather Station Office: Pitsford Hall Northamptonshire Grammar School Pitsford Northampton NN6 9AX Tel. 01604 880306 Fax. 01604 882212 E-mail weather@brixworth.demon.co.uk Web site http://www.brixworth.demon.co.uk/weather Registered member of the Climatological Observers Link Corporate Member of the Royal Meteorological Society Station grading: A Climatological Station No: 91012 Station Manager: M J Lewis, BSc(Hons), FRGS Observers: Christopher Cockrell Simon Fleming Benjamin Goodyear Alexander Jackman Andrew Sunderland Honorary Foundation Observers: Paul Dickens William Keggin Martin Sheehy Andrew Stanton Technician: Mrs S West Groundsman: Mr R Green Brief Climatological Summary The month was particularly warm with average temperatures well above the average for the time of year. A total of 10 days recorded maximum temperatures of 25C or more, and all but 4 days had maximum temperatures exceeding 20C. Rainfall was significantly below the average across the United Kingdom. At Pitsford Hall, a total of 12.2mm represented just 24.7% of the normal total for July. Met Office statistics showed this July to be the driest since 1911. The month was particularly sunny. Average cloud cover at observation was down to 65% and a total of 233 hours of bright sunshine were recorded with no days experiencing nil sunshine. Across the United Kingdom, this July was the sunniest since 1990. Statistical Analysis of Air and Ground Observations - July 1999 Temperatures: Mean Max: 23.9C Mean Min: 12.6C Mean Temp: 18.3C (mean comparison: +1.9C) Highest Max: 29.5C on 31st Lowest Max: 16.3C on 22nd Highest Min: 17.0C on 3rd Lowest Min: 8.1C on 23rd Relative Humidity: Humidities observed at 0830hrs: Max: 93% on 1st Min: 62% on 21st Mean: 81.0% All Humidities (hygrograph record): Max: 93% on 1st Min: 29% on 30th Rainfall: Total for Month: 12.2mm (mean comparison: 24.7%) Max: 4.7mm on 20th Rain Days: 4 Wet Days: 4 Duration: 5.75 hours Rainfall acidity: Lowest pH: 6.34 on 2nd & 4th Winds: Max Max Gust: 35mph on 27th Max wind speed at observation: 15mph on 21st Mean wind speed at observation: 5.5mph Max mean 24 hour wind speed: 9mph on 21st Mean mean 24 hour wind speed: 4.7mph Directions: north 3, northeast 5, east 1, southeast 4, south 0, southwest 5, west 4, northwest 9, calm 0, variable 0 Pressures: Max: 1026mb on 8th Min: 1000mb on 20th Mean: 1016.5mb Sunshine: Total: 233 hours Most in a day: 12.6 hours on 11th No of sunless days: 0 Cloud Cover: Mean cloud cover at observation: 65% Ground Observations: Lowest Grass Min: 4.8C on 15th Highest Grass Min: 15.2C on 20th Lowest Concrete Min: 7.7C on 23rd Highest Concrete Min: 16.4C on 3rd Earth Temperatures: Bare Earth mean: 17.7C max: 24.4C on 24th min: 12.9C on 23rd 5cm mean: 17.4C max: 20.5C on 9th min: 12.7C on 23rd 10cm mean: 17.8C max: 20.5C on 9th min: 14.6C on 23rd 20cm mean: 18.8C max: 21.0C on 9th min: 16.0C on 23rd 30cm mean: 19.4C max: 21.0C on 9th,31st min: 15.0C on 1st 40cm mean: 19.6C max: 21.0C on 13th,31st min: 17.0C on 1st 50cm mean: 19.6C max: 21.0C on 13th min: 17.1C on 2nd 100cm mean: 18.5C max: 18.5C on 30th,31st min: 16.4C on 3rd Other observations: Days with fog recorded at 0830 hours: 0 Mean visibility: 7 (good, up to 20km) Days with air frosts: 0 Duration of air frost: 0 hours Days with snow falling: 0 Days with snow lying at observation: 0 Days with hail observed: 0 Days with thunder heard: 1: 2nd, moderate. Days with lightning observed: 0 Gales: 0 United Kingdom Climatological Analysis - July 1999 After a cloudy night across most of the British Isles, with light rain at times in most places, daytime during the 1st saw cloudy and rather humid conditions over much of England and Wales. Warm sector air resulted in relative humidities during mid-afternoon being in the 70's and 80's in many places in the Midlands and S England. Rain over Scotland had largely cleared by midday, but another area of rain and drizzle pushed into S Ireland during the afternoon and then W Wales and N England during the evening. (Herne Bay 24C, Sella Ness 12C max, Baltasound 8C min, Cardinham 15mm, Guernsey 10.3h.) Rain continued to move N over N England and Ireland into S Scotland by dawn on the 2nd. There were fog patches in the humid air in S England which persisted until 0900 GMT in places; minimum temperatures in the 12 hours ending 0600 GMT