Monthly Summary - March 2011

   I don't tend to like March, but this one as been quite un-March like, dry, with rainfall well below average and with plenty of sun. It was also very anti-cyclonic with high pressure very much in the ascendancy; so much so that with a monthly mean of 1021.3 hpa at 0900 Hrs it is now my new holder of the highest monthly mean Hpa record. We had a reasonable number of frosts, particularly in the first eight days, but overall temperature wise the month was quite average.

   The first week of the month and hence Spring, saw very settled conditions with high pressure in charge and hence in that week we had no rainfall. An 'Area of high pressure' (AHP) (1038 hpa) was establishing itself over the UK on the 1st and come the 2nd whilst it moved NE (now 1043) it still extended a ridge over the UK and we were having fine and sunny days. At 8.4°c the temperature was pleasant enough in that sunshine, but as a result the first three days all saw widespread frost at night.

   The 1st had seen the air pressure reach 1041.2 hpa and it remained above 1030.0 hpa through to the 7th . With such conditions fog is always likely to occur and the 3rd saw fog first thing but this soon cleared to leave essentially another sunny day.

   From the 4th it all became a little chilly and cloudy for a few days as initially a cold front moved south from Scotland but only brought a trace of rain. That AHP was still in charge (typically 1035) and from mid-day on the 6th it brightened up again but was cool by both day and night and dropped to -2.9°c (26.8°F) in the early hours of the 8th. That AHP had retreated to the continent on the 7th and introduced cold and dry air from the continent but come the 8th we sat in a col between two AHP but with Atlantic weather fronts moving in and now introducing a SW'ly flow.

   We then had some rain that started with 1.7mm on the 8th and then through the evening of the 9th after a day of cool cloudy weather but with some sunny intervals. The 10th saw an 'Area of Low Pressure' ALP (980 hpa) in the Atlantic moving east and bringing showers and blustery conditions with it.

   The 11th started cloudy but bright, but the afternoon saw rain moving in that was preceeded by snow. Weather fronts moving NE met slightly colder air to start with, hence that snow, but it wasn't long before it turned to rain, which was heavy at times and with 17.9 mm was the months wettest day.

   The 12th brought another 3.9 mm of rain in cloudy and dull conditions from an ALP (999) sitting off the SW tip of Eire which had an associated warm front that ran through Eire and the north of the UK. Then the 13th again started cloudy and dull as the ALP (993) now over N. Ireland with associated cold front in the Irish sea, moved East overnight bringing a little rain; then once past us we had sunny and fresher weather for the afternoon.

   This middle period of the month had no one particular dominant feature to it and the days became quite mixed up. The 14th saw us in a slack area as a multiple centred ALP (1007) surrounded the UK but didn't encroach and the early hours saw the temp' drop to -2.9°c (ground frost of -5.6°c) which along with the 8th was the months coldest temp'. The 14th saw plenty of sun and clear skies but then the 15-17th were fairly disappointing. Light rain on the 15th brought on a weather front moving west over the UK and a cooler ESE'ly flow as we were inbetween AHP (1033) over Scandanavia and ALP (998) NW of Iberia.

   The 16th saw a day of fog as we now sat in a col with AHP to the NE+SW and ALP to the NW+SE. The 17th brought a trace of rainfall as a weakening cold front moved East, but then our weather was to return anti-cyclonic and high pressure once again dominated almost to the months end.

   The next thirteen days brought just 0.2 mm of rain (19th) at the end of which the ground had noticably dried and hardened. AHP (1022) centred south Eire began to build and establish itself and the settled and generally sunny weather began.

   Yes we were enjoying sunny days and whilst intitially day-time temps stayed below 10°c, from the 21st the temps started to pick up quite nicely (and the shorts came out!!). The AHP was 1033 Mb by the 19th and whilst it slipped East over Germany through the 20-21st it still held enough control over us and introduced a SW'ly flow. By the 22nd the AHP (1037) was back over the UK and dominant. At 15.2°c (59.4°F) the 22nd was the months warmest day. The sun continued and the days were dry; the 23rd saw the AHP peak at 1041.2 Mb and it was all fine Spring weather.

   My observation bunch of daffodils bloomed on the 25th (7th April in 2010) as the 30cm soil temp' shot up from 5.2°c on the 20th to 7.2°c by the 24th. The AHP then started a gradual decline and was replaced on the 26th by a slack pressure pattern with a weak ALP to the North of Scotland. The 27th saw us in cooler ESE'ly air (but still above 10°c) but despite the weakening high pressure it was still settled. The change came late on the 29th.

   The slack AHP (1019) retreated East on the 29th and in the late morning rain spread in as several frontal systems in the Atlantic progressed East. The month ended with some wet days, 8.0 mm 29th - 4.8 mm 30th and 11.7 mm 31st (although with 0900x0900 Hrs recording the majority of this fell on 1.4.11.). Occlusion fronts moved steadily NE on the 30th bringing mild and moist air on a S'ly flow and there was a developing ALP building SW of Eire for that rain 31-1st.

   Total rainfall was 59.9 mm and only fell on eleven days, despite the three wet days at the months end the monthly total was below the norm' for March.

   The Mean Temperature for the month was 5.55°c+         --      The Mean Max' was   9.54°c   --    The Mean Min'   1.55°c.

   We had 10 Air Frosts in the month (year 27)      --      Grass frosts totalled 13 (year 44).

   The 30 cm soil temp ranged from 4.6°c on the 8th to 7.8°c on the 31st with a monthly mean of 5.78°c


   * March 2011 rainfall was 69.33% of the March average for 08/09/10

   * March 2011 was 0.77°c warmer than March 2010   --   0.02°c colder than 2009 +

   * March saw 11 days of rain, of which 9 were wet days.

  * The 3 month mean for January/February/March 2011 is              TEMP'    4.32°c          -          RAIN    377.2 mm

* January/February/March 2010 was TEMP'    2.18°c - RAIN    140.6 mm

* January/February/March 2009 was TEMP'    4.24°c - RAIN    299.3 mm

* January/February/March 2008 was TEMP'    - RAIN    450.8 mm

   + Met office figures for March show that NW England/N. Wales had a mean temp' of 5.6°c, this being +0.4°c warmer than the reference period 1971-2000 (+1.0°c warmer than reference period 1961-90)


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   

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