January 2010 retrospective
December 2010 often steals the show in conversations and rightly so, it was a historic month where apart from England, it was the coldest of any December known on record going back to the 19th century. This is made ever more exceptional by all the background warming that has been occurring and 2010 globally was a record warm year at the time. December wasn't the only month of 2010 that contained a severe cold spell however, January did also and it was nationally the coldest January since 1985 in Ireland and 1987 in the UK. January 2010 formed as part of the coldest winter since 1978-79 (coldest since 1962-63 in Scotland) with frequently below average temperatures on and off throughout the season whilst January contained the coldest weather. This blog post will be a retrospective on the cold and snowy month of January 2010 and will hopefully bring back some memories!
To give some background context - after the 'Beast from the East' episode in mid-January 1987 which resulted in the coldest UK weather possibly since 1740 in terms of daily maxima, a significant period of winter warming occurred with most winters from 1987-88 onward to be milder than average and containing very little snow events with a few exceptions such as 1990-91, 1995-96 and 2000-01. Winter 2008-09 wasn't anything special overall either but it contained the snowiest weather in southeast England since 1991 in February 2009 and some theorised that it was a heads up from nature that the weather had something different up its sleeve in succeeding winters as compared to the vast majority since 1987. What followed was a series of cold winters from 2009 to 2013 with the exception of 2011-12 which was the "joker in the pack" though still contained a very cold spell for eastern parts of the UK during February 2012. Winter 2009-10 was the coldest of the series and as mentioned was the coldest of any winter since 1978-79 but is overshadowed by the December in the following winter which was the first subzero Central England Temperature (CET) month since February 1986. However, whilst January 2011 was also a largely colder than average month as compared to popular belief, February 2011 was exceptionally mild and the least wintry February since 1998. 2009-10 in comparison had cold weather on and off through all of the meteorological winter months which comprise of December to February with the coldest period by far occurring from mid-December to mid-January and especially through the first 10 days of January which was the coldest 10-day period for many since the mid-80s or 1991.
The year of 2010 started off appropriately so with the UK & Ireland in a cold north to northeasterly flow. Overnight snowfalls in northeast England caused disruption. Snow depths were up to 33cm at Aviemore (Highlands) and 23cm at Redesdale (Northumberland). There were snow showers through the day across the north and northeast of the UK, north and east of Ireland and light flurries across the English Midlands with heavy snow for southwest Wales later on. Frost was widespread and this would be a common theme throughout with localised ice day conditions.
The instability reduced somewhat through the 2nd to 4th as the wind veered more northerly but there were further snow showers at times in the north. There was widespread spells of crisp winter sunshine and severe frost overnight.
By the 5th however, fronts descended southward and a shallow area of low pressure formed within a cold airmass over the UK. Heavy frontal snow occurred in Scotland and northern England through the day with this snow moving down to the Midlands and southern England later on. Parts of Ireland were also affected but the snow here tended to fall more on the 6th, especially in the east. Spadeadam (Cumbria) reported a snow depth of 40cm. Some schools were forced to close in Wales as a result of the snow.
Further snow occurred over southern and eastern Britain through the 6th and indeed the 7th too forcing over 8000 schools to close across England & Wales. The Met Office had issued severe weather warnings for all regions. Accumulations were in excess of 40 cm for parts of eastern England. Six inches of snow fell in Kent in a 4-hour period early in the day. Thundersnow was reported in Dublin with significant accumulations for eastern Ireland. Depths on the 7th included 57cm at Westgate (Durham), 55cm at Oyne (Aberdeenshire), 33cm at Malham Tarn (North Yorkshire), 26cm at Reading (Berkshire) and 22cm at Wiggonholt (West Sussex).
Severe frosts followed with the coldest nights of the winter being observed on 7th and 8th January. Altnaharra (Highlands) recorded -22.3°C early on the 8th which was the lowest temperature in the UK since 1995 and lowest January temperature since 1982. Most places had their lowest temperatures since January 1982. Woodford (Greater Manchester) recorded a minimum temperature of -17.6°C on the 7th which was a record low for Manchester. With deep snow cover and very little of the UK escaping snow as well as freezing fog, there was also notable ice day conditions to be had across the country. This was less the case in Ireland where snow cover tended to be more biased to the north and east of the country. Hawarden (Flintshire) did not get above -7.8°C all day on the 7th. 7th January 2010 was overall the coldest day in the UK since 28th December 1995 - the CET min on the 7th was the lowest for any day since January 1987.
An easterly flow developed on the 9th as pressure rose over Scandinavia bringing in yet more snow showers. These snow showers merged into more persistent bands of snow through the day and into the 10th spreading westward across the south of the UK and into eastern parts of Ireland. Kildare and Wicklow were badly impacted by the snowfalls with a foot reported in places. Conditions were not great in north Wales where Gwynedd had recorded over 40 cm in accumulations adding to already deep snow cover from prior days that had not melted. Ferry services from Holyhead and Dublin were cancelled. There were 15 metre drifts over Snowdonia. It continued to be severely cold elsewhere with Altnaharra not getting above -13.5°C on the 10th.
A band of rain, sleet and snow travelled northwards through the 11th. This brought slightly milder conditions to the south and west and a thaw was slowly underway. However, the more dramatic thaw occurred on the 12th as a more active system approached from the southwest bringing heavy rain initially to southern Ireland including Valentia Observatory (Co. Kerry) having its wettest January day on record with 58.5mm. This rain bumped into the established cold air across the UK and Ireland and led to yet more snow for wide parts dropping a further 5-10cm. Odiham (Hampshire) reported a depth of 24cm. This was temporary as milder air successfully made its way decently northward but freezing rain fell onto frozen roads in northern England causing accumulations of black ice. It remained cold and snow conducive over Scotland and northern/northwestern parts of Ireland on the 13th with Knock Airport (Co. Mayo) reporting a snow depth of 20cm. This continued on the 14th with a milder conditions everywhere on the 15th ending the longest cold spell since 1981 in the UK and since 1963 for Ireland. However, that wasn't the end of the snow.
Rain from the west brought blizzards over the Welsh mountains, Shropshire hills and Pennines on the 20th. Accumulations were up to 2 feet on Snowdonia. It tended to be too mild for lower levels to observe much snow.
The month of 15th December 2009 to 15th January 2010 had a CET of bang on 0C but keep in mind this includes a slightly milder period between Christmas and New Year for the south of the UK and much of Ireland whilst Scotland remained cold throughout. Nevertheless, you have to go back to February 1986 to find a colder monthly CET.
Do you have any memories of January 2010 or indeed the entire winter of 2009-10? Do you think it gets terribly overshadowed by December 2010? Let us know on Twitter or in the comments. I hope you've enjoyed this perspective and I didn't waffle on too much with my usual gobbledygook!
Also, if you have any images you'd like to share from January 2010, feel free to send them in and they'll be added to the gallery below.
I'll conclude with an iconic satellite image of the UK snow covered on 7 January 2010 courtesy of NASA :)