Monthly Summary - February 2013

   With a mean SLP anomaly of +4 Mb February finally brought us a dry and settled month, especially the second half when high pressure became dominant and finally that run of wet and unsettled month's is broken. Rainfall of just 27.5 mm represents 38% of the February mean and it is the driest of any month since December 2010.

   But with a mean temperature of just 2.59°c (Min' of -0.81° and Max' of 5.96°), February was notably colder than average and thus continues the run of below average month's. Ten of the last twelve have been colder than average (15 of the last 24). It was the coldest February since only 2010 and before that 2001.

   Frost was frequent during the month with ground frosts recorded on 25 nights and air frosts on 19, with the last 12 days of the month all recording air frosts. Apart from the 27-28th those frosts were never too severe as there was always just sufficient cloud cover to prevent a more complete temperature loss by radiation and also a breeze to stir the (cold) air and prevent it from pooling near the ground.

   Making comparisons with the Met' Office site at Newton Rigg from 1959, using the averages for the standard period 1981-2010 (mean minimum of 0.6°c and mean maximum of 6.6°c and 74.3 mm of rain), 38 February's have been warmer and 16 have been colder.

   Locally for the 1981-2010 period Warcop would average a minimum of 0.7°c maximum of 5.7° and rainfall of 70.4 mm - Keswick 1.4°c/7.4°c and rain of 119.9 - rainfall at Shap (1989-2012) being 194.5 mm.

   February also ends the meteorological winter of 2012-13 with a mean temperature of 2.87°c - since 1959/60 33 winter's have been warmer, 18 colder and 2 have the same mean temperature.

 

   1st - 2nd    The month started quietly as low pressure (LP) over Scotland gave way to high pressure (HP) to our west that ridged and drew down a cold northerly flow, but gave a sunny day on the 2nd.

   The 'Azores High Pressure' would be present long into the month, but it never took full control of our weather, occasionally ridging to give us some settled days, but was frequently squeezed south by LP systems from the Atlantic.

 

   3rd - 4th    The HP collapsed south as LP arrived from the Atlantic and which brought a strong westerly flow of unstable Polar Maritime air that gave wintry showers. A deep depression (956 Mb) near the Faroes pushed a cold front over the UK and this saw hail showers and gales with gusts to 54 mph.

 

   5th - 6th    Those winds veered NW on the 5th, which also started with a slight cover of snow. This had fallen in the early hours due to the passage of an occluded front and wintry showers persisted for most of the day. The UK lay between HP to the west and LP to the south, drawing down winds of an Arctic origin, but which did give clearer air and the 6th was a sunny day.

 

   7th - 12th    This period started with the ever present HP to our west once again ridging over the UK and saw the day start with a frost of -3.0°c and a day-time maximum of 2.1°c (35.8°f). It remained cold into the 8th which saw another slight dusting of snow at daylight, but the day was fine and sunny.

   The rest of this period tended to be quiet and uneventful, but generally overcast and chilly with day-time temperatures ranging from 2.1°c to 4.1°c with an anomalous ESE'ly flow. A warm front, later occluding, lay north-south over the western side of the UK and this gave some wintry showers overnight on both the 9th and 10th, falling as snow above 250 metres.

   The 11-12th saw us sit within a slack pressure gradient and the days remained cloudy but with some occasional brightness and remained dry; indeed rainfall upto the 12th was insignificant at just 10.9 mm.

 

   13th - 14th    LP to the west of the UK moved east during the 13th and as the warm front collided with the colder air sat over the UK, snow fell heavily on its leading edge. The snow had started falling early morning, just give a sufficient cover by 0900 hrs to class as a 'day of laying snow' and by mid afternoon lay at a depth of 3-4 cms. However, as the LP tracked east and displaced the colder air that snow turned to rain (14.5 mm making it the month's wettest day and provided more than half of the month's rain).

   In many ways it was typical of the snowfall that we have had this winter, confined to a short period brought on the leading edge of a depression moving west-east and as it met colder air over the UK and was neither prolonged nor too disruptive.

   The LP cleared away on the 14th to fresher, brighter conditions and ahead of an extended period of settled weather.

 

   15th - 28th    Through to the month's end dry and settled was the theme although it was cold at times, but also with some lovely sunny days.

   HP initially over France ridged north and began to build over eastern Europe/Scandinavia and the 17-19th were all fine, sunny and glorious with 10.8°c (51.4°f) on the 19th. The passage east-west of a cold front on the 20th brought a colder airmass and day-time temperatures fell away accordingly with a high of just 1.6°c (34.9°f) making the 22nd the month's coldest day.

   This cold front with a trough line following behind also introduced some wintry showers through to the 24th with the occasional heavy flurry of snow.

   The HP began to migrate west from the 24th, becoming established over the UK towards the end of the period and thus provided a glorious end to the month. The 27-28th were simply superb with unbroken sunshine from dawn to dusk. The clear skies now enabled heat loss by radiation at night but that sunshine provided some warmth during the day. As a consequence the 28th provided both the warmest and coldest temperatures of the month, 10.9°c (51.6°f) and -5.1°c (22.8°f).

 

   Rainfall totalled 27.5 mm for the month, with rain recorded on 10 days of which 5 were 'Wet days' (1.0mm +).

   The Mean Temperature for the month was 2.59°c      --      The Mean Max' was   5.96°c     --      The Mean Min'   -0.81°c.

   We had 19 Air Frosts in the month (year 36)              --      Grass frosts totalled 25 (year 46).

   The 1 foot soil temp ranged from a low of 3.0°c on the 8th, 24-25th and 28th         to      a high of 4.4°c on the 1st     --      with a monthly mean of 3.5°c

   The 1 meter soil temp ranged from a low of 4.8°c on the 25-28th      to      a high of 5.3°c on the 4th-7th      --     with a monthly mean of 5.0°c

 

COMPARISONS:-

   * February 2013 rainfall was 38.7% of the February average for 2008 - 2012

   * February 2013 was 0.9°c colder than the February average for 2009 - 2012 and 1.0°c colder than the local long term average



  * The 3 month mean for December/January/February 2013 is                   TEMP'     2.87°c         --          RAIN    379.3 mm

* December/January/February 2012 was TEMP'     3.93°c -- RAIN    308.6 mm

* December/January/Febraury 2011 was TEMP'     1.73°c -- RAIN    341.6 mm

* December/January/February 2010 was TEMP'     1.20°c -- RAIN    154.0 mm

* December/January/February 2009 was TEMP'     -- RAIN    346.8 mm

* December/January/February 2008 was TEMP'     -- RAIN    472.4 mm

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OTHER WINTER INFORMATION


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                 2012-13       2011-12         2010-11       2009-10        2008-09        2007-08
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Air Frosts           48            30              40            57                                 

Ground Frosts        64            59              56            81                                 

Ice Days              3             0              13             6              1                  

Laying Snow          11             3              23            32             16              3   

Falling Snow         26            19              20            39             14                  

   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    MAY 2011    JUNE 2011    JULY 2011    AUGUST 2011    SEPTEMBER 2011    OCTOBER 2011    NOVEMBER 2011    DECEMBER 2011   

JANUARY 2012    FEBRUARY 2012    MARCH 2012    APRIL 2012    MAY 2012    JUNE 2012    JULY 2012    AUGUST 2012    SEPTEMBER 2012    OCTOBER 2012    NOVEMBER 2012    DECEMBER 2012    SUMMER 2012    REVIEW OF 2012   

JANUARY 2013   

   © Darren Rogers 2012

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