************************************************************************************** MONTHLY WEATHER REPORT JANUARY 2000 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 (Ext 314) Fax. 01604 882212 Answerphone 07967 438314 (local forecast & readings) 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 Current Officers: Richard Carruthers Charlie Cockrell Michael Franklin Thomas Gutteridge Robert Illingworth Technician: Mrs S West Groundsman: Mr R Green Brief Climatological Summary The month was generally mild with temperatures averaging at 1.1C above the January mean. The first week and a half were particularly mild with maximum temperatures typically above 8 or 9C, but a cooler spell of weather then followed with some penetrating ground frosts (-6.6C on the 10th) owing to the development of anticyclonic conditions to the west of the British Isles. The final few days of the month saw a return to very mild conditions with the highest maximum of January (13.1C) recorded on the 29th. The prevalence of anticyclonic conditions and low cloud amounts resulted in this January being the sunniest in the UK since 1959. The notable feature of January's weather was, however, the lack of rain. Only 13.5mm was recorded at Pitsford Hall, 24.4% of the average. Only a few days recorded rainfall in excess of 1mm, the notable falls being 3.8mm on the 3rd and 3mm on the 12th, the latter associated with an erratic front moving southwards. Some strong winds were recorded on a few occasions. Notable gusts were noted on the 21st (47mph) and 22nd (53mph, with 37mph recorded at morning observation). Further extremes were reported on the 28th and 29th (55mph). Statistical Analysis of Air and Ground Observations - January 2000 Temperatures: Mean Max: 7.7C Mean Min: 1.8C Mean Temp: 4.8C (mean comparison: +1.1C) Highest Max: 13.1C on 29th Lowest Max: 4.2C on 16th Highest Min: 9.5C on 31st Lowest Min: -1.6C on 27th Relative Humidity: Humidities observed at 0830hrs: Max: 97% on 1st, 3rd Min: 76% on 29th Mean: 89.1% Lowest RH (hygrograph record): 62% on 8th Rainfall: Total for Month: 13.5mm (mean comparison: 24.4%) Max: 3.8mm on 3rd Rain Days: 9 Wet Days: 4 Duration: 17.5 hours Rainfall acidity: Lowest pH: 6.16 on 21st Winds: Max Max Gust: 55mph on 28th, 29th Max wind speed at observation: 37mph on 22nd Mean wind speed at observation: 10.0mph Max mean 24 hour wind speed: 17mph on 5th Mean mean 24 hour wind speed: 7.9mph Directions: north 5, northeast 7, east 0, southeast 0, south 0, southwest 12, west 1, northwest 5, calm 0, variable 1 Pressures: Max: 1040 mb on 16th Min: 997 mb on 29th Mean: 1023.7mb Sunshine: Total: 33.9 hours Most in a day: 3.7 hours on 16th No of sunless days: 9 Cloud Cover: Mean cloud cover at observation: 70% (5.6 oktas) Ground Observations: Lowest Grass Min: -6.6C on 10th Highest Grass Min: 5.1C on 31st Mean Grass Min: -2.1C Lowest Concrete Min: -6.0C on 10th Highest Concrete Min: 5.9C on 31st Mean Concrete Min: -1.0C Earth Temperatures: Bare Earth mean: 2.9C max: 10.0C on 31st min: -4.0C on 17th 5cm mean: 2.3C max: 6.9C on 31st min: -0.4C on 9th 10cm mean: 3.2C max: 6.8C on 31st min: 0.5C on 10th 20cm mean: 3.8C max: 6.6C on 31st min: 2.0C on 10th 30cm mean: 4.1C max: 6.4C on 31st min: 2.5C on 10th 40cm mean: 4.3C max: 5.4C on 31st min: 2.6C on 10th 50cm mean: 4.9C max: 6.0C on 12th,14th min: 3.9C on 27th 100cm mean: 5.7C max: 6.4C on 18th min: 5.2C on 28th-30th Other observations: Days with fog recorded at 0830 hours: 3 Mean visibility: 6 (moderate, up to 7km) Days with air frosts: 9 Days with ground frosts: 24 Duration of air frost: 61 hrs Days with snow falling: 0 Days with snow lying at observation: 0 Days with hail observed: 0 Days with thunder heard: 0 Days with lightning observed: 0 Gales: 0 Evaporation (tank): Suspended until further notice. Register of Air and Ground Observations - January 2000 See separate file. 