included 15.4C at Shawbury, 15.1C at Waddington, 15.6C at Hemsby and 15.3C at Wittering. During the day the rain continued to move slowly N into Cent. Scotland, becoming less in time, while Cent. and S parts of England had a mainly fine but humid day. During late afternoon, however, thunderstorms occurred over SW England, and later over the Midlands, Wales, the Isle of Man and Northern Ireland. At Llansadwrn (Anglesey) moderate/heavy rain gave a total fall of 13mm in 2 hours. (London Weather Centre 29C, Loch Glascarnoch 3C, Skegness 8mm, Jersey 12.0h.) These thunderstorms spread E during the small hours of the 3rd, affecting much of the Midlands and S England before clearing the coast of East Anglia by about 1000 GMT. Many observers commented upon the brilliant lightning in these storms. Associated heavy rain led to standing water on some roads, including the A761 in Renfrewshire and the A63 in Humberside. · At Keyworth (Nottinghamshire) from 2230 to 0230 GMT today, the frequency and intensity of the lightning was amazing with 30 flashes per minute for the whole duration; 6.7mm fell at Keyworth and 9.2mm at Watnall but this fell in 10 minutes! There was flood damage at West Bridgford and Arnold (21mm here) and houses were damaged by lightning at West Bridgford and Ollerton, a sleepless night for most with a minimum of 17.2C at Keyworth. Part of the roof of Nottingham Nuffield Hospital collapsed during the storms. · There were reports of a tornado at Bloxwich, West Midlands, during the early hours. · 42.5mm fell at Reading University in the 24 hours to 0900 GMT (almost all from the the storms), while 46.2mm fell in central Reading. At nearby Mortimer, 25.8mm fell in 55 minutes from 0010 GMT - the wettest hour at the station since records began in April 1987; only 26.4 mm fell in the 24 hours ending 0900 GMT. At Wokingham, the observer noted that the start of the rain was accompanied by a wind squall to 32 mph from 260 degrees, the wind having been easterly less than 5 mph immediately before; only 15.2mm fell. The storm was indeed localised in E Berkshire; just 4.4mm fell at Bracknell. · Another wet area was Norfolk; 44mm fell at two sites in Calthorpe (where a house was struck by lightning and an anemometer broken and melted), with 45mm at Cromer. At Beverley, 12mm fell in an hour during a thunderstorm around 0400 GMT. Rain, heavy in places, continued over S Scotland during the night and morning, gradually becoming confined to Cent. Scotland by mid-afternoon. There was some some thunder in W Scotland during the morning, and outbreaks in E Scotland during the afternoon. Once the precipitation had stopped, most places in Ireland, Wales and England had a mainly cloudy day. (Gravesend 25C, Kirkwall 8C, Cromer 45mm, Folkestone 10.2h.) The area of rain and drizzle over Cent. and N. Scotland during the night continued to be slow-moving during the 4th, becoming confined mainly to N Scotland by the evening. The day was warm and cloudy over almost all the British Isles, with some intermittent light rain and showers in S England and most of Ireland; S Scotland saw more widespread showers. (Gravesend 24C, Lerwick 9C, Aberdeen 27mm, Scarborough 11.3h.) The 5th dawned with light rain still falling over N Scotland, although by the evening this was mainly confined to the Northern Isles. Overnight, skies were mainly clear over Ireland, while cloudy conditions over the remainder of the British Isles led to a warm night everywhere, with pockets of fog reported at dawn across parts of S England, the Midlands and the Isle of Man. NW Wales, parts of NW England and S Scotland had a sunny day; elsewhere temperatures soon rose and thunderstorms were reported over much of England, E Wales and parts of S Scotland, with showers over Ireland. · The storms caused widespread damage; at Rugeley (Staffordshire) there was flooding and a report of a tornado. · A tornado was also sighted at Cannock. · Another tornado in Selly Oak (Birmingham) damaged the roofs of 21 houses around 1830 GMT. · A tornado was reported near Middle Wallop around 1400 GMT. · In Lincolnshire power was lost to 4000 homes. The A59 in Harrogate was flooded and a landslide closed the A657 at the Ladybower Reservoir. In Wolverhampton flooding led to 50 homes being evacuated, and there was flodding at Sampford Peverell in mid-Devon. · Lightning struck houses in Lincoln and Grantham; at Harlaxton, Grantham, a funnel cloud was filmed and heavy hail fell at Grantham. · Local news bulletins reported flooding in S Wiltshire; Newbury, Thatcham and the surrounding area lost power for 2 hours during late afternoon. · The TV program NW tonight reported a fall of 34mm in 1 hours at Farnworth, nr. Bolton, while 27mm fell in 1 hour at Chedburgh during the afternoon. · The uk.sci.weather newsgroup also mentioned unconfirmed sightings of funnel clouds near Upavon, Ramsgate and Basingstoke. 