************************************************************************************** MONTHLY WEATHER REPORT JANUARY 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 Station grading: A 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 Statistical Analysis of Air Observations - January 1999 Temperatures: Mean Max: 7.7C Mean Min: 1.9C Highest Max: 12.0C on 3rd, 4th, 19th Lowest Max: 1.7C on 11th Highest Min: 8.3C on 20th Lowest Min: -3.0C on 12th, 23rd Relative Humidity: Max: 100% on 10th, 25th Min: 78% on 2nd Mean: 94% Rainfall: Total for Month: 77.6mm Max: 18.8mm on 19th Rain Days: 19 Wet Days:15 Duration: 57.3 hours Rainfall acidity: Lowest pH: 6.06 on 2nd, 13th Winds: Max Max Gust: 33mph on 1st, 2nd Directions: north 1, northeast 5, east 0, southeast 0, south 13, southwest 5, west 1, northwest 3, calm 3, variable 0 Pressures: Max: 1039mb on 31st Min: 987mb on 16th Mean: 1009mb Sunshine: Total: 29.1 hours Most in a day: 3.8 hours on 16th No of sunless days: 9 Other observations: Days with fog recorded at 0830 hours: 6 Days with air frosts: 7 Days with snow falling at observation: 1, slight, 12th Days with snow lying at observation: 1 (<0.5cm), 12th Days with thunder heard: 0 Days with lightning observed: 0 Gales: 3 Days with ground frosts: 10 Statistical Analysis of Ground Observations - January 1999 There is no analysis of ground observations this month. The station's new ground enclosure will start contributing to the climatological record from the end of February 1999. Register of Air Observations - January 1999 Max Min Dry Wet Rel. Temp Temp Bulb Bulb Hum. Date Temp Temp 1st 8.5 5.7 7.2 6.9 92 2nd 7.4 5.4 6.7 5.2 78 3rd 12 3.5 6 5.8 97 4th 12 3.5 9.9 8.6 83 5th 10.3 6.4 11.9 11.1 90 6th 11.8 3 10.1 10 98 7th 6.6 4 3.1 3 98 8th 6.4 1.9 2.9 2.1 86 9th 3.5 1 1 0.7 94 10th 2.8 -0.5 0 0 100 11th 1.7 -1.1 0 -1 80 12th 3.6 -3 0.8 0.7 98 13th 7 -0.6 2.2 1.8 93 14th 7.9 1.5 2.9 2 84 15th 11.2 1.4 7.8 7.5 96 16th 7 2.7 3.3 3.1 97 17th 6.7 1.6 2.5 2 91 18th 8 0.9 2.3 2.1 96 19th 12 1.5 10.9 10.7 97 20th 11.1 8.3 10.4 9.8 92 21st 6.8 2 2.7 2.5 96 22nd 3.2 -1.5 2.7 2 95 23rd 8.1 -3 2 1.9 98 24th 11.5 1.5 2.1 1.9 96 25th 11.4 2.1 11 11 100 26th 7.2 2.4 4.1 4 98 27th 8.7 0.6 1.1 0.9 96 28th 8.4 -0.1 7.2 6.9 95 29th 5.8 2.4 3 2.7 94 30th 5 2.4 4.8 4.7 98 31st 6 3.4 4 3.5 92 Rainfall Rainfall Rainfall Prev. Wind Total Duration pH Wind Vel. Hours Dir. Date 1st 0.9 2.5 6.4 s 4..5 2nd 5.9 3 6.06 s 6 3rd 8.5 4.75 6.25 s 8..10 4th tr 0 n/a s 4..6 5th tr 0 n/a s 7..9 6th 7 5.75 6.17 s 6..8 7th 5 4.75 6.18 s 4..5 8th tr 0 n/a nw 1..4 9th tr 0 n/a ne 4..6 10th tr 0.25 n/a ne 1..4 11th tr 0 n/a ne 4..6 12th 3.3 1.25 6.27 ne 8..9 13th 1 1.5 6.06 ne 1..2 14th 2.3 1.25 n/a sw 1..2 15th 10.8 5.76 6.28 s 12..13 16th 0 0 n/a w 1..2 17th 0 0 n/a sw 8..9 18th 1.1 2 6.17 sw 5..7 19th 18.8 10.25 6.44 sw 12..14 20th tr 0 n/a sw 11..12 21st tr 0 n/a calm 0 22nd 0 0 n/a calm 0 23rd 0.4 0.25 n/a s 9..11 24th 1 0.75 6.49 nw 3..4 25th 1 0.5 6.1 s 5..6 26th 1.4 2.5 6.34 s 2..3 27th 7.3 7.25 6.21 nw 3..5 28th 0.5 0.25 6.12 n 5..8 29th 1.2 2.75 6.29 calm 0 30th 0.2 n/a n/a s 4..5 31st tr 0 n/a s 0..1 Max Cloud Cloud Visibility Pres. Gust Type Cover Date 1st 33 sc 3 6 1002 2nd 33 sc 6 6 994 3rd 32 sc 8 7 988.5 4th 21 sc/cc 7 7 999 5th 20 st 8 7 1006 6th 17 ac 4 7 1005 7th 16 obs 9 3 1007 8th 13 ac 5 7 1002 9th 18 cs 1 7 1012 10th 13 obs 9 4 1015 11th 14 cu 1 7 1015 12th 21 st 8 5 1004 13th 21 ac 7 8 1003 14th 21 clear 0 9 1005.5 15th 26 ac 8 7 1004 16th 15 clear 0 8 995 17th 16 sc 1 7 1001.5 18th 24 ac 2 7 1012 19th 26 st 8 7 1003 20th 18 st 8 7 1005 21st 8 obs 9 2 1018 22nd 12 obs 9 2 1024 23rd 17 sc 8 5 1015 24th 23 ac 7 7 1015 25th 22 sc 8 7 1014 26th 23 sc 8 8 1008 27th 18 clear 0 9 1011 28th 26 sc 8 7 1008 29th 11 as 8 7 1024 30th 9 st 8 4 1030 31st 5 obs 