xmetman

passionate about weather

xmetman

Category: Temperature

AGW / Temperature

When will global temperature anomalies be 1.5°C higher than those of 1850?

The IPCC seem to be fixated on when global temperatures will be 1.5°C higher than those in pre-industrial times, no doubt naturally thinking, that there was time left to do something about it. This is what the IPCC report says about when they expect this to happen. Global warming will likely rise to 1.5 °C above pre-industrial levels between 2030 and 2052 The missing graph The isn’t a single graph of forecast global temperatures in the IPCC report of 2018 illustrating just how world temperatures are forecast to rise in the coming years to achieve the magic value of 1.5°C warmer...

Anomalies / Temperature

A cold day in the northeast

After such a lovely warm and sunny week last week, it’s back to temperatures more similar to those at the start of spring rather than those of mid May in northeast Scotland. The colder than average temperatures are well illustrated in the 12 UTC temperature anomaly chart with most places in the northeast having negative anomalies of -1 to -3°C. Eastern England on the other hand are doing very well with a range of positive anomalies between +2 and +5°C.

Cold / Snow / Uncategorized

Cold start to May in the north

It’s been quite a cold start to the month of May 2019 and their is a decent snow cover down to 2500 feet on Ben Wyvis in recent days. That’s not so surprising as the 1000-500 hPa partial thickness has been sub 528 Dm for the last week at Lerwick. I think this probably makes it one of the longest such cold spells in the entire winter-spring period of 2018-19. It’s been a long time since I saw snow falling in either October or May but it happened in a year with a comparatively mild winter. Another useful guide to...

Climate / Rainfall / Sunshine / Temperature

This year’s UK extremes so far

Here are this year’s extremes for air temperature, sunshine and rainfall I’ve extracted from the SYNOP data that I download courtesy of the OGIMET site. I forgot I had written this application so this post is as much as a reminder to me to use it every now and again! I could bemoan the fact that the Met Office refuse to release all the climate station data they have, which is why the sunshine coverage is sparser than it need be, but in the spirit of the new look xmetman website I’m just going to thank them for releasing what...

Cold / Temperature

‘Cool’ or just plain cold?

I would have thought that with today’s 1200 UTC anomalies of 5°C below the LTA for many places across the UK, that would have merited the term ‘cold’ rather than just ‘cool’ but what do I know? Although there is a tongue of warmer air across central southern England, temperatures across parts of northern Scotland are more than 7°C below the LTA this lunchtime, combined with the rain and the easterly wind that’s definitely cold in my book.

BBC / Cold / Temperature

“A little bit mixed”

According to the BBC lunchtime forecast on Saturday, the weather through this May bank holiday is “looking a little bit mixed”. I would have thought the emphasis in any forecast today should have been on just how cold it was for the time of year, with 1200 UTC anomalies on Saturday widely between 2 and 4°C below average and as much as 9.5°C (Scampton, Lincolnshire) below the LTA in any any showers in eastern areas.

Definition / Frost

Severity of frost

Frost occurs when the temperature of the air in contact with the ground, or at thermometer-screen level, is below the freezing-point of water (‘ground frost’ or ‘air frost’, respectively). The term is also used of the icy deposits which may form on the ground and on objects in such temperature conditions (GLAZE, HOAR-FROST). Since the sensation of cold depends not only on air temperature but also on the accompanying wind speed, the fourfold classification of frosts used in forecasts of this condition in the United Kingdom is varied with wind speed. Thus, frost is classified as ‘slight‘, ‘moderate‘, ‘severe‘, or...

Warm

The true hot spots on Good Friday

Good Friday (19 April 2019) was a pretty warm across large parts of the UK. Here’s a table of the highest temperatures reported at 18 UTC. But if you look at the maximum temperature anomalies that allow a comparison with maximum temperatures of the last 30 years things are a little different. All three highest anomalies in the UK where for sites in northern Scotland. The maximum temperature at Lossiemouth was 11.8°C above average, that compares with the 9.1°C at Heathrow Airport (I don’t have long-term climate data for St James park).