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 Thunder Report No reports of thunder were received this month. SYNOP Messages - January 2000 (codes are supplied inthe December 1999 issue of the report) AAXX 31094 PITSFORD 31970 82207 00037 10108 20092 30014 40166 5//// 7501/ 88400 90900 333 10122 20095 31005 886//= AAXX 30094 PITSFORD 11980 83110 00048 10098 20090 39946 40096 56010 69994 75061 88400 90900 333 10131 20081 31003 886//= AAXX 29094 PITSFORD 11980 62223 00048 10110 20074 39820 49969 54000 69934 7026/ 86056 90900 333 10011 20035 31/// 833// 834//= AAXX 28094 PITSFORD 31920 82209 00017 10035 20012 30020 40175 57020 7031/ 88400 90900 333 10049 21003 31001 886//= AAXX 27094 PITSFORD 31920 70403 00012 10015 21009 30136 40295 56010 7011/ 87400 90900 333 10049 21016 31100 876//= AAXX 26094 PITSFORD 31920 03103 00008 11004 21011 30148 40307 52010 7001/ 90900 333 10054 21010 34105= AAXX 25094 PITSFORD 11920 5//03 00010 10018 20009 30120 40279 51010 69904 7101/ 85400 90900 333 10060 21006 34106 85604= AAXX 24094 PITSFORD 31920 40403 00023 10009 20002 30080 40239 54000 7021/ 84090 90900 333 10066 20002 31102 843//= AAXX 23094 PITSFORD 31970 50409 00046 10032 20016 30084 40241 52015 7011/ 84460 90900 333 10067 20006 31102 846// 813//= AAXX 11094 PITSFORD 11970 72210 00023 10067 29900 30182 40340 54000 69904 7035/ 87500 90900 333 10069 20003 31102 876//= AAXX 10134 PITSFORD 31970 62211 00018 10050 29830 30199 40357 54000 7030/ 8054 91300 333 833// 830//= AAXX 10094 PITSFORD 31070 12206 00015 10000 29900 30202 40362 54000 7000/ 8001 90900 333 10052 21015 34107 810//= AAXX 09094 PITSFORD 11070 13104 00017 10015 29890 30088 40247 52020 69904 7021/ 8030 90900 333 10085 21001 34106 813//= AAXX 08094 PITSFORD 11070 02210 00030 10044 29850 39999 40154 52030 69974 7006/ 90900 333 10099 20038 31100= AAXX 07094 PITSFORD 11270 82215 00020 10058 20043 30013 40168 57007 69904 702// 88410 90900 333 10102 20026 31103 85607 834//= AAXX 06094 PITSFORD 11070 72211 00035 10083 20063 39935 40085 52030 60024 7026/ 87500 90900 333 10111 20041 31001 876//= AAXX 05094 PITSFORD 11370 62215 00030 10045 20027 39981 40136 57015 69901 7035/ 86050 90900 333 10062 20002 34103 863//= AAXX 04094 PITSFORD 11002 92210 00017 10005 21002 39979 40136 57010 60044 74361 89/// 90900 333 10106 21004 31104 89///= AAXX 03094 PITSFORD 11170 82212 00030 10101 20097 30010 40162 52008 69904 7501/ 88500 90900 333 10106 20099 31002 88602= AAXX 02134 PITSFORD 31470 72206 00010 10078 20050 30079 40233 50000 7022/ 87400 91300 333 87612= AAXX 02074 PITSFORD 11370 82704 00014 10058 20039 30076 40233 51005 69904 7025/ 88400 90730 333 10076 20033 31102 88608= AAXX 01094 PITSFORD 11020 00002 00015 10035 20031 30077 40234 52020 60024 7006/ 90900 333 10082 20034 31102 80///= AAXX 31094 PITSFORD 11010 80403 00022 10039 20037 30030 40185 52010 60064 7106/ 88600 90900 333 10054 20021 31000 88700= AAXX 30094 PITSFORD 11120 82210 00022 10023 20018 30013 40170 57020 69964 75550 88700 90900 333 10045 20004 34105 88702= AAXX 29094 PITSFORD 31270 30007 00017 10013 20003 39971 40128 52021 70120 83100 90900 333 10032 21007 34106 83805= AAXX 28094 PITSFORD 11920 80010 00019 10018 20009 39835 49989 52035 69914 702// 88600 90900 333 10036 20008 31102 88709= United Kingdom Climatological Analysis - January 2000 Rain cleared SE England during the morning of the 1st while in Scotland and parts of N England clearing skies led to an early air frost. Fog patches lingered for much of the day in parts of England and S Scotland, with another area of rain affecting W Ireland and Scotland during the afternoon and evening. Parts of N England had a very sunny day. (Guernsey 12C, Topcliffe -4C, Aultbea 28mm, Beverley 7.1h.) The 2nd dawned mainly cloudy; wintry showers in N Scotland during the morning were accompanied by gusts to 50kn. It remained cloudy in most places, with damp, drizzly conditions in S England, and fog in SW England for much of the day. During the evening gales spread to exposed parts of N Ireland and W Scotland with Malin Head reporting 58kn gusts at midnight. (Guernsey 12C, Shrewsbury -1C, Loch Glascarnoch 29mm, Colwyn Bay 4.8h.) The 3rd began with windy conditions over the entire British Isles, especially over N Scotland. Reports included: 0300GMT Stornoway 58kn gusts to 82kn; 0600GMT Kirkwall 53kn gusting to 80kn; 0900GMT Lerwick 63kn gusting to 89kn). At 1100GMT Lerwick was reporting 92kn gusts. Thousands of homes were without power in N Scotland, and all ferries were cancelled in the Northern Isles. This gale was of exceptional severity in the Western Isles, peaking at 0400GMT. Some islanders describe it as the worst in living memory. 