UK Weather - Winter 2010/2011

[jrj]

I think that the article proves the futility of making ANY predictions about the future.....

[Simon Culling]

The relentless cold continues with no thaw setting in yet. It has been particularly dull here in Milton Keynes (the last time we saw the sun was on friday the 17th, ie 7 days ago) and as I type at lunchtime on Christmas Eve the stratus sheet still hangs heavily in the sky and its -1*C. The north and west of the UK have fared much better with plenty of sunshine but very low temperatures indeed. The Northern Ireland record low was broken again on wednesday (23rd) morning with -18.6*C at Castlederg. The reports from the climate stations are monthly, so even lower temps may have been recorded.

James, thanks for the reminder of that silly article from 2000, when a currently esteemed climate scientist said children would only experience snow in the virtual world. Major egg on the faces of those chaps at the moment. However, as has been said before, much of the globe has been warmer than average this year....its just our little bit thats been so cold.

Forecasts indicate some very cold nights over Christmas, but at least some welcome sunshine here in the south. Fronts pushing in from the west from monday (27th) hint at something a little less cold.

[Simon Culling]

The cold weather continued over Christmas with further cold nights, but at last some wintry sunshine. Very low temperatures occured on both Christmas + Boxing Day mornings, especially in the west and north of the UK, a feature of this cold spell.

Christmas morning lows included -18.2*C at Altnaharra (Sutherland, Scotland), -17.5*C at Katesbridge (Co Down, Northern Ireland), -16.8*C at Pershore (Worcestershire) and -16.5*C at Llysdinam (Wales). At Castelderg in the west of Northern Ireland the mercury only rose to -9.9*C all day, up from a low of -15.9*C, despite being sunny all day.

Boxing Day morning was cold over England, with lows of -16.5*C at Exeter Airport (Devon) and Shobdon Airfield (Worcestershire), -16.9*C at Katesbridge (N Ireland) and -15.8*C at Credenhill, near Hereford (Worcs).

Here in Milton Keynes we had a full snow cover (of 6-7cm) on both days and minimums of -6*C and -10*C respectively and max's of -2*C and -1*C, but at least we had plenty of hazy sunshine. Milder weather slowly spread north after Christmas bringing three days of fog on the tues, weds + thurs (28th-30th) with temps between 3*C and 6*C allowing the snow to slowly thaw. The New Year has seen a return to more normal winter weather, but on the cold side, with some rain, snow, frost, sun etc. It is nice to have a break from the numbing cold.

[Andy]

Thanks for your reports Simon. Keep them coming

[Simon Culling]

The cold weather has returned to Scotland, but hasn't really made it much further south and the coming week is set to see mild Atlantic air flood into W Europe. But Friday and Saturday (7th + 8th Jan) have been sub zero in inland Scotland with further snowfall (generally only 5-10cm). Yesterday (Sat) the max was only -3.1*C at Cassley (Northern Scotland) and at nearby Altnaharra only -1.1*C after a morning minimum of -13.0*C.

Here in Milton Keynes we reached the dizzy heights of 9*C in the early hours of Saturday with some heavy rain, but the temperature fell from dawn onwards to be just 4*C in the afternoon, although clear and sunny. It was cold on the terraces at Vicarage Road watching Watford beat Hartlepool 4-1 in the 3rd round of the FA Cup.

Met Office summary for December 2010 at the link below:

http://www.metoffice.gov.uk/climate/uk/ ... ember.html

Final CET (Central England Temperature) for December was -0.7*C, only 0.1 higher than the record cold December of 1890. Indeed, only 7 Decembers (incl 2010) have had mean temperatures below 0.0*C in the whole CET record dating back to 1659. The most recent cold December was in 1981 with a CET of +0.3*C. The 2010 figure gives an anomoly of approx -5.5*C, quite close to the end of the normal distribution curve!

[Simon Culling]

It has turned a lot milder over England + Wales in the last few days, but it is taking its time to reach Scotland. Yesterday (Wednesday 12th) was very mild with max temps of 13.0*C at Exeter Airport and 12.9*C at London Heathrow. The following night was balmy as well, with minimums at these stations of 11.8*C and 11.7*C respectively. It has also been rather dull and wet, with 50-100m in places in the SW of England and Wales.

Here in Milton Keynes the temperature reached 11*C on Wednesday, the first time it had been above 10*C since the 19th November 2010. It felt very mild indeed this morning on the way to work in the rain at 12*C and suffice to say, all the snow has gone. Will it return? If the northern blocking cycle repeats itself, we may see a return to the cold by the end of January and through much of February, with the air coming from the east this time, making the southern half of the UK the coldest part. Hopefully not.

The models short term are hinting at a lot of rain (orographically enhanced) for friday in the NW of England with as much as 200mm in Cumbria and then in Wales + SW England on Sat + Sun, with upwards of 100mm in places, and this is likely to cause at least local flooding. However, with resevoirs low for the time of year (they should be full), the water companies wont be complaining.