26.8C at an unofficial station in Windermere was the highest reading there so far this year, as was 25.3C at Coventry Bablake. (Barbourne 26C, Wick 13C max, Redesdale 7C min, Middle Wallop 33mm, Morecambe 15.0h.) Overnight thunderstorms in parts of the E Midlands died down around midnight and by dawn on the 6th mist and fog patches were widespread over E and S Scotland, much of England, the Channel Islands and along Irish sea coasts. Ireland had a cloudy start with light rain in N Scotland, but minimum temperatures were not low anywhere. The fog cleared mid mid-morning in most places, and convective cloud developed over England and Wales, leading to some heavy showers with thunderstorms in the extreme SE England, East Anglia and the E Midlands. At 1715 GMT a tornado was sighted in Longbenton (Newcastle). Light rain continued to fall in NE Scotland, and after a cloudy day in Ireland rain moving E reached the SW by late evening. During the evening, lightning struck and set fire to a house in Loughton (Essex) with the result that a woman needed hospital treatment. (Gravesend 27C, Rosehearty 13C max, Shap Fell 8C min, Buxton (Derbyshire) 33mm, Aspatria 12.8h.) Pressure rose steadily across the British Isles on the 7th, as an anticyclone edged NE towards SW England; 1030 mb was reported over Cornwall and W Devon by midnight. Conditions were generally cloudy, warm and humid, with the sunniest weather over N Scotland. At Pitsford Hall (Northamptonshire) 28C was recorded. Early rain in SW Ireland moved N to affect most of Cent and N Scotland by evening; there were light falls in NW England, Devon and Cornwall, and Ireland remained cloudy with drizzle in places. (Herne Bay 26C, Sella Ness 6C, Tiree 9mm, Lerwick 12.6h.) There was some light rain overnight over Scotland and N Ireland; skies partially cleared by dawn on the 8th over areas of S England although England had a generally warm night. The anticyclone migrated to the E of the British Isles during the day; 1031.8mb was recorded in SW Wales and Cornwall at 0900 GMT. The cloud and rain over Scotland had cleared by early afternoon, and Ireland, NW Wales and Scotland then had sunny, warm weather. England remained rather cloudy until the evening, when cloud cleared from all areas except the extreme E. Fog persisted for much of the day in some coastal areas of W Wales; Aberporth reported visibility of 200m or less every 3 hours from 1200 GMT to midnight. In several places in England it was the hottest day of the year so far, with the high relative humidity (50 to 60 per cent in many places at 1500 GMT) making it feel rather unpleasant; coastal districts were, however, a little cooler. Maximum temperatures in Ireland included 25.8C at Shannon. (Barbourne 29C, Lerwick 11C, Stornoway 6mm, Swanage 12.5h.)) The 9th began with a warm night in many places; minimum temperatures (under rather cloudy skies) for the 12 hours ending 0600 GMT included 18.3C at Lyneham, 17.7C at Leeming, 17.5C at Ringway, 18.1C at Brize Norton, 18.0C at Heathrow. There was mist and fog overnight along some Irish Sea coasts and in parts of Scotland; by day Scotland, Wales and Ireland were warm and sunny while much of the E half of England was rather cloudy and humid again. Unofficial station maxima included 30.2C at Kyle of Sutherland and 29.1C at Windermere. (Prestatyn 29C, Fair Isle 15C max, Tyndrum 9C min, South Uist 1mm, Belfast 15.5h.) The 10th began with some cloud and light rain over W districts of Ireland and Scotland; this rain affected many places in Scotland during the day, with thunderstorms in SW Scotland. In a dramatic thunderstorm this afternoon at Corsock (SW Scotland) starting at about 1640 GMT, 81.6mm rain fell in 2.5 hours. Between 1650 and 1750 hours, 48.8 mm fell and at one point, the