back
graphs      CLIMATE-UK.COM'S  REVIEW  OF  THE  BRITISH  METEOROLOGICAL  SCENE
     MONTHLY  SUMMARY
     No. 568               MOSTLY DRY, WARM AND SUNNY            For    APRIL    2003
Text Box: Anticyclonic conditions prevailed until the 23rd, but the last week of the month was markedly cyclonic. Mean sea-level pressure ranged from 2.5 mbar above normal in Shetland to 2 mbar below in southwest Ireland, resulting in a southeasterly anomalous flow over the British Isles. A trough moved southeast across the country on the 1st followed by a cool northwesterly airflow, but pressure quickly rose again and an anticyclone lay over or close to the UK from the 3rd to the 8th, and a weak ridge of high pressure persisted until the 11th. A belt of rain moved southwards across all areas on the 1st followed by a cool day on the 2nd with sunny spells, wintry showers and isolated thunderstorms. The next three days were generally warmer and mainly dry; maxima of 18-21°C occurred in some areas. From the 7th to the 11th most southern, central and eastern districts were cold with maxima of 5-8°C in many places, and there were hail and snow showers on the 9th and 10th; meanwhile parts of Scotland and Northern Ireland continued relatively warm and sunny. Sharp overnight frosts occurred widely with temperatures dropping to -4 or -5°C in the coldest spots in northern England, the Midlands and Wales. From the 12th to the 17th the British Isles were sandwiched between low pressure off southwest Ireland and high pressure over the Baltic, resulting in a warm southeasterly airflow over the country. It became generally cloudy for two or three days and rain in western and northern regions deposited substantial amounts of Saharan dust, but it was much warmer than the preceding week and overnight minima of Text Box: 13-14°C on some western coasts were exceptionally high for April. After the 14th it became clear and sunny with maxima of 22-26°C widely reported from the 15th to the 18th. The high of 27.4°C at Stratfield Mortimer (Berks) on the 16th was the highest anywhere in the UK in April since 1949, the 27°C the same day at Prestatyn (Flintshire) was the highest in Wales since 1893, and the 26.9°C recorded at Lochcarron on the 17th established a new Scottish record for the month. The airflow backed easterly from the 18th to the 20th, and eastern and central regions became much cooler and cloudier. A shallow northward-moving depression on the 20th-21st was followed by a short-lived ridge of high pressure, but active Atlantic disturbances crossed the country at frequent intervals from the 24th onwards. Showers and thunderstorms were well-scattered at first, although 39mm fell at Aboyne (Aberdeenshire) on the 21st, but rain fell much more widely on the 24th and 25th; at Loftus (N.Yorks) rain on the 24th ended a 42-day period with no significant rain. The rest of the month was very disturbed with belts of rain alternating with brighter showery weather - even the showers were often heavy with hail and thunder; over 100mm fell at Cardinham (Cornwall) during the last week. It was the warmest April, averaged nationally, since 1987, the driest since 1997, and the sunniest since 1990. Mean maximum temperatures were 2-3 degC above normal and mean minima around 1 degC above. Over England and Wales rainfall averaged 20 per cent below the long-term average, while sunshine was 25-30 per cent above.
                                                                                                                                           
                       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