Category: Commentary

Friday 13th March
Thursday was a blustery day as the wind gathered strength in the morning, but it was dry. A maximum of 11.4C was logged at 16.15 being 0.6C above average for early March. Approaching cloud from two weather fronts, both cold fronts, meant the cloud thickened in the early evening and overnight that saw the thermometer stable at around 11C until midnight. After that time the cloud began to thin and the temperature slowly to fall as cooler air rushed in behind the cold fronts, hence the name, more quickly after 2.00, reaching a minimum of 3.3C at 07.18 being 0.7C above average.

The two cold fronts contained two lines of intense, but brief intense rain and strong gusty winds with a peak gust of 34mph at 23.26. The daily rainfall amounted to 15.4mm making it the wettest day since 6th February.

After dawn on Friday the hang back of cloud was relatively high but sufficiently dense to prohibit any sunshine. The day ahead is likely to be dominated by sunshine and showers as the barometric pressure is now rising steadily as the depression eases away. The wind will be from a west-southwest direction that is channelling cool air from a region between Iceland and Greenland. As a result, temperatures today will be depressed and likely a degree or two below average. The wind will continue brisk that is likely to produce an element of wind chill. Whilst I write this report, the air temperature at 08.27 had risen to 4.4C whilst outside the wind chill meant it felt more like 3.8C.

The surface pressure charts indicate that the barometric pressure will continue to rise with a minor, transitory ridge of higher pressure producing a fine day on Saturday that is likely to be dry and sunny. That will be followed by an unsettled, cool and mainly cloudy day on Sunday as yet another depression rolls in from the Atlantic heading towards Iceland that will be accompanied by brisk winds from the southwest.

There is an indication that temperatures are likely to recover a degree or two above average later next week.

Building the UK’s offshore weather stations continued.

One of the most impactful areas of the team’s work is its involvement in the Argo programme, a global array of profiling floats that measure ocean temperatures down to 2,000 metres. These floats are central to understanding ocean warming, a key indicator of climate change.

Normally, an Argo float is designed for a 2-3 year lifespan. But by adding additional batteries and carrying out enhanced pre-deployment checks, Met Office engineers have found ways to extend that lifespan up to 5-7 years, effectively doubling the number of observations each float can produce.

Considering each float costs around £20-25k, this engineering optimisation delivers significant value: more data, better global coverage, and a more cost-effective use of taxpayer funding.

Looking ahead: innovation and new capabilities.

Innovation plays a major role in the team’s work. Marine engineers are now exploring the next generation of underwater sensors that could allow the network to measure beneath the surface as well as above it, data that would significantly improve ocean forecasting models.

These new capabilities could form the basis of future PR and funding opportunities as interest grows in marine climate monitoring.

The Met Office’s engineering team has already been recognised for its innovative approach, winning the Experts by Nature award at the Met Office’s own awards ceremony for work that demonstrated creativity, bravery and technical excellence.

Thursday 12th March
Wednesday gave us a dry day with bursts of sunshine that at its peak produced a UV level of 2.1. This was the highest UV level since 30th September and the first this year to be classed as ‘Moderate’ in strength. The thermometer rose to a maximum of 11.5C at 15.03, in the afternoon sunshine, being 0.7C above average. Unusually, the minimum occurred during the late evening at 20.16 when a low of 5.8C was logged being 3.4C above average. The thermometer hovered around 6.5C most of the night before rising after 05.00 to reach 8.9C at 08.00.

Thursday arrived with weak sunshine between broken and thin cloud. The day will go down hill during the morning and afternoon as cloud builds from a deep depression close to Iceland that will see the strength of the wind increase with rain likely to start early evening and become heavy until after midnight. The surface pressure chart shows narrow lines of intense rain when squalls could occur with sudden strong gusts of wind.

By Friday the air stream, originating from near Iceland, will arrive on a west-southwest brisk wind. Don’t be fooled with the wind direction as a little later it will veer further from the south-southwest, which usually heralds mild air from the Atlantic. The Icelandic air mass, a cooler airstream, will severely limit warmth that is likely to see the maximum below average and it will feel very cool due to a contributory wind chill.

Building the UK’s offshore weather stations.

When most people think of the Met Office, they picture satellites orbiting high above the Earth or forecasters analysing weather charts.

But far fewer know about the engineering teams who work at sea, installing, repairing and upgrading the offshore weather stations that feed vital data into our forecasting models.
These teams operate in challenging marine environments, undertaking hands-on engineering that keeps the UK’s ocean observations running smoothly.

In this blog, there is a closer look at what Marine Systems Engineering actually involves, and why this work is the cornerstone of UK weather and climate science.

The Met Office’s Marine Systems Engineering team is responsible for building, deploying and maintaining the network of offshore weather stations, buoys, light-vessel installations and specialist platforms, that gather observations at sea. These stations measure wind, air temperature, waves, pressure and other variables essential for accurate marine and coastal forecasting.

Most of this work takes place at the National Oceanography Centre in Southampton, which acts as the team’s engineering base. It is here that buoys are assembled, electrical systems wired, and sensors programmed. The site is home to research vessels, heavy lifting equipment and a dedicated workshop space, an ideal environment for constructing and testing large-scale marine observing platforms before they go offshore.

The team also works closely with Trinity House, whose light vessel network in the English Channel hosts some of the Met Office’s key marine sensors. Deploying or recovering these systems requires marine coordination, deck operations and precise installation work, often in challenging weather.

