************************************************************************************** MONTHLY WEATHER REPORT AUGUST 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 August began very hot with maxima generally above 25C for the first week, a maximum of 30.8C being recorded on the 1st, the hottest day of the year. Although the remainder of the month was cool with temperatures not consistently above 20C until the last week, the exceptionally hot start resulted in a mean temperature across the month 1C warmer than average. Thundery weather with some heavy downpours also marked this month. The monthly rainfall was above average. Several days recorded rainfall in excess of 10mm, with 24.2mm falling during several thunderstorms on the 25th. The last few days were, however, fairly dry. Nationally, this was the wettest and dullest August since 1992. Statistical Analysis of Air and Ground Observations - August 1999 Temperatures: Mean Max: 21.2C Mean Min: 12.4C Mean Temp: 16.8C (mean comparison: +1.0C) Highest Max: 30.8C on 1st Lowest Max: 15.5C on 10th Highest Min: 17.3C on 3rd Lowest Min: 8.0C on 17th Relative Humidity: Humidities observed at 0830hrs: Max: 99% on 25th Min: 60% on 21st Mean: 86.8% All Humidities (hygrograph record): Max: 100% on 20th Min: 27% on 1st Rainfall: Total for Month: 99.9mm (mean comparison: 142.4%) Max: 24.2mm on 25th Rain Days: 16 Wet Days: 14 Duration: 26.2 hours Rainfall acidity: Lowest pH: 5.60 on 1st Winds: Max Max Gust: 38mph on 14th Max wind speed at observation: 10mph on 15th Mean wind speed at observation: 4mph Max mean 24 hour wind speed: 6mph on 7th,14th,19th, 23rd Mean mean 24 hour wind speed: 3.5mph Directions: north 4, northeast 4, east 1, southeast 7, south 1, southwest 3, west 2, northwest 7, calm 1, variable 1 Pressures: Max: 1025mb on 21st Min: 995mb on 18th Mean: 1013.6mb Sunshine: Total: 156.8 hours Most in a day: 11.2 hours on 28th No of sunless days: 3 Cloud Cover: Mean cloud cover at observation: 74% Ground Observations: Lowest Grass Min: 4.5C on 22nd Highest Grass Min: 15.0C on 3rd Lowest Concrete Min: 6.2C on 22nd Highest Concrete Min: 16.6C on 8th Earth Temperatures: Bare Earth mean: 16.7C max: 22.4C on 14th min: 13.9C on 19th 5cm mean: 15.2C max: 20C on 2rd min: 11.6C on 22nd 10cm mean: 16.4C max: 20.5C on 3rd min: 13.3C on 22nd 20cm mean: 17.3C max: 21.4C on 3rd min: 14.5C on 20th 30cm mean: 18.1C max: 21.7C on 3rd min: 15.8C on 20th 40cm mean: 18.4C max: 21.5C on 1st-3rd min: 16.4C on 20th 50cm mean: 18.6C max: 21.4C on 3rd min: 17C on 20th-22nd 100cm mean: 17.9C max: 19C on 3rd-5th, 8th min: 17C on 22nd-25th, 27th,28th Other observations: Days with fog recorded at 0830 hours: 5 Mean visibility: 6 (moderate, up to 7km) Days with air frosts: 0 Days with ground 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: 5 Days with lightning observed: 4 Gales: 0 Evaporation (tank): 104.46mm Register of Air and Ground Observations - August 1999 1st 2nd 3rd 4th 5th 6th 7th 8th Temperatures Air Max (C) 30.8 30.5 23 26.1 25.5 25.6 19 17.5 Air Min (C) 16 15.3 17.3 12.9 15.5 13.4 14.7 15.7 Dry Bulb (C) 19.3 17.3 18 16.1 16 16 16.5 16.5 Wet Bulb (C) 16.5 15.5 17.3 15.7 15.8 15.2 16 16.2 RH (%) 81 81 90 95 95 90 95 97 Rainfall Total (mm) 1.5 _ 3.3 11.8 _ 3.6 3.7 13.8 Duration (hrs) 0.75 _ 1.45 n/a _ n/a n/a n/a Acidity (pH) 5.6 _ 6.3 6.18 _ 6.4 6.22 6.01 Winds (mph) Direction ne nw w ne sw calm se se Speed (0830) 1 2 1 1 1 0 2 9 Speed (24 hrs) 3 3 1 2 2 3 6 5 Max Gust 23 18 10 18 17 16 25 31 Pressure (mb) At 0830hrs 1024 1024 1010 1012 1009 1013 1006 1002 From 0600hrs 0 0 0 0 1 0 0 -0.5 Insolation Cloud types st cb sc cc cb sc obs sc Cloud cover 8 4 5 4 8 3 9 8 Sunshine (hrs) 6.2 7.8 0.6 6.4 9.4 2.8 0 0 Visibility 6 6 5 3 4 7 3 3 Other Ppt Snow/sleet falling _ _ _ _ _ _ _ _ Depth of snow _ _ _ _ _ _ _ _ Hail (<5mm) _ _ _ _ _ _ _ _ Hail (>/=5mm) _ _ _ _ _ _ _ _ Other Obs Thunder heard 1 _ _ _ _ _ _ _ Lightning seen 1 _ _ _ _ _ _ _ Ground Obs Grass Min (C) 12.7 12.8 15 11.7 14.2 10.6 14 11 Concrete Min (C) 14.8 14.5 15.8 13.5 16 12.5 14.4 16.6 Bare Earth (C) 19.2 18.5 19 16.5 16.7 15.4 16.7 17.1 Soil Temps 5cm 19.5 18.3 20 13.5 18 13.2 17.9 17.5 10cm 19.7 19.5 20.5 18 19 17.8 18.5 18.4 20cm 21 21 21.4 19.5 20 19.3 18.5 19 30cm 21.5 21.5 21.7 20.2 20.5 20.3 20 19.6 40cm 21.5 21.5 21.5 20.5 20.5 20.5 20.3 19.6 50cm 21 21 21.4 20.6 20.5 20.5 20 20 100cm 18.5 18.7 19 19 19 18 18.6 19 Slab 0 1 0 1 2 1 2 1 Ground Without snow 9 1 9 1 2 1 2 1 With snow _ _ _ _ _ _ _ _ 9th 10th 11th 12th 13th 14th 15th 16th Temperatures Air Max (C) 19.2 15.5 20.5 18.6 21.1 22 19.2 20.6 Air Min (C) 13.7 11.8 10.4 12.6 13.1 13.6 11 9.5 Dry Bulb (C) 15.9 12.6 13.5 13.5 14.2 16 14 13.2 Wet Bulb (C) 15.2 12.2 10.9 12.6 13.2 14 12 11.6 RH (%) 93 95 71 90 89 79 78 82 Rainfall Total (mm) 10.7 0.1 0.5 0.1 1.9 6.1 _ 3.1 Duration (hrs) n/a _ 1.25 0.25 2.75 0.5 _ 1.5 Acidity (pH) 6.37 _ _ _ 6.5 6.62 _ 6.4 Winds (mph) Direction nw ne se se e n nw nw Speed (0830) 2 7 4 1 2 9 10 1 Speed (24 hrs) 5 3 1 2 4 6 5 2 Max Gust 30 25 10 13 18 38 26 18 Pressure (mb) At 0830hrs 1003 1011 1020 1020 1015 1003 1006 1008 From 0600hrs 1 2 0 1 -0.5 0 1 0 Insolation Cloud types st sc ac st sc cu ci,cu cc,cu Cloud cover 8 8 3 8 8 7 2 2 Sunshine (hrs) 0.8 0.3 7.8 1 2.1 9.1 9.1 7.6 Visibility 5 7 8 5 5 8 8 8 Other Ppt Snow/sleet falling _ _ _ _ _ _ _ _ Depth of snow _ _ _ _ _ _ _ _ Hail (<5mm) _ _ _ _ _ _ _ _ Hail (>/=5mm) _ _ _ _ _ _ _ _ Other Obs Thunder heard _ _ _ _ _ 2 _ 1 Lightning seen _ _ _ _ _ 2 _ 1 Ground Obs Grass Min (C) 13.9 13 8.2 12.3 12.8 13.1 8 5.9 Concrete Min (C) 14.4 13.1 10.3 13 13.6 13.9 9.3 8.1 Bare Earth (C) 17 14.3 16.1 14.7 14.7 22.4 16.5 15.4 Soil Temps 5cm 16.5 15.6 14.1 15.7 15.2 16.4 13.4 13.7 10cm 17.3 16.7 15.5 16.8 16.4 17 15 14.9 20cm 17.9 17.7 16.5 17.5 17.2 17.5 16.5 16.1 30cm 18.6 18.5 17.6 18.2 18 18.1 17.6 17.2 40cm 19 18.9 18.1 18.4 18.3 18.2 18 17.7 50cm 19.4 19.1 18.5 18.6 18.6 18.5 18.4 18.2 100cm 18.8 18.6 18.4 18.4 18.3 18.1 18 18 Slab 0 2 0 1 1 0 0 0 Ground Without snow 1 1 1 1 1 1 1 1 With snow _ _ _ _ _ _ _ _ 17th 18th 19th 20th 21st 22nd 23rd 24th Temperatures Air Max (C) 16.8 20 16.2 18.9 19 19.7 21.5 17.8 Air Min (C) 8 11 11.3 8.2 9.2 9.4 10.8 11.4 Dry Bulb (C) 11.1 13.9 13 13.4 12.7 11 13.5 14.7 Wet Bulb (C) 10.6 13.2 11.7 11.7 9.2 9.5 11.7 13.4 RH (%) 94 92 85 81 60 81 80 86 Rainfall