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25 years since this firecracker May. May 1999 was a very warm and thundery month. It has a C.E.T. of 12.9 (+1.5) and an EWP value of 56.2mm (88%). The month began warm and sunny with high pressure and 25C was reached at Saunton Sands on the 3rd. The first thundery outbreak of the month on the 7th as a large rash of thunderstorms across the continent grazed the south-east. The 10th saw violent thunderstorms in the north and west. In Wigan a thunderstorm around 12pm gave hail up to 25mm causing small dents in cars in the south of the town. The following days saw further thunderstorms scattered around with a weak trough over the country. There were multiple reports of funnel clouds on the 14th, this one at Corby. After a few quieter days the volatile weather returned on the 19th courtesy of a slack trough with a warm south-easterly flow. After a warm and humid day (24C), thunderstorms occurred over south-eastern and central southern England during the early evening, moving to the south Midlands later in the evening. Some thunderstorms were heavy in the south-east with hail in places (1cm in diameter at Maidenhead where 20mm fell in 20 minutes, the temperature fell 7C during the early evening storm, pressure rose 2mbar and roads were temporarily flooded). The NOAA12 channel 4 thermal image at 1637 GMT (courtesy of Bernard Burton) shows what appears to be a mesoscale convective system of storms during this event. At Crowthorne, 26.3mm fell between 1630 GMT and 1745 GMT. In Hampshire, golfball-size hail fell at Easton and Itchen Stoke, and the hail was still lying 15 hours after the storm. Conservatory roofs, glasshouses and guttering were damaged by the storm and gardens and crops were devastated there, and several minor roads were flooded. There were also reports of large hail on the Isle of Wight. Just before the most volatile spell of weather there was a notable thunderstorm courtesy of a strong cold front on a north-westerly wind on the 24th. What was described, on local TV and press, as a mini tornado occured at North Ferriby (near the Humber Bridge) in the evening. Although damage did occur, i.e. branches broken off trees, house windows and car windows smashed by falling trees and branches, it was very localised. The end of May 1999 featured some of the most intense storms of the month and have definitetly etched a memory in many people's minds. Low pressure associated with some exceptionally warm air (15C into the south-east) gave a very violent day on the 27th. Warm and sunny conditions at first until thunderstorms began moving north-east across south-west England, reaching Lincolnshire and Norfolk by midnight. In Bradninch (Devon), a thunderstorm began at 1800 GMT; the observer noted at least 40 cloud-to-ground strikes with a roof and tree struck; 18.8mm fell from 1800 to 2115 GMT. A thunderstorm at Keyworth (Notts.) from 2245 GMT to 0015 GMT on the 28th resulted from a line of spectacular storm cells slowly moving N across South Nottinghamshire with frequent long lasting cloud to cloud and cloud to ground strikes; a brief period of intense rain followed as the storm gradually flickered away to the north leaving a chorus of car and house alarms. Many observers commented upon the intensity of the lightning displays, while at Chalfont St. Giles a dust deposit was left by the rain. In the Solihull area damage reports included: 30000 households without power, lightning set fire to vent pipes connected to fuel tanks at a petrol station at Cradley Heath, and lightning blew a hole in the roof of a new Midland Metro tram and set it alight. The 28th was a calmer and cooler day giving a brief interlude of calmness before intense storms broke out again on the 29th. A very warm day with 27C recorded in Southampton. England and Wales began dry and sunny and became quite warm in places. An area of thundery activity (accompanied by hail in places) moved into south-west England by 0600 GMT, moving north-east and spreading to the east Midlands and East Anglia by late evening. A thunderstorm at Bristol (Totterdown) from 1215 GMT until 1515 GMT resulted in 18mm of precipitation, including 10mm from 1325 GMT to 1338 GMT when a 26 kn gust occurred. During the passage of a thunderstorm at Wokingham from 1551 GMT to 1608 GMT 15.7mm of rain fell, with a peak rainfall rate of 199 mm/hr around 1554 GMT over a two and half minute period. Thunderstorms resulted in local flooding in many areas (eg. in parts of SW and Cent S England) and there were reports of small tornadoes in the SW. Rainfall under the core of the storms was heavy, eg. 25.4mm at Cirencester (of which 15mm fell in 15 mins with winds of force 5 to 7). Several places from Birmingham to Wokingham reported rapid pressure fluctuations during these storms (associated with temperature falls as large as 5degC). Hail in a storm at Dartford was 1cm in diameter, while in Danbury (Essex) 17mm fell in 5 minutes. The 30th was a much cooler day with leftover cloud, mist and murk as is so usually the case. The high at Cirencester was just 11.8C. This paper goes far more into detail about the extraordinarily intense storms of the 29th of May, 1999 so give it a read. http://www.ijmet.org/wp-content/uploads/2016/05/241.pdf The very thundery activity continued into early June 1999. The arrival of a thundery low meant storms began to break out on the 1st. Thunderstorms were reported from Devon around 1600 GMT and the Channel islands around 1900 GMT. These moved NE during the evening to affect much of Cent S England by midnight; 17mm of precipitation fell at Hurn (Bournemouth) in the 6 hours starting 1800 GMT. The thundery activity spread to Norfolk and east Kent by dawn on the 2nd with 12-hour rainfall totals ending 0600 GMT including 26mm at Heathrow, 22mm at Hurn and 21mm at Boscombe Down. 28mm fell at Reigate during the overnight storms, while the daily rainfall total at West Totton (Hampshire) amounted to 35mm. At Lewes (East Sussex) hail 1 inch in diameter fell around 0230 GMT. The storms brought lightning, which struck a signalling cabin before dawn at Shenfield, Essex, causing rail delays to London. On the Surrey stretch of the M25 part of an embankment subsided. Flooding closed several London Underground stations. In Rayleigh (Essex) lightning struck a house and set fire to the loft. During a catamaran race in Weymouth Bay a sudden squall with a SE force 6 wind capsized 77 boats and led to the rescue of 154 competitors. Roads were flooded in many areas, and lightning disabled the emergency phones on the M1 and M45. There are unconfirmed reports of a tornado being sighted near Hockley Heath (near Birmingham), accompanying a thunderstorm with hail, during late afternoon, and also one over the Bristol Channel near Newport during late morning. In Warwick, 3 people were hit by lightning, and 5 people in York were similarly affected. During the afternoon there was an increase in wind and gustiness in S England; a gust to 49kn occurred at Worthing. In Northamptonshire the leisure centre in Rushden was closed due to flooding; 170 storm-related calls made to the Fire Brigade and 180 businesses throughout Northants were without power during the day. Radar image for 12pm on the 2nd of June, 1999 What a remarkable period for thunderstorms from the 27th of May to the 2nd of June, 1999. And indeed a remarkable year for thundery, being the thunderiest year on record. A vintage year for storm lovers. We really don't get this anymore! As of typing, some of the outlook for mid-May is looking quite thundery so perhaps 25 years later we may see similar conditons... Probably not.

I am currently writing an account of events I was involved in on the night of 3/4 January 1979 in the Southwest Approaches to the UK. There was a very significant winter storm that night and whilst I am able to write about what it was like to be in it I would like to locate some data to illustrate the account. I have found on this site a 500mb (hpa had been invented then ) chart, but would rather like to find a surface analysis as the account is intended for a non-professional audience. In addition, I would like to find either regional forecasts or reports for the period or ideally, Actual Weather Reports (Actuals) or Terminal Airfield Forecasts (TAFs) for the UK Master Diversion Airfields (MDA) . Can anyone assist me? Thanks, exmpa