Continues tomorrow

Wednesday 11th March
The intermittent broken sunshine on Wednesday transformed the day, compared to previous days. The maximum temperature of 11.3C at 12.24 was almost identical to the peak on Monday, being 0.5C above average, however, when the sun did shine it raised the UV level to a peak of 1.9, which is within touching distance of being classed as a ‘Moderate’ strength, it was also equal strongest with that logged on the 2nd. Another indicator of the strengthening sunshine was a peak solar radiation of 631W/m2, the highest since the 5th October. The peak on Saturday, under the thick cloud, was only 151W/m2.

There was welcome sunshine shortly after sunrise on Wednesday, sadly it disappeared around 08.45. Overnight two weather fronts had passed over our area that saw the barometric pressure drop to 1004.5mb at 02.02, the lowest pressure since 19th February. The rain began just after 21.00 Tuesday even and ceased just after 04.00 early Wednesday, amounting to 5.2mm, that made it the wettest day in March. The wind will increase in speed towards midday and into the early afternoon as the weather fronts traverse eastwards.

A stormy day will arrive on Thursday with strong winds from early morning until late evening, when rain will arrive, that is likely to be heavy and continue well after midnight. Friday will be a damp day with light showers, also much cooler with the maximum below average and the following night very cool, almost down to freezing as the air stream will have originated near Iceland and Greenland thanks due to a deep depression that tomorrow will head in the direction.

I attach part an interesting article on meteorology, just published.

We have a number of equations and I think all of us meteorologists have horror stories about the different math classes we took in college to try to learn them.

To use meteorological mathematics, you have to figure out the physics and dynamics of the atmosphere, which is not easy.

This means we have to predict the movements of a liquid because the atmosphere is a liquid. Then, of course, that liquid creates other liquid, meaning rainfall, snowfall and that sort of thing, which comes down to physics.

For those equations to work, you need every sort of weather data that you can think of: temperature, humidity, wind speed, how much moisture there is in the air and all of that information at different levels, too, because the layers of the atmosphere don’t act independently of each other.

To gather that data, you need weather balloons and observation stations and satellites gathering data at different altitudes.

Each one of those layers can act a little bit differently. One layer could be 30 degrees, the next one up is 32 degrees, and the wind speed might be a little stronger up aloft and a little different direction. You may have heard a meteorologist say that the European model is a little better than the Global Forecast System. Part of that is because the Euro has more layers.

Each of the variables is going to be used in the equations. We have to get all of the data as correct as possible. There’s a saying in models: “If you put junk in, you’ll get junk out.”

Tuesday 10th March
The fog and mist was very slow to clear during Monday morning and into the afternoon. However, the change in wind direction, to come from the south, a drier and slightly warmer direction, saw the cloud break up late afternoon with glimpses of sunshine. As a result the thermometer rose to 11.2C at 15.59 making it the warmest day since 5th and 0.4C above average. The thinner cloud overnight, with breaks, meant a cooler night with the thermometer dropping to 4.9C at 06.46, early Tuesday, being 2.3C above average.

Tuesday arrived with breaks in the cloud with occasional glimpses of sunshine, a distinct improvement on recent foggy and misty days. However, the Atlantic air flow will send two weather fronts heading our way as the day progresses with rain likely, possibly heavy, into the evening and night.

Unsettled covers the next few days as by Thursday the wind will strengthen significantly with rain in the evening and probably heavy for a few hours as two weather fronts spread thick cloud again followed by a very cool day on Friday as the second weather front is a cold front heralding a drop in temperature. The front will be associated with a deep area of low pressure heading towards the UK before swinging north towards Iceland.

Throughout the winter there have been headlines of heavy and extensive snow from some weather forecasters, not the Met Office, that have not materialised over southern Britain. Yesterday the Met Office put out a press release saying “Temperatures are set to plummet dramatically as snow sweeps across substantial portions of the UK, with meteorological charts suggesting a noticeable Arctic blast could materialise, being more probable towards the end of the month. Initially, hitting Scotland, Ireland and the North West, with a later band of snow advancing across southern England and Wales.

Monday 9th March
Sunday was another overcast and gloomy day although the thermometer did edge a little higher than on Saturday, however, a maximum of 9.0C at 14.50 was below average again at -1.8C. This was due to the breeze that was even lighter, a maximum movement of 10mph, couldn’t call it a gust, also the air stream had backed into the southeast, coming from the Continent, less cold than the previous easterly breeze. The thermometer only fell 3C from its peak with a minimum 6.0C at 06.25 early Monday being 3.4C above average.

Once again the start to a new day on Monday was a repeat of the two previous days under thick cloud and fog from two weather fronts crossing the area, which was if anything a little thicker, limiting visibly to around 150m after dawn. Subtle changes are afoot today as the air stream will veer from the southeast to south then later today come from the south-southwest, heralding a slightly warmer airflow that should see the maximum get closer to the early March average.

Over the next few days we will be under the influence of an Atlantic flow of air, moist and milder, that should see the maximum get closer to or slightly above average. However, later in the week the temperatures are going to drop even though the air stream will come from a predominantly southwesterly direction, from the Atlantic. The reason can be seen in the forecast surface pressure charts as the although as the air arrives here from a southwesterly quadrant, it will have originated around Iceland before streaming south then coming from the southwest around the southern section of the depression. It is likely that the cooler temperatures will arrive by Friday, accompanied by rain likely late Thursday, and into the weekend.