Monthly Summary - May 2011

   May generally disappointed, very wet, with more rain than the combined total of the three previous Mays and Cumbria had 150% of the norm'. It was noticeably windy and quite amazingly the month as a whole was the windiest recorded at this site. And then whilst the mean temperature may have been above the long term average, it was courtesy of mild nights as opposed to warm days, indeed day-time maximums were often on the chilly side.

   The month started well with settled conditions but then became generally changeable as low pressure was always dominant, either over or near to the UK.

   The 1st - 4th were pleasant days and carried on April's theme of dry, sunny days as an 'Area of High Pressure' (AHP) (1033) lay over Artic regions (Norway - Iceland) and whilst it was settled and sunny the position of the AHP drew in a cool E'ly wind that was quite brisk and hence it was chilly. We also had 2 air frosts (3rd+4th) in these few days - 4th at -1.3°c (29.7°F) the months coldest temp'.

   This run of dry days saw us qualify for a 'Partial Drought' (at least 29 days) which had commenced on the 6th April and those 29 days only amassed rainfall of 1.8mm. It also very much mimicked the partial drought of the same period last year 7.4.10. to 5.5.10. - proving to be a good time to holiday in this part of the world!

   After reaching the 29th and qualifying day of a partial drought, it all went downhill. Then rain arrived at tea-time on the 5th and there was now to be rain on every day of the month (although 19th and 31st were 'trace' days). 'Areas of Low Pressure' (ALP) were frequent visitors and sun was at a premium.

   The 5th saw an ALP (991) in the Atlantic moving east into Eire then the UK as that AHP slipped further East into Europe. That ALP (992) was persisting on the 6th and was bringing a warm and moist SW'ly flow (the month as whole was predominantly SW'ly). The 6th at 18.9°c (66°F) being the month's warmest day and also some thunder in the evening. The 7th was the months wettest day with 19.2 mm of rain with an ALP (989) West of Eire and that warm, moist SW'ly flow bringing troughs that brought the heavy rain although mainly in the evening.

   The 8th and 9th did see some sun, but also more rain as low pressure was still in the Atlantic and the dominant feature and pushing rain bearing troughs and fronts east. From the 11th an AHP built in the mid Atlantic that introduced a more W'ly airflow and whilst south and eastern parts of the UK were dry, we still had the rain.

   The rainfall amounts were not that great but with cloudy and dull skies it wasn't good. The months lowest day-time max' came on the 13th at just 12.1°c (53.8F) and indeed day-time temps' were typically in the range of 12-14°c - not good. Often the temp' at 1000 Hrs hardly increased throughout the day. It was only due to reasonably high night-time min' temps from those cloudy skies that kept the average temp' above the norm'.

   This middle period of the month became quite similar and dreary, cool by day, cloudy and with spells of rain, but in a way was better than what was to come!

   From the 20th a series of depressions passed over the UK bringing more significant spells of rain and even stronger winds. the 20th saw an ALP (984) south of Iceland with an associated cold front tracking SE that brought more showers and a devloping ALP to the west of the UK on the 21st saw rain move in by mid afternoon. It brought 16.6 mm (0900x0900 hrs readings) and gusts upto 39 Mph.

   But a depression was (992) building NW of Scotland that was quite unseasonal and this moved through on the 22nd with yet another depression (982) for the 23rd also from the NW of Scotland. They brought 11.5 mm of rain and gust upto 49 mph on the 22nd and then 13.3 mm of rain and gusts upto 53 mph on the 23rd. For May this is quite rare.

   Maximum gusts of over 30 mph were recorded on 17 days in the month and the mean wind speed of 9.6 mph for the month is a new high this site.

   And the ALP still dominated for the rest of the month. Showers were frequent, day-time temps were still typically 12-14°c and cloudy skies were the norm'.

   On the 28th an ALP (988) centred over Iceland brought a series of cold fronts SE and our way. At 1 p.m. that day in a particularly heavy rain shower the temp; dropped from 11°c to 7.8°c in the next hour.

   And so a disappointing month drew to a close, the last 11 days of the month averaged 10°c compared to 11.1°c for the first 10 days and those first ten days had seen air frosts!

   Rain fall totalled 112.6 mm for the month.

   The Mean Temperature for the month was 10.51°c+         --      The Mean Max' was   14.29°c   --    The Mean Min'   6.73°c.

   We had 2 Air Frosts in the month (year 30)      --      Grass frosts totalled 3 (year 50).

   The 30 cm soil temp ranged from 11.2°c on the 4, 24 + 25th      to      13.1°c on the 9th with a monthly mean of 11.9°c

  COMPARISONS:-

   * May 2011 rainfall was 303.8% of the May average for 08/09/10

   * May 2011 was 1.15°c warmer than May 2010   --   0.17°c colder than 2009 +

   * May saw 24 days of rain, of which 18 were wet days.



  * The 3 month mean for March/April/May 2011 is                   TEMP'    8.75°c         --          RAIN    216.2 mm

* March/April/May 2010 was TEMP'    7.33°c -- RAIN    112.4 mm

* March/April/May 2009 was TEMP'    8.21°c -- RAIN    155.2 mm

* March/April/May 2008 was TEMP'    -- RAIN    221.6 mm

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* 2011 To date TEMP'    6.77°c -- RAIN    533.5 mm

* 2010 Jan - May TEMP'    4.78°c -- RAIN    173.4 mm

* 2009 Jan - May TEMP'    6.45°c -- RAIN    410.7 mm

* 2008 Jan - May TEMP'    -- RAIN    536.5 mm

   + Met office figures for May show that NW England/N. Wales had a mean temp' of 11.2°c, this being +1.0°c warmer than the reference period 1971-2000 (+1.2°c warmer than reference period 1961-90)

   PREVIOUS MONTHS REPORTS

JANUARY 2010    FEBRUARY 2010    MARCH 2010    APRIL 2010    MAY 2010    JUNE 2010    JULY 2010    AUGUST 2010    SEPTEMBER 2010    OCTOBER 2010    NOVEMBER 2010    DECEMBER 2010   

JANUARY 2011    FEBRUARY 2011    MARCH 2011    APRIL 2011   

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