A: The short answer is yes they are. The Central England temperature series [CET] reveals that winters [DJF] are now on average 1°C warmer that they were 140 years ago back in 1878 (fig 1), and the England Wales Precipitation [EWP] series indicate that they’re also 18.6% wetter (fig 2).
I am reliably informed that the spring vernal equinox will occur at precisely 1615 UTC today this 20th day of March 2018, but the weather is in a fickle mood at the moment, and spring, well at least the start of it, looks like it will be a cold affair in our part of the world. The Met Office in their extended outlook till the middle of April (fig 1) is being its usual unequivocal self about the possibility.
In line with that outlook, the GFS model for April 1st (fig 2) is forecasting a northerly outbreak which is not at all unusual for spring across the British Isles.
Cold springs are somewhat of a rare commodity these days, and the last one to produce negative anomalies in Central England was back in 2013 (fig 3), and in the last 30 year there have only been three cold springs (2013, 1996 and 1991).
Despite the last record couple of cold days in Central England, I reckon that the average number of degree days between the winter solstice and the vernal equinox was exceeded on the 14th of March this year (fig 1).
This normally would make the first day of spring around a week early, but because springs have been occurring earlier on average (20 days earlier than in 1772 and now around the 11th of March each year), 2018 was around three days late this year, it was also the latest spring to have occurred since 2013.
I personally think that using degree days like this is a crude but effective way of coming up with a date for the start of spring, let me know if you have a better idea.
Yesterday, the 18th of March 2018 was the coldest for that particular day in March since 1853. That’s according to the latest provisional Central England mean temperatures released from the Met Office (fig 1). The maximum for Sunday was 0.6°C and the minimum -2.2°C, and the mean of -0.8°C, was almost 6.6°C lower than the 1961-1990 long-term average of 5.8°C.
Only four other years have reported negative mean temperatures for the 18th of March (fig 2 & 3) in the daily mean CET series that started in 1772, they were 1900, 1853, 1814 and 1812.
Don’t forget that you can keep an eye on the latest daily CET values here
Looking at the observations for yesterday and the reported 06 to 18 UTC maximum temperature (fig 4), many stations across central England and Wales had sub-zero maximums, in fact at a number of stations, the temperature has remained below zero the whole weekend, which just two days from the vernal equinox is highly unusual.
I think the thermograph for the last few days from Rothamsted in Hertfordshire gives a good account of how quickly the cold snap set in last Friday, and just how cold the last 48 hours have been across the country (fig 5).
A slightly premature press release from the Met Office regarding the latest cold spell and today’s snow (fig 1). Maybe it would have been better waiting for tomorrow to release it, in light of the fact that it’s still snowing across large parts of Devon and Cornwall (fig 2).
The temperature at Gravesend yesterday was 13.6°C at 12 UTC, and today at the same time it was just 0.1°C, which makes it 13.5°C colder. To be honest there are a good number of stations which are 10°C or colder than they were 24 hours ago, and I’ve outlined them on the chart (fig 1). You can of course get large variations in temperature in the late winter and early spring, but today’s must take some beating, and looking at the latest NWP it looks like there may be more large swings in temperature in the coming week.
It’s time to roll out that old cliché blog title that I’ve used a number of times before from that old Dinah Washington song – what a difference a day makes, 24 little hours – you know the rest, because temperatures in eastern parts of the country are between 4 and 8°C lower at 06 UTC this morning than they were at the same time yesterday. I think it’ll be even more interesting to compare today’s maximum with yesterday’s, so keep posted and tell all your friends.