rate of rainfall was over 80mm/h. The local burn was soon in spate and local flooding occurred. A new daily rainfall total for the station was also established. At Carnwath 24mm fell in 45 mins, and in Carluke many roads were closed by floodwaters. England and Wales had a mainly sunny day, although Ireland was rather cloudy with reports of thunder during early evening in the S. With anticyclonic conditions prevailing generally, Belmullet recorded 1032.4mb at 2100 GMT. (Lee-on-Solent 28C, Leconfield 7C, Corsock 82mm, Eastbourne 15.7h.) Light rain continued over parts of Cent Scotland early on the 11th; later in the morning cloud began clearing here to give a sunny end to the day. England, Wales and Ireland had a very sunny and warm day, although an NE breeze over most of the S and E areas of England made it feel more refreshing than in previous days. News reports later in the day suggested that as many as nine people may have drowned during the 10-11th while trying to seek relief from the heat in the United Kingdom. (Lee-on-Solent 30C, Shap Fell 6C, Kinloss 2mm, Clacton 15.6h.) A weakening area of high pressure brought mainly dry weather to the whole of the British Isles on the 12th, the exceptions being Shetland and the Moray Firth area where some drizzle fell, and W coasts of Ireland where frontal rain fell shortly before midnight. After the clearance of overnight fog in parts of Northern Ireland and Scotland, most of the British Isles had a sunny day, with high temperatures in S England and the Midlands, away from the east coast. Later in the afternoon, cloud spread to W coasts of Ireland and Scotland. (Lee-on-Solent 29C, Sella Ness 14C max, Redesdale 7C min, Lerwick 0.2mm, Morecambe 16.1h.) There was little overnight cloud over E Ireland, Wales and England (away from E areas) but cloud over W Ireland and Scotland before dawn on the 13th thickened and spread SE during the day, bringing periods of rain to most areas. In SE England, rainfall amounts were small. The cloud and rain were assoctaied with fronts that introduced a fresher W to NW airflow over the country, although not before high temperatures were again recorded in SE England. (Heathrow 26C, Leconfield 8C, Barra 8mm, Bognor Regis 12.4h.) The 14th began with cloud and some precipation in parts of W Scotland, E and SE England before dawn. The rain mainly cleared before dawn over England, and during the early morning over Scotland. The British Isles then had a day of sunny interval and rain showers, the showers tending to fall in the W. During late morning a more extensive area of rain and drizzle pushed E into Cornwall, before extending across most of SW and Cent S England by mid-afternoon and later affecting parts of SE England and East Anglia. (Herne Bay 21C, Loch Glascarnoch 9C, Southend 10.2mm, Leuchars 12.1h.) Skies cleared over much of England and Wales for a while overnight, but cloud cover had increased again in many places by dawn on the 15th. Most of the British Isles then had a mainly cloudy day, with rain in parts of NE England, SW Scotland and showers over Ireland and N parts of Scotland. (Herne Bay 24C, Aboyne 5C, Spadeadam 12mm, Clacton 12.4h.) Light rain and drizzle in Cornwall in the early hours of the 16th spread to spread to other parts of SW, Cent S England and S Wales by dawn, and to N Wales during the afternoon. Rain over Ireland and W Scotland before dawn sprad to N England and the remainder of Scotland, with the `Open' golf tournament at Carnoustie being affected for the second day by gusty winds. E areas of England and the Midlands had a mainly dry, warm and sunny day. (Nottingham 25C, Fair Isle 9C, Spadeadam 9mm, Clacton 12.5h.) Rain cleared N Scotland overnight, but another extensive area of rain affected Ireland before dawn on the 17th, before affecting much of Scotland and parts of N England and N Wales during the morning and early afternoon. Rain continued to fall in parts of S Ireland for much of the day, while the S half of England and Wales remained day, and quite warm in the SE and East Anglia. (Gravesend 27C, Aboyne 5C, Isle of Skye 14mm, Cromer 12.0h.) Rain over S Ireland before dawn on the 18th moved NE to affect much of Ireland, parts of N England and N Wales, and S and Cent scotland during the day. The remainder of England and Wales remained dry and sunny, and