Total (mm) 3.5 5.5 0.1 _ _ 0.2 _ 5.3 Duration (hrs) 1.5 4.75 _ _ _ 0.25 _ 7.75 Acidity (pH) 6.39 6.28 _ _ _ _ _ 6.36 Winds (mph) Direction w sw n ne nw se se se Speed (0830) 2 1 10 7 7 7 7 6 Speed (24 hrs) 3 5 6 4 4 4 6 5 Max Gust 20 27 26 21 21 21 22 26 Pressure (mb) At 0830hrs 1005 996 1006 1020 1025 1024 1019 1018 From 0600hrs -0.5 0 2.5 1.5 1 0 0 0 Insolation Cloud types sc,ac sc sc cu clear ci ac,sc st Cloud cover 7 8 8 3 0 2 6 8 Sunshine (hrs) 2.2 3.5 1.8 8.4 10.8 8.5 8 0 Visibility 6 7 7 7 9 8 8 7 Other Ppt Snow/sleet falling _ _ _ _ _ _ _ _ Depth of snow _ _ _ _ _ _ _ _ Hail (<5mm) _ _ _ _ _ _ _ _ Hail (>/=5mm) _ _ _ _ _ _ _ _ Other Obs Thunder heard _ 2 _ _ _ _ _ _ Lightning seen _ _ _ _ _ _ _ _ Ground Obs Grass Min (C) 5.1 9.7 9.5 4.8 5.8 4.5 8 8.4 Concrete Min (C) 7.5 11.2 10.9 6.7 7.6 6.2 8.6 10.7 Bare Earth (C) 14.4 15.5 13.9 16.3 16.5 15.4 14.5 16.1 Soil Temps 5cm 12.7 14.5 13.7 12.1 12.4 11.6 14.2 14.7 10cm 14.2 15.4 14.8 13.4 13.8 13.3 15.2 15.5 20cm 15.6 16 15.5 14.5 14.9 14.9 16.1 16.4 30cm 16.8 16.7 16.5 15.8 16 16.1 16.8 17.2 40cm 17.5 17.1 16.9 16.4 16.5 16.6 16.9 17.4 50cm 18 17.5 17.3 17 17 17 17.2 17.6 100cm 17.8 17.6 17.6 17.4 17.1 17 17 17 Slab 0 0 1 0 0 0 1 0 Ground Without snow 1 1 1 1 1 1 1 9 With snow _ _ _ _ _ _ _ _ 25th 26th 27th 28th 29th 30th 31st Temperatures Air Max (C) 21.2 20.7 20.6 23.8 23 21.2 20.9 Air Min (C) 13.6 15.4 11.1 11.4 12.3 12.1 12.7 Dry Bulb (C) 15.5 16.7 15 14.3 15.1 14.6 15.2 Wet Bulb (C) 15.4 16.2 13.9 13.7 14.2 12.9 13.9 RH (%) 99 95 88 93 90 81 86 Rainfall Total (mm) 24.2 0.1 _ _ _ _ _ Duration (hrs) 3.5 0 _ _ _ _ _ Acidity (pH) 6.33 _ _ _ _ _ _ Winds (mph) Direction s var n nw sw nw n Speed (0830) 3 8 4 3 1 1 4 Speed (24 hrs) 2 4 3 2 3 4 2 Max Gust 14 18 20 13 16 20 14 Pressure (mb) At 0830hrs 1013 1010 1018 1023 1021 1020 1018 From 0600hrs -0.5 1 2 0.5 0 1 0 Insolation Cloud types sc sc sc ac,cs ac,ci ci ac Cloud cover 8 8 7 4 6 4 8 Sunshine (hrs) 1 4.5 9 11.2 6.9 9.1 0.9 Visibility 4 7 7 6 5 8 7 Other Ppt Snow/sleet falling _ _ _ _ _ _ _ Depth of snow _ _ _ _ _ _ _ Hail (<5mm) _ _ _ _ _ _ _ Hail (>/=5mm) _ _ _ _ _ _ _ Other Obs Thunder heard 2 _ _ _ _ _ _ Lightning seen 2 _ _ _ _ _ _ Ground Obs Grass Min (C) 13 13.3 9.1 9.1 8.8 9.6 9.5 Concrete Min (C) 14.2 14.7 10.1 10 10.9 11.8 12.3 Bare Earth (C) 16.5 17.3 15.7 18.3 20 19.4 16.7 Soil Temps 5cm 15.7 16.5 13.8 13.8 14.7 15.2 15.7 10cm 16.1 16.9 14.9 15 15.6 16.1 16.6 20cm 16.5 17.2 15.9 16 16.6 17 17.4 30cm 17 17.5 16.9 17.1 17.5 17.6 17.9 40cm 17.1 17.4 17.2 17.3 17.6 17.8 18 50cm 17.4 17.5 17.5 17.6 17.9 18 18.2 100cm 17 17.1 17 17 17.1 17.3 17.3 Slab 1 1 0 0 0 0 0 Ground Without snow 1 1 1 1 1 0 9 With snow _ _ _ _ _ _ _ Cloud, Visibility and Ground Observation Codes Standard cloud types Cirrus Ci Cirrocumulus Cc Cirrostratus Cs Altocumulus Ac Altostratus As Nimbostratus Ns Stratocumulus Sc Stratus St Cumulus Cu Cumulonimbus Cb Visibility codes X Dense Fog <20m E Dense Fog up to 20m 0 Thick Fog up to 40m 1 Thick Fog up to 100m 2 Fog up to 200m 3 Moderate Fog up to 400m 4 Very poor visibility up to 1000m 5 Poor visibility up to 2km 6 Moderate visibility up to 7km 7 Good visibility up to 20km 8 Very good visibility up to 30km 9 Excellent visibility 40km Ground Observations Without snow Surface dry (without cracks) 0 Surface moist 1 Surface wet (with puddles) 2 Surface flooded 3 Surface frozen 4 Glaze on ground 5 Surface partly covered in dry dust 6 Surface covered in dry dust 7 Thick covering of dry dust 8 Surface very dry with cracks 9 With snow Ground mostly ice covered 0 Wet/compact snow covering < half 1 Wet/compact snow covering half 2 Ground evenly covered by wet/compact snow 3 Ground unevenly covered by wet/compact snow 4 Dry/loose snow covering < half 5 Dry/loose snow covering half 6 Ground evenly covered by dry/loose snow 7 Ground unevenly covered by dry/loose snow 8 Complete snow cover, drifting 9 Observations of the Concrete Slab Dry 0 Moist 1 Wet 2 Icy 3 United Kingdom Climatological Analysis - August 1999 The 1st dawned cloudy in S England, with fog patches in the Northern Isles and in parts of N England and Ireland. Patchy cloud persisted over Ireland during the day; much of England and S Scotland had another warm day - the hottest day of the year so far in many places with temperatures of 30C or more from S England to Lincolnshire. Over England, N Wales and SW Scotland there were widespread thunderstorms during the afternoon and evening. In Pendleford, near Wolverhampton, there were flash floods for the second time in 4 weeks, with water 1.5m deep in places. At Edgmond, 43.9mm feel during a storm from 1234 to 1440 GMT, with 5 to 8 mm diameter hail falling. (Heathrow 32.7C, Leuchars 15C max, Aviemore 8C min, Edgmond 44mm, Aberdeen 14.8h.) Minimum temperatures at 0600 GMT on the 2nd included 18.1C at Manston, 17.0C at Wattisham, 18.8C at Heathrow and 17.2C at Ferryhill. There was some light rain and showers overnight in Ireland, and cloud and fog formed along N and E costal areas of Scotland and N England. After a cloudy day over much of Wales and the S half of England, thunderstorms occurred during the afternoon and evening in Cent S England, W Midlands, N Wales and N England and into SW Scotland. These storms were heavy in places, with power cuts in places. Ireland remained mainly cloudy during the day with rain at times, with Scotland and E England remaining mainly dry. During late evening, an area of rain began to affect parts of S England. (Honington 32.7C, Fair Isle 17C max, Aboyne 7C min, Eskdalemuir 15.0mm, Cleethorpes 13.8h.) Rain spread to most parts of S England, W Midlands, Wales and Northern Ireland by 0900 GMT on the 3rd, and later spread to parts of N England and East Anglia. There were thunderstorms in East Anglia during the late afternoon. After a cloudy start in Scotland, with fog in E coastal districts, much of N and Cent. Scotland had a sunny day, although it remained cloudy in the S. The warmest temperatures occurred over inland areas of Scotland and N England; over much of England it was a humid day with dew points of 17C and more being widespread during the afternoon. 