Monthly Summary - April 2011

   April was simply an amazing month, very warm (nationally the warmest April recorded), dry and very sunny. High pressure was virtually present for the whole month, either over the Uk or nearby. What more could you want? It doesn't get any better than this.

   By the months end we had recorded several temps over 20°c and were well on the well to drought conditions and most will have forgotten that the month had actually seen a very wet start.

   That wet start ensured a reasonable monthly rainfall total, just up on the average of the last three years, but what followed was warm, dry and sunny days and at the months end the ground was hard and dry and beginning to show signs of loose dust, the river was also running very low.

   The 1st was a wet and windy day with 11.0 mm of rain brought on a series of frontal waves that moved NE up the country and being mainly active in our part of the world. Heavy rain continued overnight into the 2nd and into the morning as 'An area of Low pressure' (ALP) (970) near Iceland extended a waving cold front south across the UK, ahead of which was a warm sector with strong winds and a trough that was responsible for that heavy rain. Fresher conditions then followed once the trough had moved through.

   The 3rd continued the fresher theme with sunny intervals but then the 4th was a truly awful day. 26.8 mm of rain fell, that was to be 61% of the monthly total (the 1st and 4th combined provided 88% of the months rain). It was windy as well, gusting to 46 Mph as we were in a strong westerly flow and an occlusion front brought that rain.

   The 5th again saw rain, 2.6mm as a strong SW'ly flow with as a series of fronts moved through. This was to be the last significant rain of the month and the last day to be classed a 'wet day' (day of 1.0mm+), which with just three wet days recorded in the month is the lowest such total to be recorded at this site.

   'An area of high pressure' (AHP) was building over the continent and it was this that was to dominate our weather for some time.

   The 6th had seen rain overnight into the morning but that cleared to leave a sunny but windy day. The 6th was to become the first day of a 'partial drought'. We now entered a period of settled weather that brought a run of sunny days. That AHP over France was now nudging North and our weather became settled, dry and warm, the best of it even managed to fall on weekends and bank hoildays!!

   The 7th saw the AHP (1028) in Biscay and initially this brought a NW'ly flow over the top edge of the high pressure, but as the AHP developed and became more established over the UK the airflow returned to a SSW'ly. Whilst the 7th only saw 12.9°c (55.2°F) the next few days saw the temp's climb and the weekend of the 9/10th saw 19.7°c on the Saturday and 19.8°c (67.6°F) on the Sunday as the AHP (typically 1029) was now established over the UK. It was dry, the skies were clear and the sun was beating down. At the end of that weekend I had eaten out in my garden more times than in the whole of 2010!!

   A fantastic weekend was followed by a noticeable dip in temperatures over the next few days and through the 11-13th we saw a little rain, fresher conditions and by the 13th only 7.6°c (45.7°F) as a a day-time max', this being the months coldest day. A weak cold front had moved through on the 11th, but a fresh W'ly flow was introduced on the 12/13th due to AHP (1038) centred in the Atlantic to the SW of the UK and a ALP (997) to the west of that.

   From the 13th AHP (1031) over France began to extend a weak ridge over the UK, but we had a little rain in the form of showers due to that ALP (1006) to the west of Eire. The 14/15th saw cloudy days follow early mist due to a slack AHP (1019) over the Uk. Gradually the temperatures began to rise as that AHP took control and maintained settled conditions. A period of exceptional warmth was to follow.

   That AHP was in charge through to the 22nd and from the 19th the sunny days returned and on the 20th we recorded 20.7°c (69.3°F). This is by far the earliest in the year on which 20°c has been recorded at this site, we had just missed out earlier in the month, but now we had three successive days over this mark (it should be noted that April 2007, now relegated to the 2nd warmest April on record, was also very warm and even Shap recorded 21.5°c that month,).

   The months warmest day came on the 21st, an amazing 23.1°c (73.6°F). We may have been on the westen edge of that AHP sitting over Europe, but it controlled our weather. The 22nd saw 21.4°c and the days whilst a little hazy were sunny.

   The 23rd saw some rain through the early hours as a cold front lay over the West of the UK and associated troughs moved through, the AHP was now gone - but not for long. The 24th was back to lovely sunny weather as we sat in a Col between AHP's to the NE and SW and ALP to the NW and SE and from the 25th the AHP was back, but this time there was a slight difference.

   The difference was a cool E-ESE'ly wind caused by the AHP being located to the North of the UK and migrating further North, leaving us at its southern most edge and hence drawing in those cooler winds from off the continent. The days were sunny, the 28th especially and whilst the temp's were never going to threaten that 20°c mark, they were respectable at 16-17°c - BUT, that wind was brisk, noticeable and had a distinct chilly edge to it. It all became quite repetitive, 'Sunny, little cloud, but chilly wind', but hard to complain when its sunny all day. Although the weather folklore saying of 'When the wind is in the East, tis' no good for man nor beast' did seem quite apt.

   The early hours of the 28th saw the temp' dip to -0.3°c, the months solitary air frost and coldest temp'.

   By the months end we had gone 25 days with just 1.8 mm of rain, a prolonged 'Dry Spell' but well on the way to what would become a 'Partial Drought' on the 4th May (29th day) when the days still remained rainless. This was a direct mimic of last year when we had a partial drought from 7th April through to the 5th May.

   But simply it was the warmth and the sun that made April a record breaker and a quite exceptional month.

   The Mean Temperature for the month was 10.2°c+         --      The Mean Max' was   15.1°c   --    The Mean Min'   5.3°c.

   We had 1 Air Frost in the month (year 28)      --      Grass frosts totalled 3 (year 47).

   The 30 cm soil temp ranged from 8.2°c on the 1st to 12.2°c on the 23rd and 25th with a monthly mean of 10.35°c

  COMPARISONS:-

   * April 2011 rainfall was 110.4% of the April average for 08/09/10

   * April 2011 was 2.3°c warmer than April 2010   --   1.4°c warmer than 2009 +

   * April saw 9 days of rain, of which 3 were wet days.



  * The 3 month mean for February/March/April 2011 is                   TEMP'    6.9°c         --          RAIN    278.3 mm

* February/March/April 2010 was TEMP'    4.7°c -- RAIN    122.0 mm

* February/March/April 2009 was TEMP'    6.1°c -- RAIN    113.3 mm

* February/March/April 2008 was TEMP'    -- RAIN    285.1 mm

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* 2011 To date TEMP'    5.8°c -- RAIN    420.9 mm

* 2010 Jan - April TEMP'    3.6°c -- RAIN    158.6 mm

* 2009 Jan - April TEMP'    5.4°c -- RAIN    339.5 mm

* 2008 Jan - April TEMP'    -- RAIN    511.3 mm

   + Met office figures for April show that NW England/N. Wales had a mean temp' of 10.6°c, this being +3.6°c warmer than the reference period 1971-2000 (+3.8°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   

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