Monthly Summary - January 2013

   January had a little bit of everything. An unseasonably mild and notably dry start to the month was followed by a colder spell that whilst not experiencing anything too severe, did provide us with more snow than the whole of 2012! The month then finished with a westerly, cyclonic regime that brought a succession of wet days that became increasingly stormy.

   But the month with a 'bit of everything' quite remarkably became the eighth successive month to record in excess of 100 mm of rain (111.6 mm). Eight successive is remarkable in itself, but January only had 10.9 mm of rain at 0900 Hrs on the 25th and demonstrates how quickly the weather can change.

   Mean pressure showed an anomaly of -1Mb and despite 17 air frosts, the mean minimum temperature for the month (0.81°c) was actually a fraction above average, demonstrating that those frosts were not too severe. The mean maximum temperature of 4.97°c was 1° below average with the run of cold daytime temperatures through mid month more than off-setting the mild start and end to the month.

   With the month being just colder than average it continues the run of colder than average months, with only one of the last ten (August) being warmer than the local long term average.

   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 6.1°c and 101.5 mm of rain), 30 January's have been warmer, 22 have been colder, with 2 having the same mean temperature.


   1st - 6th    How often a change of month coincides with a change in the weather as the month started quietly under the influence of a slight ridge of high pressure (HP). It then became unseasonably mild as HP to the south of the UK saw Cumbria at its most northerly extent, but within a broad warm sector with that HP pushing any weather systems from the Atlantic north. But this was mild sub-tropical Atlantic air and the result was seen in the temperatures with both the 2nd and 3rd attaining 11°c (11.7°c / 53.1°f the month's highest temp, 3rd) - but with it came the murk.

   Under such conditions it was only ever going to be cloudy and long spells of drizzle were common although daily rainfall totals were insignificant and still the sun was an absent friend!


   7th - 8th    And the HP slipped south allowing fronts off the Atlantic to move east. However, rain was still only slight but still the murk persisted.


   9th - 10th    HP once again began to build behind a cold front from the 8th and this gave drier, clearer, cooler conditions and the 9th was a perfect sunny day! It also marked a steady change to much colder weather as now frost became a common feature and altogether a little bit more wintry and the 10th whilst overcast only peaked at 2.1°c.


   11th - 14th    HP over Scandinavia was building and this introduced much colder air from the continent and it also slowed the progress of any Atlantic low pressure (LP) systems. This effect of a 'blocking high' over Scandinavia was subject to an early forecast based on a 'Sudden Stratospheric Warming' (SSW) and was another term that was gaining wider public knowledge.

   When any weather systems did make progress east, they met that colder air and this gave us some wintry showers (13-14th) and until the 24th an anomalous ESE'ly flow that was both brisk and cool.


   15th - 20th    Initially during this period we sat in a slack area but still with a feed of cold continental air and the HP over Scandinavia then began to ridge south again and this saw the 16th start with the month's coldest temperature of -7.1°c (19.2°f) and a maximum of just -0.3°c saw it remain below freezing all day.

   The days through this period were bitter cold with a biting ESE'ly wind and a few light wintry showers. Ahead of a forecast for heavy snow on the 18th (Friday), Morrison's was unduly busy, but the snow did not arrive as the course of a LP system from the Atlantic was steered away from Cumbria, but with a maximum temperature of just -0.6°c (30.9°f) it was truly bitter and the month's coldest day.

   The diurnal range of temperatures became quite narrow as whilst night-time frosts were not severe, typically -0.1 to -1.0°c, daytime temperatures were only struggling to 0.4°c and considerably below the norm' for January.


   21st - 24th    An occluded front associated to LP that was moving north up the eastern side of the UK did manage to make sufficient progress east overnight 20/21st and this brought snow that lasted into the afternoon. The 'block' that is the Pennines to weather systems travelling east-west didn't prevent that snow, but it did greatly reduce its impact. A level depth of 3-5 cms was typical on the morning of the 21st, becoming 4-6 cms on the 22nd, although the further east you ventured the greater the depth of snow and the longer it prevailed.

   Light snow showers persisted throughout the period and with a fifth day of laying snow on the 24th, we had had more snow on the ground than in the whole of 2012!

   Cold air from that Scandinavian HP still sat over the UK and that HP once again ridged over the UK 23rd-24th and even gave a brief glimpse of a watery sun during the afternoon of the 24th.


   25th - 26th    With just 10.9 mm of rain the month had been very dry upto this point, but yes, that now changed. After one final cold night 24/25th, (-3.2°c) a succession of Atlantic LP systems persisted through to the month's end and marked the return to milder, but also wetter conditions.

   However, the LP system that would push the HP away on the 25th saw its pair of occluded fronts collide with the cold air of that HP and especially through tea-time and overnight, snow fell readily and caused disruption on the roads with trans Pennine routes in particular worst affected.

   The snow was sporadic and at times more sleet than snow, but during the late evening and into the 26th the snow became dominant and widespread. Roads became virtually impassable as one certain 'weather watcher' discovered on his way home from work at 1 a.m., after a few detours, one abandoned car and trudging the final 1.5 miles home to get back at 3.15 a.m. just as the snow stopped!

   Despite quickly melting snow on the 26th a winters scene greeted us and at 0900 Hrs a level snow depth of 7cms (melted equated to 15.0 mm) and even some sun. The next LP system arrived during the evening of the 26th and brought heavy rain (26.7 mm) overnight into the 27th, the month's wettest day and the snow was all gone.


   27th - 31st    To the month's end a strong SW'ly flow was dominant as a succession of depressions arrived off the Atlantic. The days became wet and stormy with gales recorded on each of the last four days of the month.

   The last week of the month saw just over 100 mm of rain and winds gusted to 51 Mph on both the 28th and 31st. It was also milder with 10.6°c reached on the 29th.

    The month ended with 7 'days of laying snow', snow fell on 13 with hail on two days. There were 2 'Ice days' and gales were recorded on 4.


   CONCLUSION    An intriguing month of weather that somehow, overall, nearly ended up as 'average'. I'm also coming to the point that I can't find the evidence not to term this run of 100mm+ month's of rainfall as 'unprecedented'!


   Rainfall totalled 111.6 mm for the month, with rain recorded on 17 days of which 12 were 'Wet days' (1.0mm +).

   The Mean Temperature for the month was 2.89°c      --      The Mean Max' was   4.97°c     --      The Mean Min'   0.81°c.

   We had 17 Air Frosts in the month (year 17)              --      Grass frosts totalled 21 (year 21).

   The 1 foot soil temp ranged from a low of 2.4°c on the 21st         to      a high of 7.0°c on the 8th     --      with a monthly mean of 4.3°c

   The 1 meter soil temp ranged from a low of 4.5°c on the 27-30th      to      a high of 7.0°c on the 8th-11th      --     with a monthly mean of 5.9°c



   * January 2013 rainfall was 77.25% of the January average for 2008 - 2012

   * January 2013 was 0.5°c warmer than the January average for 2009 - 2012, but 0.3°c colder than the local long term average

  * The 3 month mean for November/December/January 2013 is                   TEMP'     3.76°c         --          RAIN    538.3 mm

* November/December/January 2012 was TEMP'     5.47°c -- RAIN    379.7 mm

* November/December/January 2011 was TEMP'     1.42°c -- RAIN    295.0 mm

* November/December/January 2010 was TEMP'     3.02°c -- RAIN    446.8 mm

* November/December/January 2009 was TEMP'     -- RAIN    402.5 mm

* November/December/January 2008 was TEMP'     -- RAIN    447.9 mm



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   

   © Darren Rogers 2012

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