26.3C was recorded at Stornoway, the highest temperature there since records began in 1871, while 24.2C was recorded at Sella Ness. (Topcliffe 29C, Valley 17C max, Glenlivet 9C min, Belfast 32mm, Lerwick 14.4h.) Fog patches formed before dawn on the 4th over oastal disricts of SE Scotland, and in parts of N England, the Midlands and East Anglia. Other areas started off mainly dry, except in SW Ireland. Most of the British Isles, except for Cent. and N scotland had a mainly cloudy, warm and humid day with rain in SW England during the morning moving E and N during the day. by midnight rain, heavy in places, was falling in the N half of Ireland, England and Wales, leading to some flooded roads, and across much S England. Thunderstorms occurred during the evening over SE England, and parts of the Midlands, S Wales and SW Scotland. (Herne Bay 26C, Fair Isle 14C max, Sella Ness 6C min, Tiree 9mm, Lerwick 12.6h.) England, Wales and Ireland had a wet, misty and humid night, with clearer conditions in N parts of Scotland. Minimum temperatures on the 5th were quite high in parts of England and Wales, e.g. 16.9C at Ronaldsway, 16.8C at Valley, 17.0C at Ringway, 17.5C at Heathrow, 17.7C at Manston. As the area of rain in the S moved N, it brightened up in S England; waterspouts were reported around Lands End at about 0900 GMT. Thunderstorms occurred in parts of Cent. Ireland and N England during the afternoon and evening. (Gravesend 27C, Glenlivet 6C, Fishguard 47mm, Stornoway 13.3h.) Overnight cloud and rain over much of Scotland, SW England and SW Ireland spread to remaining parts of the British Isles by mid-afternoon on the 6th, with skies clearing a little over Scotland. Rainfall was heavy in SW England. There were thunderstorms over W Ireland during the late afternoon and evening. (London 28C, Fair Isle 15C max, Shap Fell 7C min, Cardinham 28mm, Norwich 13.4h.) The 7th was a cloudy and rather wet day over many parts of the British Isles, although N Scotland remained mainly dry and NW Scotland had the best of the sunshine. There were early morning coastal fog patches in SW England and S Wales, and during the afternoon it turned dry over S England, Wales and most of Ireland. (Bristol Weather Centre 26C, Fair Isle, Spadeadam 14C max, Glenlivet 1C min, Aberdaron 57mm, Stornoway 11.9h.) The 8th was a day of heavy rain over many areas of S England and the Midlands; thunder occurred in S wales, S England and east Anglia during the afternoon and evening, with a tornado reported at Farnborough. 46mm of rain fell in 3 hours at Coleshill, with over 60mm at Coventry (the wettest August day there on record); some parts close by received less than 10mm. Other areas of the British Isles were mainly cloudy, with rain in S Ireland, parts of Wales and Cent. Scotland. Floodwater was reported to be 30 cm deep in Brighton during the evening. (Herne Bay 25C, Stathallan 6C, High Wycombe 44mm, Falmouth 11.1h.) The 9th dawned cloudy in most places. fronts associated with a depression off SW England (moving along the English Channel during the day) brought more heavy, thundery rain to England and Wales, There was flooding in Staffordshire, Norfolk and Sussex. The rainfall total for Necton (Norfolk) amounted to 114.3mm in less than 2 days. Radio Norfolk reported that during a late morning storm 43 mm of rain had fallen in one hour at Lowestoft and there was severe flooding in the town. People took shelter in the local cinema until the water burst through the doors and came into that as well. A man was killed by lightning at Reydon near Southwold while fishing with his family. While parts of S England and the Midlands have already had over 100mm in the first 9 days of August (or twice the August average), parts of Northern Scotland (including Fair Isle) have seen no rain since 27th July. Thunderstorms were confined to East Anglia, the E Midlands, Cent. and SE England, and a tornado was sighted at Larkhill. At Mortimer (Berkshire) the 24-hour rainfall total commencing 0900 GMT was 57.1 mm; this is the highest daily fall since 6 August 1982, when 58.4 mm fell. (Herne Bay 27C, Aviemore 11C max, Loch Glascarnoch 7C min, Birmingham 50mm, Herne Bay 12.9h.) Rainfall over England and Wales gradually cleared to the E during the 10th. Other parts of the British Isles were mainly dry as a weak ridge developed over W districts. A tornado was reported in Wisbech. The sunniest and warmest weather of the day occurred in Cornwall, Devon and W Scotland, while during late afternoon there were sferics reported over Kent. (Penzance 22C, Lerwick 12C max, Saughall 2C min, Hemsby 63mm, Tiree 12.6h.) The weak ridge extended to most of the British Isles on the 11th to give a mainly dry day in most places, although a depression approaching SW Ireland brought some rain to S Ireland and SW England later in the day. There was dissapointing cloudcover for those observing the full solar eclipse in SW England; parts of the Channel Isles had the best views while further north a 90-95 per cent eclipse was viewed in many places with bright skies. A notable temperature drop was recorded in places such as Northampton. (Northolt 21C, Sella Ness 12C max, Altnaharra -1C min, Margate 5mm, Cromer 10.5h.) Pressure rose to 1023 mbar in N Scotland early on the 12th and it dawned mainly clear in Scotland, W England and Ireland. Rain fell in parts of E and SE England, and as pressure fell steadily over Scotland it clouded over there with rain over Ireland and much of Scotland by midnight. A funnel cloud was observed at Swales. (Mumbles 23C, Sella Ness 13C max, Altnaharra -1C min, Cranwell 18mm, Margate 12.0h.) The 13th was a generally cloudy day everywhere, with most places seeing some rain during the day as fronts and troughs moved E. Thunderstorms occurred over NW, E and NE England and in parts of S and E Scotland, mainly during the evening. (Gravesend 23C, Lerwick 12C max, Baltasound 9C min, Stornoway 19mm, Eastbourne 8.0h.) Low pressure over Scotland on the 14th resulted in some rain there during the day. Elsewhere there were sunny spells and thundery showers. Hail fell at Bedford, and a thunderstorm in Norfolk gave 15mm in as many minutes at Norwich. Thunderstorms were widely observed over much of England (away from S coast counties), E Ireland and SE Scotland during afternoon and evening. At Dun Laoghaire 11mm fell in 40 minutes during a thunderstorm. (Poole 23C, Altnaharra 9C, Scarborough 24mm, Oxford 9.6h.) There were further showers over Scotland on the 15th, although much of