it was warm in SE England, East Anglia and parts of the Midlands. Shortly before midnight, an area of thundery activity moved N to the E English Channel with lightning observed in Kent and Sussex. At Chipstead Valley (Surrey), the diurnal temperature range was 21.3degC (maximum 29.3C, minimum 8.0C). (Gravesend 30C, Biggar 8C, Capel Curig 15mm, Eastbourne 14.2h.) Thunderstorms continued to move NE through Sussex and Kent in the early hours of the 19th, with thunder also reported from Felixstowe; elsewhere there was rain overnight over Scotland, Ireland and W Wales. This area of rain moved slowly E and NE during the day, affecting the Midlands, SW and Cent S England and the whole of Wales by early evening. The brightest weather was consequently in the extreme SE. Light thunderstorms occurred in the Dorset area during the late evening. (Gravesend 28C, Altnaharra 6C, West Freugh 28mm, Clacton 12.1h.) Light rain and drizzle fell overnight and into the morning of the 20th across S England and East Anglia, with rain also affecting Ireland, N England and Scotland. It remained rather cloudy over much of the British isles throughout the day and while precipitation over S areas dispersed, it remained wet for most of the day over Scotland and parts of N Ireland. At Altnaharra, 16.8mm was reported to have fallen in 1 hour during heavy rain. Thunderstorms occurred in NE Scotland during the late afternoon and early evening; heavy rain fell in Caithness with the Thurso/Latheron road under water in a number of places and 36mm fell in 3 hours at Thurso. (Margate 25C, Lerwick 12C, Altnaharra 36mm, Cromer 7.9h.) Cloudy conditions continued into the night and throughout much of the 21st over the most of British Isles; overnight rain in Scotland spread S to reach N England by late evening. There were showers over Ireland, and scattered light showers over England and Wales, and a blustery NW airflow made it feel autumnal in Scotland and N England. Fog and drizzle were reported from Fair Isle for much of the day, while further S there were gales in some exposed places; reported gusts included 47kn at Malin Head, 41kn at Crosby and Dublin. (Poole 22C, Lough Fea 10C, Lusa 15mm, Lowestoft 11.2h.) The 22nd was a rather cloudy day over much of Scotland, E and SE parts of England. Overnight rain over Scotland stopped by mid-afternoon, while early rain over N England affected other areas of England and Wales during the morning with some light falls in parts of SE England during the afternoon. Following the clearance of early-morning showers, Ireland had a mainly dry and sunny day; Wales and W districts of England and Scotland had sunny spells during the afternoon before another area of cloud spread to NW Ireland and W Scotland before midnight. (Cardiff Weather Centre 21C, Loch Glascarnoch 8C, South Uist 11mm, Isle of Man 10.3h.) Mainly clear skies over much of England and Wales led to a cooler night than of late, while light rain fell in W Ireland and Scotland before dawn on the 23rd. England and Wales then had a warm and mainly sunny day, although N England, along with Scotland and Ireland was cloudy with some rain and drizzle, the rain being heaviest in Scotland. In Surrey, Chipstead Valley reported a minimum of 5.4C followed by a maximum of 25.7C - a large diurnal range. Pressure rose to 1028mb in S Wales, Devon and Cornwall during the day. (Barbourne 27C, Benson 8C, Lerwick 20mm, Fishguard 15.0h.) On the 24th cloudy conditions with light rain persisted for most of the day over Northern Ireland and Scotland, extending to S Ireland and parts of N England during the afternoon. Over England and wales it was sunny, and hot in places. At Bristol Totterdown 29.8C was recorded, the highest in the city since 22nd July 1996 when 31.8C was recorded (29.8C was also recorded on 10th August 1997). Other unofficial station maxima include 29.8C near Winchester, 30.1C at Reigate; official maxima included 29.8C at Heathrow. (Herne Bay 30C, Mumbles 7C, Isle of Skye 9mm, Newquay 15.1h.) The cloudy area over Scotland and Ireland moved further S to the rest of N England and the Midlands by dawn on the 25th, and then continued to spread further S to extend to most of the British Isles by early evening. The cloud was associated with a cold front and fresher conditions; clearing cloud over N Scotand led to