9 4 1035 Sun Grass Concrete Hours Min Min Temp Temp Date 1st 1.8 3.2 4.5 2nd 2.9 3.9 4.5 3rd 0.5 0.9 1.3 4th 0.6 2.2 3.2 5th 0 5.7 7 6th 0.4 6.7 8.6 7th 0.4 1.1 2.1 8th 1.1 0.2 1.3 9th 2.4 -0.9 0 10th 0.7 -1.6 -0.7 11th 0.4 -1.9 -2 12th 0 -2.7 -3.8 13th 0 n/a n/a 14th 2.4 n/a n/a 15th 0 1 2.3 16th 3.8 2.5 3.5 17th 3.7 -0.4 1 18th 0.5 -1.4 0.1 19th 0.4 0 1.4 20th 1 8.8 8.9 21st 0.7 1.8 3 22nd 0.1 -1.3 -1.8 23rd 0 n/a -1.6 24th 0 -0.2 1.6 25th 1 1.9 2.2 26th 1.4 0.8 2.5 27th 1.4 -0.8 0.1 28th 1.5 -0.2 0.5 29th 0 0.5 1.9 30th 0 2.1 2.6 31st 0 3 3.3 Cloud and Visibility 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 United Kingdom Climatological Analysis - January 1999 1999 started with a spell of unsettled weather. On the 1st a southerly wind brought warm and bright conditions to much of the UK, although there were some showers and longer spells of rain, especially in the north. (Torquay 12C, Clacton 6.1h, Tulloch Bridge 21mm.) Blustery showers were more widespread on the 2nd with hail and thunder in parts of south Wales and southern England. At Euston, London, hail up to 15mm diameter was reported. In between the showers it was sunny over much of England (Leeds 5.9h, Tulloch Bridge 36mm) while avalanche warnings were issued in parts of central Scotland as temperatures rose after recent snowfall. On the 3rd a rapidly eastward-moving depression brought a spell of heavy rain, with gusts over 50kn in exposed locations, to much of southern England by lunchtime, and heavy snow over the Peak District made driving difficult, while the rest of the UK again had a mixture of sunshine and showers. Later in the day another area of rain with gales approached western districts. Strong winds brought down trees in parts of southern England, and the Whitstable lifeboat capsized in rough seas. 2 people died in West Susses and Somerset. A combination of high tide and gale force winds, caused a breach in the sea defences of the west beach at Selsey, West Sussex, which resulted in local flooding. (Torquay 12C, Loch Glascarnoch 19mm, Swanage 4.6h). At Cardiff Weather Centre there was a pressure rise of 13.7mb in the period 0800 -1100 GMT and gusts over 70kn were recorded in places. The 4th saw cloudy but mild conditions (13C was reported at many places at 0600GMT) in the south and southwesterly gales (and gusts over 70 kn) across Scotland, Northern Ireland and N England disrupting flights and ferries (Herne Bay 15C, Lusa 30mm, Aberdeen 2.9h). A severe thunderstorm hit the Western Isles in the early hours of 4th. On Lewis and Harris this caused the entire island to lose power from 0200hrs for two hours. The lightning display was noted as spectacular on Lewis and North Uist, and was one of the most severe thunderstorms to have hit the islands in recent years. On the 5th and into the 6th there was some heavy rain over S Scotland and N England with falls of over 100mm in 24 hours in Cumbria leading to local flooding. It was again mild in southern Britain (cloudy on the 5th but sunnier on the 6th) in a SW airflow, but Scotland was colder with some snow falling on higher ground. Extremes on the 5th included Hawarden 15C, Windermere 114mm, Capel Curig 102mm and Jersey 7.3h, and on the 6th Gravesend 16.3C, Eastbourne 7.1h. Later on the 6th a cold front brought an end to the mild spell with sharp temperature falls occurring - 6degC falls in 1 hour at Gloucester and Coventry, and 4degC falls in 30mins at Birmingham and Manchester. Before the temperature fall, 16C was recorded at Kensington and 15.7C at the rooftop site of London Weather Centre - the highest January readings in London since 1841. The 7th was a cooler day, with a band of rain moving eastwards across Ireland, then England and Wales, before becoming almost stationary over N England and S