England, Wales and Ireland was dry with sunny spells. There were some exceptions to this, however, for example a band of rain (with thunderstorms in Kent) affected S England during the afternoon and evening. (Heathrow 21C, Wick 7C, Tain Range 21mm, Anglesey 11.0h.) Skies clearly overnight in most areas as the showers died down, but by 0600 GMT on the 16th much of S England had turned cloudy again. The westerly airstream brought showers to many areas of the British Isles during the day, these being heavy and thundery generally S of a line from Liverpool-Hull. Thunder was also reported in Northern Ireland and in parts of NE England. A tornado was reported from Gwent, while thunderstorms knocked out Essex FM's transmitter in Southend-on-Sea. Overnight, the Sunderland Lifeboat had been called out when explosions were heard and flares seen at sea, but these turned out to be attributable to an electrical storm and a meteor shower. (Great Malvern 22C, Benson 6C, Shoeburyness 18mm, Fishguard 12.2h.) Skies cleared for a while in most areas before dawn on the 17th, except in parts of Cent. and N Scotland where there was further rain. However, a depression moved across SW Ireland later in the day, with associated fronts bringing a band of rain that moved NE, affecting most of Ireland, England, Wales and S Scotland before midnight. The rain was followed by heavy showers, these being thundery in many places. Thunderstorms N and E of Dublin produced a funnel cloud in Co. Cavan. The extreme N Scotland remained mainly dry and sunny. At Westruther (Berwickshire), after a cool night (air minimum 2.0C, grass minimum -2.8C) there was heavy rain during the afternoon and overnight (in 16 hours from 1530 GMT 30.4mm fell). Air pressure fell to 991.9mb at Shannon Airport at 1800 GMT. (Penzance 21C, Westruther 2C, Penzance 23mm, Lerwick 11.0h.) The weather on the 18th was dominated by the passage of a slowly-filling depression from SW Ireland to sea area Tyne. Overnight rain over Cent. and S Scotland retreated slowly E during the morning; thereafter there was heavy rain in parts of NE England and SE Scotland. Over England, Wales and Ireland there were widespread, heavy showers and thunderstorms; S and Cent. Scotland were also affected by showers, but the extreme N remained mainly dry. Hail fell from some of the storms. A golfer was killed after being struck by lightning on a golf course in Chigwell (Essex). In Hampton (Middlesex) a tornado ripped the roof off a social club, and another tornado in the Battle and Sedlescombe area of Sussex damaged roofs and a campsite. In Newcastle, lightning blew up an alarm and scorched a house. At 1045 GMT a tornado was also reported near Brize Norton. (Torquay 21C, Eskmeals 8C, Newcastle 56mm, Fishguard 10.9h.) Overnight rain and showers over Cent. S England and E districts of England and Scotland on the 19th gradually became confined to N parts of East Anglia, NE England, SE and come central parts of Scotland as pressure rose gradually over the British Isles. This rise was associated with the approach of an Atlantic anticyclone, and a N airflow over the British Isles. Sferics were reported in the early hours of the morning from Sussex to Suffolk, and there were occasional showers over W Ireland and N Scotland during the afternoon. At around 1630 GMT two waterspouts were observed over the English Channel between Calais and Dover - about 8-10 km from the ferry lanes. (Cardiff 23C, Saughall 4C, Boulmer 26mm, Ross-on-Wye 12.9h.) High pressure continued to spread over the British Isles from the W on the 20th. Overnight there was a band of cloud and rain over N East Anglia, NE and E England, with this rain persisting until afternoon. Elsewhere it was generally dry and except for some light rain in Cent. Scotland and some cloudy spells in parts of S England. Pressure reached 1028mb over W Scotland at 2100 GMT. (Poole 23C, Pembrey Sands 4C, Marham 6mm, Tenby 13.7h.) The 21st was dry almost everywhere as high pressure continued to persist. An E airflow (westerly over extreme N Scotland) kept temperatures low considering the prolonged sunshine away from E coast districts; and clear skies resulted in a cold night in places. Pressure rose to 1028mb over W and Cent. Scotland at 0000 GMT. Before midnight frontal rain began falling in Cornwall. A small whirlwind was observed A508 Pitsford and Brixworth (Northamptonshire) at around 1145 GMT; a small vortex carrying leaves/straw etc. up to 10m height followed the main carriageway southwards. (Jersey 23C, Glenlivet 0C, Skegness 0.7mm, Tiree 14.0h.) The influence of high pressure persisted over most of the British Isles throughout the 22nd with an E airflow over Ireland, England and Wales. Parts of Cent. Scotland had an air frost before dawn, and broadly speaking it may have been the coldest August night of the last 50 years or so; at Luton 2.8C was the lowest August minimum since 1940. Other minima included Aviemore 0.0C, Westruther 1.0C, Eskdalemuir 1.9C, Copley 1.6C, Durham 2.7C, Redesdale 0.4C. However, an advancing area of low pressure SW of Ireland pushed frontal cloud over much of England, Wales and Ireland during the day, with rain falling in S Ireland, S Wales and SW England. Over Scotland, away from the E coast, it remained generally sunny; 24.3C at the unofficial site of Kyle of Sutherland. (Jersey 23C, Tulloch Bridge -1C, St. Mary's Scilly 27mm, Tiree 14.2h.) The anticyclone over N areas of the British Isles weakened during the 23rd, but not before clear skies over had resulted in another cool night over central parts of Scotland. At Westruther the minimum air temperature was -0.4C, with a grass minimum of -6.0C. Further S it was a mainly cloudy night, and it remained cloudy during the day over most of England, Wales and Ireland with overnight rain in the SW England lasting until late morning. Rain in S Ireland led to a few mist patches and some coastal fog. Although the Northern Isles remained cloudy until late afternoon, the best of the sunshine was in W and N districts of Scotland. Lightning was observed at Valentia around 2100 GMT. (Southampton 24C, Lerwick 13C max, Westruther -0.4C min, Pembrey Sands 10.0mm, Stornoway 14.2h.) Low pressure to the SW of the British Isles resulted in the 24th being generally cloudy over most of England, Wales and Ireland; overnight