afternoon sunshine there. Before the arrival of the cloud it was hot again in S England. Maxima at unofficial stations included 29C at Ermington (Devon) and 28.9C at Maidenhead, while an unofficial minimum of 5.0C occurred at Westruther (Berwickshire). (Southampton Weather Centre 30C, Sella Ness 11C max, Redesdale 6C min, Sella Ness 2mm, Bournemouth and Exmouth 14.9h.) Parts of England began the 26th with cloudy skies, and there were some slight falls of rain in parts of S England during early morning. S England, once this cloud had cleared by early afternoon, then joined most of the rest of the British Isles in having a warm and dry day, although there was a noticeable NE wind in S England. The exceptions to this sunny weather were the Northern Isles, where it remained cloudy with light drizzle at times for most of the day, and parts of East Anglia where it was cloudy in places. Earlier, the clear skies had led to a ground frost in sheltered parts of Scotland (e.g. -2C grass minimum at Aviemore, -1C at Eskdalemuir and -3.5C at Westruther); the clear skies occurred under an anticyclone with pressure rising to 1030mb in W Scotland. (Poole 25C, Sella Ness 12C max, Aviemore 2C min, Benson 0.4mm, Tiree 15.8h.) Nearly-clear anticyclonic skies prevailed over much of the British Isles on the 27th. The only exceptions to this were a cloudy region along the coast in E England, S Ireland during the afternoon, and N Scotland and the Northern Isles where some light rain and drizzle fell. Early mornign ground frost occurred in places sheltered from the NE and E wind; grass minima include -1C at Aviemore, -2C at Shawbury and -2.5C at Westruther. In S England and the Channel Islands there were gusts of 30 to 40kn in places. An unofficial station at Kyle of Sutherland recorded 27.4C. (Bishopton 25C, Glenlivet 2C, Lerwick 0.5mm, Newcastle 15.8h.) Cloud spilled inland on a E breeze to cover S and E England by dawn on the 28th; elsewhere it was a mainly clear night except in the Northern Isles (where cloud was to persist all day) and the extreme N of Scotland. Ground frosts occurred in parts of Scotland (at Westruther, the air minimum was 3.6C and the grass minimum -1.1C). Most of the British Isles than had a warm and sunny day, although cloud persisted in parts of S England, and in NE England where it gave some slight drizzle. From a caravan site near St. David's in SW Wales there was a report of "damage caused by a whirlwind - like a tornado", although this may have been a strong dust devil. (Lee-on-Solent 27C, Biggar 4C, Newcastle 0.3mm, Tiree 15.4h.) The 29th saw little cloud over the British Isles again, with warm sunny weather during the day from S England to Cent. Scotland. Exceptions to this were E and S England and E Scotland (where cloud developed from the E overnight before burning back slowly during the morning) and parts of the Northern Isles where it remained cloudy all day after some overnight fog patches). During the afternoon, high cloud spread NE across S Ireland, with more extensive lower cloud during the evening. (Poole 29C, Glenlivet 4C, South Uist 0.4mm, Stornoway 15.0h.) Overnight cloud invaded Ireland from the W, and E and S England from the E by dawn on the 30th; fog patches also formed for a while in parts of SE Scotland, NE England and the N Midlands. Most areas gradually became sunny and warm as early cloud burned back, although patchy cloud remained over much of Ireland and Scotland during the day, with some mist and fog in the Northern Isles. At the unofficial station of Bristol Totterdown 31.2C was measured. (Northolt 30C, Inverbervie 13C max, Aboyne 0C min, South Uist 0.8mm, Hunstantion 15.3h.) A continuation of the warm weather and light winds resulted in the issuing of a smog warning on the 31st. The day dawned with cloudy skies over Ireland and Scotland, mainly clear skies over England and Wales and with some patchy fog along E coasts of N England and S Scotland. Most areas away from the Northern Isles (where mist and fog lingered for most of the day) had a warm and sunny day, with some mid-level cloud development during the afternoon heralding the movement of thunderstorms N during late afternoon and evening. Thunderstorms occurred over S England and the E Midlands, and a tornado at Detling (Kent) caused minor damage at an antiques fair. At Benson 