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graphs      CLIMATE-UK.COM'S  REVIEW  OF  THE  BRITISH  METEOROLOGICAL  SCENE
     MONTHLY  SUMMARY
     No. 646 For   OCTOBER  2009
A QUIET, MOSTLY DRY, RATHER DULL MONTH WITH FEW GALES. OFTEN RATHER COLD UNTIL THE 21ST, THEN WARM.
Text Box: September’s long anticyclonic spell ended as October opened, but there was a further anticyclonic period from the 12th-18th, and an anticyclonic/southerly spell during the last week. Overall, westerly and southwesterly winds blew less frequently than usual and there were few gales. With the late-September anticyclone receding to mid-Atlantic, a deepening depression tracked from Iceland to southern Scandinavia between the 2nd and 4th bringing rain and strong winds to most regions. The rain was very heavy and prolonged in the north and west -- 100mm at Cassley (Sutherland) and 97mm at Cluanie (Lochaber) in 48h -- but amounts were small in the south and east. The gust of 61kn at Tain (Cromarty) on the 3rd was the month’s highest. In the wake of the depression the 4th was drier and brighter, but with widespread frost that night in Scotland. A complex depression which included the remnants of Tropical Storm ‘Grace’ crossed the UK on the 5th and 6th, with a frontal zone lingering over southern England on the 7th. Rain fell in all areas on the 5th and 6th, but it was warm and muggy for a time, the temperature reaching 21.2°C at Coningsby (Lincs) on the 6th under cloudy skies. The minimum the following night at Jersey airport was 17.0°C. Further heavy rain affected southern England on the 7th, but it was drier and brighter further north, and the next day was generally sunny though it was rather cold after an overnight frost. There were further outbreaks of rain or showers between the 9th and 11th, and it remained rather cold in the north; the maximum of 7.2°C at Loch Glascarnoch (Wester Ross) on the 9th was the month’s lowest. Pressure rose steadily across the country on the 11th and 12th, and an anticyclone covered the UK from then until the 18th. The 12th and 13th were sunny over England
Text Box: and Wales (10.5h and 10.2h at Southampton on the respective dates), but low cloud and local drizzle became embedded in the circulation of the high thereafter, although there was still some local sunshine -- for instance on the 15th in the extreme Southeast where it became warm briefly, and in Scotland and Northern Ireland on the 16th and 17th where night frost developed widely. The temperature fell to -4.0°C early on the 17th at Tyndrum (Stirlingshire) and to -3.7°C on the 18th at Aboyne (Aberdeenshire). Low pressure lay off southwest Ireland from the 19th-22nd and a broad belt of rain crossed all regions, lingering for much of the 21st and 22nd over northeast Scotland where 83mm fell in 48h at Dyce (Aberdeenshire). Another vigorous depression crossed Ireland and Scotland on the 24th and 25th bringing further rain and strong winds; 79mm fell in 48h at Tyndrum. From the 26th onwards a broad southerly flow covered the UK, and the weather was warm but rather muggy and cloudy at times with further rain, heavy at times, in northern and western regions. Courtesy of a föhn effect, the temperature at Aber (Caernarfon) reached 20.2°C on the 27th, 19.9°C on the 29th and 20.5°C on the 30th. Averaged nationally, this was the warmest October for three years, the driest for two, and the dullest for four. Although it was predominately rather cold until the 21st, the warmth of the last ten days lifted the mean monthly temperature about 1degC above the 1971-2000 average in most regions, although in northern Scotland the excess was less than 0.5degC. Rainfall was rather above average in northern and eastern Scotland, but 20-40 per cent below over much of England and Wales. Sunshine totals were widely below the long-term average, but generally by less than 30 per cent.
                                                                                                                                             
                       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
   
Lowest minimum
   
No. of days with grass minimum below 0ºC
   
Days of no sunshine
 
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
             
Highest
   
Lowest
 
Year
       
             
Date
   
Date
         
Date
         
Year
         
Date
         
Year
           
                                                                     
      ºC       ºC       ºC       ºC             Hrs       Hrs         Hrs       Hrs       mm       mm         mm     mm          
                                                                                                                                             
  *Hampstead   15.4   +1.2   08.9   +0.8   18.0   06   03.5   18   02   00   03   07.2   08   074   069   1910   169   1997   050   1976   15   08.6   07   037   056   1910   177   1987   05   1947   00   00   00  
  Thorney Island   16.0   +0.9   09.5   +1.8   19.5   01   00.6   18   01   00   03   10.5   12   102   083   1958   176   1994   076   1963   14   20.2   07   065   076   1941   213   1987   02   1969   00   00   00  
  *Wattisham   14.8   +0.7   08.2   +1.5   18.9   06   02.5   18   02   00   05   09.8   08   076   068   1968   155   1997   055   1976   10   18.6   21   052   098   1960   139   1960   03   1972   00   00   00  
  *Wittering   14.9   +1.2   07.9   +1.2   19.9   06   03.0   09   03   00   04   09.1   13   085   077   1950   165   1959   051   1976   19   11.2   06   041   077   1948   126   1960   04   1978   00   00   00  
                                                                     