4,700 houses without power in Western Isles, most had power restored by 2000hrs. At Stornoway airport 13 vehicles had their windows smashed by flying debris and a gust of 92kn was recorded at 0400GMT (resulting in the issuing of an emergency FLASH weather message). At Ness (Isle of Lewis) there was considerable structural damage to many buildings; Cross Free church roof was badly damaged, and a number of caravans and sheds were completely destroyed. On the Isle of North Rona a gust of 125mph was recorded. Conditions over Cent. Scotland and S'wards were much less severe, although the ski slopes in the Cairngorms were closed due to blizzard conditions; however, many people braved 60mph winds on the slopes at Glenshee and the Lecht. 600 construction workers at the oil rig at Nigg on the Cromarty Firth, working on the largest steel structure ever made for the North Sea, were sent home as winds gusted to 80mph. Over S counties of England it remained damp with rain and drizzle for much of the day, this spreading to parts of the Midlands and east Anglia for a while; further N it was generally brighter with showers, these being of hail and snow over parts of Scotland. (Guernsey and Culdrose 12C, Fylingdales and Aviemore 3C, Bournemouth 22mm, Scarborough 4.1h.) The 4th again dawned dull over S England, with drizzle and fog patches, the latter extending into the Midlands during the morning. There was some flooding in SW and Cent. S England. Further N it was a showery day, with snow and hail in Scotland, N England and N Ireland. During the afternoon and evening skies cleared in all areas, with the exception of a few wintry showers over W coasts and on high ground in Scotland. A tornado was reported from the village of Wideopen, about 12km N of Newcastle upon Tyne, at approximately 1400GMT, and thunder was reported from Anglesey around midday. (Guernsey 12C, Aboyne -3C, Eskdalemuir 16mm, Jersey 4.4h.) The 5th clouded over before dawn in most areas and temperatures rose, but in the extreme SE there was still a ground frost by 0600GMT. It was a mild day everywhere, with bands of rain and strong S winds moving SE across the British Isles; the rain was heavy in parts of Scotland and was followed by showers in the W later with skies clearing over Ireland. Gusts to 60kn were widely reported during the morning over exposed N and W coasts. (Falmouth 12C, Tulloch Bridge 8C max, Redhill -3C min, Tulloch Bridge 49mm, Guernsey 4.2h.) SW winds (with gusts over 40kn in the NW) brought a mild start everywhere on the 6th, although these turned to a more NW direction in all places during the day as an area of rain moved S. Skies cleared after the rain, although only temporarily over Ireland and Scotland as further rain and gales extended to many araes there by midnight. (Falmouth 15C, Loch Glascarnoch 1C, Loch Glascarnoch 23mm, Scarborough 6.2h.) Northern parts of the British Isles began the 7th with rain and strong winds, which resulted in several bridges being closed to high-sided vehicles. Over S England clear skies led to an air frost in places, before skies clouded over as the rain moved slowly SE, reaching the Midlands and SW England by midnight. Strongest gusts included 68kn at Stornoway (0000GMT), 66kn at Belmullet (0600GMT) and 48kn at Valley (1500GMT). The clearance of the rain was floowed by showers of rain and hail in W Scotland and W Ireland. (Rosehearty and Penzance 12C, Redhill -3C, Stornoway 35mm, Bognor Regis 3.9h.) The cloud and rain cleared SE England by mid-morning on the 8th, with the British Isles then having a sunny day. There were showers of hail (13mm diameter reported from Fair Isle) and rain on W coasts of Ireland and Scotland (with stong gusts in the N including 69kn at Lerwick at 0600GMT), with snow showers over high ground in Scotland (and later N England) and thunder in the Northern Isles. (Torquay 12C, Fylingdales 1C, Shap Fell 20mm, Folkestone 6.7h.) The 9th dawned frosty over much of England, and with snow showers in parts of Northern Ireland, Scotland and NW England. These showers gradually died out as pressure built everywhere although by midnight the wind had backed to the SW in NW areas of Scotland and Ireland, gusting to 45kn at Stornoway at midnight, and cloud pushed E there.