28mm fell in 1 hour during a thunderstorm, and at Crowthorne hail up to 12mm in diameter fell. At the unofficial station of Bristol Totterdown 32.1C was measured. (Barbourne 32C, Fair Isle 12C max, Aboyne 7C min, Wittering 9.4mm, Aspatria 14.5h.) Information supplied courtesy of Roger Brugge, Climatological Observers Link. A message from Roger Brugge: The Climatological Observers Link, a group of about 400 amateur meteorologists in the UK, is currently collecting monthly data for the period 1991-2000 to compile a booklet of climatological averages and extremes, following on from its successful version for the periods 1971-80 and 1981-90. I am, therefore, trying to locate as many observers (both amateur and professional) as possible, who might be interested in contributing to the project. Data on temperature, rainfall, sunshine, soil temperatures and days with certain weather types are needed. Please contact me at brugge@met.rdg.ac.uk or see the webpage at http://www.met.rdg.ac.uk/~brugge/col.html if you are interested. You do not need to be able to provide a complete 10-year period of data to help us. Roger Brugge, COL Secretary. Notable Weather Events in Northamptonshire The following report is taken from the weather station's web site 7 July Warmest day of the year so far. 28.0C recorded at Pitsford Hall. 5-12 July 8 consecutive days without rain. Substantial cracks developing on the bare earth in the ground enclosure. Earth temperatures rising to 20.9C at 50cm depth. 11 July Sunniest day recorded so far this year: 12.6 hours (Campbell-Stokes recorder). 24 July Warmest day of the year so far: 28.5C, beating last year's highest maximum. Followed by warmest night of the year: 16C, also higher than last year's highest minimum. 31 July Warmest day of the year so far: 29.5C. Culmination of the driest July in the UK since 1911. July rainfall at Pitsford saw only 12.2mm, 24.7% of the monthly average. Reports from Northants Weather Watchers Reports received from Pitsford Hall weather station's network of weather enthusiasts across Northamptonshire. The weather station is not responsible for any inaccuracy contained in these reports. They are supplied for interest only. From Jeremy Borrett : WILBY'S TOTAL MONTHLY & YEARLY RAINFALL (BETWEEN 1994 AND 1999) ______________________________________________________________________ 1994 (mm) 1995 (mm) 1996 (mm) 1997 (mm) 1998 (mm) 1999 (mm) ______________________________________________________________________ January 80 83 44 22 88 109 February 44 76 56.5 66.5 8 21 March 46 55 36.5 11.5 82 37.5 April 54 31 51.5 19 175 76 May 62 36 24.5 92.5 16 68 June 24 95 34.5 149 126 77.5 July 24 19 69 49 19 31.5 August 36 9 70.5 66 62 September 122 121 11 42 60 October 76 28 45.5 81.5 130 November 52 82 79 84 45 December 62 96 55 78 56 ______________________________________________________________________ WILBY'S AVERAGE DAILY TEMPERATURE (1995 TO 1999) ___________________________________________________________ 1995 (°C) 1996 (°C) 1997 (°C) 1998 (°C) 1999 (°C) ___________________________________________________________ January 4 3 1 5 6 February 6 5 7 9 6 March 7 4 3 7 8 April 12 12 14 10 15 May 16 12 16 19 19 June 19 19 20 17 19 July 25 21 24 20 21 August 26 21 27 25 September 19 18 21 19 October 14 13 13 11 November 6 4 9 5 December 1 2 5 6 ___________________________________________________________ WILBY'S AVERAGE AIR PRESSURE (1995 TO 1999) ___________________________________________________________ 1995 (mb) 1996 (mb) 1997 (mb) 1998 (mb) 1999 (mb) ___________________________________________________________ January 1008 1010 1024 1011 1014 February 1005 1018 1014 1022 1017 March 1009 1012 1024 1020 1008 April 1016 1016 1023 1001 1011 May 1015 1014 1015 1017 1017 June 1012 1020 1010 1013 1017 July 1013 1017 1021 1013 1019 August 1017 1024 1017 1019 September 1013 1017 1023 1012 October 1016 1014 1017 1011 November 1014 1010 1001 1016 December 1016 1015 1009 1009 ___________________________________________________________ WILBY'S AVERAGE DAILY WIND SPEED (1995 TO 1999) ________________________________________________________________ 1995 (mph) 1996 (mph) 1997 (mph) 1998 (mph) 1999 (mph) ________________________________________________________________ January 9 4 1 8 1 February 5 3 7 5 5 March 7 4 3 7 3 April 3 3 4 7 7 May 5 4 7 2 5 