[Simon Culling]

The very mild conditions have continued with copious rainfall on the western slopes of the UK, but not too much making it across the mountains. In the 24 hours to 2100GMT on Saturday 15th, 111.6mm fell at Capel Curig (N Walea, 216m amsl), 104.2mm at Shap Fell (Cumbria, 255m) and 45.4mm at Eskdalemuir Observatory (Southern Uplands of Scotland at 242m). The local ascent was the classic for a 'warm converyor belt' with no wind change through height (ie no airmass change), it was sturated to 500mb and the freezing level was way up at 9000ft (700mb). With the air saturated to 500mb any ascent would precipitate out this moisture and the cloud efficiency would be near 100%, hence the high rainfall in prone areas. Thankfully there was little flooding.

High temperatures on the 15th were 13.5*C at Hawarden (Flintshire, Wales) and 13.2*C at Church Fenton (Yorkshire). The coldest place by day was Eskdalemuir with a max of 7.9*C. This is a far cry from the bitter cold of last month.

Models suggest a weakening of the Atlantic systems this week with high pressure taking control bringing cooler and quieter weather with fog + frost.

[Simon Culling]

The weather has been quiet and anticyclonic for the last week or so with nothing much to report. Some frost and fog, but generally cloudy with patchy rain + drizzle and daytime temperatures between 3*C and 7*C. The pressure reached 1040mb last friday/saturday (21st/22nd) and has remained high until the last couple of days. A low has moved SE (almost the 'wrong' way) into France from Scandinavia and will introduce cold continental air into the southern half of the UK tonight (Weds 26th) with a few snow flurries for the next couple of days.....then the high pressure returns.

It was quite cold on the 20th Jan with o/night lows of -10*C in N Ireland and NW England and it remained below freezing all day where fog persisted, with day max's of -2.2*C at Brampton (Cumbria) and -2.1*C at Castelderg (N Ireland).

[Richard]

Interesting Simon you say that the weather has been mostly anticyclonic while been generally cloudy with patchy rain or drizzle,is that common?rain while under the influence of high air pressure would be largely unheard of here,though we can get the odd cloudy anticyclone

[Simon Culling]

Richard, I must apologise for the time taken to reply to your question, but I have had a few problems with my computer in the last couple of months. We suffer from cloudy high pressures in winter here in the UK from time to time, and it is not unusual for there to be small amounts of precipitation, even with the pressure above 1030mb. I will find a couple of recent examples and expand on this at a later date.

Winter 2010/2011 turned out a little colder than average, thanks to the exceptionally cold December. The CET came in at 3.0*C for the winter, which is 1.1*C below the 1971-2000 average.

[Richard]

No worries Simon,great to see ya back

[Simon Culling]

Here is a recent example of precipitation from an anticyclone. On Saturday 22nd January 2011 light rain, sleet, snow and freezing rain fell across the southen half of England despite the pressure being near 1040mb, with 2.0mm at Manston (Kent), 1.8mm at Camborne (Cornwall), 1.0mm at High Wycombe (Buckinghamshire) and 0.8mm at Bedford. The latter two are within aprrox 30km of my location. The west of the UK was clear and sunny, with a sharp frost o/night, with mins of -7.3*C at Shap (Cumbria) and -6.3*C in Belfast. The map below gives the synoptic sitiuation at 00:00 on the saturday morning.

Here in Milton Keynes there was an overnight frost (minimum was -2*C) but it clouded over around 5am, with a period of light rain between 05:30 and 08:30 in the morning which started as freezing rain, giving a little rime ice on vegetation but not on the cars or roads. It remained cloudy and cold all day (max temp 4*C) with a few light rain showers in the afternoon and just a light N breeze.

Synoptic map courtesy of the Met office

[Simon Culling]

The final CET for the winter came out at 3.13*C which is -0.94*C below the 1961-1990 average, but all of this was due to the very cold December. Individual months were:

December -0.7*C (-5.3*C)
January 3.7*C (-0.1*C)
February 6.4*C (+2.4*C)

This illustrates the huge contrast between the exceptionally cold start to winter and the very mild end. During the former the NAO was very negative, but it swung back to positive towards the end of December as a single polar vortex reformed and the weather warmed up quickly. A feature of the winter over England (especially) was that it was drier and sunnier than average.

[Simon Culling]

A few more temperature figures taken from the COL Bulletin (Climatological Observers Link) from A rated stations that conform to Met Office site requirements.

The morning of Monday 20th December 2010 was the coldest over central England, with minimums of -17.0*C at Chipstead Valley (a frost hollow in the South Downs, Surrey), -16.9*C at Great Gaddesden (Hertfordshire) and also -16.1*C at Gestingthorpe (Essesx).