The Pacific Decadal Oscillation

Until last week I knew that the PDO was an acronym for the Pacific Decadal Oscillation but little else. I now know a little more thanks to the Wikipedia and this very informative article from the North Carolina Climate Office of all places (fig 1). Two data sets I had got a little confused when looking for monthly data to graph the series with. I now realise that there are in fact two versions of PDO series one maintained by the people who discovered the relationship in 1997 called the Mantua PDO, and the other maintained by NOAA known as the NCEI PDO and based on the Matua PDO: “The […]

The mysterious uplifting going on in Devon

I came across this wonderful snippet in a BBC news article by Jonathan Amos about the subtle warping of the land surface that’s being measured by the European Union’s Sentinel-1 satellites. According to the article Geomatic Ventures Limited [GVL] have now produced an interactive online map of the UK for you to browse the data with, and chief technical officer, Dr Andy Sowter says: “Probably the weirdest example we’ve come across is the 2 cm per year uplift at a place called Willand in Devon. It’s a small place on the M5 motorway. We’ve spoken to the Environment Agency and the British Geological Survey, and right now we can’t explain […]

Coldest March since 2013

Nothing very spectacular about this March as a whole despite the record cold start to the month. The mean temperature of 4.93°C was 0.74°C below the 1961-1990 long-term average, and made it the coldest since the record cold March of 2013 that everyone seems to have quickly forgotten about (fig 1). Three new record low daily maximum temperatures since 1878 were set during March (blue diamonds fig 2), and of course the 1st of March as well as having the lowest maximum also had the lowest mean temperature since the daily series started in 1772. The March of 2018 was only the sixth cold March in the last 30 […]

Extreme Easters in Central England

Because Easter Sunday’s can fall on any date between the 22nd of March and the 25th of April so they are a bit of a moving target when it comes to measuring how cold or warm each one has been. I’ve measured Easter periods as the five days between Maundy Thursday right through to Easter Bank Holiday Monday since 1772 in the central England temperature series. It might surprise you to find that the mildest Easter on record occurred as recently as 2011, when Easter Sunday fell on April 24th, and the mean temperature for the 5 days was 14.5°C making it 5.6°C warmer than average (fig 2). Conversely […]

A correlation between El Niño and global CO2

It was only when I read the Met Office news release “La Niña cools 2018 CO₂ forecast” that it occurred to me that there might be a link between ENSO events in the central Pacific Ocean and global CO2 measured at nearby Mauna Loa. So today I cobbled together a hybrid application made up of code from my ENSO and CO2 programs to plot charts of both of them to see what I can find, never really expecting to see very much in the way of a link, I was wrong. In the above image (fig 1) the top chart is of the 12 monthly change in global CO2 measured at Mauna Loa, […]

Rapid cyclogenesis in action!

Low Carola is deepening very quickly at the moment, and the curl of cloud she is spinning up makes an impressive site in the latest satellite imagery to the southwest of Ireland (fig 1), as do the plotted observations and barograph from the weather buoy 62029 better known as ‘K1’ (figs 2 & 3). As far as I can see Carola easily breaks the barrier for rapid cyclogenesis of 24 hPa in 24 hours, the pressure there has fallen by 37.4 hPa in 12 hours, in fact I don’t think I have ever seen sustained pressure falls like that on a chart from an extra tropical low. No doubt […]

Are winters becoming milder and wetter?

Q: Are winters becoming milder and wetter? 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).

Spain’s snow-covered mountains

Rather more geographical than meteorological I know, but I think I’ve identified these four snow-covered mountain ranges in Spain which are standing out so well on today’s satellite picture (fig 1). I reckon that after a bit of research they are: The large striking Montes de León range of which the highest peak is Teleno at 2,188 M. The isolated Peña Canchera at 1,592 M is the highest point in the Sierra de Gata range. The Sierra de Gredos range peaking out from some cloud of which the highest point is Pico Almanzor at 2,592 M. The snow-covered mountains close to the south coast are of course the Sierra Nevada’s or ‘snowy mountains’ in Spanish, […]

21 March 2018 – Interesting satellite image

An interesting satellite picture day of clouds across the bay of Biscay from the NOAA Worldview website (fig 1). If anything, the grey scale image from the Met Office taken a little later looks even better (fig 2). As far as I can tell it all looks like a sheet of low stratocumulus cloud at under the anticyclone, with a cloud base of around 4,000 feet, but I could be wrong.

The snowfall of February and March 2018

I thought that I would take a retrospective look back (excuse the tautology) at the last two cold snaps that we’ve had, and some of the snow depths that were reported by various AWS around the country. The graphs show accumulated and fresh snow depths that I’ve gleaned from SYNOP reports which in the UK helpfully include hourly snow depths (NWS please take note). The blue bar chart in the graph represents fresh snow, that is the difference in snow depth between each hour, red bars indicate snow melt, and the light blue bar series is the hourly snow depth. Bars that span more than an hour are because […]