Scotland. Northern Scotland was cool and cloudy. (Guernsey 11C, St. Bees Head 22mm, Cromer 3.6h.) Once the rain passed skies cleared giving a widespread ground frost and icy roads, especially over parts of Scotland and Wales early on the 8th. The rain area moved generally SE during the 8th, introducing northerly winds over the British Isles. There were snow showers over a cool Scotland and down the east coast (Penzance 11C, Glascarnoch -5C, Leeming 14mm, Margate 6.1h). Pressure rose on the 9th, which began with sub-zero temperatures in Scotland, N England and Northern Ireland, and icy roads in places. It remained cold with northerly winds, with snow showers over Scotland, Northern Ireland and down the east coast; Cornwall, however, was relatively mild (Penzance 9C, Glascarnoch -6C, Loftus 7mm, Torquay 8.0h). The 10th started cold everywhere; freezing fog all day in parts of Northern Ireland kept temperatures below freezing there in places all day, and there were further falls of snow in the north and down the east coast (many associated with the passing of troughs, including reports of 5cm in east Kent). (Tiree 8C, Belfast -2C max, Glasgow -8C min, Herne Bay 9mm, Newquay 7.7h.) The 11th dawned with a widespread air frost over much of the British Isles and with freezing fog in places; in many parts of Ireland the fog lingered until early afternoon. There were further snow showers over Scotland and E England and it was another cold day away from extreme W coastal areas (Penzance 8C, Aviemore -8C, Folkestone 9mm, Torquay 7.8h); At Wilmington (Kent) the temperature did not rise above 3.1C. A southerly airstream bringing rain began spreading from the W over Ireland and W Scotland later in the day, turning to snow over Northern Ireland and mainland Scotland. By dawn on the 12th 9cm of snow had fallen over parts of Northern Ireland; as the front moved east snow fell over England and Wales before turning to rain as the temperature rose. The snow was heavy in parts of Wales, Scotland and N England. (Torquay 11C, Redesdale -7C min, Scarborough 1C max, Capel Curig 34mm, Edinburgh 5.1h). After a cold start in places, rain spread eastwards across the British Isles on the 13th with gale force winds in W and N Scotland. Peak gusts included 60kn at Malin Head, and it was generally cloudy (Torquay 11C, Tulloch Bridge 13mm, Folkestone 1.6h). Following the clearance of the rain, skies cleared and the 14th dawned bright in most places with some snow showers on high ground in Scotland. Frontal rain spread rapidly across the British Isles from the W, followed by squally showers; peak gusts included 64kn at Malin Head and 61kn at Tiree. Snow closed some main roads in Scotland (Torquay 12C, Sella Ness 42mm, Eastbourne 7.2h). After a warm night over England and blustery rain over S Scotland, the 15th saw rain spreading to most parts of England. There were wintry showers over high ground in Scotland giving moderate to heavy falls of snow, and it was windy in S England and Wales with gusts to 60kn. Flooding of roads occurred in Cumbria and S Wales. (Hawarden 13C, Aviemore -6C min, Aviemore -1C max, Eskdalemuir 45mm, Kinloss 1.4h.) In the 24 hours starting at 0900 GMT on the 15th between 50 and 70 mm fell over the mountains of N Wales, while on the island of Harris a severe SW gale in the morning caused widespread minor damage. After heavy rain in S and SE England overnight, the 16th dawned with roads flooded in Worcestershire, S Wales, Herefordshire and Cumbria. Roads were also blocked by snow in Derbyshire and parts of the Scottish highlands. At Weston Coyney (near Stoke-on-Trent) the temperature fell from 8.8C in heavy rain at 0000GMT, to 1.1C at 0200 GMT in heavy snow. There were frequent heavy snow showers leading to blizzards in the Scottish Highlands, with