rain in S Ireland, SW England and S Wales moved slowly N and E during the day to Northern Ireland, N Midland and East Anglia. After a clear start with ground frost in sheltered areas, Scotland was mainly dry and sunny. Thunderstorms occurred during the late evening over W Ireland; heavy rainfall during the day led to flood warnings being issued for S and SE Ireland and 12-hour rainfall totals of 15mm at Belmullet (starting 0600 GMT), 14mm at Cork Airport and 17mm at Casement Aerodrome (both starting 1800 GMT). (Jersey 25C, Fair Isle, Lerwick 14C max, Aboyne -1C min, Culdrose 30mm, Kinloss 14.0h.) The 25th was a mainly cloudy day in many areas. A depression moved NE to the W of Britain with bands of rain, thundery in many areas of England, Wales and Ireland, moving generally NE. It ws quite warm in parts of East Anglia and SE England. There was a significant fall of dust rain in showers at about 1400 GMT (possibly also in the morning's rain about 1030 GMT) in both Bracknell and Stratfield Mortimer. (Honington 27C, Altnaharra 3C, Milford Haven 68mm, Stornoway 8.8h.) Overnight (in places thundery) rain over Scotland and NE England cleared during the morning of the 26th except for some areas of W Scotland where it persisted until the evening; there was also rain over Ireland and parts of England during the morning with showers during the afternoon. It was a mainly cloudy day over the British Isles, although cloud cleared over much of Ireland during the evening. (No extremes currently available.) The 27th saw the development of high pressure over S England. Cloud spread across Ireland before dawn and there was some light rain here later in the day. Scotland was cloudy for most of the day with rain in places; after a dull start cloud cleared over most of England and Wales during the day. (No extremes currently available.) An anticyclone passed over the British Isles during the 28th, with pressure rising to 1025 mb over parts of S Wales and SW England. Light winds resulted in some overnight fog in SW and Cent S England; this soon cleared and most of England, Wales and S Scotland had a sunny day. Ireland clouded over during the day as further fronts approached from the W, while N Scotland was rather cloudy with some fog and light precipitation in the Northern Isles. (London 26C, Eskdalemuir 5C, Lerwick 2mm, Hove 13.3h.) Widespread fog formed over S England and the Midlands by dawn on the 29th. This cleared as cloud spread from the W to most places. Cloud spread over Ireland and Scotland during the night with early rain in W Scotland and W Ireland moving E to affect N England and most of Scotland during the day. Hail was reported from Kirkwall at 1800 GMT, while during the evening there was some light rain and fog in SW England. (Gravesend 25C, Redesdale 6C, Stornoway 3mm, Folkestone 12.4h.) On the 30th cloud affected much of Scotland, and the N half of Ireland, and N England. Wales, S England and the Midlands had sunny spells, following the clearance of overnight fog from parts of S Wales, SW and Cent S England. (Southampton 24C, Topcliffe 6C, Tiree 13mm, Torquay 11.1h.) A ridge of high pressure built over England, Wales and S Ireland during the 31th, leading to mainly dry but cloudy conditions here. Light rain and drizzle continued to affect much of Scotland and N Ireland. (Gravesend 25C, Baltasound 6C, Tiree 5mm, Jersey 11.4h.) Information supplied courtesy of Roger Brugge, Climatological Observers Link. Notable Weather Events in Northamptonshire The following report is taken from the weather station's web site 1 August Hottest day of the year: 30.8C recorded, followed by night-time minimum of 15.3C. Maximum on the 2nd: 30.5C, culminating in thundery activity at 18.00 hours, but no rainfall. Cumulonimbus development at morning observation on the 2nd. 3 August Warmest night of the year: 17.3C recorded at morning observation. Relative humidity recorded at 90%, visibility reduced to 2km owing to dense haze. 8 August 13.8mm rainfall recorded leading to localised flooding in Northampton on the 9th in the Bedford and Cliftonville Road areas. Rainfall in Northampton substantially less than that recorded in other parts of the Midlands and East Anglia where 24 hour totals up to 60mm were recorded. 11 August 94.20% partial solar eclipse at 11.19BST. Significant effects on local weather patterns from first contact at 10.03am. Phase of maximum eclipse saw drop in temperature (1.8C), increase in relative humidity (9%), reduction in light intensity (1.8% of pre-eclipse levels), variations in cloud types and cover (notable absence of convective cumulus and development of high level clouds), reduction in barometric pressure (0.4mb), reduction in wind speed and sudden reversal of wind direction prior to maximum eclipse. A full eclipse weather report is available on this web site. 21 August Small whirlwind observed today on the A508 Northampton to Market Harborough Road between Pitsford and Brixworth at around 12.45pm. Small vortex carrying leaves/straw etc. up to 10m height and following the main carriageway southwards. Cars slowed down to watch. 25 August Torrential rainfall accompanied by moderate thunder and lightning causes traffic chaos in Northampton. Two major downpours (15.50-16.45BST and 17.25-17.45BST) causes localised flooding on major commuter routes out of town and reduced visibilities to 15m. Maximum rainfall intensity recorded at Pitsford Hall 23.2mm/hr. Total rainfall (0830 on 25th to 0830 on 26th) 24.2mm, 21.6mm falling between 15.50 and 17.45BST. Thunder Report Date Start Finish Lightning Other Remarks 1 August 1999 18:30 19:20 Yes 14 August 1999 15:45 16:20 Yes Significant activity in vicinity of 17:45 18:05 Yes station 16 August 1999 17:35 17:55 Yes Storm passed through quickly with little rain 18 August 1999 13:30 13:40 No Very distant thunder, no lightning detected 17:00 17:50 No Very distant thunder. Sharp heavy showers. No lightning detected. 