(Penzance 11C, Chipstead Valley -7.4C, St Angelo 9mm, Folkestone 7.1h.) England, Wales and S Scotland woke to a widespread air frost on the 10th; over N Scotland and Ireland cloud and rain moved E during the early hours with gusts to 60kn in the W. The cloud spread SE during the morning to affect all but the extreme SE corner of England. The rain lessened as it spread SE, giving only light falls in the Midlands and East Anglia by midnight, while a clearance behind the rain over N and W districts was followed by rain showers. (Falmouth 11C, Holbeach 3C min, Redhill -6C, Lusa 28mm, Herne Bay 6.4h.) Early on the 11th partly-clear skies led to a few ice patches on untreated roads in Scotland. However skies soon clouded over and the day was a cloudy one over all of the British Isles, with spells of rain or drizzle in most places. Falls were very light in the S, but heavier during the afternoon over N Ireland, N Wales, NW England and S Scotland. (Hawarden 13C. Aboyne 0C, Capel Curig 62mm, Jersey 2.7h.) The 12th was another cloudy day almost everywhere, with rain and drizzle in most areas at some time. Many roads in Cumbria were flooded by dawn after recent heavy falls, while there were reports of sleet in NW Scotland. 54.6mm fell in the previous 24 hours in Brampton, NE Cumbria; river Eden burst its banks in Carlisle and Haltwhistle to the E was under 4ft of Water after the River South Tyne had burst its banks. During the late afternoon and evening the cloud cleared partially over Ireland and W Scotland, with scattered showers. Over Ireland rainfall amounts rainged from 40mm in the SW to about 20mm in the E. Heavy rain that had affected North Wales since the 10th cleared today; in the period 0900 on the 10th to 1800 on the 12th, Capel Curig (Gwynedd) recorded 163 mm and Llansadwrn 86 mm rain. The 24-h fall at Llansadwrn ending 0900GMT today was 40.6 mm - the largest fall since 8.12.1983. Many roads and some houses were flooded in Anglesey; at Beaumaris the moat at the Castle overflowed and flooded the main street. In Gwynedd the A55 Expressway was flooded as was the A498 at Nant Gwynant. Later in the evening rain turned to sleet/snow in NW Wales and parts of NW England and Staffordshire. (Falmouth 11C, Kinloss 3.5h.) Overnight rain over much of England moved steadily SE during the 13th, finally clearing E Kent by mid-afternoon. Clear skies led to a widespread ground frost in Ireland and a sharp air frost in parts of Scotland. Showers affected Scotland and W parts of Ireland and Britain, with snow falling on high ground in Wales and Scotland, and N gusts to 50kn reported from NW coastal areas. The summits of Snowdon and the Carneddau mountains were this morning covered with a moderate fall of snow, this extending with slight covering down to 300 m in the Nant Ffrancon Pass and elsewhere. There was a snow cover above 250m over Birdlip and the north Cotswolds, and some sleet fell in the early hours in Cirencester. In Aberdeen surface glaze was observed in the afternoon. A lack of heavy snow over recent days, however, meant that most snow cover was restricted to the high ground of the Highlands, with a few patches in S Scotland and N England. (Exmouth 9C, Spadeadam 1C max, Aboyne -6C min, Scarborough 16mm, Leeds 5.9h.) A clear start to the 14th led to air frost in many places in England, although cloud over Scotland and in the E produced light snow as far S as Hampshire and freezing drizzle during early morning in East Sussex. Light precipitation continued to fall at times over E parts of Scotland and England during the day, this being wintry in places. Ireland, Wales and W areas of England had a mostly sunny day. (Penzance 8C, Benson -6C, Scarborough 17mm, Penzance 7.3h.) The 15th saw a continuation of dull weather over E and S England, although East Anglia brightened up later. Precipitation fell here as light rain, and rain also