Monthly Summary - December 2012

   If November went from bad to worse, then what can be said for December? With 240.2 mm (9.45 inch) it became the second wettest month on record at this site and we have now also endured 7 consecutive months of over 100 mm of rain.

   Slightly surprising that with 547.4 mm the Oct-Dec period is not the wettest of any 3 month period as Nov' 1974 to Jan' 1975 at Crosby Ravensworth all recorded over 200mm for a final total of 699.2 mm (Newton Riggs highest 3 month total being 540.6 mm in December 1989 - February 1990).

   However, apart from a wet day on the 6th, the first two weeks were relatively dry. They were also cold with some wintry spells and frosts were common, some of which were severe and which despite a recovery in the temperature from mid month, were mainly responsible for the month ending slightly cooler than average with a mean temperature of 3.12°c. We also had the peculiar situation of the month's highest temperature occurring in the early hours of the morning!

   From the 14th the month became cyclonic with a series of rain bearing frontal systems arriving off the Atlantic and which became increasingly stormy towards the month's end and which saw both the 9+10th wettest days recorded at this site.

   Making comparisons with the Met' Office site at Newton Rigg from 1961, using the averages for the standard period 1981-2010 (mean temperature of 3.4°c and 105.0 mm of rain), 33 December's have been warmer, 17 have been colder, with 1 having the same mean temperature.

 

   1st - 2nd    The month continued where November finished, under the influence of high pressure (HP) and this made for cold days with a northerly flow, although quite pleasant with plenty of sun. The night-time frosts were keen though, with -6.2°c (20.8°f) on the 2nd. But late evening on the 2nd saw the arrival of a frontal system connected to low pressure (LP) near Iceland and as these fronts came up against the cold air, snow was the outcome.

 

   3rd - 4th    The snow from overnight (2nd) gave a slight covering on the morning of the 3rd. However, as that frontal system pushed through, the snow quickly turned to rain. Behind those fronts troughs circulated in an unstable airmass that saw showery conditions on the 4th with an occluded front slowly moving south out of Scotland that brought a little more rain.

 

   5th    Saw a return to HP and a perfect sunny day, but at just 1.3°c (34.3°f) it was cold and still with a northerly flow.

 

   6th    Was a truly awful day as LP to the north of the UK replaced the HP and brought heavy rain (26.1 mm) on its associated fronts. However, as with the 2nd, as the warm front met the colder air, snow fell, heavily, on its leading edge during the morning, giving upto 1.5" of laying snow. The snow then turned to rain and which, especially during the afternoon, fell heavily. However, on ground above approximately 250m's the snow continued and caused some disruption on the roads.

 

   7-9th    Was a mixed picture as both HP and LP systems visited. A little snow fell overnight into the 7th and HP began to build to give a settled day. After a fairly insignificant passage of LP on the 8th, the 9th whilst milder than previous days, felt cold in a brisk WNW'ly but with clearer air behind the fronts from the 8th.

 

   10th - 13th    Marked a cold downturn in our weather, but the much heralded 'Beast from the East' failed to appear as forecast! HP became established from the north, extending a significant ridge over the UK and gave a bright day on the 10th. The 11th started with a frost of -4.3°c and fog, that whilst never too thick, lingered all day. This saw an 'Ice Day' (temperature remained below freezing for the entire 24hr period) at Maulds Meaburn with the year's coldest day of -0.9°c (30.4°f).

   However, due to a fairly classic 'inversion' of temperature, this fog and the coldest temperatures where to be found in the valley's, whilst higher locations such as Shap (1.3°c) were warmer and above the fog and enjoyed a fine sunny day.

   After dark the temperature plummeted quickly to a month's low of -7.1°c (19.2°f) but cloud built during the night and temperatures recovered. However, the 12th was still a cold day, but brighter and the temperature did rise above freezing.

   And the final day of this period (13th) was a fine sunny day, but the HP was collapsing due to the presence of LP in the Atlantic and now the rest of the month would revert to type; cyclonic, unsettled and wet.

 

   14th - 17th    The LP sat in the Atlantic was vast, stretching from the eastern seaboard of America, over to the UK and down to North Africa and circulating within were numerous fronts and troughs. It did also bring milder conditions, but only marginally above the average maximum of 6.4°c for the time of year.

   Gloom greeted us on the 14th and then in the afternoon it rained (12.4 mm). Pressure dropped to a two year low of just 969.8 Mb and the 15th was much a repeat of the 14th with a further 10.6 mm. Pressure slowly rose and whilst the 16th was a dank day, the fact that we had avoided anything significant with the bar dropping so low, was a surprise.

