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graphs      CLIMATE-UK.COM'S  REVIEW  OF  THE  BRITISH  METEOROLOGICAL  SCENE
     MONTHLY  SUMMARY
     No. 584 For   AUGUST   2004
  VERY WET WITH FREQUENT THUNDER; HOT FIRST WEEK THEN PROGRESSIVELY COOLER
Text Box: Pressure was almost uniform over the British Isles during the first week, but a cyclonic type prevailed from the 8th-25th followed by almost a week of westerlies. Overall, this was the eighth least westerly and the ninth most cyclonic August in the last 100 years. Mean sea-level pressure anomaly ranged from -1mbar in Shetland to -8mbar in southwest Ireland. The hot weather of late-July continued until the 8th with maxima of 26-30ēC daily in southern, central and eastern districts, peaking at 31.5ēC at Northolt (London) on the 8th, and the temperature climbed as high as 27ēC even in northern Scotland on the 2nd. The night of 8th/9th was abnormally warm with several local records broken: at Marham, Norfolk, the minimum was 21.7ēC. However, haar affected North Sea coasts and the Northern Isles, and Lerwick had no sunshine for seven consecutive days to the 4th. Thunderstorms broke out widely on the 3rd and 5th; worst hit areas included London and the Thames valley, the Midlands, northwest England and southwest Scotland. Eskdalemuir collected 61mm on the 3rd, and High Wycombe 42mm in 40 minutes the same afternoon. Large hail was reported from Bracknell on the 5th. A deep depression (in part ex-hurricane Alex) lay to west or southwest of the UK from the 8th-11th before crossing the country on the 12th/13th. A new depression settled west of Ireland from the 14th-18th, and yet another (ex-hurricane Charley) tracked along the English Channel on the 18th/19th. Throughout this period the weather was very disturbed, thundery, and often humid. Prolonged heavy rain affected all except northern Scotland between the 8th and 11th, during which period 100mm-plus fell widely; Aberfeldy recorded 143mm and serious flooding ensued. Over the next several days rainfall was mainly convective in
Text Box: character, and a fall of 200mm (nearly all in four hours) at Ottersham, north Cornwall, led to the catastrophic flash flood at Boscastle on the 16th. Short-lived tornadoes were observed on several occasions. Further notable falls of rain included 62mm at Camborne, Cornwall, on the 17th; 82mm at Lerwick, Shetland, on the 18th/19th, and 56mm (mostly in one hour) at Thurleigh, Beds, on the 20th. On the 20th a northerly airstream set in temporarily behind a cold front, the day's maximum at Wilsden (West Yorks) was 12.7ēC, and under a short-lived ridge of high pressure the temperature dropped to -0.8ēC at Tulloch Bridge, Lochaber, overnight 21st/22nd. A depression tracked north-eastwards across the UK between the 23rd and 25th bringing further widespread rain followed by heavy thundery showers but for the remainder of the month the depression track shifted to the north of Scotland, with westerly and north-westerly winds over the UK. Gusts to 70kn were reported from northern Scotland on the 27th, but several places in eastern and southern England ended the month with four dry days. The 31st was dry and sunny almost everywhere. The main feature of August's weather was its exceptional wetness. Over England and Wales there has been none wetter since 1956; monthly totals exceeded 300mm locally in southern Scotland and northern England, and a few sites here collected more than three times the long-term average. By contrast, several places in northern Scotland were drier than normal. Sunshine was generally close to the long-term mean, and in Shetland it was a very sunny month, but central and south-east Scotland together with northeast England reported a shortage. In spite of the cool last ten days, mean temperature was everywhere above average, typically by 1-2 degC, and the CET was the 12th highest in the 345 year-long record.
                                                                                                                                             
                       TEMPERATURE                                SUNSHINE                             RAINFALL                                                       
                                                                                                                                     
                                                                                                                                     
                   
No. of days with grass minimum below 0ēC
                      Highest and lowest totals    
Maximum fall in 24 hrs (beginning 09 h)
                Highest and lowest totals    
Days with snow or sleet
 
Days with fog (Vis <220 yards at 09 h)
 
     
Difference from average
   
Difference from average
             
Days of no sunshine
                      on record for month                         on record for month        
                                                                                         
           
Highest maximum
   
Lowest minimum
         
Maximum duration
       
First year of record
         
Days of no rainfall (0.1 mm or less)
         
First year of record
         
Days with thunder
     
       PLACE  
Mean Maximum
   
Mean minimum
             
No. of air frosts
       
Total for month
                   
Total for month
                   
                               
% of average
                   
% of average
                 
                                                                     
                                   
Highest
   
Lowest
 
Year