gusts to 60kn leading to road closures and drifting of snow. Lying snow depths of about 30cm were reported at Aviemore. Snow also fell in Northern Ireland, Wales and the Pennines. Rain finally cleared much of SE England by midday, leading to a bright day over England and Wales with a few showers in the W. Six people were rescued from cars near Machynlleth in Powys. Melton Mowbray was cut off for most of the night 15/16th, and blocked storm drains flooded homes in Cranleigh, Surrey. The Leeds to Carlisle train was derailed by a landslide near Kirkby Stephen in Cumbria, and lightning strkes knocked out power in N Scotland and Western Isles. (Shoeburyness 11C, Aviemore 0C max, Aviemore -2C min, Coleshill 29mm, Oxford 6.7h.) A southwesterly airstream brought some thundery showers to parts of the British Isles on the 17th, with rain in parts of S Scotland, and snow showers over higher ground in the N. (Southampton 10C, Moyola -1C, Loch Glascarnoch 24mm, Bristol 7.5h.) After largely clear overnight skies over England and Wales, the 18th dawned cold. Cloud and rain quickly spread from the W across the British Isles with gusts to 60kn in many places in the W. There was more flooding along River Severn in Herefordshire and Worcestershire. (St Marys 11C, Brize Norton -2C, Capel Curig 24.2mm, Norwich 4.2h.) There was more heavy rain in mid and S Wales early on the 19th, spreading to much of W and S England during the day. There were blustery showers in N England and Scotland, although it was generally a mild day. (Hawarden 14C, Aviemore 1C, Eskdalemuir 22mm, Belfast, Newcastle 4.1h.) On the 20th a mild SW wind brought showers to Scotland, with more rain over England moving E. There was some flooding in Oxfordshire and Buckinghamshire, and the rain took all day to clear East Anglia and SE England. There were also reports of localised flooding in Towcester, Northamptonshire. The ground was heavily saturated throughout that county, particularly in clay areas, after the recent rains. (Torquay 13C, Aboyne -3C, Little Rissington 25mm, Newquay 6.9h.) A weak ridge began building over S Britain from the W on the 21st. It was bright and sunny over much of Britain, with some freezing fog patches in SE England at first, and wintry showers over 300m in Scotland. In parts, the fog lingered all day. (Torquay 21C, Shoeburyness -4C, Lerwich 11mm, Fishguard 7.6h.) The 22nd began with a cold, icy, foggy start in England and E Wales. The fog again persisted all day in places, disrupting air traffic over much of SE England. An area of rain moved across Scotland later in the day. (Guernsey 11C, Marham 0C max, Shawbury -7C min, Lusa 24mm, Torquay 8.2h.) The fog finally began to clear on the 23rd, which was a dull day with rain spreading from the W over most of the British Isles. (Torquay 12C, Larkhill -5C, Lusa 33mm, Herne Bay 2.5h.) Fog reformed around dawn again on the 24th in parts of S England; however this soon cleared as rain spread over Ireland from the W, and into S Scotland and England. Precipitation amounts were small in S England, with moderate/heavy rain and blustery winds in S Scotland and N England. (Torquay 12C, Pembrey Sands - 1C, Castlederg 17mm, Stornoway 3.5h.) In Corsock (Kirkcudbrightshire) 33.2 mm fell in the 24 hours starting 0900 GMT on the 24th, with most of this falling between 1700 and 2300 GMT. During the evening of the 24th, moderate to heavy rain turned to snow and continued into the night over many parts of lowland Scotland, in particular Fife and the Lothians. For example, several cm accumulated in the Lochgelly areas of central Fife at about 150m asl, where roads were impassable. The 25th began with a moderate falls of rain in parts of S England. Further bands of showery rain spread to most areas later in the day with falls of sleet