25 August 1999 16:05 16:25 Yes Torrential rain until 17:00 17:25 17:30 Yes Special Report on the Solar Eclipse of 11 August 1999 The solar eclipse of 11 August 1999 was the first total solar eclipse to be seen on the United Kingdom mainland since 1927. Although the total eclipse (complete coverage of the solar disc by the moon) was only experienced in Devon and Cornwall, Northamptonshire had a maximum 94.2% partial eclipse at 11.19am, 8 minutes after the total eclipse in the West Country. Unfortunately for Cornwall, the day started dull and overcast with rain spreading from the west such that views of the eclipse were restricted to further east in Devon. Northamptonshire meanwhile began the day with broken cloud and, although partial, good views of the eclipse were possible from first contact at 10.03 to maximum eclipse at 11.19. The weather chart shows the weather system 'S' over the Atlantic which did so much to destroy the eclipse in Cornwall, whilst central and eastern parts of the United Kingdom had clearer skies within a weak high pressure system. The absence of significant cloud enabled the weather station at Pitsford Hall to monitor some significant changes in weather patterns during and immediately before and after the eclipse. These changes were far more significant than had been anticipated with notable perturbations occuring in temperatures, relative humidities, wind strength and direction, barometric pressure and light intensity. Temperature and Vapour Pressure The fall of temperature during an eclipse is clearly defined. Temperatures start to fall shortly after first contact and reach a minimum between 2 and 20 minutes after totality or maximum eclipse. The graph shows that up to 1045 a steady increase in temperature was experienced to a maximum of 16.2C, the drop at 1000 associated with increasing cloud cover. From 1045 the decrease in temperature was noticeable reaching a minimum of 14.6C at 1130, 11 minutes after maximum eclipse. The recovery of temperature was then quite rapid with pre-eclipse values reached at 1200. The variation of water vapour pressure during the different phases of the eclipse was striking and confirms observations made elsewhere. It has been reported that there is an increase in vapour pressure at around 50 minutes preceding totality. Although the rapid increase in vapour pressure recorded at 1000 may be due mainly to the fall in air temperature at that time, the graph clearly shows that the vapour pressure did rise steadily up to the point of maximum eclipse at 1119. The tendency for a minimum to coincide with totality or maximum eclipse was not observed here, although a minimum vapour pressure was recorded shortly afterwards at 1130. Furthermore, the observations of a second maximum some 30 minutes after totality were also confirmed here with a marked peak in vapour pressure recorded at 1145. Vapour pressure during an eclipse may vary as cooling tends to stabilise the lower atmosphere preventing the dispersion of water vapour added through evaporation. Thus an increase in vapour pressure on the approach of totality or maximum partial eclipse can be expected. Relative Humidity During an eclipse the relative humidity is expected to increase for two reasons. Firstly, cooling air approaches saturation, and secondly the water vapour pressure increases due to evaporation causing the relative humidity to increase. The graph shows that at Pitsford, relative humidity remained largely constant until 1100, increasing during and immediately after maximum eclipse and then falling after 1145. Clouds - Type and Coverage The main effect of eclipse cooling is to prevent the formation of convective cloud. At Pitsford Hall, the rise in temperature up until 1045 was clearly seen in the presence of cumulus as the dominant cloud type, with altocumulus developing from 5 to 6 oktas between 1000 and 1030. From 1100 and through maximum eclipse, cumulus clouds had disappeared completely leaving the higher level altocumulus which had formed an extensive blanket at 7oktas. The progressive increase in higher level cloud during an eclipse is well documented and is believed to be caused by cooling of moist layers of the atmosphere at height as the lunar shadow approaches. By 1145, cloud types had changed dramatically; altocumulus having lifted to cirrocumulus and convective cumulus having returned under the marked increase in temperature which marked the post-eclipse phase. Light Intensity The dimunition of light intensity at Pitsford Hall was more striking than was antipated. Light dimunition is generally gradual in the early stages following first contact, but is rapid around totality or maximum eclipse. The graph shows that the first significant dimunition occurred around 1030, 27 minutes after first contact and reached a minimum (1.8% of the pre-contact light intensity) at maximum eclipse (1119). Recovery of light levels was then rapid. By 1045 the dimunition of light had caused a significant sharpening of shadows and had resulted in fooling local songbirds into an evening chorus. Atmospheric Pressure The variation in atmospheric pressure is not noticeable with conventional aneroid barometers. However, precise measurements of pressure using a mercurial barometer reveals a number of interesting changes. The graph of pressure readings at Pitsford Hall reveals maxima and minima around the eclipse phases. The pressure readings obtained from the mercurial barometer are uncorrected for gravity and give pressure at station level (125m). The graph reveals a marked increase in pressure from 1000 to 1045, i.e. in the phase immediately following first contact, then a gradual reduction in pressure through maximum eclipse until 1145 when pressure stabilises and rises again. Again, the fall in pressure during a partial eclipse is well documented and this has coined the term 'eclipse cyclone'. Winds The drop in wind speed on the approach of maximum eclipse is also well documented and tends to be as marked as the reduction in temperature. The time of maximum eclipse tends to be marked by a lull. There is often a change in wind direction. Both these changes were observed at Pitsford Hall. The graph clearly shows the lull between 1119 and 1145, but a dramatic increase in wind speed from 1200 to 1215. Such large increases in wind velocity are termed eclipse 'gust fronts' and occur roughly 40-50 minutes before and after totality or maximum eclipse. The short peak in wind strength at 1030 may thus have been associated with the pre-eclipse gust front. The prevailing wind direction, as determined by the broader pattern of isobars on the 11th, was from the south-east. Thus the graph