fell in N Scotland. W districts again had a mainly fine day, after a cold start, under the influence of a building anticyclone. (Guernsey 9C, Machrihanish -5C, Scarborough 15mm, Ronaldsway 7.1h.) The 16th was mainly dry everywhere as pressure continued to rise. Parts of S Scotland had a cold start to the day, and cloud cover was extensive in some areas of the British Isles during the day. The MSl pressure reached 1047.2mb at Belmullet at 1200GMT. (Aboyne 11C, Eskdalemuir -5C, Folkestone 2mm, Penzance 6.4h.) The northerly flow around the large anticyclone to the W continued on the 17th. Clear skies brought early fog patches to parts of S England and freezing fog to parts of S Scotland. The fog clearance was followed by sunny spells over much of Scotland and N England but by cloudy conditions (with some light precipitation) over much of Ireland and parts of S England. Fog reformed by midnight in many places from Hampshire to S Scotland. (Boulmer 12C, Morecambe 3C mx, Eskdalemuir -6C min, Kirkwall 1.5mm, Leeds 7.4h.) The 18th was a rather cloudy day in many areas, a notable exception being parts of S Wales and SW England. Mist and fog was reported intermittently thoughout the day in parts of NW England, the Midlands, S England and S Wales - being particularly persistent at Ringway. Light rain and drizzle fell from the cloud over Ireland and Scotland, and down the E coast of England. Fog during the evening led to the cancellation of the Carlisle-Wigan football match. (Leuchars 12C, Redhill -3C, Loch Glascarnoch 5mm, Teignmouth 7.8h.) With pressure remaining close to 1040mb over the British Isles, 19th was another quite day. Most araes were cloudy, with light falls of precipitation over E coast districts and in SE England. Even Valentia was reporting recent drizzle at 0900 GMT with MSL pressure of 1040.3mb. Fog and mist affected parts of England and S Scotland during the morning, and later in the evening. (Guernsey 9C, Saughall -1C, Clacton 3mm, Leeds 5.1h.) Clear skies away from the coast over England led to a frost in places by dawn on the 20th, and early fog was reported widely over Cent. S England as anticyclonic conditions persisted. The fog soon cleared as a cloud cover developed with most of the British Isles then having a mainly cloudy day. There was rain or drizzle at times over many parts of the British isles, although SE Scotland remained mainly sunny once pre-dawn cloud had cleared. It was noticeably cold in SE England. (Strathallan 9C, Kenley and Herstmonceux 3C max, Benson -6C min, Loch Glascarnoch 6mm, Leuchars 5.8h.) The 21st began with some fog patches in the Midlands and N England, and an air frost in S Scotland and parts of N England. Light precipitation over W Scotland and W ireland around dawn extended to Wales and S England during the morning while mist and fog reformed during the afternoon over N England and S Scotland. Most other parts of E England had a mainly sunny day, while over N Scotland a cold front introduced wintry showers and gusts to 40kn. (Penzance 10C, Eskdalemuir -4C, Baltasound 8mm, Leeds 7.6h.) The cold front moved S over the entire British Isles on the 22nd, introduced a cool N airflow. Gusts to 50kn were recorded in N scotland and on the E coast of England and there were snow showers over the Northern isles and on high ground in Cent. Scotland. Hail fell as far S as SE England with thunder in S London, and slight snow showers also fell down the E coast of England. (Penzance 10C, Lerwick 0C, Loch Glascarnoch 17mm, Bournemouth 6.2h.) An air frost occurred on the 23rd in S Scotland and N England as the N airflow continued. Wintry showers fell over Scotland and snow pellets fell as far S as S England. During the afternoon cloud moved E across Scotland, introducing milder air and rain to many areas by midnight. (Guernsey 10C, Saughall -5C, Newcastle-upon-Tyne 3mm, Bognor Regis 8.0h.) Skies clouded over from the E over Ireland and Wales before dawn on the 24th, with sleet reported from Dorset and snow in the Midlands by dawn. Light rain over Scotland moved S to N England and Ireland during the morning, later reaching N Wales. Inland parts of S England cleared during the