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graphs      CLIMATE-UK.COM'S  REVIEW  OF  THE  BRITISH  METEOROLOGICAL  SCENE
     MONTHLY  SUMMARY
     No. 569          A CHANGEABLE MONTH WITH A HOT FINISH; DULL AND WET IN THE WEST AND NORTH       For     MAY      2003
Text Box: A changeable southwesterly regime prevailed until the 25th, although there were brief northwesterly interludes around the 14th and 24th. High pressure built across the UK during the last six days of the month. Mean sea-level pressure ranged from 6 mbar below normal off northwest Scotland to 4 mbar above over the Bay of Biscay, resulting in a strongly westsouthwesterly anomalous flow over the British Isles. The first three days of May were very unsettled with outbreaks of rain, heavy locally, but southern, central and eastern districts were warm and sunny on the 4th with highs approaching 23°C. Between the 6th and 10th a showery southwesterly airstream prevailed, with longer periods of rain at times in western and northern regions, and it was windy around the 7th/8th with gusts over 60kn in the Western Isles. Throughout this period eastern England and the Midlands were pleasantly warm and quite sunny with only isolated showers. However, showers broke out more widely between the 11th and 14th as low pressure transferred eastwards across northern Britain, and winds gradually veered northwesterly. Some of the showers were heavy with hail and thunder, but they died down after dark leading to widespread ground frost on several nights. Many places had a moderate air frost overnight 14th/15th, the temperature falling to -4.3°C at Loch Glascarnoch (Wester Ross) and to -3.4°C as far south as Bastreet (Cornwall). The 15th itself was a largely dry and bright day as a ridge crossed the country, and the fine weather continued on the 16th in the far north, with Lerwick (Shetland) enjoying 14.8 hrs of sunshine. Text Box: A disturbed southwesterly weather type returned from the 16th to the 23rd, veering northwesterly on the 24th and 25th. Belts of rain crossed all districts from time to time, with brighter showery weather between; many of the showers were heavy and some brought hail and thunder. There was a general paucity of sunshine during this period, and daytime temperatures were close to or slightly below the seasonal average. A strong rise of pressure began on the 25th, and an anticyclone developed over the British Isles thereafter. It was generally cloudy and rather muggy at times especially in western and northern Britain, but southern and eastern districts became sunnier with maxima around 25°C from the 28th onwards; on the last two days highs of 28-29°C were common and the 31st was the hottest May day since 1953 at several sites in the Midlands and the South. Monthly mean temperatures were around 1 degC above normal in most regions, and 2 degC above in East Anglia and northeast England. Most regions were wetter than average, with more than twice the normal amount of rain locally in southwest Scotland, northern England and north Wales, but it was another dry month in some southern counties (from Devon to Sussex) and in the south Midlands. Sunshine was up to 30 per cent below normal in western Scotland and Northern Ireland, but generally within 10 per cent of average over the rest of the UK.
                                                                                                                                         
                       TEMPERATURE                                SUNSHINE                             RAINFALL        
                                                                                                                                 
                                                                                                                                 
                                          Highest and lowest totals                     Highest and lowest totals        
                                              on record for month    
Maximum fall in 24 hrs (beginning 09 h)
                    on record for month    
Days with snow or sleet
 
Days with fog (Vis <220 yards at 09 h)
 
                                                                                         
     
Difference from average
   
Difference from average