shows a consistent south-easterly until 1100, but then the wind was observed to swing round to the north-west immediately before the lull at maximum eclipse. Such eclipse winds have received some attention and may be due to the subtle variations in pressure associated with the eclipse cyclone. However, in a recent article in 'Weather' magazine, such eclipse winds were dismissed as 'legend'. Register of Observations made on 11 August, 1999 Dry Wet Vapour Rel Cloud Time Bulb Bulb Pressure Humidity Cover 930 15.4 12.3 11.82 67.59 4 1000 15 12.7 12.84 75.33 5 1030 16 12.8 12.22 67.22 6 1045 16.2 13 12.41 67.43 4 1100 16 12.9 12.39 68.2 7 1119 15 12.5 12.49 73.27 7 1130 14.6 12.2 12.28 73.96 7 1145 14.9 12.7 12.92 76.29 4 1200 16.1 13 12.49 68.3 3 1215 16.6 13.6 13.17 66.88 3 1230 17.6 13.9 12.92 64.21 6 Cloud Light Station Wind Wind Time Types Intensity Pressure Direction Strength 930 cc 285 1006.1 ese 2.5 1000 cu,ac 244 1006.1 ese 1.6 1030 cu,ac 116 1006.3 ese 2.6 1045 cu,ac 71 1006.4 ese 0.5 1100 ac 30 1006.3 nnw 0.86 1119 ac 5 1006.2 calm 0 1130 ac 18 1006.1 calm 0 1145 cc 119 1006 calm 0 1200 as 187 1006 ese 0.16 1215 cu 233 1006.3 e 2.8 1230 cu 303 1006.4 ese 3.3 Satellite image taken at 11.19 BST, showing the lunar shadow over the British Isles at the time of maximum partial eclipse in Northampton. Acknowledgements United Kingdom Meteorological Office Royal Meteorological Society This eclipse weather report is available separate from the Monthly Weather Report, price £1 per copy. The findings of Pitsford Hall weather station are assisting the publication of a more comprehensive report in the Royal Meteorological Society's journal, 'Weather'. 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 87 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 ______________________________________________________________________ TOTAL (mm) 682 731 577.5 761 867 507.5 ______________________________________________________________________ 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 19 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 1014 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 3 September 3 3 6 4 October 3 2 6 8 November 2 1 4 1 December 2 1 6 7 WILBY'S AUGUSTY 1999 MONTHLY WEATHER REPORT =========================================== Wind direction -------------- North: 0 days South: 1 day East: 3 days West: 4 days North-west: 2 days North-east: 0 days South-west: 8 days South-east: 4 day Variable: 4 days Calm winds: 5 days Total: 31 days Wind speed ---------- Average wind speed (mph): 3mph Highest wind speed (mph): 27mph (14th) Lowest wind speed (mph): 0mph (3rd,12th,18th,28th,31st) Temperature ----------- Average temperature: 19°C Highest temperature: 28.7°C (2nd) Lowest temperature: 7.1°C (22nd) Rainfall -------- Total rainfall (mm): 87mm Highest rainfall (mm): 14mm (25th) Air pressure ------------ Average air pressure: 1014mb Highest air pressure: 1027mb (21st) Lowest air pressure: 996mb (18th) From Jim Bennett: Sunday 1 August 1999 Just finished BBQ when thunder started to rumble round at 18:30 have had rain (briefly heavy) on and off since then (now 19:20). Some loud cracks of thunder and intermittent lightening but nothing spectacular. Temp 22.5C and feeling very very sticky, more to come hopefully. I see BBC weather page has severe weather warning re storms until midnight Another report from Jim: 1 August 1999 At 14:10 temp 30.2C chasing yesterday's highest of year 30.6C Who needs the Mediterranean come to oven like Northampton Max 29 July 25.5 30 27.3 31 30.5 1 Aug 30.6 From Steve Jackson, Crick: 9 August 1999 Just downloaded the weather readings for Sunday up until 10-00pm to find we have recorded over 60mm of rain today in Coventry. A quick scan through the records, which date back to 1892 reveals that thus has been the wettest day in Coventry in August since records began. My Dad, who lives in SW Birmingham, near Lickey hills measured only 7mm over there, while in Crick (Northants) where I live it is much the same story - light but intermittent rain all day. In Coventry a massive thunderstorm cracked off at 7-00pm and flooded rhe main A45 road which had to be closed to traffic heading for Birmingham -in the other direction, the traffic jusy crawled through water up to the sills of the car. BTW - it is still raining, so who knows what the total will be. In Coventry, the all time record dating back to 1892, is only 72mm and that was on 31st December 1899 with 7 foot floods in the city centre heralding the start of the 20th century. Steve Jackson continues: 9 August 1999 ctd As far as I can see, there were sveral thunderstorms embedded in the front that gave the persistant but mainly light rainfall in the Midlands for much of Sunday. The one that affected Coventry tracked across Kenilworth and Leamington and thence northwards, so missing you but the edge must have caught Coleshill. I think Northamptonshire, where I live, missed it too. We got 61.0mm from 10am to 10am making it the weetest day in Coventry this century! Over the weekend (Friday to Sunday) we recorded 75mm in total. Local press have been asking the usual questions about changing weather patterns etc:-0) Of course I blamed the eclipse (tongue very much in cheek!!!!!!!!) -- From Jim Bennett, Eclipse Report: 11 August 1999 Temps here in Northampton during partial eclipse 11:06 15.8 11.07 15.8 11.08 15.7 11.09 15.6 11.10 15.6 11.11 15.5 11.13 15.4 11.15 15.5 11.16 15.2 11.17 15.2 11.19 15.0 11.21 14.9 11.22 14.9 11.25 14.9 11.26 14.9 11.29 14.9 11.33 14.7 11.37 14.9 We had a very eerie soft twilight here and I noticed a build up of high level thin cloud, practically clear skies prior to start of eclipse, which was burnt away again by 11.50. Message received from John Harris, Radley College wx station: UK total solar eclipse - 11 August, 1999 John Harris, Head of Geography, Radley College, Abingdon UK. mjh@radley.org.uk and www.rmplc.co.uk/eduweb/sites/radgeog/ "The coming eclipse will be a lifetime memory for those who are caught up in it. No television or photograph can do it justice; it must be experienced. Plan to be there." How could the Harris family resist, having read Jay Anderson's of Environment Canada, "The enchantment of eclipses" in the July 1999 edition of Weather, published by the Royal Meteorological