June 2 2 13 4 2 July 3 3 7 7 5 August 3 3 9 8 September 3 3 6 4 October 3 2 6 8 November 2 1 4 1 December 2 1 6 7 ________________________________________________________________ WILBY'S JULY 1999 MONTHLY WEATHER REPORT ======================================== This report excludes the weather data from the 3rd to the 9th of this month as I was on holiday. Wind direction -------------- North: 1 day South: 4 days East: 1 day West: 4 days North-west: 4 days North-east: 0 days South-west: 5 days South-east: 1 day Variable: 2 days Calm winds: 2 days Total: 24 days Wind speed ---------- Average wind speed (mph): 5mph Maximum wind speed (mph): 38mph (21st) Minimum wind speed (mph): 0mph (18th, 31st) Temperature ----------- Average temperature: 21°C Highest temperature: 28.3°C (24th) Lowest temperature: 10.2°C (27th) Rainfall -------- Total rainfall (mm): 31½mm Highest rainfall (mm): (5th) A neighbour told me that this date had the most rainfall so I can't confirm a total! When I returned on the 10th, a total of 27½mm of rain was recorded in my rainpot. Air pressure ------------ Average air pressure: 1019mb Highest air pressure: 1027mb (26th) Station Notes The weather station's Hook-gauge evaporimeter was brought into service at the end of July following the exceptionable period of dry weather. Records will be kept of evaporation rates from now until the autumn. They will be available on a daily and weekly basis direct from the weather station, and as monthly totals recorded in this report. Work commenced on roof repairs at Pitsford Hall during July. Roof repairs within the enclosure have already been completed, but further repairs are necessary on the roof above the station office. There will be no interuption to daily observations. Work will also include the fitting of a permanent external access ladder from the rooftop enclosure to the top roof of Pitsford Hall to allow the installation of further equipment, mainly relating to the automatic weather station. The weather station will be manned throughout the morning of 11 August to record weather phenomena associated with the solar eclipse. Only a 95% partial eclipse will be experienced in the county, yet the station has been approached to maintain a close record of events for publication in the Royal Meteorological Society's journal 'Weather'. A special eclipse report will feature in next month's weather report. Routine maintenance was conducted at the ground enclosure during July involving an inspection of all earth thermometers and the installation of stronger supporting retort stands for the insulated pattern thermometers. The 5cm thermometer was found damaged and replaced with an equivalent new instrument supplied by MetCheck, Milton Keynes. The scales on the angle-type Casella instruments were found to be badly worn and will be returned for replacement as soon as they are safe to extract from the earth plot. Appendix Weather Station Inventory (including equipment in active use as of 1 June 1999) Rooftop Enclosure and Office Standard Stevenson screen containing Mahogany mounted maximum and minimum thermometers (Casella type) Wet and dry bulb hygrometer Large pattern Stevenson screen containing Sheathed pattern maximum and minimum thermometers (UK Met Office with calibration certificates) Sheathed pattern wet and dry bulb thermometers (UK Met Office with calibration certificates) Thermograph (UK Met Office) Hair Hygrograph (UK Met Office) Campbell-Stokes Sunshine Recorder (UK Met Office MKII) Snowdon-type pattern raingauge (UK Met Office) British Association pattern raingauge (for recording rainfall acidity) Tilting syphon rainfall recorder (UK Met Office MKI) Wind vane (UK Met Office) Totalising Cup-Counter Anemometer (UK Met Office, mounted on 5m mast) Digital wind direction system (Digitar, for determination of maximum gust) Fortin-pattern mercury barometer Open-scale micro-barograph (UK Met Office) High resolution digital pH meter (Hanna) Two PC's with modem links and dedicated fax/phone line Ground Enclosure Soil thermometers (5cm, 10cm, 20cm, 30cm, 40cm, 50cm, 100cm) (Negretti and Zambra) Grass and concrete minimum thermometers (UK Met Office with calibration certificates) Hook Evaporimeter (Negretti and Zambra, used periodically) Bare Earth thermometer (Negretti and Zambra) Bare Earth Plot and Concrete Slab