  Lyneham   14.6   +0.7   08.5   +2.0   18.1   06   02.7   18   03   00   05   09.9   12   113   100   1952   161   1999   053   1968   16   08.2   07   040   059   1945   176   1949   05   1978   00   00   00  
  Ross-on-Wye   15.6   +1.4   08.6   +1.8   19.3   06   02.6   08   01   00   04   07.7   12   092   092   1915   156   1919   037   1915   18   12.8   06   045   068   1859   216   1907   09   1969   00   00   00  
  *St Athan   15.2   +1.3   09.8   +1.7   18.2   06   03.3   17   00   00   06   10.1   12   091   086   1954   153   1997   045   1968   13   13.0   23   071   081   1954   249   1998   11   1978   00   00   00  
  Culdrose   15.4   +1.1   10.4   +1.5   18.1   05   04.9   13   00   00   06   09.5   08   090   077   1961   145   1999   059   1968   13   23.7   19   079   083   1961   227   1987   15   1969   00   00   00  
                                                                     
  *Edgbaston   14.5   +1.3   09.2   +1.9   19.0   06   04.8   08   00   00   01   08.7   12   077   075   1887   152   1997   027   1893   15   14.6   31   048   056   1887   191   1998   07   1969   00   00   00  
  *Valley   15.1   +1.0   10.0   +0.9   19.1   29   03.5   17   02   00   05   10.0   12   088   078   1946   151   1965   053   1968   13   24.8   06   073   091   1941   208   2000   09   1947   00   00   00  
  *Woodford   14.5   +1.2   07.4   +0.8   19.3   06   -00.2   12   08   01   05   09.6   12   073   071   1945   136   1959   062   1960   13   12.2   31   048   059   1942   191   2000   14   1946   00   00   00  
  *Watnall   14.7   +1.0   08.3   +1.6   19.8   06   03.7   08   03   00   05   07.9   13   083   074   1948   133   1995   045   1960   15   17.6   06   058   108   1942   143   1960   08   1947   00   00   00  
                                                                     
  *Leeming   14.4   +0.9   07.3   +0.8   16.8   06   -01.0   18   03   02   07   09.5   08   090   091   1945   144   1981   047   2005   10   08.8   31   044   076   1945   134   2004   07   1962   00   00   01  
  *Boulmer   13.4   +0.7   08.3   +1.4   17.2   31   02.8   18   01   00   12   09.0   03   070   065   1945   156   1986   046   2005   07   26.0   21   081   116   1945   159   2002   07   1985   00   00   00  
  *Eskdalemuir   12.5   +0.9   05.5   +0.9   14.9   15   -02.5   07   11   04   12   09.0   16   068   082   1911   130   1959   037   2005   06   33.0   24   147   090   1911   334   2008   12   1951   00   00   01  
  *Bishopton   13.4   +0.4   07.7   +1.4   16.8   15   00.7   17   04   00   07   09.7   16   096   111   1921   138   1993   030   1940   06   25.4   30   131   116   1921   266   1995   20   1951   00   00   00  
                                                                     
  *Leuchars   13.6   +0.7   07.2   +1.2   18.1   14   01.7   16   10   00   09   09.9   03   089   082   1922   152   1986   048   1960   09   13.4   27   065   102   1922   183   2004   05   1951   00   00   00  
  *Dyce   12.5   +0.1   07.7   +1.8   17.8   28   -00.5   09   03   01   09   09.6   03   088   089   1941   156   1986   030   1960   08   61.6   21   181   204   1941   230   2002   08   1985   00   00   00  
  *Stornoway   12.5   +0.6   07.8   +1.1   15.5   30   02.2   07   07   00   08   06.5   07   074   092   1880   135   1898   034   1921   03   22.0   02   138   093   1943   231   1989   19   1946   00   00   00  
  *Aldergrove   14.1   +1.3   09.0   +1.9   16.3   24   00.7   17   03   00   08   07.3   08   069   079   1927   117   1939   049   1954   11   15.2   31   076   079   1927   176   1976   19   1951   00   00   00  
                                                                     
                                                                                                                                             
  Stations marked with an asterisk record sunshine electronically; comparisons      
  with earlier records are therefore somewhat speculative.   Thorney Island's      
  sunshine figures are made at a nearby site.