 

   18th    Saw a reasonable day with some hazy sunshine as a weak and very temporary ridge of HP gave a quiet day, but only ahead of the next series of unsettled weather arriving from the Atlantic.

 

   19th - 31st    And these days were depressing. Heavy and prolonged rain with gloomy and dank conditions being the order of the day and with some stormy conditions. For the period 19-29th we had eleven days of solid cloud, 100% cloud cover at the morning observations on every day!

   LP with multiple centres sat in the Atlantic and these in turn would move east, pushing a series of frontal systems over the country. These systems contained warm and moist air bringing that rain and a brisk and cool feeling ESE'ly wind. This resulted in rain of 23.7 mm (19th) and 22.9 mm (20th). This rain took the monthly total above the 100 mm mark. The 'dry' day (3.3 mm) of the 21st was probably the gloomiest with a patchy fog settling in after dark.

   LP was still sat across the Northern Atlantic on the 22nd and this pushed yet another complex frontal system up from the SW across the UK. This brought yet more rain (12.2 mm) and then overnight into the 23rd the temperatures climbed to the dizzy heights of 10.8°c (51.4°f), which was quite staggering in that this temperature came in the early hours and was 3.1°c warmer than the anything else in the month to date!

   These temperatures came courtesy of a warm front, quickly followed by a cold front and they brought gale force winds with a maximum gust of 56 Mph and to the month's end the winds turned south westerly. Behind these fronts the 23rd, after a showery start, brightened up but with a brisk and mild Sw'ly wind.

   The big day (25th) was drizzly and overcast, but we still had a lot of weather to come! The 28th saw LP (979 Mb) in the Atlantic push a warm front north east over the UK that brought wind and rain and then the passage of the connected cold front occurred during the evening and into the 29th and this gave a stormy night with frequent gusts over 50 Mph, peaking at 56 Mph. With 35.8 mm of rain it was to be the 10th wettest day at this site.

   Unbelievably worse was still to come as the 30th saw a new frontal system arrive during the evening and after a day of showers, this system brought yet more 50 Mph winds and heavy rain, which with 36.4 mm became the 9th wettest day. In just the three days we had had 79.7 mm and the impact of this rain on already saturated ground is by now well known.

 

   CONCLUSION    Possibly an appropriately terrible end to a terrible year says it all.

 

 

   Rainfall totalled 240.2 mm for the month, with rain recorded on 22 days of which 20 were 'Wet days' (1.0mm +).

   The Mean Temperature for the month was 3.12°c      --      The Mean Max' was   5.67°c     --      The Mean Min'   0.57°c.

   We had 12 Air Frosts in the month (year 62)              --      Grass frosts totalled 18 (year 136).

   The 1 foot soil temp ranged from a low of 2.4°c on the 14-15th         to      a high of 6.1°c on the 29th     --      with a monthly mean of 4.0°c

   The 1 meter soil temp ranged from a low of 5.5°c on the 16-18th      to      a high of 7.5°c on the 1st-2nd      --     with a monthly mean of 6.1°c

 

COMPARISONS:-

   * December 2012 rainfall was 219.9% of the December average for 2007 - 2011

   * December 2012 was 1.34°c colder than December 2011      --      5.1°c warmer December 2010      --      1.18°c warmer than 2009



  * The 3 month mean for October/November/December 2012 is                   TEMP'     5.30°c         --          RAIN    547.4 mm

* October/November/December 2011 was TEMP'     7.82°c -- RAIN    400.9 mm

* October/November/December 2010 was TEMP'     3.51°c -- RAIN    241.8 mm

* October/November/December 2009 was TEMP'     6.18°c -- RAIN    472.6 mm

* October/November/December 2008 was TEMP'     -- RAIN    395.6 mm

* October/November/December 2007 was TEMP'     -- RAIN    283.3 mm

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* 2012 TEMP'     8.26°c -- RAIN    1415.9 mm

* 2011 TEMP'     9.17°c -- RAIN    1305.4 mm

* 2010 TEMP'     7.42°c -- RAIN     702.9 mm

* 2009 TEMP'     8.84°c -- RAIN    1264.5 mm

* 2008 TEMP'     -- RAIN    1381.3 mm

   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    SUMMER 2012    REVIEW OF 2012   

   © Darren Rogers 2012

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