and snow above about 300m in the N. It was mild in S England before the rain cleared with 13.5C at Buxton (Norfolk). (Gravesend 14C, Tain Range -3C, Eskdalemuir 43mm, Aberdeen 3.9h.) There was rain over Ireland and S England during the morning of the 26th. Later in the day a line of heavier (in places thundery) rain crossed the S, with reports of ball lightning near Winchester around 1630 GMT and heavy hail in Reading during the passage of an active cold front. Gusts reached 60kn at Shoreham. It is also reported that something `just like a tornado' removed the roof from a house near Petersfield with trees and power lines being brought down, while sleet fell around Birmingham. (Littlehampton 12C, Redhill -1C, Bristol 16mm, Stornoway 6.8h.) As the rain passed the sky cleared and the 27th saw a cold start in many parts of the N with subzero temperatures and icy roads. Further frontal rain spread across Ireland, and later across all of Britain, with snow on higher ground in Scotland. (Penzance 13C, Shap Fell -3C, Cromer 11mm, Bognor Regis 6.1h.) The 28th saw early morning flooding in Staffordshire after overnight rain. A frontal band of rain moved southwestwards during the day over England and Wales, gradually decaying and introducing clearer and cold air from the N, as pressure rose under the growing influence of an anticyclone to the SW of the British Isles. There were a few showers in Scotland, while much of Ireland was rather cloudy with drizzle for much of the day. (Penzance 14C, Baltasound -2C, Capel Curig 43mm, Leeds 7.4h.) The final three days of January were anticyconic in nature, and generally cloudy. On the 29th a band of light rain and drizzle crossed Britain from W to E, and there was little sunshine except in the Channel Islands. It was warmer in the W, and relatively cold in the E. (Penzance 12C, Benson -2C, Loch Glascarnoch 5mm, Jersey 5.0h.) The 30th began with patchy fog in places from central Scotland to southern England. Pressure continued to rise, reaching 1041.2 mb at Manston (Kent) by 2100 GMT. There was some sunshine in E Scotland, but elsewhere it was dull with light rain and drizzle in places. (Aberdeen 12C, Manston 1C, High Wycombe 5mm, Aberdeen 6.7.) There was further patchy fog around dawn on the 31st, which was cloudy except in the Channel Islands and parts of E Scotland and extreme SE England. Pressure rose to 1042.9 mb at 1200 GMT around Southampton. (Tain Range 12C, Manston -2C, Colwyn Bay 4mm, Jersey 7.9h.) Information supplied courtesy of Roger Brugge, Climatological Observers Link. Notable Weather Events in Northamptonshire The following reports are taken from the weather station's web site 12 January First snow of the winter recorded at Pitsford Hall. Depth of lying snow <0.5cm. 19 January 18.8mm rainfall lasting 10.25 hours. Reports of localised flooding around Towcester. Nene catchment heavily saturated. Reports from Northants Weather Watchers The Weather Watchers network was only launched formally at the end of January. Consequently, no reports have been received to date for publication. Updated reports will become available via the web site at: http://www.brixworth.demon.co.uk/weatherwatchers.htm Appendix Weather Station Inventory (including equipment in active use as of 31 January 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, not in active use) Fortin-pattern mercury barometer (currently being serviced) 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 (scheduled to be commissioned towards the end of February) Soil thermometers (5cm, 10cm, 20cm, 30cm) (UK Met Office and Casella types) Grass and concrete minimum thermometers (UK Met Office with calibration certificates) At the time of going to press the weather station is contemplating the acquisition of a Hooks type evaporimeter.