late afternoon and evening (following some light snowfall in Hampshire), to give a widespread air frost by midnight. (Strathallan 10C, Buxton (Derbyshire) 3C max, Loch Glascarnoch 14mm, Leuchars 7.3h.) The 25th dawned with a patchy cloud cover over the British Isles; a widespread air frost occurred where the cloud failed to form, and there were freezing fog patches in parts of the Midlands, East Anglia and S England. Light snow fell around the Cotswolds before dawn. It remained dull and turned increasingly misty over S and E England during the day (becoming foggy in S England during the evening), while in Cent. Ireland many places had thick fog from mid-morning onwards. Some light rain and drizzle fell in parts of N Scotland and NE England. (Red Wharf Bay 9.3C, Redhill -7C, Loftus and Bedford 1.2mm, Jersey 8.2h.) The 26th started with clear skies in most parts of the British Isles, and a widespread air frost except in N Scotland and in coastal areas. Freezing fog affected parts of the Midlands, S England and E Ireland around dawn, and this fog persisted for much of the day in parts of Ireland, S Midlands and Cent. S England with temperatures hovering around freezing point in places. N and W parts of Scotland reported some light precipitation but most other places had a sunny day, although during the evening cloud and light precipitation did spread to S Scotland and N Ireland. At Dun Laoghaire fog persisted all day, having started on the 25th, being thick at times with a maximum temperature of 2.7C (the coldest day for 3 years). (Guernsey 9C, Brize Norton 0C min, Larkhill -8C, Aultbea 2mm, Jersey 8.7h.) Clear skies brought another cold start to S England and S Wales on the 27th with patches of thick freezing fog. Cloud and light precipitation over Scotland and N Ireland spread S, finally clearing the fog around Dublin and giving some light rain as far S as Wales and Cornwall by midnight. In the Norther Isles hail fell, while SE England remained clear and a widespread frost formed there after dark again. (Penzance 9C, Pershore 1C max, Chipstead Valley and Redhill -9C, Loch Glascarnoch 5mm, Teignmouth 8.6h.) The 28th dawned wet in many areas of Ireland, Scotland, Wales and W England, while temperatures rose in SE England before dawn as cloud spread over the area. It remained cloudy across the British Isles with rain at times in most places, while over Scotland falling pressure later in the day was accompanied by an increase in wind speed and widespread gusts to 50kn. A warm sector moving NE over S Ireland and Wales after dark led to rising temperatures here. At Dun Laoghaire the 15 day anticyclonic spell (13th-27th) resulted in only 2mm of rain. (Aberdeen 9C, Lerwick 5C max, Lusa 24mm, Aberdeen 8.6h.) Much of the British Isles (apart from N Scotland) had a mild night with temperatures up to 10-11C in many places by dawn on the 29th. It remained cloudy in most places during the day (NE England was an exception) with rain spreading SE. It was a windy day in all districts with gales at exposed sites, and gusts reaching 80kn in N Scotland. At 1200GMT Kirkwall reported 65kn mean speed with 87kn gusts and showers of hail and snow fell in N and Cent. Scotland as the rain moved SE. MSL pressure fell to 946.8mb at Lerwick at 1200GMT. Nacreous cloud was seen from Lincolnshire to Dundee around 1640GMT. (Marham 14C, Lerwick 1C, Loch Glascarnoch 26mm, Newcastle 6.1h.) The 30th dawned frosty in parts of N and Cent. Scotland and cloudy elsewhere with some light precipitation, but cloud spread rapidly E across Scotland and there were some heavy falls of rain in parts of Scotland and Northern Ireland during the day. It was another blustery day everywhere with gales in N Scotland and gusts to 60kn here later in the day; warm conditions persisted everywhere except for N and Cent. Scotland. At Dun Laoghaire 13C was reported. (Hawarden 14C, Lerwick 2C max, Baltasound -3C min, Tyndrum 47mm, Oxford 4.9h.) A warm night in S England, S wales, the Midlands and S Ireland resulted in an overnight minimum temperature on the 31st of 10.8C at Southend-on-Sea (the highest in 22 years of records for January). Other minima included 10.3C at