Society? Furthermore there was an urgent appeal for eclipse weather data from Edward Hanna at the Department of Meteorology, University of Reading, UK. We packed a tent, recording equipment and emergency provisions and joined the million or so UK eclipse watchers who travelled south west to Devon and Cornwall to the narrow zone of totality which stretched from Newfoundland in the west across Europe, Turkey, Iraq , Iran, Pakistan to India. We camped at Yelverton on the edge of Dartmoor with its fascinating granite tors, wild horses and moorland walks. The preceding few days were mainly clear and sunny and conditions seemed hopeful for good viewing conditions. We walked, cycled, explored and waited...... The morning of 11th August dawned bright and cloudless but by 7 am ominous cloud was building from the west and the radio reported rain in Cornwall. Meanwhile the general UK forecast suggested that most of central, eastern and northern UK in the partial eclipse zone would benefit from a ridge of high pressure with clear skies and good viewing conditions. Having heard the pessimistic local forecast we jumped into the car and rushed through narrow country lanes to the Dart Valley at Dartington (latitude 50.26N, longitude 3.41W), 12 km inland, west of Torbay in South Devon. This proved to be a good choice. We arrived at 09.30 GMT and set up equipment to record temperature, wind and pressure recordings at 5 minute intervals. Readings were taken at 1 metre and 5 cm above ground level (in a shaded location above a gravel surface, 4 metres from the main A385 road). Excitement mounted as we watched the moon encroach. We continued to have frequent glimpses despite a thin covering of cloud. Cloud obscured our final views during the short period of totality and so we were not able to observe the diamond ring, Baily's Beads, corona or other special effects. Fortunately we were subsequently able to see pictures filmed from planes flying above cloud level. The temperature dropped, though not consistently (see data table and graph), during the period leading up to and following totality. In the last 15 minutes prior to totality the air felt damp and chilly. An overall drop of 1.9 deg C was recorded at 1 metre and 2.3 deg C at 5 cm. The overall lowest temperature of 15.7 deg C was recorded at ground level a few minutes after totality, thus creating a minor temperature inversion effect. Temperatures then began to slowly rise. There was a slow and steady reduction in light level during the 45 minutes preceding totality. Cows clustered and birds nested as "twilight" descended. An eerie hush descended. The most rapid light reduction was in the final few seconds before totality as the moon's shadow rushed overhead. During totality an orange glow remained along much of the horizon. House and car lights shone brightly and the skies rapidly filled with celebratory fireworks. Thin cloud obscured our view of any stars or planets. Within a minute the sky rapidly lightened. A slight westerly wind (1 kph) continued intermittently during the observation period, possibly as a result of our location in the west-east trending Dart valley. There was no increased "eclipse wind" at the time of totality as had been predicted by some researchers. Pressure remained constant at 1022 mb and there was no apparent change in cloud type or density. Totality passed all too quickly in a frenzy of flash bulbs, fireworks and clapping. We felt elated and were thrilled to have been part of this great event. We spent the rest of the day blissfully unaware of the 38 mile long traffic jams as eclipse watchers flooded out of south west England. This was quite literally the experience of a lifetime since the next UK eclipse will not be until 2090. Table 1: Temperature changes at Dartington, Devon UK, 11 August, 1999 Shade readings were taken at 1 metre and 5 cm above ground level. Times are GMT. Totality was at 10.11 GMT Time 1 m 5 cm 09.40 17.9 18.0 09.45 17.4 17.1 09.50 17.6 17.5 09.55 17.2 17.2 10.00 17.3 17.3 10.05 16.8 16.9 10.10 16.5 16.4 10.15 16.4 16.6 10.20 16.0 15.7 10.25 16.1 15.8 10.30 16.6 15.8 10.35 16.6 16.5 10.40 16.8 16.4 From Jeremy Borrett, eclipse weather readings at Wilby: Time Wind direction Wind speed Temperature Air pressure Cloud cover 10:00am SE 1mph 16.9°C 1024mb 6/8 10:20am Calm Calm 16.6°C 1025mb 6/8 10:40am Calm Calm 15.2°C 1025mb 5/8 11:00am Calm Calm 14.7°C 1024mb 3/8 11:10am SW 2 13.6°C 1025mb 3/8 11:15am S 1 13.4°C 1024mb 4/8 11:20am Calm Calm 13.0°C 1025mb 3/8 11:25am Calm Calm 12.7°C 1025mb 5/8 11:30am Calm Calm 12.7°C 1025mb 6/8 11:40am Calm Calm 13.5°C 1024mb 6/8 11:50am Calm Calm 14.3°C 1025mb 6/8 12:00am SE 3mph 14.3°C 1025mb 1/8 12:10pm SW 4mph 14.9°C 1024mb 1/8 12:20pm S 3mph 14.9°C 1024mb 2/8 12:30pm SE 2mph 15.2°C 1024mb 3/8 12:40pm SE 2mph 16.0°C 1024mb 1/8 Station Notes The weather station is grateful to the Royal Meteorological Society for agreeing to endorse its annual prize for the most diligent sixth-form observer. To be awarded on the school's Speech Day on 18 September, the Hadley Meteorology Prize has been given to Martin Sheehy. Martin, who studied geography in the sixth-form and was awarded a B grade in his final exams, has been a keen amateur meteorologist since he was a small child, setting up his own weather station in his back garden in Daventry. Martin, is one of the four honorary foundation observers of the weather station. The solar eclipse on 11 August drew crowds to the weather station office where the event was being relayed live from Cornwall. A report on the weather changes associated with the partial eclipse in Northamptonshire has been incorporated into this specially extended monthly weather report. A separate eclipse weather report can be purchased from the station, price £1. The new term in September will see a new round of training at the weather station. New A-level geography students will begin the six-week training course in theoretical meteorology and observational practice before taking over from the current team in October. The enclosure fencing of the ground enclosure suffered damage during August during routine gang mowing of the representative area. Fortunately, the thermometry was undamaged and the fencing has now been repaired at little cost. 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