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graphs      CLIMATE-UK.COM'S  REVIEW  OF  THE  BRITISH  METEOROLOGICAL  SCENE
     MONTHLY  SUMMARY
     No. 628            For    APRIL    2008
    A SHOWERY MONTH WITH FREQUENT HAIL AND THUNDER; COLD PERIOD 5TH-19TH
Text Box: The north-westerly and northerly winds which had so dominated March returned from the 5th-16th, but the remainder of the month was rather episodic with short easterly, south-westerly, anticyclonic and cyclonic spells. Over the month as a whole, pressure was below normal over Europe and the Atlantic south of latitude 60degN but above normal further north, and markedly so over Greenland. Over the UK it was both the most northerly and the most cyclonic April for seven years. The first four days were rather cloudy but warm with high pressure centred near south-western Britain and a moist westerly airflow covering the country; the best of the limited sunshine was found along the English Channel coast. The temperature reached 15-18°C widely, with 18.9°C at Inverbervie (Kincardineshire) on the 3rd. A strong rise of pressure in the Iceland area led to the development of a deep northerly flow between the 5th and 7th; temperatures dropped sharply, there was extensive frost at night and widespread wintry showers by day, and on the 6th a trough embedded in the northerly flow brought a longer period of snow which was heaviest in Southeast England and the Thames Valley - a snow-depth of 11cm was noted at several locations in Oxon, Berks, Hants, Surrey and Kent. That morning’s lows included -6.0°C at Warcop (Cumbria), while afternoon maxima were no higher than 1.9°C at East Malling (Kent) and 2.0°C at Kenley (Surrey) making this the coldest April day in these counties possibly since 1966. Lerwick (Shetland) reported a gust of 57kn, the month’s highest. Low pressure lay over or close to the British Isles from the 9th to the 15th, maintaining a very showery regime; some of the showers were heavy and prolonged, often falling as hail, and occasionally accompanied by thunder. Showers were fewest, and sunny spells longest, in western and southern coastal districts. Daytime temperatures remained well below the seasonal norm in all regions, while frost developed widely at night, and the lowest temperatures of the month occurred overnight 13th/14th and 15th/16th with minima of -6.8°C and -6.6°C respectively, both at Braemar (Aberdeenshire).
Text Box: A brisk east to north-easterly flow covered the UK from the 16th-22nd, maintaining the generally cold weather. All eastern, central and southern districts were cold and dull during the 17th-19th with rain at times, but it became less cold and somewhat brighter here from the 20th. Western Scotland, meanwhile, enjoyed prolonged sunshine, but with frosty nights. Altnaharra (Sutherland) logged -5.1°C on the morning of the 21st, while Tiree (Inner Hebrides) recorded 112h of sunshine in the 10-day period 12th-21st. The flow veered south-westerly from the 23rd-26th, bringing showers or longer periods of rain to all areas, and Broadford (Skye) collected 42mm on the 25th. It became progressively warmer, and the 26th was a fine and very warm day with the temperature climbing above 20°C quite widely, and reaching 22.0°C at Weybourne (Norfolk). The mercury fell no lower than 13.4°C the following night at Hampstead (London). It was only slightly less warm on the 27th, but showers and thunderstorms broke out quite widely that day and the next. A deep depression crossed southern England on the 29th and 30th (central pressure 985 mbar) bringing periods of rain, heavy at times, to nearly all parts of the country. Both mean maximum and mean minimum temperatures were within 0.5 degC of the long-term average in all regions; nonetheless it was the coldest April since 2001. Although rain fell frequently, often in showery form, amounts were generally not large (except on the 29th-30th) and it was actually a moderately dry month over much of East Anglia, the Midlands, northwest England and Northern Ireland. Hail was unusually frequent, being reported on as many as 12 days at some sites. As for sunshine, there was a marked contrast between inland parts of northern England and southern Scotland where it was a very cloudy April, and western and southern coastal districts where it was a sunny one. Sunshine totals ranged from 85 hours at Eskdalemuir (Dumfriesshire) to 238 hours at Portland (Dorset) and 240 hours at Guernsey airport (Channel Is).
                                                                                                                                             
                       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
 
Highest maximum