Heathrow and 10.6C at Valentia. It was cloudy day in most places, with rain or drizzle at times S of a line from Tiree-Dundee, and showers to the N or here. These showers were of hail in the Northern Isles; during the late afternoon and evening an area of rain (heavy in places) pushed E across much of Scotland. (Great Malvern 14C, Lerwick -1C, Keswick 18mm, Poole 6.0h.) Information contained in the Climatological Summary supplied courtesy of Roger Brugge, Climatological Observers Link. Notable Weather Events in Northamptonshire No reports of notable weather events were added to the weather station's web site this month. Annual Weather Report for 1999 CLIMATOLOGICAL SUMMARY FOR 1999 January Mainly mild, windy and wet but with some generous sunshine. Dull and quiet towards the end of the month. The mean at Pitsford Hall was recorded at 1.1C above the January average. Rainfall was recorded at 77mm, 139% of the average, with a notable fall of 18.8mm on the 19th resulting in some flooding around Towcester. January 12th saw the first snow of the winter season, but lay at less than 0.5cm depth and quickly melted. Nationally, this was the sunniest January since 1991 and the fourth sunniest since 1909. The mildest (along with 1994) since 1993. February Another generally mild month. The mean at Pitsford Hall was 4.7C, 1.0C above the norm for February. Changeable and windy at times with snow in the second week. A gust of 52mph was recorded on the 22nd, and snow fell at 0900 hrs on three days: 9th, 10th and 22nd. Sunny and dry away from the west. Some notable sunshine occurred on the 7th with 5.3 hours, the sunniest day since 12 October 1998. Nationally, this has been the 10th sunniest February since 1909. March Mainly mild & changeable. Some snow in places first week. The mean temperature at Pitsford Hall was 7.3C, 1.7C above the March average. April Mostly unsettled and rather wet. A total of 68.4mm was recorded at Pitsford Hall (143% of the average). The period 20-23 April was particularly wet. There was, however, a wintry spell mid month with some snow. The last few days saw a return to very mild conditions. Nationally, this was the warmest April since 1993 and the sunniest since 1995. May Mostly warm and changeable. The north-west of the British Isles was rather more unsettled that Northants which saw some good sunshine and mild conditions. Breezy start to fourth week with thunderstorms later. A tornado was reported in the Corby area on the 14th. The close of the month was particularly stormy with some notable rainfall amounts: 4.5mm of rain falling in half and hour at Pitsford on 27th and 17mm over 2.5 hours on 29th. Nationally, this was the dullest May since 1994 and the sixth month in succession to be warmer than normal. June Rather wet. Some severe thunderstorms at first, then mainly cool and unsettled but with some very warm days at times. Notable rainfall amounts included 19.9mm on the 1st. On the 2nd, flooding, lightning strikes and power cuts occurred throughout the county. The leisure centre in Rushden, East Northants, was closed due to flooding. 170 storm-related calls were made to the Fire Brigade. 180 businesses throughout Northants were without power during the day. Nationally, this was the coldest June since 1991. July Mostly very warm and sunny especially in the south, but cooler in the north and northwest. It was notably dry over some parts of England. Only 12.2mm of rain fell at Pitsford, 25% of the expected average. Rain fell on only 4 days during the month. Nationally, this was the driest July since 1911 and the sunniest since 1990. August Very hot start (30.8C on the 1st, hottest day of the year), then mostly rather cool and unsettled. Frequent thunderstorms and heavy downpours. On the 25th, torrential rainfall accompanied by moderate thunder and lightning caused traffic chaos in Northampton. Two major downpours (15.50- 16.45BST and 17.25-17.45BST) caused 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. The end of the month was warm and dry. Nationally. This was the wettest and dullest August since 1992. September Very warm at first. Generally very unsettled with frequent