Storm Emma made itself felt on Thursday with sustained strong winds, frequently gusting to 20mph-30 mph, producing a wind chill of -9C. The thermometer hovered around -3.1C all day but late afternoon and evening eased upwards to -2.0C.
Snow fell for most of the day, light and dry, that in the strong winds caused blizzard conditions and considerable drifting.
The snow eased off over night so that today it is cloudy with the wind rising again, peaking at 37mph. No further snow has fallen since dawn.
Friday update at 11.15: temperature -1.9C and wind chill -7C. No new snow this morning, just occasional flakes in the air and what looks like light drizzle earlier but likely to be freezing rain – not venturing out to check!
Friday update at 13.00: heavy snow just started. Temperature-2.0c, wind chill -8.1C.
Friday update at 15.30: wind over last three hours beginning to fall a little lighter, dropping about 5mph on earlier gusts, as barometric pressure begins to rise again as storm Emma eases away. Temperature still -1.9C and wind chill dropped to -7C.
Update at 21.00: temperature rising gradually as milder air eases northwards, now up to -1.6C, warmest for three days.
Summary for February 2018 and Winter 2017/18
Winter returned with a vengeance in February. There was a brief mild spell during the third week but on only eight days did the maximum exceed the 34-year average. This day occurred on the 19th when the thermometer rose to the dizzy heights of 10.9C, being 3.6C above the average. In contrast the thermometer did not get above freezing on the 28th with a maximum of just -1.2C.
For exactly half the month there were air frosts of some degree, some very hard, with the coldest night occurring on the 28th when the thermometer dropped to -9.8C. Therefore it is not surprising to find that the average temperature for the month was 2.2C below the long-term average. It was the coldest February since 1991 and the 4th coldest since 1984, when this station began recording, only 1985, 1986 and 1991 being colder.
The last week of February was bitterly cold. The stratospheric warming of the higher atmosphere temporarily reversed the flow of the Jet Stream so that instead of winds coming from the west, for eight days they came from the northeast bringing cold air direct from Siberia. Adding to the cold were the strong winds gusting between 20 and 30mph producing wind chill that at the end of the month meant it felt more like -11C.
It was the second consecutive month with below average rainfall. A total of 54.9mm of precipitation was recorded being 10.3mm below the 34-year average. Over half the rainfall occurred on two days with 13.2mm and 17.5mm on the 8th and 14th respectively.
The high pressure over Scandinavia that brought the northeasterly winds meant that we enjoyed many hours of sunshine on a number of days. I recorded 110 hours of strong sunshine (100w/sq.m.) during the month with 8.5 hours and 9.2 hours on the 24th and 25th respectively. That is almost twice the average over the past four years since this instrument was installed.
The soil temperature at a depth of 5cm averages around 3C for February but the exceedingly cold days and strong winds meant that frost penetrated deep into the soil. The average for 2018 was 1.4C with a reading of -1.7C on the 27th.
There were 5 days when snow flurries or showers were recorded, but no great depth of snow occurred.
The past winter was the coldest for five years being 0.3C below the 34-year average. January was 1.2C above average but February being 2.2C below meant that overall it was a below average temperature season.
Rainfall for the past winter was again below average, the second successive drier than average season with 244mm in total being just 4mm below the 34-year average. The past two winters have now shown a deficit of 97mm of rainfall, which is much needed to refill the aquifers.
After the previous dismal winter, when just 121 hours of sunshine were recorded, the past winter total was 213 hours.