thunderstorms, heavy downpours and local flooding in places. A total of 22.9mm was recorded at Pitsford on the 19th. The period 22nd-26th was particularly wet. On 24th September, 6.6mm of rain fell between 19.20 and 20.05BST. On 26th September, 8.3mm of rain fell between 23.00 and 3.25BST, of which 6.7mm fell in two hours between 1.00 and 3.00BST, and 3.4mm fell between 2.20 and 2.55BST. Nationally, this was the warmest September since 1949 and the sunniest since 1991. October Very sunny and dry most of the time after a breezy start with some thunder. Unsettled beginning of 4th week with gales and heavy rain around 24th/25th. Mainly sunny and dry thereafter. 93.4 hours of sunshine were recorded at Pitsford. Nationally, this was the sunniest October since 1959. November Mainly mild and dry the first fortnight. Cold spell third week with some wintry/thundery showers. Strong south-westerly winds buffet the county from 24th to 28th, gusting up to 43mph on 25th, 42mph on 26th and 41mph on 28th. Mean wind speed at observation (0830hrs) on 26th: 25mph. No gales or significant reports of structural damage received. Nationally this was the driest November since 1990. Pitsford Hall was reported as being the driest COL reporting stations. December A disturbed month with frequent gales and some snow in the north. Sunshine well above normal but very wet with local flooding. On the 3rd high winds gusted up to 53mph and rain lashed the county during the morning. Mean wind speed recorded at observation (0830GMT) at Pitsford Hall: 33mph. Pressure trend over the 3 hours prior to 0830GMT: -6mb. Reports were received of a lorry careering out of control down an embankment on the A14 and of power losses and train delays on the Northampton line. A wintry spell third week and a cold end to the month. Nationally, this was the sunniest December since 1962 and the wettest since 1993. ANNUAL STATISTICS FOR 1999 Temperatures Mean Max: 14.6C Mean Min: 6.8C Mean: 10.7C Difference from average: +1.3C Highest Max: 30.8C on 1st August Lowest Max: 0.7C on 5th February Highest Min: 17.3C on 3rd August Lowest Min: -4.9C on 20th December Lowest Grass Min: -8.8C on 20th December Duration of Air Frost: 160.5 hours Mean Relative Humidity at 0900 hrs: 86.6% Rainfall Rainfall Total: 692.7mm (105.2% of average) Rain days: 171 Wet days: 125 Most in a day: 24.2mm on 25th August Rainfall Duration: 510.6 hours Sunshine Total: 1393.5 hours Most in a day: 12.8 hours on 18th June Sunless days: 54 Mean Cloud Cover at 0900 hrs: 69.3% Winds Days with gale: 0 Days with wind from: N: 46 NE: 40 E: 12 SE: 41 S: 38 SW: 71 W: 34 NW: 67 Calm: 13 Variable: 2 Mean wind speed: 5.3 mph Maximum gust: 57 mph on 13th April & 24th December Pressures Mean sea-level pressure at 0900hrs: 1012.9 mb Max sea-level pressure: 1041mb on 9th November Min sea-level pressure: 975 mb on 24th October Other Observations Days with Air Frost: 26 Days with Ground Frost: 66 Days with Sleet/snow falling: 10 Days with Snow lying at 0900 hrs: 7 Days with Thunder: 14 (& Lightning 9) Days with Hail (<0.5mm): 7 Days with Hail (>=0.5mm): 0 Days with Fog at 0900 hrs: 30 Northants Weather Watchers' Reports WILBY'S JANUARY 2000 MONTHLY WEATHER REPORT supplied by Jeremy Borrett in Wilby Report from 1st January 2000 to 31st January 2000. A total of 29 weather days were recorded. Wind direction -------------- North: 0 days South: 1 day East: 0 dayS West: 6 days North-west: 6 days North-east: 1 day South-west: 0 days South-east: 0 days Variable: 4 days Calm winds: 11 days Total: 29 days Wind speed ---------- Average wind speed (mph): 4mph Highest wind speed (mph): 40mph (28th) Temperature ----------- Average temperature: 6.3°C Highest temperature: 13.0°C (28th) Lowest temperature: -1.3°C (10th) Rainfall -------- Total rainfall (mm): 22½mm Highest rainfall (mm): 4½mm (4th) Air pressure ------------ Average air pressure: 1023mb Highest air pressure: 1041mb (16th) Lowest air pressure: 998mb (28th) Appendix Weather Station Inventory (including equipment in active use as of 7 February 2000) 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) Three networked PCs 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